Prognostic Evaluation of HER2-positive Early Breast Cancers Using Clinico-pathological Criteria.

Background/Aim: HER2-positive breast carcinomas (BCs) generally behave more aggressively and show higher cytological and histological grade than HER2-negative BCs. However, the clinical properties of HER2-positive early BCs have not been studied extensively. Hence, the therapeutic significance of neoadjuvant chemotherapy (NAC) for this BC remains debatable. Patients and Methods: We retrospectively examined the clinicopathological features of 94 HER2-positive early BCs who perioperatively received anti-HER2 drugs, without undergoing NAC prior to surgery. Results: The patients' five year-disease free survival (DFS) and overall survival (OS) rates were 95.6% and 100%, respectively. Univariate analysis demonstrated significant differences in distant metastasis-free survival (DMFS) between clinical and pathological tumor stages (T stages). Pathological T1 stage and clinical T1 stage tumors showed significantly higher DMSF than pT2-3 and cT2-3 (p=0.0002 and 0.0294). Multivariate analysis disclosed no significant differences in DFS, OS, and DMFS with respect to preoperative clinical tumor stage, patient age, type of surgery, postoperative therapy, and pathological factors. Recurrences occurred in nine patients: four (4.3%) and five (5.3%) patients showed local and distant recurrences, respectively. One patient with cT2 BC died of disease. Interestingly, four of the five BCs with distant recurrence pathologically demonstrated lymph vessel invasion. The prognoses of patients with HER2-positive stage cT1/2N0M0 BC were highly favorable. Conclusion: The indications for NAC in small, localized, and node-negative HER2-positive BC should be carefully assessed based on the presence of a larger tumor size, postoperative pathological evaluation of tumor size, and lymph vessel invasion.