Shorter course of whole breast radiation therapy may be better

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Shorter course of whole breast radiation therapy may be better than the longer course of treatment according to researchers as those who received shorter course experienced less toxicity and improved quality of life.

The study by researchers at The University of Texas MD Anderson Cancer Center suggests a fresh look at previous studies that didn’t find shorter course as being beneficial to patients. The study, published in Jama Oncology, paves way for a treatment option called hypofractionated whole breast irradiation (HF-WBI), which the researchers believe should be communicated to women as part of the shared decision-making between breast cancer patients and their physician.

Women diagnosed with early stage breast cancer in the US are normally given small doses of radiation for a longer time – a treatment that is conventionally fractionated whole breast irradiation (CF-WBI). Researchers have found through randomised studies in the UK and Canada that both the treatment have equal rates of recurrence in both groups and have equal survival rates as well. However, the oncology community in US still continues to opt for longer course therapy.

Simona Shaitelman, M.D., assistant professor, Radiation Oncology, explains that previous studies that didn’t show benefits of shorter course therapy over longer course were done with now-antiquated technologies. Shaitelman says that since those studies, there have been many advancements in the field and other subsequent studies have proved that longer course therapy is no better than shorter course.

Researchers note in the latest study that only one-third of patients for whom HF-WBI is currently recommended as appropriate treatment by the American Society of Radiation Oncology (ASTRO) actually receive the shorter course of therapy.

“So the question is, with modern technology, and knowing that the survival and recurrence outcomes are equal, can we offer patients a better option? It was essential that we look at how we were giving therapy and if that therapy impacted patients’ quality of life, both acutely during treatment and in the short-term after treatment.”

For the latest study, 287 women with early breast cancer were randomized to receive either CF-WBI or HF-WBI, 149 and 138 patients, respectively. The women were all above 40 years of age or older, treated with breast conserving surgery and had Stage 0 – 2 disease; 76 per cent of the patients were overweight or obese. Of note, previous studies with HF-WBI excluded patients with a larger body mass index (BMI), despite obesity being a strong associated risk factor for the disease.

Also, the MD Anderson study included a “boost dose” as part of the treatment. The researchers note that previous HF-WBI studies did not systematically look at this practice of giving additional treatment to target the tumor bed with a higher dose.

Researchers used a questionnaire to assess the quality of life of breast cancer patients with participants self-reporting their overall well-being prior to treatment and six months after completing their therapy. Physicians assessed patient toxicities weekly during treatment and six months after completing radiation.

The study found that compared to the CF-WBI cohort, those randomized to HF-WBI experienced less acute toxicity during treatment, including: breast pain, dermatitis, skin darkening and fatigue. At six month follow up, toxicities were generally similar between the HF-WBI and CF-WBI patients, although the HF-WBI patients were noted to have less fatigue, and better ability to care for their family, compared to those treated with CF-WBI.

“Patients who received the shorter course reported less difficulty in caring for their families’ needs. This is a major priority for women undergoing breast cancer radiation,” says Shaitelman. “Most are busy working mothers, working inside or outside the home, and are juggling a number of priorities. It’s paramount that we address this need.”

The findings provide some of the first data to show a benefit with the shorter course of treatment – not just an alternative for patients, says Benjamin Smith, M.D., associate professor, Radiation Oncology, MD Anderson.

“This study fills in a missing piece in the literature,” says Smith, the study’s corresponding author. No longer do I regard the shorter course of treatment as just an option for patients, but rather the preferred starting point for discussion with patients if they need whole breast radiation.”

Tumor control outcomes continue to be followed; to date no meaningful difference in survival has been found, say the researchers. Also, data like this and other studies are substantive enough that Smith feels it would be worthwhile for organizations like ASTRO and NCCN to consider expanding recommendations for patients to receive HF-WBI.