Follow-Up for Patients With Colorectal Cancer After Curative-Intent Primary Treatment

The introduction of effective anesthetics in the midnineteenth century permitted the rapid development of surgery, which remains the primary form of therapy for colorectal cancer. Some patients were rendered grossly disease-free by surgery, creating a population at risk for recurrence for the first time in history. A few decades later, surgical salvage of relapse was attempted and, in a few instances, patients were cured. This provided a rationale for trying to diagnose recurrence early, while resection was still feasible. It was known at that time that individuals with one cancer were unusually likely to develop another, particularly in the same tissue as the index lesion. This provided further justification for patient follow-up, but posttreatment surveillance strategies evolved unevenly and largely without clinical trials to demonstrate effectiveness. Efforts to diagnose and treat recurrent colorectal cancer reached a peak with planned “second-look” laparotomy for patients with various intra-abdominal cancers judged to be at high risk for local-regional relapse. 1 Over half of these patients had node-positive colorectal cancer and nearly 50% of them had relapse documented at exploration. Most importantly, some patients were rendered tumor-free at operation, and a few of these were long-term disease-free survivors. The very high morbidity and mortality rates (to say nothing of the costs) associated with this strategy soon became apparent, but the introduction of modern diagnostic tools such as computed tomography (CT) and carcino-embryonic antigen (CEA) measurement now permit clinicians to select patients for salvage attempts much more precisely. Many of the wealthier nations of the world are now able to provide access to modern medicine to all or most of their citizens, with concomitant increases in the duration and quality of life. A by-product of the increase in the average life span has been a large increase in the total number of people afflicted with colorectal cancer, as the incidence of the disease increases with age. Costs of care also have risen dramatically, and therein lies one of the conundrums of modern clinical practice: how to use costly resources wisely. In an attempt to rationalize care, the concept of the randomized trial was introduced in the mid-twentieth century. The results of one million randomized trials have been published since then, 2 but very few have dealt with follow-up of patients with colorectal carcinoma. This poses an important problem because there are many patients at risk and the costs of diagnosis (and treatment, if needed) are high. 3 The American Cancer Society predicts that, in the