Triple-negative, basal-like, and quintuple-negative breast cancers: better prediction model for survival.
BACKGROUND
Triple-negative breast cancers (TNBCs) and basal-like breast cancers (BLBCs) are known as poor outcome subtypes with a lack of targeted therapy. Previous studies have shown conflicting results regarding the difference of prognostic significance between TNBCs and BLBCs. In this study, we aimed to characterize the prognostic features of TNBCs, in view of BLBCs and quintuple-negative breast cancers (QNBC/5NPs).


METHODS
Using tissue microarray-based immunohistochemical analysis, we categorized 951 primary breast cancers into four or five subtypes according to the expression of ER, PR, HER2, and basal markers (CK5/6, EGFR).


RESULTS
The results of this study showed that both TNBCs and BLBCs were associated with high histological and/or nuclear grades. When the TNBCs are divided into two subtypes by the presence of basal markers, the clinicopathologic characteristics of TNBCs were mainly maintained in the BLBCs. The 5-subgrouping was the better prediction model for both disease free and overall survival in breast cancers than the 4-subgrouping. After multivariate analysis of TNBCs, the BLBCs did not have a worse prognosis than the QNBC/5NPs. Interestingly, the patients with BLBCs showed significant adjuvant chemotherapy benefit. In addition, QNBC/5NPs comprised about 6~8% of breast cancers in publicly available breast cancer datasets


CONCLUSIONS
The QNBC/5NP subtype is a worse prognostic subgroup of TNBCs, especially in higher stage and this result may be related to adjuvant chemotherapy benefit of BLBCs, calling for caution in the identification of subgroups of patients for therapeutic classification.
Choi
Yoon-La
YL
Laboratory of Cancer Genomics and Molecular Pathology, Samsung Medical Center, Seoul, Korea.
Oh
Ensel
E
Park
Sarah
S
Kim
Yeonju
Y
Park
Yeon-Hee
YH
Song
Kyoung
K
Cho
Eun Yoon
EY
Hong
Yun-Chul
YC
Choi
Jong Sun
JS
Lee
Jeong Eon
JE
Kim
Jung Han
JH
Nam
Seok Jin
SJ
Im
Young-Hyuck
YH
Yang
Jung-Hyun
JH
Shin
Young Kee
YK
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000378:metabolism* / Q000401:mortality*; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D017404:In Situ Hybridization, Fluorescence; D008495:Medical Oncology / Q000379:methods; D008875:Middle Aged; D015999:Multivariate Analysis; D020411:Oligonucleotide Array Sequence Analysis; D011379:Prognosis; D016896:Treatment Outcome