Background: A higher than expected incidence of second primary malignancies in patients with gastrointestinal carcinoids has been reported. How patients with such concurrent neoplasms should be managed and whether or not the discovery of an incidental carcinoid at the time of operation for another malignancy affects patient management or outcome, has never been previously addressed.
Study design: We retrospectively reviewed our 20-year experience with gastrointestinal carcinoid tumors with the purpose of determining the appropriate management and eventual outcome of patients with these multiple malignancies.
Results: Sixty-nine patients with carcinoids of the gastrointestinal tract were discovered, of whom 29 (42 percent) had second synchronous tumors and three (4 percent) had metachronous tumors. The gastrointestinal tract accounted for 42.9 percent of the tumors, and carcinoma of the colon and rectum was found in seven (21.9 percent) of 32 patients. None of the 29 patients with a second synchronous tumor presented with symptoms referable to their carcinoid, each of which was incidentally discovered: nine at autopsy and 20 at laparotomy for the treatment of other tumors. All of the 20 surgical patients had the gastrointestinal carcinoids resected for cure, although three had histopathologic criteria for invasion. None of the 29 patients died as a result of, had recurrence of, or had their postoperative therapy altered by the carcinoid diagnosis.
Conclusions: Gastrointestinal carcinoid is associated with a high incidence of second primary malignancy, 46 percent in this study. The most common site for the second primary malignancy in these patients is the gastrointestinal tract, suggesting a site specific predisposition to malignant degeneration. Most gastrointestinal carcinoids are incidentally discovered at laparotomy or autopsy. The discovery of an asymptomatic gastrointestinal carcinoid during the operative treatment of another malignancy will usually only require resection without additional treatment and will have little affect on the prognosis of the individual.