Abstract P1-15-24: Skin toxicities of obese African American breast cancer patients treated with hypofractionated radiation therapy

Abstract

Abstract Objective: Hypofractionated radiation therapy (HFRT) for early stage breast cancer is an established treatment option with equivalent cancer outcomes and better cosmetic results than standard fractionation. There is limited published information about expected skin changes of African-American breast cancer patients (pts) undergoing HFRT. While HFRT is not recommended for women with large breasts, the use of prone position may allow for homogeneous HFRT plans. We prospectively monitored and reported on skin changes in African-American pts who received HFRT for their breast cancer. Methods: A retrospective analysis at a single institution from 12/2012 to 08/2013 was performed to identify early stage breast cancer pts who underwent breast conservation surgery and received adjuvant whole-breast HFRT. An assessment form had been created to prospectively document weekly changes in radiation dermatitis (CTCAE V.4 Grade 0-4) and hyperpigmentation (none, faint, moderate, severe). Photographs of the treated area were collected before and at the end of treatment. Treatment planning guidelines were per RTOG 1005. Results: There were 15 African-American pts with Tis-T2N0M0 breast cancer who were treated with HFRT to a dose of 4256 cGy in 16 fractions (266 cGy per fraction) followed by a lumpectomy cavity boost of 1000-1250 cGy (250cGy per fraction). There were 12 (80%) pts with right-breast cancer and 6 (40%) who were treated in the prone position. The median age was 61 (36-70). The median body mass index (BMI) for the pts treated in the prone position (42.2 [36-54]) was greater than the median BMI for pts treated in the supine position (29.7 [26-43]). The median breast volume of the prone pts (2335cc [2163-3369]) was more than twice the median volume of supine pts (920cc [231-1459]). The median separation distance for prone and supine pts were 25.1cm (17.5-31.2) and 22.5cm (17.5- 31.8), respectively. Radiation dermatitis: None (6%), Grade 1 (60%), Grade 2 (34%), Grade 3 (none). Only three pts had desquamation:1 pt had dry, and two pts had both dry and minimal moist desquamation in the infra-mammary fold. Hyperpigmentation: none (6.5%), faint (40%), moderate (47%), severe (6.5%). The areas of severe hyperpigmentation correlated to areas of desquamation. The median DMax, mean heart dose, and ipsilateral lung V20Gy were 107.2% (105.2 – 109.9), 60 cGy (29 – 544), and 8.25% (0.0 – 23), respectively. Conclusion: African-American pts treated with HFRT experience minor skin toxicities with mostly Grade 1 dermatitis and moderate hyperpigmentation changes. Obese African-American pts can safely be treated with HFRT if they can be placed in the prone position. Some pts with a separation of > 25cm can be safely and effectively treated with HFRT. Citation Format: Arun G Paul, Amy Collins, Gregory Dyson, Neha Amin. Skin toxicities of obese African American breast cancer patients treated with hypofractionated radiation therapy [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P1-15-24.