Risk factors of breast intraductal lesions in patients without pathological nipple discharge

The majority of breast cancer arises from the ductal epithelium. It is crucial in the diagnosis and treatment of breast cancer by detecting intraductal lesions at an early stage. The typical clinical characteristic of intraductal lesions is pathological nipple discharge (PND), although many patients with intraductal lesions do not exhibit PND. It is a serious challenge for clinicians to detect patients with intraductal lesions without PND at an early stage. The aim of the present study was to investigate the risk factors associated with intraductal lesions in patients without PND. This retrospective database review, conducted between April 2016 and April 2017, included 370 lesions from 255 patients with intraductal lesions (intraductal papilloma, atypical intraductal hyperplasia, intraductal carcinoma in situ) and non-intraductal lesions (fibroadenoma, adenosis, cysts, lobular carcinoma in situ), diagnosed through surgical pathology. The patients were divided into two groups based on pathological diagnosis and clinical parameters were evaluated using univariate and multivariate analyses. Univariate analysis revealed that 9 of 14 factors were statistically significant. Five factors were identified to be associated risk factors in patients without PND through the multivariate logistic regression analysis: Age between 35 and 49 years and age ≥50 years [odds ratio (OR)=4.749, 95% confidence interval (CI)=2.371-9.513, P<0.001; OR=2.587, 95% CI=2.587-14.891, P<0.001; respectively], non-menstrual breast pain (OR=1.922, 95% CI=1.037-3.564, P=0.038), breast duct dilatation as seen using ultrasonography (OR=9.455, 95% CI=3.194-27.987, P<0.001), lesion distance from nipple ≤2 cm (OR=2.747, 95% CI=1.668-4.526, P<0.001) and lesion size ≤1 cm (OR=1.903, 95% CI=1.155-3.136, P=0.012). In conclusion, for patients without PND but with risk factors, such as the patient being >35 years, with non-menstrual breast pain, breast duct ectasia, lesion distance from nipple ≤2 cm and lesion size ≤1 cm as seen using ultrasonography, clinicians should be highly concerned about the possibility of intraductal lesions, in order to prevent misdiagnosis and reduce the misdiagnosis rate.