Immunohistochemical assessment of hormone receptor status using a new scoring system (J-Score) in breast cancer.

The assessment of hormone receptor status in breast cancer is essential to decide whether endocrine therapy is indicated or not. Immunohistochemistry (IHC) is thought to be the best method for examination of estrogen receptor (ER) and progesterone receptor (PgR) in routine practice. However, the cutoff point of IHC is still controversial. The St. Gallen consensus meeting in 2005 demonstrated that in patients with more than 10% ER stained tumor cells, hormone therapy will be " effective " but in those with 1 to 10% ER stained tumor cells will have an " uncertain " response. Based on the cutoff value of the St. Gallen consensus meeting, a new scoring system (J-Score) which only evaluates the positivity cell rate without taking the staining intensity into account was established. In this paper, the ER status results of 486 patients evaluated by the J-Score and A-Score (Allred Scoring system) were compared. The " uncertain " patients with ER positive cells 1 to 10% (J-Score 2) composed only 0.9% and " borderline " cases (A-Score 3 to 4) including " uncertain " cases (J-Score 2) composed 3.2% of the total patients. Thus, the number of patients determined as " uncertain " by the J-Score is very small and the number considered " borderline " by the A-Score is slightly larger. Although the J-Score system is thought to be easy and convenient for evaluating ER status in routine practice and the cutoff values adjusted to St. Gallen recommendation might be meaningful for clinical studies, many pathological and clinical studies are necessary before it is accepted as a standard method.