Pancreatic Cancer: Types, Genetic Testing & Treatment

Pancreatic cancer develops in the cells of the pancreas, an organ located deep in the abdomen behind the stomach that produces digestive enzymes and hormones such as insulin and glucagon. The vast majority of cases, roughly 90 to 95 percent, are pancreatic ductal adenocarcinoma, which arises from the exocrine cells that line the ducts carrying digestive enzymes into the small intestine. A much smaller proportion of cases, generally under 5 percent, are pancreatic neuroendocrine tumours (PanNETs), which arise from hormone-producing islet cells and often behave quite differently, typically growing more slowly and sometimes secreting hormones that cause distinct symptoms.

Because the pancreas sits deep within the abdomen and is not easily felt or seen on routine examination, tumours can grow for months or longer before causing noticeable symptoms. By the time symptoms such as pain, jaundice, or weight loss appear, the cancer has often already invaded nearby blood vessels or spread to other organs, most commonly the liver, peritoneum, or lungs. This is a central reason why pancreatic cancer is frequently diagnosed at a locally advanced or metastatic stage rather than at an early, more easily treatable stage.

Pancreatic ductal adenocarcinoma is also biologically distinct from many other solid tumours in that it tends to be surrounded by a dense layer of fibrous tissue, known as stroma, which can make the tumour harder for chemotherapy drugs to penetrate and can also shield it somewhat from the immune system. This dense stroma is one reason pancreatic cancer has historically been more difficult to treat effectively than some other cancer types, and it remains an active area of research.

The disease can occur sporadically, without any clear inherited cause, or it can arise in the context of inherited genetic syndromes that increase risk, such as hereditary BRCA1/BRCA2 mutations, Lynch syndrome, or familial atypical multiple mole melanoma syndrome. Chronic inflammation of the pancreas (chronic pancreatitis), long-standing diabetes, and smoking are also recognised contributors to risk. Understanding whether a particular case has an inherited component can matter both for treatment selection and for informing family members about their own risk.

Outcomes vary considerably depending on the stage at diagnosis, whether the tumour can be surgically removed, and increasingly, the tumour's molecular features. While pancreatic cancer remains one of the more difficult cancers to treat, meaningful progress has been made in recent years through improved chemotherapy combinations, better surgical and radiation techniques, and the identification of molecular subgroups that respond to targeted therapies or immunotherapy.

Receiving a diagnosis of pancreatic cancer can feel overwhelming, particularly given its reputation as a difficult disease to treat. It is important to know that treatment decisions are highly individualised, based on the exact location and extent of the tumour, whether it can be surgically removed, your overall health, and increasingly, specific molecular and genetic findings from your tumour and, where relevant, from your own inherited genetic makeup.

Asking your care team directly about your tumour's resectability status, the results of any genetic or molecular testing performed, and whether a clinical trial might be appropriate for your situation can help you understand your options more clearly. Many people find it helpful to seek a second opinion or evaluation at a high-volume pancreatic cancer centre, since experience with pancreatic surgery and complex chemotherapy regimens can meaningfully affect both safety and outcomes.

Early pancreatic cancer often causes no symptoms at all, which is one of the main reasons the disease is frequently found at a later stage. When symptoms do appear, they are often nonspecific and can be mistaken for other digestive conditions, including persistent upper abdominal or back pain, unexplained weight loss, loss of appetite, nausea, and fatigue.

Jaundice, a yellowing of the skin and eyes caused by a blocked bile duct, is a more distinctive symptom that often prompts urgent medical evaluation, particularly when accompanied by dark urine, pale stools, or itchy skin. Tumours located in the head of the pancreas, near the bile duct, are more likely to cause jaundice earlier than tumours in the body or tail of the organ.

New-onset diabetes, particularly in someone without typical risk factors, or a sudden worsening of previously stable diabetes, can occasionally be an early clue to an underlying pancreatic tumour, since the cancer can interfere with the pancreas's hormone-producing function. Digestive difficulties, such as pale, oily, foul-smelling stools, can occur when the tumour blocks the flow of digestive enzymes into the intestine.

Because these symptoms overlap with many benign conditions, they do not necessarily indicate cancer, but persistent or unexplained symptoms, especially in combination, such as unexplained weight loss with new abdominal pain or jaundice, warrant prompt medical evaluation to determine the underlying cause.

Pancreatic ductal adenocarcinoma develops through the accumulation of genetic changes in pancreatic duct cells over time. The KRAS gene is mutated in the large majority of pancreatic ductal adenocarcinomas and is considered a key early driver of the disease, activating signalling pathways that promote uncontrolled cell growth. Other genes commonly altered include TP53, CDKN2A, and SMAD4, which are involved in controlling cell division and cell death; their loss of normal function contributes to tumour progression.

In a meaningful subset of patients, these genetic changes are inherited rather than acquired purely through chance. Germline mutations in BRCA1, BRCA2, PALB2, ATM, and genes associated with Lynch syndrome (such as MLH1 and MSH2) increase the lifetime risk of developing pancreatic cancer and can also influence treatment choices, since some of these alterations affect the tumour's ability to repair DNA damage, making it more sensitive to certain drug classes such as platinum-based chemotherapy and PARP inhibitors.

