Breast cancer subtypes based on ER/PR and Her2 expression: comparison of clinicopathologic features and survival.
OBJECTIVE
To compare the clinicopathologic features and survival in the four breast cancer subtypes defined by immunohistochemistry (IHC) expression of estrogen receptor (ER) or progesterone receptor (PR) and human epidermal growth factor receptor 2 (Her2): ER/PR+, Her2+; ER/PR+, Her2-; ER/PR-, Her2+; and ER/PR-, Her2-.


METHODS
A 7-year retrospective study of 1134 invasive breast cancer subjects. Clinical and pathologic features and survival of the four subtypes were compared.


RESULTS
Using ER/PR+ and Her2- as a reference, ER/PR-, Her2- had the worst overall survival (hazard ratio, 1.8; 95% confidence interval [CI], 1.06-3.2) and the worst disease-free survival (hazard ratio, 1.5; 95% CI, 0.8-3.0). In ER/PR+, Her2-, chemotherapy conferred significant overall and disease-free survival advantages. Subtype comparison revealed statistically significant differences in outcomes.


CONCLUSIONS
The triple negative subtype has the worst overall and disease free survival. Efforts should be directed at standardization of current testing methods and development of more reliable and reproducible testing.
Onitilo
Adedayo A
AA
Department of Hematology/Oncology, Marshfield Clinic Weston Center, Weston, Wisconsin 54401, USA. onitilo.adedayo@marshfieldclinic.org
Engel
Jessica M
JM
Greenlee
Robert T
RT
Mukesh
Bickol N
BN
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D001943:Breast Neoplasms / Q000378:metabolism* / Q000401:mortality* / Q000473:pathology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism*; D011960:Receptors, Estrogen / Q000378:metabolism*; D011980:Receptors, Progesterone / Q000378:metabolism*; D012189:Retrospective Studies; D016896:Treatment Outcome
D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; C508053:ERBB2 protein, human