Osteoporosis self-assessment tool for Asians as a simple risk index of identifying a poor prognosis in women surgically treated for colorectal cancer

Abstract

Background: Osteoporosis and colorectal cancer (CRC) in older women are considered enormous public health burdens. The effects of osteoporosis on the oncologic outcome of CRC surgery are poorly understood. We evaluated the use of the Osteoporosis Self-assessment Tool for Asians (OSTA) for predicting postoperative outcome in older women after receiving surgical treatment of CRC.

Materials and methods: The present single-institution retrospective study analyzed patients who had undergone surgery for CRC in 2002-2008. To characterize the major population of women with osteoporosis, which consists of postmenopausal women, only patients aged 50 years and older were analyzed. Their OSTA scores were evaluated for correlations with cancer-specific survival after surgery for CRC by performing univariate, multivariate, and survival analyses.

Results: During a 7-year period, 440 women were studied. The cancer-specific mortality and overall mortality rate was 28.4% and 33.4%, respectively. The univariate analyses revealed that significant predictors of cancer-specific mortality after CRC surgery were the International Union Against Cancer (UICC) stage, OSTA category, histologic grading, lymph node metastases, and tumor invasion depth. After risk adjustment, the UICC stage and OSTA risk index were independent predictors of mortality. A comparison of OSTA risk index among patients with different UICC stages showed that the accuracy of the index in predicting cancer-specific survival after CRC surgery was greatest for patients with stage II and III disease.

Conclusions: The UICC stage and OSTA risk status showed independent positive associations with postoperative mortality in aged female patients with CRC. Moreover, the OSTA index had a particularly strong association with cancer-specific mortality in patients with UICC stage II and III.