Survival analysis of pancreatic and periampullary collision cancers

OBJECTIVE: Collision cancers are malignancies in the same organ or anatomical site that comprises at least two different tumor components, with no mixed or transitional area between two components. Collision cancers are very rare in the pancreas and periampullary region. The aim of this study was to analyze the clinical and pathological features and prognosis of collision cancer in the pancreas and periampullary region. METHODS: Patients with collision cancers of the pancreas and periampullary region (n= 10) who had undergone radical surgery were retrospectively studied. Their clinical and pathological features were summarized and the prognostic data were compared with patients with pancreatic adenocarcinomas who underwent radical surgery (n= 87) and with patients with pancreatic or periampullary malignancies who underwent palliative surgery (n= 89). RESULTS: Compared with other cancers at these sites, collision cancer presents no specific clinical features. However, the median survival period of patients with such malignancies was only 10.0 months, which was much less than those with pancreatic adenocarcinomas who underwent radical surgery (27.0 months) and those who received a palliative operation (20.9 months) only. CONCLUSION: Collision cancers of the pancreas and periampullary region are difficult to diagnose preoperatively. Their prognosis is poor even after radical resection and adjuvant chemotherapy were given.