Increased Incidence of Second Malignancies Associated with Small Bowel Adenocarcinoma

BACKGROUND:Some data suggest that there is an increased incidence of second malignancies associated with small bowel adenocarcinomas, but this has not been reviewed in the context of a tumour registry.OBJECTIVE:To review tumour registries based on population statistics to determine whether there is an increased incidence of second malignancies associated with small bowel adenocarcinomas.METHODS:The authors reviewed the tumour registries of two Canadian provinces (British Columbia and Manitoba) for small bowel adenocarcinoma to determine whether an increase in associated malignancies existed compared with those expected in the respective populations.RESULTS:A greater than eightfold increase in second malignancies was associated with small bowel carcinoma. The majority (73%) occurred before the diagnosis of the small bowel malignancy. Twenty-nine per cent were associated with cancers of the colon, rectum or both.CONCLUSIONS:There is an increased association of malignancy and the diagnosis of small bowel cancer. Generally, small bowel cancer is the second malignancy to be diagnosed, and the diagnosis is most often made in the elderly. Does this represent a syndrome related to an unstable gene (or genes) or a lack of repair, which makes individuals susceptible to this malignancy as they age?