First-degree relatives (parents, siblings and children) of patients with pancreatic cancer are roughly twice as likely as the general population to develop pancreatic cancer themselves, according to a study published in the journal Cancer.
Pancreatic cancer has one of the highest mortality rates of all cancers; it accounts for approximately 2 percent of all newly diagnosed cancers in the United States each year, but 5 percent of all cancer deaths. Pancreatic cancer is often called a silent killer because it usually does not cause any recognizable symptoms until it is advanced and has spread outside the pancreas. As a result, the majority of pancreatic cancers are not diagnosed until they have reached advanced stages and are considered incurable.
The current study evaluated the risk of several types of cancer among first-degree relatives of pancreatic cancer patients. The goals of the study were to collect information that would be useful for counseling family members about their cancer risk and to collect clues about the causes of pancreatic cancer.
The study evaluated 3355 first-degree relatives of 426 pancreatic cancer patients seen at the Mayo Clinic. The frequency of cancer among the relatives was compared to the frequency of cancer in the general population. Information about the frequency of cancer in the general population was collected from the Surveillance, Epidemiology, and End Results (SEER) cancer registry.
First-degree relatives of pancreatic cancer patients were roughly twice as likely as the general population to develop pancreatic cancer. When the pancreatic cancer patient had developed cancer before the age of 60, first-degree relatives had an even greater risk; they were roughly three times more likely to develop pancreatic cancer than the general population. Relatives of pancreatic cancer patients were also more likely to have liver cancer, though researchers speculate that some of the cancers reported as liver cancer could be pancreatic cancers that had spread to the liver. Risks of several other cancers were less common in relatives of pancreatic cancer patients than in the general population. The cancers that were underrepresented among the relatives of pancreatic cancer patients were lymphoma, bladder cancer, breast cancer, lung cancer and prostate cancer. The researchers question whether these cancers were truly less common among relatives of pancreatic cancer patients or whether they were simply under-reported.
The researchers conclude that having a family history of pancreatic cancer increases the risk of pancreatic cancer. A family history of pancreatic cancer does not appear to increase the risk of other types of cancer, with the possible exception of liver cancer. Individuals with a family history of pancreatic cancer should speak with their physician regarding their individual risk of developing pancreatic cancer and possible screening measures for early detection of the disease or the participation in a clinical trial evaluating novel screening measures for this disease.
Reference: McWilliams RR, Rabe KG, Olswold C, et al. Risk of malignancy in first-degree relatives of patients with pancreatic carcinoma. Cancer. 2005;104:388-94.