Indonesia’s most dangerous fires are burning underground

 Tropical peatland fires rank among the most dangerous and stubborn fires on Earth. Instead of racing through trees and vegetation, these fires smolder through dried wetland soils and large deposits of peat, often continuing underground at relatively low temperatures. That makes them extremely difficult to extinguish and exceptionally polluting.

By one estimate, peat fires produce three times more fine particulate matter than other tropical forest fires, along with five times more sulfur dioxide, three times more organic carbon, and twice as much methane and carbon monoxide.

Satellite Images Reveal Indonesia's Fire Season

Indonesia's 2026 fire season was already underway when the MODIS (Moderate Resolution Imaging Spectroradiometer) instrument aboard NASA's Aqua satellite captured an image of the region on September 1, 2026.

On the annotated map, each red dot represents a "fire detection." This means the satellite sensor and an algorithm identified a pixel containing thermal anomalies associated with fire. A single fire can produce multiple detections.

Peat fires are a persistent problem in Indonesia, which contains about 36 percent of the world's tropical peatlands. During severe droughts, these normally wet landscapes can dry enough to ignite. Over the past three decades, such conditions have repeatedly produced long-lasting fires that blanket large areas in smoke for weeks and disrupt the lives of millions of people.

El Niño Is Intensifying the Dry Season

Wildfires occur in Indonesia every year, but some of the most destructive seasons in recent decades came during El Niño, particularly in 1997 and 2015.

NOAA assessed El Niño as present and strengthening in August 2026. The climate pattern commonly reduces rainfall across Indonesia. The drying can become even more pronounced when El Niño occurs alongside a positive phase of the Indian Ocean Dipole, which was also underway.

"Indonesia is only about three weeks into its fire season, but we're seeing fire activity track sharply upward, similar to 2015," said Robert Field, a Columbia University researcher who developed a tool called the Global Fire Weather Database that produces experimental, real-time fire weather forecasts.

"The strong El Niño is making the dry season drier over the fire-prone parts of the country and exacerbating burning -- just as we anticipated it would," he said.

The comparison with 2015 is significant. After more than three months of burning that year, Indonesia's fires had emitted 1.75 billion tons of greenhouse gas equivalents -- more than Japan emits in an entire year. By September 2, the 2026 fires had been burning for about a month and had already released roughly 10 percent of the amount produced during the 2015 crisis.

Underground Peat Fires Can Burn for Months

Indonesia was also experiencing severe, widespread drought during the summer of 2026, much as it did in 2015. Data from the Indonesian meteorological agency showed that about 90 percent of the country received little or no rainfall in early August.

Under normal conditions, peat deposits in Kalimantan, Sumatra, and Papua are too wet for fire to move underground. Drought changes that dramatically, allowing flames to enter the peat itself and continue smoldering below the surface.

"Surface fires are less of a concern, but when fires get underground, they just won't stop," Field said. "They'll keep burning until the rains come in October or November."

Indonesia relies on observations from NASA and NOAA satellites to follow active fires in near-real-time. MODIS and VIIRS are among the main instruments used. Indonesia's Ministry of Forestry operates the SiPongi fire-monitoring platform using MODIS and VIIRS data, and the system counted 946 hotspots on August 31, 2026.

The Worst Fires Can Be Hardest to See From Space

Satellite monitoring has important limitations, however. MODIS and VIIRS can struggle to detect fires hidden by thick smoke or clouds, burning beneath the forest canopy, or smoldering underground inside peat deposits.

In fact, when Indonesian fires become especially intense, the number of fires detected by MODIS or VIIRS can sometimes decline because the smoke itself blocks the satellites' view.

"The worst smoke events, paradoxically, can be the hardest to observe from space with MODIS and VIIRS," said Mark Cochrane, an ecologist at the University of Maryland Center for Environmental Science who has conducted field research on peat fires in Indonesia for nearly a decade.

Some of Indonesia's modern fire vulnerability can be traced back decades. According to Cochrane, extensive construction of irrigation canals and drainage of peat swamps during the 1990s, undertaken in part to create massive rice farms, lowered water tables across wetland areas and made the landscape more combustible. Oil palm plantations and other plantation forestry are also widespread in the region.

