Duration of Chemotherapies in Phase III Studies on Metastatic Colorectal Cancer Treated With a Continuous Approach: A Seven-Year Survey

In last years, many phase III studies have addressed the role of chemotherapy or chemo/biotherapy in metastatic colorectal cancer (mCRC); most of these studies planned their treatment to be continued until disease progression or intolerable toxicity with the aim to obtain a long-term control of the cancer. However, the real duration of this approach might be significantly lower than planned. We made a survey to describe the real duration of chemotherapy in published phase III trials from January 2008 to December 2014. Twenty relevant publications were selected for a total of 48 treatment arms and of 24.475 patients. Median duration of chemotherapy in first-line studies ranged from 4,8 to 7,8 months; in second line from 2,4 to 5,2 months. Most common reasons of discontinuation were: progressive disease (PD), adverse events (AE) and patient request (PR). From 11.0% to 45.0% of patients discontinue treatment for toxicity or their request independently from the efficacy. PR was the third cause ranging from 4,6% to 26,0% of patients; in some studies, it overcame the AE-related withdrawals. Causes of PR for therapy discontinuation should be explored and analyzed to reduce the proportion of withdrawals in phase III studies.