Long Term Follow-Up of a Single-Institution Prospective Study.

Abstract

PURPOSE/OBJECTIVE(S)\nThe administration of concurrent chemotherapy and radiotherapy (RT) is advantageous as it addresses both the local disease, potential sites of metastatic disease and delivering both together may provide a synergistic effect resulting in better tumor control. The purpose of this analysis was to report the long-term overall survival, disease free survival and local control from our institutional study of the efficacy of post-operative doxorubicin/cyclophosphamide followed by concurrent paclitaxel and reduced dose radiotherapy in patients with node-positive breast cancer.\n\n\nMATERIALS/METHODS\n44 women with Stage II or III pathologically confirmed node-positive breast cancer were enrolled in a Phase II, prospective, single-arm trial from June 2000 through December 2004. All patients received breast-conserving surgery and 4 cycles of doxorubicin (60 mg/m2)/cyclophosphamide (600 mg/m2) followed by 4 cycles of paclitaxel (175 mg/m2) which was delivered every 3 weeks. RT was concurrent with the first 2 cycles of paclitaxel. The breast received 39.6 Gy in 22 fractions with a tumor bed boost of 14 Gy in 7 fractions. Regional lymph nodes were treated, when indicated, using a dose of 45 Gy in 25 fractions. There was no inclusion of the internal mammary nodal chain. The diffusing capacity for carbon monoxide (DLCO) was measured as a means to evaluate functional lung volume. Pulmonary function tests with DLCO were obtained before and after RT, after completion of chemotherapy, and annually for 5 years. Breast cosmesis before initiation of RT was evaluated by the treating radiation oncologist, and scored using Harvard criteria. Cosmesis was scored weekly during RT, 1 month after RT, and every 3 months thereafter for 1 year.\n\n\nRESULTS\nAt a median follow-up of 205 months (17 yrs), overall survival is 75% and disease-free survival is 86.4%. There were 2 local recurrences yielding a local recurrence free survival of 95.5%. One of the patients with a local recurrence previously had a stage IIA (T1N1M0), grade 2 infiltrating ductal carcinoma, ER 90%, PR 50%, HER2 negative. The recurrence was stage IIA, (T1N1M0) grade 2, invasive lobular carcinoma, triple negative, considered a new primary. The two patients who experienced a local recurrence were successfully salvaged and are disease free. There were no cases of radiation pneumonitis. There was no significant change in the diffusing capacity for carbon monoxide either immediately after radiotherapy (P\u202f=\u202f0.51) or with extended follow-up (P\u202f=\u202f0.63) CONCLUSION: With long-term follow-up, the use of concurrent chemotherapy with low dose radiation as adjuvant treatment for node positive breast cancer has continued to demonstrate efficacy with excellent disease-free survival, overall survival and local control with acceptable toxicity.