Following the unusually grim fire season of 2015, governments and other organizations attempted to reverse some of that damage. Projects have included blocking irrigation canals to help restore wetlands, strengthening firefighting capabilities, and stepping up efforts to prevent accidental human ignitions.

2026 Could Be a Major Test of Fire Protections

"This year will be a real stress test of the measures that were put in place after 2015," said Shi Jun Wee, a University of Maryland graduate student.

Wee is part of a team working with NASA and MapBiomas to develop improved methods for spotting understory fires that MODIS and VIIRS may miss. Their approach uses shortwave infrared observations from Landsat and Sentinel-2 satellites.

As the 2026 fire season continues, Wee plans to follow conditions using NASA's Worldview data browser, FIRMS (Fire Information for Resource Management System), HLS (Harmonized Landsat and Sentinel-2) observations, and GFED (Global Fire Emissions Database).

Hazardous Smoke Is Already Disrupting Daily Life

For people living in Indonesia and neighboring countries, the effects are already being felt. Indonesian officials have warned that large portions of the population have been exposed to hazardous smoke.

According to news reports, some schools have begun switching to remote learning, nine national parks have closed, and several flights have been delayed because of heavy smoke.

Cochrane cautioned that attention to the problem often rises during major El Niño fire seasons and fades once conditions improve.

"People tend to focus on these fires during an El Niño and then forget about them," Cochrane said. "We need sustained focus, even during the years when they aren't as bad, to solve this," he said. "These fires create a tremendous amount of emissions."

Source: ScienceDaily

Antarctica gained a record 695 billion tons of ice. Scientists found the surprising reason

 A persistent patch of unusually warm tropical ocean helped intensify snowfall over East Antarctica, contributing to a temporary net ice sheet mass gain of about 695 billion tons, according to a new study published in Nature on August 19.

Researchers found that sustained warming in the tropical warm pool during 2021-23 set off a chain of atmospheric changes that ultimately affected weather thousands of miles away in Antarctica. The warming generated a Rossby wave train that traveled toward the continent, helped establish a north-south circulation pattern over East Antarctica, altered the movement of moisture, and increased regional snowfall. Together, these changes temporarily slowed the Antarctic Ice Sheet's overall loss of mass.

A Remarkable Antarctic Ice Gain

The Antarctic Ice Sheet is a major source of uncertainty when scientists estimate how much global sea levels could rise in the future. During the past two decades, Antarctica has lost ice at an average rate of approximately 140.5 billion tons per year.

Yet between 2021-23, that pattern briefly shifted. The ice sheet gained about 695 billion tons of mass, making it the largest Antarctic mass gain observed by the GRACE satellite missions.

To understand what caused the unusual increase, researchers led by the Institute of Oceanology of the Chinese Academy of Sciences (IOCAS) brought together several types of evidence. They analyzed gravity satellite measurements, snow accumulation records preserved in ice cores, and simulations of atmospheric circulation. Their goal was to determine where the extra moisture came from and how weather patterns delivered it to East Antarctica.

A Climate Signal From the Tropics

The team identified sustained warming in the tropical warm pool during 2021-23. This region lies where the tropical western Pacific meets the eastern Indian Ocean and contains some of the planet's warmest ocean waters.

That warming triggered what scientists call a Rossby wave train, a large-scale pattern of atmospheric waves capable of transmitting changes in weather and circulation across enormous distances. The disturbance traveled toward the high southern latitudes and helped reorganize atmospheric conditions around Antarctica.

Eddy mean flow feedbacks strengthened and prolonged the resulting circulation pattern. This produced a north-south dipole, with unusual low pressure south of Australia and unusual high pressure along the East Antarctic coast.

The resulting pressure pattern changed the routes taken by moisture moving through the atmosphere. In particular, it strengthened the transport of water vapor from the midlatitude Indian Ocean toward East Antarctica through atmospheric rivers.

Atmospheric Rivers Fueled Heavy Snowfall

Atmospheric rivers are relatively narrow corridors in the atmosphere that can carry enormous amounts of water vapor over long distances. When they reach cold regions such as Antarctica, that moisture can fall as heavy snow.

