Clinical, demographic, and follow-up characteristics of patients with two primary metachronous tumors, one of them being in the colon.

The clinical characteristics of 152 patients diagnosed with two primary metachronous tumors--one or both of them in the colon--were studied. Nineteen patients had both primary tumors in the colon (Group I), 59 had the first primary tumor in the colon and the second tumor elsewhere (Group II), and 74 had the second primary tumor in the colon and the first primary tumor elsewhere (Group III). The group in which the second primary tumor was in the colon included significantly more female patients than did the other two groups, with a younger median age at diagnosis of first tumor. The median time interval between the two primary tumors was 44, 57, and 62 months in Groups I, II, and III, respectively. The number of clinic visits during the year before diagnosis of the second primary was similar in all groups, but only 60 percent of the patients kept their follow-up appointment. In most instances, the diagnosis was made after the patients' symptoms, although only a small percentage of the second primary tumors (15-30 percent) were diagnosed during routine follow-up. The second primary tumor occurred in the field of radiotherapy of the first primary tumor in 27 of 35 patients who received radiotherapy. To increase the number of patients diagnosed in an earlier stage of disease, they should be urged to keep their follow-up appointment, and physicians following patients with single tumors should be aware of the increased likelihood of a second tumor. To increase the cure rate of those tumors, efforts toward early diagnosis are warranted. This includes physical examination and mammography to detect breast cancer in women, annual occult blood tests and rectal examination, and sigmoidoscopy or colonoscopy at three-year intervals to detect colon cancer early.