Proton beam radiotherapy appears to control breast cancer with minimal side-effects

A treatment that has virtually no side effects has been found to be an effective weapon for fighting early-stage breast cancer, according to results of a clinical trial conducted at Loma Linda University Medical Center.

Results of the Phase II clinical trial conducted by researchers at Loma Linda University Medical Center Department of Radiation Medicine indicate that partial breast radiotherapy delivered with proton beam appears to provide excellent disease control within the breast with minimal risk of side-effects. Apart from being less toxic to the patient, the treatment reduces the amount of radiation treatment time to two weeks, instead of the typical seven weeks.

Disease-free survival rates at five years for the patients who took part in the study was over 90 percent; while overall survival rate was close to 100 percent. The study results were presented at the American Society for Radiation Oncology (ASTRO) meeting last fall, and will be published in the peer-reviewed scientific journal, Clinical Breast Cancer, this summer.

"The study results show that we are able to offer early stage breast cancer patients a treatment program that is less risky and can be completed in less time," said Dr. David Bush, vice-chairman of the Department of Radiation Medicine at Loma Linda University Medical Center and one of the study's principal investigators.

At present, most women diagnosed early with breast cancer would undergo surgery to remove the tumor from the breast. Radiation treatment is then performed over the entire breast. The study looked at treatment results by using proton beam radiation to just the area where the tumor was located, instead of the whole breast.

"The size of the radiation area is reduced significantly, lessening radiation exposure to the heart, lungs and other parts of the body. Proton beam allows us to do this better than any other type of radiation treatment," Dr. Bush said.

Proton therapy is a precise form of radiation treatment that uses machines to generate beams that penetrate the body from outside and destroy cancerous tumors and cells, with minimal damage to surrounding tissue and organs. It was two decades ago when Dr. James Slater turned Loma Linda University Medical Center into the first hospital to offer proton radiation treatment to treat prostate, brain and other types of cancer. Over 15,000 patients have since been treated at the James M. Slater Proton Treatment and Research Center at Loma Linda University Medical Center.

Ann Hughes, of Highland, Calif., maintained an active lifestyle as a semi-retired hairdresser when she was diagnosed with breast cancer in 2006. After having the tumor removed by surgery, she sought out more information and signed up to participate in the Loma Linda clinical trial after overhearing a client talk about it at the salon.

"The hope that I wouldn't have to have chemotherapy was very appealing," she said.

Ms. Hughes said she was glad not to lose her hair and feel nauseous during the treatment. Five years after the proton beam treatment, she remains cancer free and is able to lead an active life.

"Cancer is a very scary word, but once you get to the point that it doesn't have to be a death sentence, then you can think more clearly and be open to all the options," she said.

The breast cancer clinical trial investigated the safety and efficacy of utilizing proton beam radiotherapy to deliver partial breast radiotherapy following lumpectomy for early stage breast cancer.

Initially, 50 patients who had invasive (non-lobular) carcinoma and had undergone a lumpectomy, were enrolled in the clinical trial. The patients had invasive breast cancer with primary tumors that were 3 centimeters or less and the cancer had not yet metastasized. During treatment, the patients were made to lie in a prone position in a customized foam mold and, over a two-week course, received daily proton beam treatment.

SOURCE Loma Linda University Medical Center