Water vapor tracking simulations showed that the dipole circulation directed moist air from the midlatitude Indian Ocean toward East Antarctica and allowed more atmospheric rivers to reach the continent. This produced sustained heavy snowfall across the Queen Mary Land-Wilkes Land region, adding substantial mass to the ice sheet.

Atmospheric circulation model experiments provided further evidence that warming of the tropical warm pool directly drove both the circulation changes and the increase in snowfall.

The researchers also examined how much of the snowfall increase could be attributed to anthropogenic forcing. They found that this contribution was equivalent to only 9% of the observed snowfall anomaly. That result suggests that the general increase in atmospheric moisture associated with global warming was not the main explanation for this particular event.

A Remote Antarctic "Regulator"

Additional observations and simulations indicate that comparable periods of sustained warming in the tropical warm pool occur approximately once every decade.

The researchers therefore describe the tropical warm pool as a remote "regulator" that can influence snowfall and ice mass in East Antarctica over periods lasting several years. Changes in tropical ocean temperatures can alter atmospheric circulation in ways that ultimately affect how much snow falls on the distant Antarctic continent.

The findings reveal a long-distance climate connection in which conditions in the tropics can have major consequences for Antarctica.

Antarctica Is Still Losing Ice Over the Long Term

Despite the striking 695-billion-ton increase, the researchers emphasize that the event was temporary and does not reverse the long-term decline of the Antarctic Ice Sheet.

The West Antarctic Ice Sheet continues to lose mass. Some outlet glaciers in East Antarctica also remain vulnerable as warm ocean water melts ice shelves from below and contributes to faster ice flow.

The study shows how sustained warming in the tropical warm pool can temporarily increase the mass of the Antarctic Ice Sheet through changes in atmospheric circulation and snowfall. It also identifies the north-south dipole circulation over East Antarctica as an important link connecting tropical climate conditions with changes in Antarctic ice mass.

"We found a previously underrecognized 'tropical warm pool-East Antarctic Ice Sheet' teleconnection pathway," said Yunhe Wang from IOCAS, first author of the study. "Our research provides a theoretical basis for understanding Antarctic ice-sheet mass changes and conducting future research on the East Antarctic climate."

Source: ScienceDaily

UNESCO warns there’s close to a 100% chance of a Mediterranean tsunami

 On the French Riviera, a tsunami could arrive before a warning reaches people on the beach. In some local scenarios, the first waves could reach shore in under 10 minutes. France's national warning center, meanwhile, is designed to send its initial alert to authorities within 15 minutes of a potentially dangerous earthquake. Those two timelines leave no room for delay.

That is why researchers and local officials around Nice are doing more than improving alerts. They are mapping walking routes, identifying refuge sites, and helping residents and visitors recognize when they need to leave the coast immediately. The goal is to make the first decisions before an emergency begins, rather than after the sea starts behaving strangely.

What UNESCO's Mediterranean Tsunami Warning Means

The Mediterranean is often treated as an unlikely setting for a tsunami. UNESCO has warned against that assumption. On June 22, 2022, the organization stated that "the probability of a tsunami wave exceeding 1 meter in the Mediterranean in the next 30 years is close to 100%."

The details matter. That estimate concerned an event somewhere in the Mediterranean basin over the following three decades, roughly through 2052. It was not a prediction of an imminent disaster, a guarantee that the French Riviera would be struck, or a forecast that every Mediterranean coastline would experience the same waves.

Nevertheless, the region has the ingredients needed to generate dangerous tsunamis. Earthquakes can occur along active faults in the Ligurian Sea, near the French and Italian coasts. Farther south, the movement of the African and Eurasian plates creates another source of potentially powerful earthquakes off North Africa. Underwater landslides provide an additional, sometimes much more local, trigger.

The Danger Is Not Just a Giant Wave

A tsunami begins when a large volume of water is suddenly displaced, often by an earthquake, landslide, or volcanic eruption. The disturbance spreads outward, potentially traveling long distances before reaching the coast. Historically called tidal waves, raz-de-marée in France or maremoti in Italy, tsunamis can bring both sudden flooding and extremely powerful currents.

They do not always resemble the towering wall of water people imagine. A tsunami can appear as a rapid rise or retreat of the sea, followed by repeated surges. Flooding can range from centimeters to several meters, while fast currents can exert forces equivalent to several tons per square meter against coastal structures. The first wave is not necessarily the largest.

