ER-negative /PR-positive breast carcinomas or technical artifacts in immunohistochemistry?
BACKGROUND
Evaluation of estrogen (ER) and progesterone (PR) receptors is important in the management and prognosis of breast cancer patients. Immunohistochemistry (IHC) is currently the worldwide accepted methodology for detection of ER/PR receptors in breast carcinomas. However, technical artifacts may alter the results. Since most authorities believe that there are no true ER-negative/PR-positive breast tumors, therefore we hypothesized that technical artifact in IHC might cause ER-negative/PR positive cases.


METHODS
The clinical records of 2432 patients treated by surgery at six community hospitals for different histologic subtypes of breast carcinoma were reviewed. Among them, 43 (1.8%) patients reported as ER-negative/PR-positive were re-evaluated in a reference laboratory. Expressions of ER and PR were evaluated by IHC on the same paraffin block used for the initial testing.


RESULTS
The repeat study showed that of the 43 patients with the initial results of ER-negative/PR-positive, 24 (55.8%) were ER-positive/PR-positive, 15 (34.9%) were ER-negative/PR-negative, and 4 (9.3%) were ER-positive/PR-negative. In none of the 43 cases were the initial results (ER-negative/PR-positive) confirmed.


CONCLUSIONS
Technical artifacts in IHC may alter ER/PR results in breast carcinomas. The technical factors affecting steroid receptor IHC ought to be properly controlled to provide reliable results.
Department of Pathology, The Johns Hopkins Hospital, 600 Wolfe St., Baltimore, MD 21287, USA. zmaleki1@jhmi.edu
Zahra
Z
Maleki
Siamak
S
Shariat
Mehrdad
M
Mokri
Morteza
M
Atri
D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000737:chemistry*; D005188:False Negative Reactions; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008875:Middle Aged; D011960:Receptors, Estrogen / Q000032:analysis*; D011980:Receptors, Progesterone / Q000032:analysis*; D012189:Retrospective Studies
D011960:Receptors, Estrogen; D011980:Receptors, Progesterone