An evaluation of postoperative follow-up tests in colon cancer patients treated for cure

Currently patients with colon cancer who are potentially cured by surgery are followed periodically with physical examinations, blood tests and imaging studies to detect tumor recurrence early, on the presumption that intervention can effect outcome. There is little information to indicate whether frequent visits to the doctor's office or frequent testing improves survival or quality of life.

Ninety-eight patients with resected stage B2, B3 or C (modified Astler-Coller) colon cancer who developed recurrent disease while enrolled in prospective adjuvant trials at Mayo Clinic sponsored by the North Central Cancer Treatment Group were studied to evaluate the utility of follow-up tests to detect the first recurrence of colon cancer and the outcome following various interventions for these recurrences. These patients had a history, physical examination, complete blood count, chemistry panel and chest x-ray approximately every 3-4 months in the 1st year and then every 6-12 months thereafter for a total of 5 years. Bowel evaluation was done at 6 months, 12 months and annually thereafter. In addition, a minority of patients had carcinoembryonic antigen (CEA) testing, and radioisotope liver scans at various intervals.

Symptoms signaled the diagnosis of recurrent disease in 55 patients, physical examination in 4 patients, and abnormalities in chest x-ray in 18 patients. An elevated CEA was the initial abnormal test in 5 patients, abnormal liver scans in 5 patients, elevated liver function tests in 6 patients and laparotomy for other reasons in 2 patients. Hemoglobin, barium enema, and fecal blood testing were useful in 1 patient each. Thirty-one percent of recurrences were diagnosed between scheduled visits. In our series, histories, physical examinations, and chest x-rays led to the detection of 79% of the recurrences while liver function tests, liver scans and CEAs led to the detection of 16% of recurrences. Sixteen patients underwent resection for cure for their first recurrence; the diagnosis of recurrence was signaled by symptoms in 6 patients, chest x-ray in 6 patients and abnormal liver function tests, CEA, hemoglobin, and laparotomy for colostomy closure in 1 patient each.

The majority of tumor recurrences were detected by symptoms, physical examinations and chest x-rays. Testing for asymptomatic tumor recurrences during the 1st follow-up year is likely to be much less fruitful for detecting resectable recurrences than testing patients in the 2nd through 4th follow-up years. Patients who had a disease recurrence in the 1st postoperative year were less likely to be candidates for curative intent surgery. Lower tumor grade at initial diagnosis correlated both with likelihood of undergoing secondary surgical resection and the chance of doing well following this. These data may be helpful for defining more appropriate follow-up test for detection of tumor recurrence in patients with resected colon cancer.