Development and relapse of Breast Cancers

A study published in the Annals of Surgical Oncology and funded primarily by the Avon Foundation for Women revealed that scientists and physicians at the Oregon Health & Science University Knight Cancer Institute had discovered stem cell mutations that may cause the development and reoccurrence of breast cancer. Very often, cell functions are controlled by mutated cells that are unaffected by chemotherapy and radiation, which cause the relapse of disease.
Lead study author and associate research professor in the division of surgical oncology at the OHSU Knight Cancer Institute, SuEllen J. Pommier, Ph.D., said: “By studying normal and malignant cells that were collected from breast tissues removed during surgery, we were able to look at what is occurring in the body.”

Pommier said that the findings of this study were established by working on samples taken directly from surgeries that enabled a one-of-a-kind comparison of the actual biology of breast stem cells with the corresponding malignant cells. It many previous studies, it has been observed that cultured cell lines are incapable of revealing accurate information about normal breast stem cells.

According to the study, even if some current therapies can target cell mutations in the tumor, they are unsuccessful in ruling out the possibility of a disease relapse. The study also proposes further research in two areas:

• Establishing the role of PIK3CA/AKT1 signaling mutations seen in 73% of fresh tumor specimens of the study. This rate is much higher than that detected in stored tumor samples.
• Determining the significance of the loss of CD24 expression. Previously, this was considered a prerequisite for all breast cancer stem cells, but not characteristic of them.

The OHSU Knight Cancer Institute is primarily focused upon understanding the biology of individual tumors. Pommier said, “This study provided us with new insights into breast cancer stem cells and possibly into the earliest mutations. That information is crucial for developing treatments.”

Apart from Avon Foundation for Women, a collaborative Research Grant by a Vertex Pharmaceutical/Oregon Health & Science funded this study.