Even relatively small tsunamis deserve attention. Italy's National Institute of Geophysics and Volcanology notes that a tsunami with an amplitude of just 50 centimeters can be dangerous because of the energy and sustained movement of the water, which can behave more like a rushing torrent than ordinary surf.

Globally, tsunamis have killed more than 250,000 people since 1970. The December 26, 2004, Indian Ocean disaster and the March 11, 2011, tsunami in Japan account for much of that devastating toll.

The French Riviera Has Been Hit Before

The Montpellier researchers describe the Mediterranean as having the largest historical tsunami record after the Pacific. Along the French Riviera, they cite roughly 20 reported events between the 16th century and the early 2000s, including waves exceeding two meters. Several episodes show how differently the danger can unfold.

On February 23, 1887, an earthquake in the Ligurian Sea, with an estimated magnitude between 6.5 and 6.8, triggered a tsunami along the coast. Historical accounts describe the sea falling by about one meter in Antibes and Cannes, leaving fishing boats stranded. Waves approaching two meters then swept over the beaches.

A very different event occurred on October 16, 1979. Part of the construction site for a new commercial port in Nice (Alpes-Maritimes), beside the airport, collapsed into the sea. The resulting landslide and tsunami caused eight deaths, according to a reconstruction published in Natural Hazards. Effects were reported in Nice, Antibes, and Cannes, with disturbances observed in Antibes for about half an hour. The later study found that water reached elevations of 3.5 meters locally and flooded as far as 150 meters inland.

The May 21, 2003, Boumerdès earthquake (Algeria) demonstrated that the trigger could also lie across the Mediterranean. Its effects reached the Riviera about 75 minutes later. Investigators documented abrupt sea level drops (from 50 cm to 1.5 m), partially emptied harbor basins, swirling water, strong currents, and damaged boats in eight marinas. Harbor resonance, in which the shape of a basin reinforces the water's oscillations, helped explain why neighboring ports experienced different effects.

Mediterranean tsunamis are not confined to those older events. On December 4, 2022, a flow of hot volcanic material entered the sea at Stromboli and generated a small tsunami, activating the island's warning system. Italy's geological institute reported no damage, but the event provided another reminder that the region's tsunami activity is real and ongoing.

Why an Alert May Not Be Enough

France has operated its national tsunami warning center, the Centre d'alerte aux tsunamis (Cenalt), since July 2012. Working within the international system coordinated by UNESCO, it monitors earthquakes that could generate tsunamis and sends initial messages to French emergency authorities and other warning centers.

The warning then has to reach the public. In France, the chain includes the interdepartmental crisis management operational center (Cogic), followed by authorities responsible for issuing instructions. One channel is FR-Alert, which can send notifications to mobile phones in the threatened area. Detecting an earthquake and getting people moving are therefore separate steps.

Distance makes a crucial difference. A tsunami generated off North Africa may take less than 90 minutes to reach the Riviera. A nearby source in the Ligurian Sea, between Corsica and the Italian coast, can leave far less time. Local landslides are particularly challenging because their effects can develop quickly and may not be preceded by a felt earthquake. A functioning warning system cannot always overcome such a short travel time.

Mapping a Way Off the Beach

Planning starts with identifying where evacuation may be necessary. French government agencies and the University of Montpellier have defined a coastal evacuation zone using elevation, distance from the sea, and historical information. It generally covers land below five meters in elevation and within 200 meters of the shoreline. Around river mouths, the distance extends to 500 meters from the estuary. These are planning boundaries, not a prediction that a future wave will be five meters high.

Across the French Mediterranean coast, including Corsica, that zone encompasses about 1,700 kilometers of coastline, 187 towns, and at least 164,000 residents. At the height of summer, planners must also consider an estimated 835,000 beach users. Those figures describe the scale of potential evacuation planning, not a forecast that one tsunami would affect everyone at once.

In the Nice Côte d'Azur metropolitan area, dense development and heavy tourism make the challenge especially demanding. The research team used photographs and computer modeling to estimate beach attendance (between 10,000 and 87,000 people on the beaches, depending on the season and time of day).

