Dirbas Clinical Research Group

Triple-negative breast cancer (TNBC) is the deadliest and 2nd most common subtype of breast cancer in the United States. Although promising new drugs based on PARP inhibition and immunotherapy can extend survival in selected patients, 1 in 3 patients die from TNBC. Increasing evidence suggests that human breast tumors harbor immature cancer cells which are a distinct subset of tumorigenic cancer cells, are less-differentiated, capable of replenishing cancer cell populations indefinitely, and strongly implicated in drug resistance. Unfortunately, existing marker genes for studying these cells are not specific, precluding rational drug development. We hypothesize that precise identification of immature cancer cells could present new therapeutic opportunities to revolutionize TNBC treatment.

Dr. Dirbas is working on this study in conjunction with Aaron Newman, PhD. Learn more.

FLASH is a type of ultra-fast delivery of radiotherapy in excess of 40 Gy/s; normal dose rates are about 0.03 Gy/s. Although the effects of FLASH on bacteria has been studied since the 1970s, it wasn't until two years ago that a team of scientists in France began to revisit FLASH. These researchers found that, for reasons that are currently inexplicable, that FLASH radiotherapy had the same effect on tumors as conventional radiotherapy but with much less toxicity on normal tissue. Conventional radiotherapy can cause painful side effects anywhere from a bad sunburn to a thickening of the breast tissue, which can make reconstruction more difficult.

Aim 1: Does FLASH radiotherapy have the same effect on breast carcinomas as those found in the lung?

Aim 2: If the normal tissue seems to be preserved to a greater extent, how does the therapy work in the short term?

This study recently received funding from the Stanford Women’s Cancer Center, Stanford Cancer Institute.

We also have a significant interest in improving methods of breast conserving surgery. Radiotherapy after lumpectomy is known to reduce in-breast tumor recurrence and is a standard of care for most women who undergo breast conserving surgery (also referred to as lumpectomy). Radiotherapy treatment normally lasts over 6 weeks. Accelerated radiotherapy after lumpectomy decreases radiotherapy treatment times from these 6 weeks to just 1 to 5 days.

Preliminary results show comparable efficacy between standard whole breast radiotherapy and accelerated radiotherapy. One form of accelerated radiotherapy available at Stanford, intraoperative radiotherapy (IORT), delivers a single dose of radiation at the time of lumpectomy while the patient is asleep without any postoperative radiotherapy treatments required. We have been using this approach as part of a clinical trial for 5 years.