Proton beam therapy may shorten breast cancer treatment: Study

SAN FRANCISCO: Proton beam therapy, known for its precision in targeting cancer cells while preserving healthy tissue to reduce the risk of side effects, may help cut down duration of breast cancer treatment, finds a study.

The study, published in The Lancet Oncology, uncovered the evidence supporting a shorter treatment time for breast cancer patients.

Researchers compared two separate dosing schedules of pencil-beam scanning proton therapy, the most advanced type of proton therapy.

Breast cancer is the second leading cause of cancer death among women.

However, survival rates continue to improve due to advances in diagnosis and treatment, such as proton therapy.

It is a type of radiation therapy that uses protons rather than x-rays and painlessly delivers radiation to treat some types of cancer.

Before the study, all patients received a conventional 25 to 30 day course delivered five days per week over five to six weeks called proton postmastectomy radiotherapy (PMRT).

The researchers hoped to demonstrate that condensing the course of proton beam therapy, a form of particle therapy that could spare the heart and lungs from radiation damage, may result in a similar side effect profile.

"The study provides the first prospective data supporting the use of shorter-course proton PMRT, including in patients with immediate breast reconstruction, and the first mature results of a randomised trial in the field of breast particle therapy," said Robert Mutter, a radiation oncologist and physician-scientist at Mayo Clinic Comprehensive Cancer Center.

The team involved 82 patients with indications for PMRT, many of whom had prior breast reconstruction, were randomised to either conventional fractionation (fractions of radiation dose) administered in 25 days, or a condensed 15-day hypofractionated schedule.

In the study, researchers found that both conventional and hypofractionated proton therapy resulted in excellent control of the cancer while sparing surrounding normal tissue. But with hypofractionation, a larger dose of radiotherapy is delivered with each treatment, allowing all radiotherapy to be completed in just three weeks.

"We can now consider the option of 15 days of therapy with patients based on the similar treatment outcomes observed as the longer conventional course. Of note, the short course actually resulted in reduced skin side effects during and after treatment" Mutter said.

This therapy spares patients additional inconvenience, cost, and other burdens associated with the longer regimen.