Intraoperative frozen section can reduce unnecessary second operation in breast cancer patients that failed to be diagnosed by previous core needle biopsy: a retrospective analysis of Chinese clinical practice

Objective: The value of frozen section in the intraoperative diagnosis of breast cancer that failed to be diagnosed by previous core needle biopsy (CNB) is indeterminate. To evaluate and improve the clinical utility of frozen section on this kind of breast cancer, we conducted a retrospective data analysis and constructed a prediction model. Method: We reviewed data of breast cancer patients that failed to be diagnosed by previous CNB (CNB-undiagnosable) in Fudan University Shanghai Cancer Center (FUSCC) from May 1, 2006 to December 31, 2019. Clinical characteristics of patients were collected. the correlation between clinical features and false negative rate (FNR) of frozen sections was explored with logistic regression analysis, after which a nomogram was constructed to predict the probability of false negative. Result: The diagnostic sensitivity of frozen section on CNB-undiagnosable breast cancer was 67.18%, and the FNR was 32.82%. In multivariate analysis, papillary lesion (OR, 4.251; 95% CI, 2.804-6.492; P<0.0001) and sclerosing adenosis (OR, 3.727; 95% CI, 1.897-7.376; P= 0.0001) on CNB were risk factors of false negative, while clustered microcalcifications on mammography (OR, 0.345; 95% CI, 0.216-0.543; P < 0.0001) and ultrasonic BI-RADS category 4C-5 (OR, 0.250; 95% CI, 0.081-0.777; P = 0.0157) were favorable factors of true positive. The false negative rate of frozen section could be controlled at about 11% or less by the prediction of nomogram. Conclusion: Frozen sections are valuable in the intraoperative diagnoses of CNB-undiagnosable breast cancers. It is recommended to implement the intraoperative frozen sections for high-risk breast lesions with a low probability of false negative indicated by prediction, so as to minimize the occurrence of unnecessary second operation.