Long-term radiation sequelae after breast-conserving therapy in women with early-stage breast cancer: An observational study using the LENT-SOMA scoring system

Purpose: To evaluate the long-term toxicity after breast-conserving therapy in women with early-stage breast cancer. Methods and Materials: Late toxicity according to the late effects of normal tissue-subjective, objective, management, and analytic (LENT-SOMA) criteria and cosmetic outcome (graded by physicians) were evaluated in 590 of 2943 women with early-stage breast cancer who were irradiated between 1983 and 1995 using the following fractionation schedules: group A, 1983-1987, 2.5 Gy 4x/wk to 60 Gy; group B, 1988-1993, 2.5 Gy 4x/wk to 55 Gy, group C, 1994-1995, 2.0 Gy 5x/wk to 55 Gy. Results: LENT-SOMA Grade 3-4 toxicity was observed as follows: group A (median follow-up 171 months; range 154-222 months), fibrosis 16% (7 of 45), telangiectasia 18% (8 of 45), and atrophy 4% (2 of 45); group B (median follow-up 113 months; range 78-164 months), pain 2% (8 of 345), fibrosis 10% (34 of 345), telangiectasia 10% (33 of 345), arm edema 1% (2 of 345), and atrophy 8% (27 of 345); and group C (median follow-up 75 months, range 51-96 months, n = 200), occurrence of Grade 3-4 late morbidity ≤2%. The cosmetic outcome was very good to acceptable in 78% (35 of 45) of patients in group A, 83% (286 of 345) in group B, and 94% (187 of 200) in group C. Conclusion: In our population, the long-term side effects after breast-conserving therapy were not rare, but were mainly asymptomatic. The LENT-SOMA breast module is a practical tool to assess radiation-induced long-term toxicity.