Self-defensive response to bone disorder after gastric cancer surgery

Background/Aims: Changes in estradiol that inhibits bone resorption were examined to investigate the in vivo defensive response to progression of bone disorder after gastric cancer surgery. Materials and Methods: Women who might show effects of menstruation were excluded because estradiol was examined. The subjects were 17 men with a mean age of 60.4 years who had undergone gastrectomy because of gastric cancer and were followed as outpatients. Microdensitometry was used to evaluate bone disorder. The duration after surgery until bone assessment was a mean of 3.5 years. The surgical procedure was total gastrectomy with Roux-Y reconstruction in 4 patients and subtotal gastrectomy with Billroth-I reconstruction in 9 patients and with Billroth-II reconstruction in 4 patients. Results: Bone disorder requiring treatment was observed in 6 out of the 17 patients (35.3%). Estradiol showed higher than normal values in 10 patients (58.8%). The incidence of bone disorder was high in patients with high estradiol levels, but the difference was not significant. Blood levels of estradiol in patients with bone disorder requiring treatment were high but again the difference was not significant (P = 0.119). Conclusions: Although the difference was not statistically significant, the increase in estradiol observed in patients with progressive bone disorder suggested to be caused by in vivo inhibition of enhanced bone metabolism after gastric cancer surgery.