Chronic inflammation of the pancreas, whether from long-standing alcohol use, gallstones, or hereditary pancreatitis, is thought to contribute to cancer development over time by promoting an environment of ongoing cellular damage and repair. Similarly, long-standing type 2 diabetes has been associated with an increased risk, and the relationship between diabetes and pancreatic cancer appears to run in both directions, since the cancer itself can sometimes cause new diabetes.

Pancreatic neuroendocrine tumours have a distinct biology, arising from hormone-producing islet cells and sometimes occurring as part of inherited syndromes such as multiple endocrine neoplasia type 1 (MEN1) or von Hippel-Lindau disease, though many cases occur sporadically without an identifiable inherited cause.

Non-modifiable risk factors for pancreatic cancer include increasing age, since most cases occur in people over 60, and a family history of pancreatic cancer or related hereditary cancer syndromes involving BRCA1/2, Lynch syndrome, or familial pancreatitis. Certain inherited conditions substantially raise lifetime risk, and people with a strong family history may be offered genetic counselling and, in some cases, pancreatic cancer screening with imaging.

Modifiable risk factors include cigarette smoking, which roughly doubles risk and is one of the most significant preventable contributors to the disease, as well as long-term heavy alcohol use, which can lead to chronic pancreatitis. Obesity and a diet high in red and processed meats have also been associated with a modestly increased risk, while regular physical activity and maintaining a healthy body weight may offer some protective benefit.

Long-standing diabetes, particularly type 2 diabetes present for many years, and chronic pancreatitis from any cause are both recognised risk factors. Certain occupational exposures to chemicals used in dry cleaning and metalworking have also been linked to modestly increased risk in some studies, though the overall contribution of occupational exposure is generally smaller than that of smoking or genetic factors.

It is worth emphasising that many people who develop pancreatic cancer have no identifiable risk factors, and having one or more risk factors does not mean cancer will definitely develop; these factors describe population-level associations rather than individual certainty.

Diagnostic work-up typically begins with imaging, most often a contrast-enhanced CT scan of the abdomen using a specific pancreatic protocol, which can identify a mass, assess its relationship to nearby blood vessels, and check for signs of spread to the liver or other organs. MRI and endoscopic ultrasound (EUS) are also commonly used, with EUS offering the additional advantage of allowing a needle biopsy to be taken directly from the pancreas under ultrasound guidance.

A tissue biopsy, most often obtained via EUS-guided fine needle aspiration or biopsy, is generally required to confirm the diagnosis and determine the specific tumour type before treatment begins, except in some cases where the tumour is clearly resectable and surgery itself will provide the diagnostic tissue. Blood tests, including the tumour marker CA 19-9, can support diagnosis and monitoring, although this marker is not specific enough to diagnose pancreatic cancer on its own and can be elevated in other conditions or, conversely, normal in some people with true pancreatic cancer.

Endoscopic retrograde cholangiopancreatography (ERCP) may be used both diagnostically and therapeutically, particularly when a bile duct blockage needs to be relieved with a stent to treat jaundice. Once a diagnosis is confirmed, additional staging imaging, such as CT of the chest or PET scanning in select cases, helps determine the full extent of disease before a treatment plan is finalised.

Pancreatic cancer is staged using the TNM system (tumour size and local extent, lymph node involvement, and distant metastasis), which is combined into overall stages from I through IV. However, in clinical practice, oncologists and surgeons often use a more treatment-relevant classification based on resectability: resectable, borderline resectable, locally advanced (unresectable), and metastatic disease.

Resectable tumours are those that have not grown into critical blood vessels and can likely be completely removed with surgery. Borderline resectable tumours have some involvement of nearby blood vessels but may still be removable, often after initial chemotherapy (and sometimes radiotherapy) is given to shrink the tumour and improve the chances of a complete surgical removal. Locally advanced, unresectable tumours have grown extensively into surrounding blood vessels or structures such that surgical removal is not considered feasible, even though the cancer has not spread to distant sites.

Metastatic disease refers to cancer that has spread beyond the pancreas and surrounding area to distant organs, most commonly the liver, peritoneum, or lungs. This resectability-based framework, alongside formal TNM stage, is what most directly determines the initial treatment strategy, since it distinguishes patients who may be candidates for potentially curative surgery from those who will be treated primarily with systemic therapy.

Molecular and genetic testing plays an increasingly important role in pancreatic cancer care. Germline (inherited) genetic testing is now recommended for most patients with pancreatic ductal adenocarcinoma, regardless of family history, to look for mutations in BRCA1, BRCA2, PALB2, ATM, and Lynch syndrome-associated genes, since these findings can affect treatment choices and have implications for family members.

Tumour (somatic) testing, often through next-generation sequencing (NGS) of the biopsy or surgical specimen, looks for actionable alterations including KRAS mutations (present in most cases, though certain rarer KRAS variants can now be targeted with specific drugs), BRCA1/2 mutations occurring specifically within the tumour, NTRK gene fusions, and microsatellite instability (MSI) or mismatch repair deficiency, which can identify candidates for immunotherapy.

