Reduced-dose radiotherapy as effective as full dose in breast cancer patients—with fewer side effects

Women who opt for partial or lower-dose radiotherapy during breast cancer treatment may experience fewer side effects while maintaining the efficacy of a full dose, researchers reported at the European Breast Cancer Conference in Barcelona this month.

In a follow-up to the IMPORT LOW study, which determined in 2016 that partial and reduced-dose radiotherapy could be as effective as whole breast radiotherapy in controlling cancer rates at five years, U.K.-based researcher Idrani Bhattacharya said she and her team surveyed over half of the original study population in an attempt to gauge their side effects and body image five years after radiotherapy. 

The IMPORT LOW trial randomized thousands of women to receive either standard radiotherapy at 40 Gy to the whole breast, 36 Gy to the whole breast and 40 Gy to the part of the breast containing the original tumor, or 40 Gy directly to the site of the original tumor. The results were positive, Bhattacharya said.

“The findings from this study are reassuring for women who are offered either whole breast or partial breast radiotherapy using this technique of radiotherapy, which is simple to deliver and already available in centers worldwide,” she said in a release. “This new information will help doctors discuss the risks and benefits of this type of radiotherapy with patients and may improve shared decision-making, as well as enabling them to tailor treatment for individual patients.”

When the researchers asked 1,265 of the women from the original study about their patient-reported outcomes six months and one, two and five years post-radiotherapy, they found patients were largely concerned with their breasts’ appearance after treatment.

The most common side effect reported was “overall change in breast appearance,” the author said. Women were also asked about hardening of tissue, any pain, oversensitivity of the treated area and fluid buildup. 

“Now that we can identify these patients who are at higher risk of reporting side effects, this knowledge can be discussed with patients, may modify treatment and enable doctors to put in place more personalized and frequent monitoring if necessary,” Bhattacharya said. “For example, patients with higher levels of anxiety and depression could be offered psychosocial support at the start of treatment, although we do not know from this study whether this would reduce the reporting of side effects.”