Source: ScienceDaily

Wasps are disappearing this summer, and scientists are worried

 Summer can be lovely – until a wasp turns up. Whether they present as an irritating picnic visitor or an uninvited loft guest, common social wasps are as much a part of our summer as festivals, sun cream and the growing despair of how to entertain children who’ve forgotten how to be bored.

But summer 2026 is breaking the norm, and there don’t seem to be many wasps about. As a wasp biologist, I’ve noticed it acutely, because my students need wasps for their experiments, and we simply can’t find them.

A second sign that something is wrong is the absence of wasp stories in the media. Wasps tend to be more active in warmer weather. Their colonies grow faster and bigger, and they end up making news headlines by bothering humans. This time last year – also a warm spring and hot summer – the media airwaves were filled with “plagues of wasps” stories. Now, even professional pest-controllers tell me it’s a quiet year with very few requests to remove wasp nests.

Admittedly, these are anecdotes not data: the Big Wasp Survey – the only national wasp monitoring survey – is yet to start sampling this summer. But the signs are not good.

If data back this up, their absence worries me greatly because – love them or hate them – wasps are important in ecosystems as pest-controllers, pollinators and decomposers.

So, what’s happening?

Spring started well for wasps. In the warm, dry spring a glut of glorious foundresses – new queens – emerged from hibernation to start their nests alone, carrying out all the nest building, egg laying, foraging and brood rearing. This nest-founding period is a risky time. If a new queen survives until her first brood emerges as adult workers, though, then the odds are in her favour as she no longer needs to undertake risky foraging.

But spring 2026 was strange: the warm, dry start should have been good. Warm, dry spring weather improves a nest’s chance of survival as it ensures a good nectar supply for the queen to develop her ovaries and good prey populations for her to feed the brood. But we experienced unprecedented heat for the time of year, punctuated by cold, damp days and followed by unexpectedly chilly nights.

Such weather extremes may have caused queens to abandon their nests or die, reducing the initial spring queen bounty to a more modest population.

Temperature tolerance

And then came the heatwave. And another. And another. Some insects may benefit from this. Wildlife charity Butterfly Conservation is hoping 2026 could be a “bumper summer of butterflies” because warm, dry days mean uninterrupted foraging, mating and egg-laying.

But all insects have a thermal tolerance called critical thermal maximum (CTmax). If their CTmax is exceeded, insects succumb to desiccation, muscle spasms and eventual stupor.

For honeybees, this is around 49°C – which might sound high, yet ground surfaces exceeded 50°C in the UK heatwaves this summer. But the temperature doesn’t need to reach an animal’s CTmax to affect their productivity and behaviour. For example, bumblebee cognition and foraging efficiency are impaired by heatwaves of 32°C.

Bumblebee Conservation Trust raised concerns that 2026 may exacerbate a declining trend in bumblebee populations as flowers wither and bees fail to forage effectively.

Wasps are thought to be quite resilient to extreme weather. They are one of the most successful invasive species around the globe. And as a social insect, their thermoregulation behavior (such as wing fanning to cool the larvae) and nest architecture (which has insulating envelopes surrounding the brood combs) may help buffer any environmental perturbations.

Insects also have waxy molecules called cuticular hydrocarbons that coat their exoskeletons protecting them from desiccation. Social wasp cuticular hydrocarbons change structure in response to heat, better protecting them from desiccation in excessive heat.

Their varied diets should also buffer them from imbalances in prey populations. However, their CTmax may be lower than other social insects – at around 45°C (113°F) – which may have made them especially vulnerable to the high ground temperatures of the 2026 heatwaves.

Why are the wasps so small?

There’s something else that I’ve noticed: the few wasps I’ve seen are rather small. The adult size of many insects is fixed during their development, depending on the quality and quantity of food they receive as larvae. Wasps don’t get bigger once they’ve pupated.

The first workers to emerge in spring are usually small because the queen is limited in how much food she can provide for them alone. But by early August, the foraging capacity of the colony has increased exponentially, brood are better fed and the emerging workers are substantially larger.

