The continuum of care: a paradigm for the management of metastatic colorectal cancer.

New agents for the treatment of metastatic colorectal cancer have extended median overall survival to more than 20 months, an increase that has changed the view of advanced colorectal cancer from an acute to a chronic condition. This article proposes a shift in treatment strategy from the concept of successive "lines" of therapy, in which chemotherapy is continued until disease progression, to that of a continuum of care, in which the use of chemotherapy is tailored to the clinical setting and includes switching chemotherapy prior to disease progression, maintenance therapy, drug "holidays," and surgical resection of metastases in selected patients. In this approach, the distinction between lines of therapy is no longer absolute. This represents a paradigm shift in the management of metastatic colorectal cancer to that of a continuum of care approach that includes individualized planning, in which patients are given the opportunity to benefit from exposure to all active agents and modalities while minimizing unnecessary treatment and toxicity, with the ultimate goal of improving survival as well as quality of life.