Bloody nipple discharge is a predictor of breast cancer risk: a meta-analysis

Nipple discharge is a common complaint of patients with breast disease. The color of nipple discharge is always the first alarming symptom for patients. It is controversial whether the discharge color is an indicator of an underlying malignancy. The electronic database PubMed was searched for relevant articles. A meta-analysis about the association between the color of nipple discharge and breast cancer risk was conducted. Eight studies, including 3,110 patients, were eligible for this meta-analysis. Compared with patients in non-bloody nipple discharge group (179/1,478), patients in bloody nipple discharge group (404/1,632) had a markedly higher breast cancer risk (OR: 2.27, 95% CI: 1.32-3.89, P < 0.001 for heterogeneity). Compared with patients in clear/serous group (71/575), patients in bloody nipple discharge group (326/1,271) also had a higher risk (OR: 2.49, 95% CI: 1.25-4.93, P = 0.011 for heterogeneity). Furthermore, compared with patients in the colored group (55/448), patients in bloody nipple discharge group (296/1,124) (OR: 2.00, 95% CI: 0.74-5.45, P = 0.009 for heterogeneity) had no significant difference. Besides, there was no significant difference between patients in colored group (55/448) and clear/serous group (61/470) (OR: 1.35, 95% CI: 0.83-2.18, P = 0.707 for heterogeneity). Therefore, bloody nipple discharge could be a predictor of breast cancer risk among different colors of discharges. The symptom of bloody nipple discharge is helpful to the stratification of preoperative patients.