Patient Reported Outcomes and Cosmesis Following Once Weekly Hypofractionated Breast Irradiation

Abstract

Once weekly hypofractionated breast irradiation (WHBI) is a novel treatment in the setting of breast conservation, but data regarding cosmetic and functional outcomes are limited. We report physician and patient report outcomes (PROs) from a phase II trial to determine whether WHBI is associated with adverse cosmetic, functional, and pain outcomes. Women with stage 0-II breast cancer treated with breast conserving surgery and negative margins were enrolled on this institutional review board-approved, phase II trial. WHBI was 28.5-30 Gy in five weekly fractions of 5.7-6 Gy delivered with field-in-field tangents, with or without a boost. Regional nodal irradiation was not permitted. Ipsilateral breast tumor recurrence (primary endpoint), survival times, and acute toxicity have previously been reported. Physician reported cosmesis and patient reported quality of life outcomes were secondary endpoints and are reported herein. PROs were assessed at baseline, 6 months, 1 and 3 years using the Breast Cancer Treatment Outcome Scale (BCTOS) which includes three subscales of cosmetic changes, arm function, and breast pain. Physician rated cosmesis was assessed using the Harvard Scale and recorded at the same time points. BCTOS outcomes were compared with baseline values using a two sided t test with each patient serving as her own internal control. From January 2011 to October 2015, 158 women were enrolled, of whom 73% (n=115) had sentinel node biopsy, 12% (n=119) had axillary dissection, 21% (n=33) had re-excision of margins, and 29% (n=45) received chemotherapy. The median follow up for cosmetic and functional assessments was 30 months (range, 5-46). Eighty patients received 30 Gy, 78 patients received 28.5 Gy, and 28 (18%) received a boost. PROs indicate adverse changes in arm function (p=0.001) and breast pain (p=0.001) outcomes at 6 months post-treatment, however, no detectable adverse change when compared to baseline at 1 (function p=0.419, pain p=0.564) and 3 years (p=0.673, p=0.636). Adverse changes in cosmetic PROs were also detected at 6 months (p<0.001) and 1 year (p=0.008), with a trend towards significance at 3 years (p=0.06). At last follow up, the cosmetic PROs most commonly noted to be moderately or largely different than the untreated breast were breast size (26% moderate difference, 5% large difference), shape (21%, 9%), scar tissue (16%, 8%), texture (18%, 5%), and elevation (16%, 6%). Physician rated cosmesis was excellent/good in 84% (n=133) and fair/poor in 16% (n=25). The most common physician reported changes effecting cosmesis were volume loss in 21%, scarring in 21%, and retraction/contour defect in 14%. WHBI was associated with transient worsening in arm function and breast pain. Adverse changes in cosmetic PROs persisted longer following treatment but were typically mild or moderate in severity. Physician rated cosmetic outcomes were acceptable.