RSS feedPancreas cancer carries with it a bad reputation because it is quite ‘silent’ when the tumour is small. Most patients with pancreas cancer tend to present with a history of progressive, painless jaundice (yellowing of the skin and the white of the eyes). The jaundice occurs when the common bile duct, which drains the secretion from the liver (called bile) into the duodenum, is obstructed by the tumour. When the bile cannot reach the duodenum, the blood bilirubin level becomes abnormally high and this leads to the yellow discolouration of jaundice. When patients present with jaundice, a large proportion of them will have an inoperable cancer in the head of the pancreas, either because it has spread locally or it has involved the portal vein. (The portal vein is the main vein which carries blood from all the intestines to the liver. It is three-quarter wrapped by the head and uncinate process of the pancreas during its course to the liver.) What is the water-shed size that predicts better or worse outcome for patients with pancreatic cancer?
Researchers from the St Louis University School of Medicine studied patient survival and tumour resectability in 65 patients who were treated at the MD Anderson Cancer Centre between December 2000 and December 2001 (Pancreas 2008; 36: e15 – e20). The number of patients with tumours 20 mm or smaller, 21 - 25 mm, 26 – 30 mm and > 30 mm were 12, 12, 14 and 27, respectively. The tumours were successfully resected in 10 of 12 (83.33%) tumours < 20mm in size, 8 of 12 (66.66%) tumours 21 – 25 mm in size, 5 of 14 (35.71%) tumours 26 – 30 mm in size and 2 of 27 (7.4%) tumours > 30 mm in size. The median survival of the patients was significantly affected by the tumour size. The survival, in months, for tumours < 20 mm, 21 – 25 mm, 26 – 30 mm and > 30 mm was 17.2, 12.3, 8.5 and 7.6, respectively. This study showed that as the size of the tumour increased from 20 mm to 30 mm and beyond, the chance of survival is adversely affected.
The finding of this study merely confirms the findings of several earlier published studies. Smaller pancreatic cancer means a higher chance of its removal. Like all solid organ cancers, complete surgical removal gives the best patient outcome and potential for cure. As the tumour size increases, the chance of a successful removal decreases. The presence of a pancreatic tumour 30 mm or greater in size does not automatically mean no surgery and certain death. It merely means the chance of surgery is reduced. If the tumour is still resectable, all attempts must be made to remove it as this will give the patient a chance of cure.
Despite the fact that we have faster and better computer tomography (CT) scanning and magnetic resonance imaging (MR), for most patients with pancreatic cancer, the average tumour size at the time of diagnosis is around 30 mm. In the above study, the average tumour size was 32.9 mm. The challenge for us doctors is to discover the pancreatic cancer when small, preferably less than 20 mm. However, the lack of early symptoms and signs make it difficult. While it is possible for the CT and MR to detect a 20 mm tumour, the CT and MR findings are subtle and can be easily overlooked. Until we have a new and sensitive cancer marker or molecular marker for pancreas cancer, we can only rely on clinical vigilance. While this is not much comfort to future pancreatic cancer patients, the medical community is working hard to solve this vexatious problem.
