Study proves proton therapy effective for breast cancer patients

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With breast cancer getting lots of attention this time of year, women should know that research has shown patients experience excellent survival rates and cosmetic results with proton therapy.

Loma Linda University’s Proton Treatment and Research Center conducted the clinical trial on patients with early stage invasive (non lobular) breast cancer. The 2014 study, “Partial Breast Radiation Therapy With Proton Beam: 5-Year Results With Cosmetic Outcomes,” represents the most solid data set to date on proton therapy and breast cancer outcomes.

The phase-two clinical trial followed 100 patients who received proton therapy and were monitored for an average of five years following treatment. Results show that the in-breast recurrence-free survival rate was 97 percent with minimal side effects to the breast, lungs and heart. The cosmetic results as assessed by patients and physicians were good to excellent in 90 percent of cases, which was maintained throughout the five years of follow-up. Other published series using photon radiation treatment has shown that good cosmetic results diminish over time, likely due to increased scarring of the breast that occurs as a result of increased exposure of normal breast tissues when conventional or photon radiation is used. In addition to being less toxic to the patient, the breast cancer treatment also reduced the duration of radiation treatment time from seven to two weeks.

The current standard of treatment for most women diagnosed early with breast cancer includes surgery to remove the tumor followed by conventional radiation treatment performed over the entire breast. The Loma Linda University Medical Center study looked at treatment results by using highly targeted proton beam radiation isolated to the specific area of the tumor. With proton therapy, the size of the area impacted by radiation is reduced significantly, lessening exposure to the heart, lungs and other parts of the body.

The study began in 2004 with initial results presented at the American Society for Radiation Oncology meeting in 2010. These results were published in the peer-reviewed scientific journal Clinical Breast Cancer in August 2011.

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 carcinoma and had undergone a lumpectomy were enrolled in the clinical trial, with 50 more being treated after initial analysis. The patients had invasive breast cancer with primary tumors that were three centimeters or less and the cancer had not metastasized. During treatment the patients were placed in a prone position in a patented, customized foam mold to improve the precision of the treatment. Proton treatment was given in 10 sessions over a two-week course. All showed excellent results.