PR+ cells add prognostic value in luminal A breast cancer

PR+ cells add prognostic value in luminal A breast cancer
Semiquantitative immunohistochemical expression of progesterone receptor-positive tumor cells improves prediction of survival within luminal A breast cancers, according to a study published online Dec. 10 in the Journal of Clinical Oncology.

(HealthDay)—Semiquantitative immunohistochemical expression of progesterone receptor-positive tumor cells improves prediction of survival within luminal A breast cancers, according to a study published online Dec. 10 in the Journal of Clinical Oncology.

Aleix Prat, M.D., from the University of North Carolina at Chapel Hill, and colleagues analyzed gene expression and pathologic features in primary tumors across five independent cohorts to improve current immunohistochemical subtyping of genomically defined luminal A and B subtypes. The researchers derived and independently tested optimal cut-offs of percentage of PR positive tumor cells to predict survival.

The researchers found that in luminal A tumors there were consistently higher rates of PR positivity, human 2 (HER2) negativity, and histologic grade 1, compared to B subtypes. Luminal A tumors also had significantly higher quantitative PR gene and . Independent of endocrine therapy administration, an empiric cut-off of more than 20 percent of PR-positive tumor cells was significant for predicting survival differences within immunohistochemical-defined luminal A tumors. The immunohistochemical 4 score had no additional prognostic value within hormonal receptor (HR) positive/HER2-negative disease when intrinsic immunohistochemical-based subtypes were used that included more than 20 percent PR-positive

"Semiquantitative immunohistochemical expression of PR adds prognostic value within the current immunohistochemical-based luminal A definition by improving the identification of good outcome breast cancers," the authors write. "The new proposed immunohistochemical-based definition of luminal A tumors is HR positive/HER2 negative/Ki-67 less than 14 percent, and PR more than 20 percent."

Several authors disclosed financial ties to BioClassifier.

More information: Abstract
Full Text (subscription or payment may be required)
Editorial

add to favorites email to friend print save as pdf

Related Stories

Breast cancer recurrence defined by hormone receptor status

Oct 01, 2012

Human epidermal growth factor (HER2) positive breast cancers are often treated with the same therapy regardless of hormone receptor status. New research published in BioMed Central's open access journal Breast Cancer Research shows ...

Recommended for you

Video: Is that double mastectomy really necessary?

15 hours ago

When Angeline Vuong, 27,was diagnosed with cancer in one breast earlier this year, her first reaction was "A DOUBLE MASTECTOMY. NOW. " Turns out, she's far from alone: a recent JAMA study of 190,000 breast cancer cases in ...

User comments