[Immunologic responses following surgical resection of gastrointestinal carcinomas]

The amount of IgG, IgM, IgA, C3, C4 and C5 in serum, and the response to delayed hypersensitivity tests with PPD, varidase, candidin and mumps antigens were estimated in patients submitted to radical surgery for gastric and colorectal cancer (group I), before and at intervals after the operation was performed, and compared with cancer patients undergoing palliative abdominal surgery (group II), and with patients submitted to major abdominal surgery for diseases other than cancer (group III). Group I showed a decrease of all the immunoglobulins (Igs) and complement fractions (F) during the first week after operation, and a significant increase after one month. Similar changes were observed in group III, the augmentation of Igs and F after one month being somewhat smaller. Group II showed a larger number of positiveness than either group I or II in both the preoperative and early postoperative periods (p = 0.001). After 2 and 3 months, the number of positive cases was larger in group I than in group II (p = 0.05). According to these results, the immune response is recovered one month after the excision of gastric and colorectal malignant tumors, being this the best moment to receive a complementary cytoreductive therapy.