Abstract B26: Analyzing health benefits beyond the treatment period

B26

When studying cancer treatments, the benefits and risks are usually reported following a specific duration of time. For example, the probability of recurrence might be reported with and without the treatment after five years. However, cancer treatments often provide benefits which last beyond the duration of the treatments themselves. Studies have demonstrated this clearly for calcium supplements in preventing recurrence of colorectal adenomas (1), and for isotretinoin in head and neck tumors (2).

The risks associated with such treatments, on the other hand, usually persist only as long as the treatments are being applied. It is therefore impractical to compare the reduction of one risk with the increase of others at any single point in time in these cases. This is especially true for treatments that carry multiple risks, such as tamoxifen (3). A preferred method would be to consider the patient's survival curves both with and without the treatment. Adjusting the patient's initial (cancer-free) survival curve according to a disease-specific survival curve and a risk-specific survival curve yields the patient's probability of survival over time, accounting for all factors relevant to the treatment decision. This is a much more effective method for weighing the risks of a treatment against its benefits. In this work, we describe the process of the analysis, and apply it to specific cases.

Citation Information: Cancer Prev Res 2008;1(7 Suppl):B26.