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Lack of RB Gene Suggests Better Response to Neoadjuvant Chemotherapy

TOP - Daily

Before surgery, many patients with breast cancer receive neoadjuvant therapy to reduce the size or extent of the disease. Complete response of the tumor to such treatment signifies an improved overall prognosis. At this time, no marker is applied to identify tumors that will respond to such treatment.

However, a retrospective study by researchers at Thomas Jefferson University Hospital and the Kimmel Cancer Center at Jefferson showed breast cancer patients whose tumors lacked the retinoblastoma (RB) tumor suppressor gene had an improved pathological response to neoadjuvant chemotherapy.

“We found that loss of RB was associated with better pathological response rates in breast cancer patients – at various stages and representing multiple molecular subtypes – who were administered neoadjuvant chemotherapy,” said Agnieszka Witkiewicz, MD, Associate Professor of Pathology, Anatomy and Cell Biology at Thomas Jefferson University.

Erik Knudsen, PhD, Professor of Cancer Biology and the Hilary Koprowski Chair in Cancer Biology, said, “This represents a potential new biomarker that could be used to tailor treatment plans for women considering neoadjuvant therapy and is a testament to the importance of cancer research.”

The study, published in a recent online issue of Clinical Cancer Research, included over 1000 breast cancer patients who had undergone neoadjuvant therapy. Researchers performed a combination of gene expression profiling to identify those with RB loss and direct histological analysis. These patients represented distinct subtypes of breast cancer and were treated with multiple different therapeutic regimens.

The researchers discovered that a lack of RB was associated with an improved response to all the neoadjuvant regimens investigated in the major subtypes of breast cancer.

“Together, these data indicate that the loss of RB, which occurs relatively frequently in locally advanced disease, could be a useful tool for defining patients who experience an improved response to neoadjuvant chemotherapy,” Witkiewicz said.

Source: Kimmel Cancer Center.