Source: ScienceDaily

Global warming is breaking a 400-year climate link between two oceans

  A new study suggests that the climate connection between the tropical Indian and Pacific oceans can be disrupted by major volcanic eruptions, while human-caused greenhouse gas emissions may now be driving an even more unusual breakdown in that relationship.

Researchers at the Woods Hole Oceanographic Institution (WHOI) combined paleoclimate evidence with climate model simulations to examine how closely the two ocean basins have behaved over the past several centuries.

Their findings indicate that volcanism can temporarily weaken the climate link between the Indian and Pacific oceans. More recently, however, human-driven climate forcing has produced what the researchers describe as an "exceptional" shift in the way climate variability in the two regions is connected.

The study was published in Nature Communications under the title "Coupling of Pacific and Indian Ocean variability disrupted by 19th century volcanism."

A Climate Connection That Usually Moves in Step

Climate conditions across the Indian Ocean often respond to changes occurring in the Pacific Ocean. This connection helps shape broad patterns of rainfall, temperature, and atmospheric circulation across the tropics.

Since the 1980s, however, scientists have noticed that this relationship has weakened. The Indian Ocean has increasingly behaved differently from what would normally be expected based on conditions in the Pacific, a change that researchers have linked to climate warming.

One challenge is that reliable instrumental climate records cover less than a century. That makes it difficult to determine whether the recent change is truly unusual or simply part of a longer natural cycle.

To look further back in time, the WHOI team turned to tropical paleoclimate records preserved in corals, tree rings, and stalagmites. These natural archives allowed the researchers to reconstruct Indian and Pacific Ocean climate conditions back to the early 1600s.

Volcanoes Disrupted the Ocean Link in the 1800s

The paleoclimate evidence shows that the Indian and Pacific oceans remained closely connected through most of the past 400 years.

One period stood out.

Between 1810 and 1850, the relationship between the two ocean basins changed significantly. Researchers linked that disruption to a series of major tropical volcanic eruptions, which appear to have weakened the Pacific Ocean's usual influence over climate conditions in the Indian Ocean.

Computer simulations covering the past thousand years supported that interpretation.

The strength of the disruption depended on both the size of the volcanic eruptions and the background climate conditions that existed at the time.

"This is one of the first studies to examine the breakdown in the connection between the Pacific and Indian oceans using evidence from past climates, modern observations, and climate models," said co-author Caroline Ummenhofer, a senior scientist at WHOI.

Modern Changes Appear Far More Unusual

The volcanic connection was only part of what the researchers uncovered. By comparing the modern climate with several centuries of past conditions, they were also able to judge how unusual the current weakening of Indian and Pacific Ocean coupling really is.

"The modern data we have is limited and doesn't go back far enough. With climate models and paleo-records, we are now able to say with more confidence that the recent changes we are seeing are really quite exceptional," said lead author Shawn Wang.

Wang is a former WHOI graduate student and postdoctoral researcher, and he is currently a postdoc at the University of Colorado Boulder.

The findings suggest that although volcanic eruptions can temporarily interrupt the connection between the two ocean basins, the modern breakdown appears to be driven by a different force.

"A key finding is that global warming and human emissions are now overwhelming the Pacific's natural influence on the Indian Ocean," Ummenhofer said.

Why the Indian Ocean Matters for Climate Predictions

Understanding how strongly the Indian and Pacific oceans influence each other is important for climate forecasting.

Connections between ocean basins can help scientists anticipate shifts in rainfall and other major climate patterns. If those relationships weaken or change, forecasts based on historical behavior may become less reliable.

Much past research has examined major ocean basins separately. This study instead focuses on the ways they interact, and on what happens when those connections begin to weaken.

Source: ScienceDaily

Scientists find hidden pathways pancreatic cancer uses to spread

 A new study from Brazil, published in the journal Molecular and Cellular Endocrinology, sheds light on how pancreatic cancer gains the ability to spread at an early stage. Researchers found that a protein called periostin, along with stellate cells in the pancreas, plays a crucial role in helping cancer cells invade nearby nerves. This early nerve invasion raises the risk of metastasis and is closely tied to how aggressive the disease becomes. The findings also highlight potential targets for more precise and personalized cancer treatments.

The research shows that pancreatic tumors do not act alone. Instead, they alter parts of the surrounding healthy tissue, effectively reprogramming it to support cancer invasion. This process helps explain why pancreatic cancer is so difficult to control once it begins to spread.

