Hypofractionated Postmastectomy Radiation in Breast Cancer
In a phase II trial, Khan et al found that hypofractionated postmastectomy radiotherapy, completed in 15 treatment days, was safe and effective in women with stage II to IIIa breast cancer. The study was reported in the Journal of Clinical Oncology.
Study Details
In the study, 67 women from 2 institutions received radiotherapy at 36.63 Gy in 11 fractions over 11 days to the chest wall and draining regional lymph nodes, followed by an optional mastectomy scar boost of 4 fractions of 3.33 Gy (n = 65). The primary outcome measure was freedom from grade ≥ 3 toxicities.
Toxicity and Local Tumor Control
Median follow-up was 32 months. No grade ≥ 3 toxicities were observed. A total of 29 grade 2 toxicities occurred, with skin toxicity being the most common (24%), followed by fatigue (7.5%), pain (4.5%), and lymphedema (4.5%).
A total of 41 patients had breast reconstruction or a temporary expander, with 3 having temporary expanders removed before radiotherapy. Among the 38 remaining patients, implant loss or failure occurred in 9 (24%), most commonly due to infection, and unplanned surgical correction occurred in 3 (8%), yielding a total complication rate of 32%.
Isolated ipsilateral chest wall tumor recurrence occurred in two patients (3%). Estimated 3-year rates were 89.2% for local recurrence–free survival and 90.3% for distant recurrence–free survival.
The investigators concluded: “To our knowledge, our phase II prospective study offers one of the shortest courses of [postmastectomy radiotherapy] reported, delivered in 11 fractions to the chest wall and nodes and 15 fractions inclusive of a boost. We demonstrated low toxicity and high local control with this schedule. On the basis of our data, we have designed a cooperative group phase III prospective, randomized trial of conventional versus hypofractionated [postmastectomy radiotherapy] that will activate soon.”
The study was supported by grants from the National Cancer Institute and Breast Cancer Research Foundation.
Atif J. Khan, MD, of Rutgers Cancer Institute of New Jersey, is the corresponding author of the Journal of Clinical Oncology article.
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