Is diverticular disease associated with colonic malignancy?

Colon cancer and diverticular disease have common characteristics; there are increases in the incidences in both disease entities and these diseases are more common in the westernized world. There is also an increase in the age-specific incidence with advancing age. Similar dietary features have been implicated for both diseases and already during the 1960s it was postulated by Burkitt that there is an association. Observational studies initially were able to demonstrate that patients with a history of diverticular disease of the colon had an increased risk of colon cancer, especially in the left side. However, the results from these studies have not been consistent, and problems like selection bias and confounding by indication have been major drawbacks in order to interpret the results and infer causality. Recent studies, which have had a better assessment of diverticular disease by new diagnostic methods, do not support such an association to the same extent as previously. Moreover, surveillance bias has become an increasing problem as patients with diverticular disease of the colon are subjected to a higher diagnostic intensity than other individuals in a population-based setting. A critical evaluation of the studies published so far therefore clearly indicates that the proposed association between diverticular disease and colonic malignancy is not evidence based, which should have an impact on clinical practice as well as on how to deal with these patient groups within the realms of a screening program.