A Rare Cancer With a Deadly Impact

The most common form of pancreatic cancer is adenocarcinoma, which develops in the glandular cells that produce pancreatic juice. This type accounts for about 90% of all pancreatic cancer diagnoses. While pancreatic cancer is not among the most frequently diagnosed cancers, it is known for being especially aggressive. Its death rate nearly matches its diagnosis rate.

Worldwide, there are roughly 510,000 new pancreatic cancer cases each year, with nearly the same number of deaths reported annually.

In Brazil, estimates from the National Cancer Institute (INCA) point to about 11,000 new cases and 13,000 deaths each year. "It's an aggressive cancer that's difficult to treat. Around 10% of patients have a chance of long-term survival, such as five years after diagnosis," says Pedro Luiz Serrano Uson Junior, an oncologist and one of the study's authors.

Why Nerve Invasion Matters

One reason pancreatic cancer is so dangerous is a process known as perineural invasion. This occurs when cancer cells move into and spread along nerves. The process can cause severe pain and also helps the tumor reach other parts of the body more easily. "Perineural invasion is a marker of cancer aggressiveness," Uson explains.

Because nerves connect different regions of the body, cancer cells that enter these pathways gain new routes for expansion.

Mapping the Tumor's Hidden Support System

The research was carried out at the Center for Research on Inflammatory Diseases (CRID), one of FAPESP's Research, Innovation, and Dissemination Centers (RIDCs). The study was led by researcher Carlos Alberto de Carvalho Fraga, with Helder Nakaya serving as principal investigator. Nakaya is also a senior researcher at Einstein Israelite Hospital and a professor at the University of São Paulo's School of Pharmaceutical Sciences.

To uncover how nerve invasion occurs, the team used advanced tools that analyze the activity of thousands of genes in individual cells while mapping their exact locations within tumor tissue. "We were able to integrate data from dozens of samples with extremely powerful resolution," Nakaya says.

The researchers examined 24 pancreatic cancer samples and found that the stroma, the connective tissue that supports the tumor, plays an active role in cancer progression rather than serving as a passive structure.

The Role of Periostin and Tissue Remodeling

One of the study's most important findings involved pancreatic and stellate cells that produce large amounts of periostin. This protein is known for its ability to reshape the extracellular matrix - the structure that organizes and maintains healthy tissue.

Tumor cells rely on major changes to this matrix in order to push through tissue and reach nearby nerves. This remodeling process involves specialized enzymes and widespread tissue disruption. "Periostin participates in this remodeling, paving the way for tumor cells to invade," Nakaya explains. Once cancer cells reach a nerve, it can act like a "road" that helps them spread further.

Why Treatments Struggle to Reach the Tumor

As the tumor environment changes, it triggers a desmoplastic reaction. This involves the buildup of dense, fibrous tissue around the tumor, made up of cells and proteins that stiffen and inflame the area. The hardened tissue makes it harder for chemotherapy and immunotherapy drugs to penetrate the tumor.

This protective microenvironment allows cancer cells to survive and continue spreading. "That's why pancreatic cancer is still so difficult to treat," says Uson.

Early Spread Leads to Poor Outcomes

According to Uson, the tumor's ability to infiltrate surrounding tissue is a major reason for the poor outlook faced by many patients. "Perineural invasion is a sign that cancer cells have gained mobility. They escape the tumor mass, travel through healthy tissue, and reach nerve and lymphatic bundles, which carry them to other regions of the body, facilitating the development of metastases."

More than half of pancreatic cancer cases already show signs of perineural invasion at an early stage. However, this spread is usually discovered only after surgery. "Unfortunately, we discover this perineural invasion after it's already occurred. It's only seen in the surgical specimen when it goes for biopsy," Uson says.

Source: ScienceDaily

Scientists find the genetic switch that makes pancreatic cancer resist chemotherapy

 Researchers at Duke-NUS Medical School have discovered a molecular "switch" that determines whether pancreatic cancer cells respond to chemotherapy or resist it. The finding points to a way to potentially shift some of the most treatment resistant tumors into a state where existing drugs can work more effectively.

