Pancreatic cancer has one of the poorest outcomes of any cancer, and the reason is built into the disease: it causes few symptoms while it is small and curable, so most people are diagnosed only after the tumour has invaded local vessels or spread. Survival is therefore dominated by the stage at diagnosis, and by whether the tumour can be completely removed.
Survival by stage
In the United States, the overall 5-year relative survival for pancreatic cancer is about 14%. That average conceals very different groups, and the difference between them is the clearest single fact about the disease:
| Stage at diagnosis | Share of patients | 5-year relative survival |
|---|---|---|
| Localised (confined to pancreas) | about 15% | about 44% |
| Regional (spread to lymph nodes) | about 28% | about 17% |
| Distant (metastatic) | about 51% | about 3% |
Only about 15% of patients are diagnosed while the cancer is still localised, which is why the overall figure sits far below the localised one. About half are already metastatic when the diagnosis is made.
The effect of resection
The highest chance of cure comes when a tumour is truly confined to the pancreas and can be completely resected. Even then the outlook is guarded: for small, localised cancers without lymph node spread or extension beyond the pancreatic capsule, complete resection gives an actuarial 5-year survival of about 18% to 24%. Because recurrence — usually at distant sites — is common even after a complete operation, resection is combined with systemic chemotherapy, and patients with any stage of the disease are candidates for clinical trials.
Other factors refine the estimate within a stage. Whether the tumour has spread to lymph nodes is one of the two strongest predictors of outcome, alongside resectability. Tumours of the body and tail tend to present later, with more advanced disease, than tumours of the head.
The outlook is poor because the disease is usually found late, which is the reasoning behind screening limited to people at high risk.