Acute and late toxicity associated with sequential bleomycin-containing chemotherapy regimens and radiation therapy in the treatment of carcinoma of the nasopharynx

Abstract

Between 1975 and 1984, 33 patients with squamous cell carcinoma of the nasopharynx received adjuvant chemotherapy before and/or after definitive radiotherapy at UT M. D. Anderson Hospital. The favored chemotherapy regimens during this time were BCMF (bleomycin, cyclophosphamide, methotrexate, and 5-FU) and PMB (cisplatinum, methotrexate, and bleomycin). Total radiation doses to the primary site averaged 65 Gy for T1 and T2 lesions and 70 Gy for T3 and T4 lesions. Neck nodes were given boost treatments to a maximum of 70 Gy, depending on the extent of the disease. The outcome of treatment in these patients was compared to that of a stage-matched group of 71 patients treated during the same time period with radiotherapy alone. However, the groups were not matched with regard to histologic subtypes: 45% of the radiation-only group had prognostically unfavorable keratinizing squamous carcinomas (WHO 1) compared with 18% of the combined modality group. Overall disease-free survival at 5 years was 63% in the combined modality group and 44% in the radiation only group ( p = 0.15). Both acute reactions and late treatment complications were much more frequent and severe in patients receiving combined modality treatment. In patients treated with chemotherapy prior to radiation therapy, 10 20 (50%) experienced severe acute toxicity (RTOG Grade 3 or 4) versus 9 71 (13%) in the radiotherapy-only group. Severe late normal tissue injury occurred in 15 33 (45%) of the combined modality group versus 5 71 (7.0%) in the control group. The majority of the late complications in the adjuvant chemotherapy group consisted of severe soft tissue and muscle fibrosis. The average total bleomycin dose in the patients with severe late soft tissue and muscle fibrosis was 336 mg. The actuarial risk of developing a severe late complication by 2 years after treatment was 68% in the combined modality group versus 8% in the radiation-therapy-only group ( p = .001). The probability of remaining both disease-free and complication-free at 5 years was 40% in the radiation-only group and 22% in the combined-modality group ( p = 0.08). Comparison of these results with other published reports emphasizes the importance of late toxicity data in assessing the ultimate value of combined modality therapy.