The study, published in the Journal of Clinical Investigation, explains how this switch operates at a molecular level. The results suggest that pairing targeted therapies with standard chemotherapy may improve outcomes for patients whose tumors no longer respond to treatment.

Why Pancreatic Cancer Is So Difficult to Treat

Pancreatic cancer is one of the deadliest cancers worldwide. In Singapore, it ranks as the ninth most common cancer but the fourth leading cause of cancer related death. Because symptoms often appear late and current treatments have limited impact, most patients depend on chemotherapy, which typically provides only modest benefit.

Over the past decade, scientists have identified two main molecular subtypes of pancreatic cancer, classical and basal. Tumors in the classical subtype tend to be more organized at the cellular level, and patients with this form are more likely to respond to treatment. In contrast, basal subtype tumors are more disorganized and aggressive, and they are often resistant to chemotherapy.

Importantly, pancreatic cancer cells are not fixed in one subtype. They can shift between these states, moving from a more treatable form to a more resistant one. This flexibility is known as cancer cell plasticity.

The Role of GATA6 in Tumor Behavior

The research team focused on a gene called GATA6, which helps maintain pancreatic cancer cells in the more structured and less aggressive classical state. When GATA6 levels are high, tumors tend to grow in a more organized way and are more likely to respond to chemotherapy. When GATA6 levels fall, cells lose that structure, become more aggressive, and are harder to treat.

Professor David Virshup of Duke-NUS's Programme in Cancer & Stem Cell Biology, the study's lead author, said:

"We have known that pancreatic cancer cells can switch between these two states. What we didn't understand was the mechanism driving that switch. By identifying the pathway that suppresses GATA6, we now have a clearer picture of how tumors become resistant -- and potentially how to reverse that process."

KRAS and ERK Pathway Drive the Switch

The researchers traced the switch to a chain of signals inside pancreatic cancer cells. A gene called KRAS, which is mutated in nearly all pancreatic cancers, sends constant growth signals that drive tumor development. KRAS passes these signals through a partner protein known as ERK, which relays the instructions further inside the cell.

When the ERK pathway becomes highly active, it protects another protein that interferes with the production of GATA6. As GATA6 levels drop, cancer cells lose their organized structure, shift toward the more aggressive basal state, and become much less responsive to chemotherapy.

Using genetic screening, molecular analysis in cancer cells, and drug treatments, the team demonstrated that blocking the KRAS and ERK pathway lifts this suppression. When that happens, GATA6 levels rise again. The cancer cells then shift back toward the more organized state and regain sensitivity to chemotherapy.

Combination Therapy Shows Stronger Effects

The study also found that higher levels of GATA6 on their own made pancreatic cancer cells more responsive to treatment. When drugs that inhibit the KRAS and ERK pathway were combined with standard chemotherapy, the anti cancer effects were stronger than with either approach alone. However, this enhanced benefit occurred only when GATA6 was present, highlighting its central role in determining which patients might benefit most from combination therapy.

These findings help clarify why patients with higher GATA6 levels often respond better to certain chemotherapy regimens. They also provide a scientific foundation for ongoing clinical trials that are testing new treatments aimed at KRAS and related pathways.

Professor Lok Sheemei, Duke-NUS' Interim Vice-Dean for Research, said:

"Pancreatic cancer remains one of the toughest cancers to treat. These findings provide a mechanistic explanation for why tumors respond poorly to chemotherapy and offers a rational strategy for combining targeted therapies with existing drugs."

Broader Implications for Other KRAS Driven Cancers

The implications may extend beyond pancreatic cancer. Many other cancers fueled by KRAS mutations show similar shifts in cell behavior and treatment response. Understanding how cancer cells transition between different states could help researchers address therapy resistance in additional cancer types.

Professor Patrick Tan, Dean and Provost's Chair in Cancer and Stem Cell Biology at Duke-NUS, commented:

"This work demonstrates how basic science can uncover actionable insights into treatment resistance. Understanding how cancer cells switch states gives us a more strategic way to design combination treatments."

Duke-NUS Medical School is internationally recognized for its leadership in medical education and biomedical research, combining fundamental discoveries with translational expertise to improve health outcomes in Singapore and beyond.

Source: ScienceDaily