Temporal changes in neuro-immuno endocrine system with adjuvant radiotherapy for advanced rectal cancer

The purpose of this study was to evaluate the effect of adjuvant radiotherapy for advanced rectal cancers on the human neuro-immuno-endocrine system. Fifty-seven patients with rectal cancer were investigated. Abdominoperineal resection (APR) was carried out on all of them. The levels of serum IAP in 4-12 weeks after operation were significantly higher in the preoperative radiotherapy group compared with those of non-preoperatively irradiated (p < 0.05). With preoperative radiotherapy, serum IAP levels in patients with postoperative intracavitary cone irradiation returned to normal values within three months of operation; however, those with postoperative external pelvic irradiation continued to be significantly elevated until six months after operation. We conclude that preoperative radiotherapy combined with post-operative external pelvic irradiation is likely to exert unfavorable effects on the human immuno-endocrine system.