Fractionated evaluation of immunohistochemical hormone receptor expression enhances prognostic prediction in breast cancer patients treated with tamoxifen as adjuvant therapy.
OBJECTIVE
To compare the prognostic prediction between dichotomized and fractionated evaluations of hormone receptor expressions.


METHODS
Patients with stages I-III breast cancers, who received adjuvant tamoxifen, were enrolled. The expression of estrogen receptor (ER) and progesterone receptor (PR) was evaluated by immunohistochemistry (IHC). A fractionated score (F score), the percentage of positive-staining nuclei (0=none, 1=1%-10%, 2=11%-30%, 3=31%-50%, 4=51%-70%, and 5=71%-100%), was assigned to each case. The dichotomized scoring method defines an F score >1 as positive. The prognostic values of both scores were compared by multiple Cox's proportional hazard models of disease-free survival (DFS) and overall survival (OS).


RESULTS
Four hundred and sixteen patients with a median follow-up of 78.0 months were included. F scores for ER and PR correlated directly with DFS and OS. Although both the dichotomized and fractionated ER and PR scores were significantly associated with DFS and OS in univariate analyses, only fractionated ER and PR scores remained as independent prognostic factors of DFS and OS in the final multiple Cox's proportional hazard models.


CONCLUSIONS
Fractionated IHC hormone receptor expression evaluation enhances the prognostic prediction compared with a dichotomized assessment.
Lin
Ching-hung
CH
Department of Oncology, National Taiwan University Hospital, Taiwan, Taipei 10016.
Lien
Huang-chun
HC
Hu
Fu-chang
FC
Lu
Yen-shen
YS
Kuo
Sung-hsin
SH
Wu
Ling-chu
LC
You
San-lin
SL
Cheng
Ann-lii
AL
Chang
King-jen
KJ
Huang
Chiun-sheng
CS
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000175:diagnosis / Q000188:drug therapy* / Q000378:metabolism*; D017024:Chemotherapy, Adjuvant / Q000379:methods*; D018572:Disease-Free Survival; D005260:Female; D005786:Gene Expression Regulation; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods*; D008875:Middle Aged; D011379:Prognosis; D016016:Proportional Hazards Models; D011960:Receptors, Estrogen / Q000096:biosynthesis; D011980:Receptors, Progesterone / Q000096:biosynthesis; D013629:Tamoxifen / Q000494:pharmacology*
D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; D013629:Tamoxifen