Adjuvant chemotherapy in rectal cancer—an issue or a nonissue?

Abstract

Adjuvant therapy after primary surgery in colorectal cancer, as in other tumour types, aims at eradicating subclinical tumour deposits wherever they are in the body. If treatment has sufficient cell kill effect, this will improve time to recurrence. In clinical trials, recurrence or disease-free survival (DFS) is often used as the end point, including deaths from other causes, secondary malignancies and treatment-related deaths [1]. Since most recurrences in colorectal cancer is fatal, it is hoped that the magnitude of the benefit is so large that the gain in DFS will translate into an overall survival (OS) gain. In order to be accepted by patients and health care, the magnitude of the gain must be sufficient considering toxicity and costs, although the minimum level of this magnitude is poorly known. In order to be accepted by the health care system, it is also usually required that there is sufficient scientific evidence from clinical trials. Without this knowledge, it ought to be almost impossible to correctly inform the patients about pros and cons so that the patient may make a proper decision. On the other hand, studies have shown that some patients accept treatment also for no gains [2, 3].