Comparative Analysis of Acute Radiation Dermatitis in Breast Cancer Treatment: Concomitant Versus Sequential Paclitaxel and Radiation Therapy

Abstract

Radiation and chemotherapy have defined roles in the multidisciplinary management of breast cancer, the optimal sequence is controversial. We evaluate the acute radiation dermatitis in patients with different paclitaxel regimens and radiation therapy. A prospective analysis of acute skin toxicity according to RTOG criteria in 41 patients with operable breast cancer stage IA-IIIC, that received adjuvant chemotherapy with doxorubicin/cyclophosphamide (AC) and subsequent radiation therapy with concurrent paclitaxel regimen (CP) (n = 22, 53.66%) administrated weekly (Qw) or every 3 weeks (Q3w) vs sequential paclitaxel (SP) (n = 19, 46.34%). The irradiation fields were determined by surgery and pathology reports. The mean age was 50.92 years, the 90.24% performed conservative surgery vs. 9.76% mastectomy. Stage IA: 7 (17.07%), IIA: 18 (43.90%), IIB: 10 (24.39%), IIIA: 2 (4.88%), IIIC: 4 (9.76%). The 95.12% had invasive ductal histology. Three-dimensional Conformal treatment was performed in 26 (63.41%) and conventional radiation therapy in 15 (36.58%). An increase in G2 skin toxicity incidence was evidenced in the CP group 12/22 (54.55%) vs SP 2/19 (10.53%), and G3 toxicity CP 2/22 (9.09%) vs. SP 0% (p = 0.002). The relative risk of acute G2/3 skin toxicity in patients with CP scheme was 2.73, (p = 0.0005). Moist dermatitis occurred in 10/41 patients (24.39%): CP arm 8/10 (80%) vs SP arm 2/10 (20%). The need for temporary interruption of treatment (split) in CP arm was 11/22 (50%): Qw 7/11 (63.64%), Q3w 4/11 (36.36%) p = 0.279, the mean dose at split was 36 Gy (27-45 Gy), the mean time of split was 1.5 weeks. In an attempt to reduce treatment interruptions due to severe dermatitis, the boost was intercalated in 10/22 patients of CP arm (45.5%) vs 1/19 SP arm (5.26%) (p = 0.004). We observed in the CP arm a tendency to greater skin toxicity with Qw regimen 63.64% vs. Q3w regimen 36.36%, p = 0.279. The different breast diameters did not act as a modifier of toxicities between the regimens. There was no evidence of symptomatic pulmonary toxicity during the follow up. Treatment of concurrent paclitaxel and radiation therapy for breast cancer significantly increases the acute G2/3 skin toxicity (RR 2.67) and treatment time despite strict monitoring; therefore, we discourage weekly concomitant paclitaxel and radiation therapy, and the Q3W concomitant regimen must be carefully assessed before administration.