For patients whose tumours carry a BRCA1/2 mutation (either inherited or tumour-specific), platinum-based chemotherapy tends to be particularly effective, and maintenance therapy with a PARP inhibitor may be an option after initial chemotherapy response in advanced disease. Tumours with high microsatellite instability or mismatch repair deficiency, while uncommon in pancreatic cancer, may respond to immune checkpoint inhibitor therapy. The tumour marker CA 19-9 is also used, not to diagnose the disease, but to help monitor response to treatment and detect recurrence over time.

Pancreatic ductal adenocarcinoma is by far the most common form of pancreatic cancer, accounting for roughly 90 to 95 percent of cases, and arises from the exocrine cells lining the pancreatic ducts. Less common exocrine subtypes include acinar cell carcinoma and adenosquamous carcinoma, which are rarer and can behave somewhat differently in terms of growth pattern and treatment response.

Pancreatic neuroendocrine tumours (PanNETs) make up a small minority of pancreatic cancers but are clinically important because they generally grow more slowly and can be either "functioning," meaning they secrete hormones that cause distinct symptoms (such as insulinomas causing low blood sugar, or gastrinomas causing excess stomach acid), or "non-functioning," meaning they do not cause hormone-related symptoms and are often found incidentally or once they grow large enough to cause other symptoms.

Within pancreatic ductal adenocarcinoma, tumours are increasingly understood to have different molecular subtypes based on gene expression patterns, though this classification is used more in research settings than routine clinical practice at present. Precursor lesions, such as pancreatic intraepithelial neoplasia (PanIN) and intraductal papillary mucinous neoplasms (IPMNs), represent earlier, sometimes precancerous changes that can be monitored or removed before they progress to invasive cancer, particularly when identified incidentally on imaging performed for other reasons.

Treatment approach depends heavily on whether the tumour is resectable, borderline resectable, locally advanced, or metastatic, and is best planned by a multidisciplinary team including surgical, medical, and radiation oncology. For resectable tumours, surgery, most often a Whipple procedure (pancreaticoduodenectomy) for tumours in the head of the pancreas, or distal pancreatectomy for tumours in the body or tail, is the primary treatment, typically combined with chemotherapy given either before surgery (neoadjuvant) or after surgery (adjuvant) to reduce the risk of recurrence.

For borderline resectable disease, neoadjuvant chemotherapy, sometimes combined with radiotherapy, is commonly used first to shrink the tumour and increase the chances of achieving a complete surgical removal with clear margins. This approach has become increasingly favoured in recent years as evidence has grown supporting its benefit over surgery-first approaches in this group.

Locally advanced, unresectable disease is generally treated with systemic chemotherapy, sometimes followed by radiotherapy (often delivered as stereotactic body radiotherapy) to help control the tumour locally, although surgery is usually not part of the initial plan unless the tumour responds well enough to become potentially resectable.

Metastatic pancreatic cancer is treated primarily with systemic chemotherapy, most commonly combination regimens such as FOLFIRINOX or gemcitabine plus nab-paclitaxel, chosen based on a patient's overall fitness and organ function, since these combinations carry meaningful side effects. For patients whose tumours carry a BRCA1/2 mutation and have responded to initial platinum-based chemotherapy, maintenance therapy with a PARP inhibitor may be considered to help prolong disease control. In the rare cases with high microsatellite instability or mismatch repair deficiency, immune checkpoint inhibitor therapy may be an option.

Supportive and palliative care is an essential component of treatment at every stage, addressing pain management, nutrition, relief of bile duct or bowel obstruction (sometimes with stents placed endoscopically), and psychological support, and can be integrated alongside cancer-directed therapy rather than only offered once other treatments are stopped. Pancreatic neuroendocrine tumours are treated differently, often with somatostatin analogues, targeted therapies, or, in some cases, surgery or liver-directed treatments, depending on tumour grade, hormone activity, and extent of disease.

Survival statistics for pancreatic cancer vary substantially by stage at diagnosis and reflect outcomes across large populations rather than predictions for any individual patient. According to data compiled by sources such as the U.S. National Cancer Institute's SEER program, the overall 5-year relative survival rate for pancreatic cancer across all stages is approximately 13 percent, reflecting the fact that many cases are diagnosed at an advanced stage.

When the cancer is diagnosed while still localised to the pancreas, the 5-year relative survival rate is considerably higher, in the range of approximately 44 percent, and for tumours that are eligible for complete surgical removal, outcomes are generally more favourable still. For regional disease, where the cancer has spread to nearby lymph nodes or tissues but not to distant organs, 5-year survival is approximately 16 percent, while for metastatic (distant) disease, it is approximately 3 percent.

It is important to understand that these figures represent population averages based on people diagnosed some years ago and do not account for individual factors such as overall health, response to treatment, tumour molecular features, or newer treatment approaches that continue to be developed. Pancreatic neuroendocrine tumours generally have a considerably more favourable prognosis than ductal adenocarcinoma, particularly when low-grade and diagnosed before spreading beyond the pancreas. Your own oncology team is best placed to discuss what statistics may or may not mean for your specific situation.