CBCRisk model to determine the risk of contralateral breast cancer in sporadic breast cancer

Abstract

Introduction: The great majority of breast cancer (BC) cases are diagnosed in women who have no known family history of the disease and are not carriers of any risk mutation. During the past few decades an increase in the number of contralateral prophylactic mastectomy (CPM) has been produced in these patients. The CBCRisk model calculates the absolute risk of suffering from contralateral breast cancer (CBC); thus, it can be used to counselling patients with sporadic breast cancer.

Method: An observational, retrospective study including sporadic breast cancer patients treated with contralateral prophylactic mastectomy has been conducted between 2017 and 2019. A descriptive and comparative study with one variation of logistic regression has been carried out in order to identify predictive factors of occult tumors (OT) and medium/high risk damage (MHRD). Evaluation of the CBCRisk model published in 2017 and different limit values for the CPM recommendation.

Results: 42 patients were selected. Incidence of MHRD and OT was lower than that described in the literatura (9.52%MHRD, 2.38%OT). None of the evaluated variables reached statistical significance for predicting injuries. The average value of CBCRisk 5 years ahead found in patients with pathological findings was 2.08 (DE 0.97), higher than the average value of the whole group (1.87 ± 0.91) and the subgroup without pathological findings (1.84 ± 0.91). Only values >3 for CBCRisk were considered statistically significant (P = .04) for the prediction of histological lesions.

Conclusion: Patients with sporadic breast cancer should be adequately informed about the estimated risks and benefits of undergoing a contralateral prophylactic mastectomy. The CBCRisk may be useful for the counseling of these patients, but it requires validation in larger and prospective cohorts.

Keywords: Breast cancer; CBCRisk; Contralateral prophylactic mastectomy; Cáncer de mama; Mastectomía profiláctica contralateral; Mastectomía reductora de riesgo; Riesgo; Risk assessment; Risk-reducing mastectomy.