Clinicopathological Analysis Of Basal-like And Non-basal-like Triple-negative Breast Cancer

Objective: Triple-negative breast cancer(TNBC)is a subtype of breast cancer in which the estrogen receptor and progesterone receptor’s expression is negative and the Human epidermal growth factor receptor-2 gene is not overexpressed or amplified.According to the expression of CK5/6 and EGFR,TNBC can be subdivided into basal-like triple negative breast cancer(BL-TNBC)and non-basal-like triple negative breast cancer(NBL-TNBC).A number of foreign studies have shown that BL-TNBC and NBL-TNBC have different clinicopathological features and prognostic factors.In this study,we compared and analyzed the differences of clinicopathological parameters(age of onset,tumor size,pathological type,histological grade,lymph node metastasis,expression of Ki67 and p53)between BL-TNBC and NBL-TNBC,and explored the similarities and differences between subdivided molecular subtypes of triple negative breast cancer,so as to find a new idea for individualized treatment of patients.Methods: The data of patients with breast cancer treated in the Department of Breast surgery,affiliated Hospital of Hebei University were collected.All patients were diagnosed by pathological examination.The patients whose immunohistochemical results were ER(-),PR(-)and Her-2(-/ 1 +)were selected as TNBC.Among the TNBC patients,the patients with CK5/6+ and / or EGFR+ were selected as BL-TNBC group,and the other TNBC patients were identified as NBL-TNBC group.The clinical data of all patients were complete and all patients had informed consent.Statistical software was used to compare the differences between the two groups of TNBC in age of onset,tumor size,pathological type,histological grade,lymph node metastasis,expression of Ki67 and p53,and further subgroup analysis according to lymph node status to explore the difference between BL-TNBC and NBL-TNBC.Results: A total of 146 patients with TNBC were included in this study,including BLTNBC94(64.4%)and NBL-TNBC52(35.6%).Statistical analysis showed that BL-TNBC patients had younger age of onset,larger tumor volume,higher histological grade of invasive ductal carcinoma,higher positive rate of p53 expression and relatively higher expression of Ki67 than NBL-TNBC patients,but there was no significant difference in pathological type and lymph node metastasis between the two groups.Further subgroup analysis was conducted according to the status of lymph nodes.In the subgroup without lymph node metastasis,BLTNBC patients had younger age of onset,larger primary tumor volume,higher histological grade,higher positive rate of p53 and higher expression of Ki67 in invasive ductal carcinoma than NBL-TNBC patients.In the subgroup with lymph node metastasis,the above clinicopathological differences were not statistically significant.Conclusions:1.Patients with basal-like triple negative breast cancer had younger age of onset,larger tumor volume,higher histological grade of invasive ductal carcinoma,higher positive rate of p53 expression and relatively higher expression of Ki67 than patients with non-basal-like triplenegative breast cancer.2.There was no significant difference in pathological type and lymph node metastasis between basal-like triple-negative breast cancer and non-basal-like triple negative breast cancer.3.In the subgroup with negative lymph node metastasis,patients with basal-like triplenegative breast cancer had younger age of onset,larger primary tumor volume,higher histological grade,higher positive rate of p53 and higher expression of Ki67 than patients with non-basal-like triple negative breast cancer,but there was no significant difference in the above pathological features in the group with positive lymph node metastasis.4.It can be inferred that basal-like triple-negative breast cancer has a higher degree of malignancy and worse prognosis than non-basal-like triple negative breast cancer due to the differences in the above-mentioned clinicopathological features.