Prediction of risk of osteoporosis after gastrectomy for gastric cancer

Introduction There are few guidelines for screening of osteoporosis in patients who have undergone gastrectomy. This study aimed to develop and validate a nomogram to predict the risk of osteoporosis after gastrectomy in patients with gastric cancer. Methods Bone densitometry results for 522 patients with gastric cancer and 2088 individuals from a health-promotion centre were compared using propensity score matching to develop a nomogram to predict osteoporosis after gastrectomy. External validation was performed using an independent data set. Results In the 10 years after gastrectomy 53.5 per cent of patients developed osteoporosis. In multivariable analysis, the odds ratios of subtotal gastrectomy and total gastrectomy were 5.46 and 8.69 (P < 0.001 for both). Seven risk factors (type of gastrectomy, age, sex, BMI, and serum levels of albumin, creatinine and phosphorus) were incorporated into the nomogram. The prediction accuracy of the nomogram in the development set was 0.830 (area under the curve (AUC)); (95 per cent c.i. 0.812 to 0.848). In the validation set, the AUC was 0.807 (95 per cent c.i. 0.741 to 0.873). Conclusion Gastrectomy was a risk factor for osteoporosis, and its incidence in the first 10 years after surgery was high. This nomogram can help clinicians to identify patients with gastric cancer most at risk of developing osteoporosis after surgery. There are only a few guidelines for screening of patients with gastric cancer for osteoporosis after gastrectomy. The authors developed a nomogram to predict the risk of osteoporosis after gastrectomy for gastric cancer. This prediction model can help clinicians to identify patients with gastric cancer who should undergo bone densitometry.