Clinicopathological characteristics of multifocal breast cancer

Abstract

Objective To explore the clinicopathological characteristics of different lesions in multifocal breast cancer patients and provide the guidance for clinical treatment. Methods The clinical data of 41 multifocal breast cancer patients in the Department of Breast Surgery, the First Affiliated Hospital of Nanjing Medical University from November 2014 to August 2016 were retrospectively analyzed. Conventional pathological findings, immunohistochemical results and molecular subtypes between different lesions in multifocal breast cancer patients were analyzed. χ2 test was used to compare the lesion size, histological grade, lymph node status and intravascular tumor thrombus between 41 multifocal breast cancer patients and 150 unifocal breast cancer patients enrolled in the same period. Results Among 41 multifocal breast cancer patients, 32 were detected with 2 lesions, 8 with 3 lesions, 1 with 4 lesions. The maximum diameter of the lesion was no less than 2 cm in 18 cases, more than 2 cm in 23 cases. The different lesions of one patient belonged to the same pathological type in 33 cases (80%), different pathological types in 8 cases (20%). The different lesions of one patient had the same histological grade in 38 cases (93%), different histological grades in 3 cases (7%). The different lesions of one patient presented the different expression levels of ER, PR, HER-2 and Ki67 in 3 cases (7%), 6 cases (15%), 5 cases (12%)and 3 cases (7%), respectively. Five cases (12%) had the different molecular subtypes. There were significant differences in histological grade 3 [51%(21/41) vs32%(48/150), χ2=5.154, P=0.023], lymph node metastasis [59%(24/41) vs 41%(61/150), χ2=4.163, P=0.041] and intravascular tumor thrombus [29%(12/41) vs8%(12/150), χ2=13.257, P<0.001] between multifocal and unifocal breast cancer patients, while the lesion size showed no significant difference [56%(23/41) vs 56%(84/150), χ2=0.001, P=0.991]. Conclusions Clinicopathological results may vary in the lesions of multifocal breast cancer, so routine pathological and immunohistochemical examination should be carried out in all lesions so as to provide accurate and comprehensive pathological evidence for the optimal treatment. Multifocal breast cancer is prone to lymph node metastasis and intravascular tumor thrombus, indicating a poor prognosis. Key words: Breast neoplasms; Pathology; Immunohistochemistry; Molecular subtypes