Results of Converntional Radiotherapy in Oropharyngeal Cancer

Chung, Woong Ki; Ahn, Sung Ja; Nah, Byung Sik; Nam, Taek Keun

Abstract

PURPOSE: We tried to evaluate the role of conventional radiotherapy alone or with neoadjuvant chemotherapy in oropharyngeal cancerin terms of survival rates and to identify prognostic factors affecting survival by retrospective analysis.
METHODS
AND MATERIALS: Forty seven patients of oropharyngeal cancer were treated by conventional radiotherapy in our hospital from Nov. 1985 to Apr.1993. Of these. twenty six patients were treated by conventional radio therapy alone. and 21 patients with neoadjuvant chemotherapy of mostly two or more cycles of cisplatin and pepleomycin. The patient characteristics of radiotherapy alone group and neoadjuvant chemotherapy group were not different generally. Radiotherapy was performed by 6MV-LINAC and the total radiation doses of primary tumors were 54.0-79.2 Gy and cervical lymph nodes were 55.8-90.0 Gy with a fraction size of 1.8 or 2.0 Gy per day. The rangeof follow-up periods was 3-102 months and median was 20 months. The range of age was 33-79 years old and median was 58 years old.
RESULTS
Overall 3-year actuarial survival rate (3YSR) of all patients was 39%. The 3YSRs of stage I (n=5), II (n=11), III (n=12) and IV (n=19) were 60, 55,33 and 32% respectively. The 3YSRs of T1+2, T3+4 and No, N+ were 55, 18% (p=0.005) and 43,36% (p>0.1), respectively. There was no difference in 3YSRs between radiotherapy alone group and neoadjuvant chemotherapy group (38 vs 43%, p>0.1). According to the original site of primary tumor, the 3YSRs of tonsil (n=32), base of tongue (n=8), soft palate or uvula(n=6) and pharyngeal wall (n=1) were 36,38,67 and 0%, respectively. The patients of soft palateor uvular cancer had longer survival than other primaries but the difference was not significant statistically (p>0.1). Of 32 patients of tonsillar cancer, 22 patients who had primary extension to adjacent tissue showed inferior survival rate to the ones who had not primary extension, but the difference was marginally significant (24 vs 60%, p=0.08). On Cox multivariate analysis in entire patients with variables of age. T stage. N stage. total duration of radiotherapy, the site of primary tumor and the use of neoadjuvant chemotherapy. only T stage was a significant prognostic factor affecting 3YSR.
CONCLUSION
The difference of 3YASRs of conventional radiotherapy alone group and neoadjuvant chemotherapy group was not significant statistically. These treatments could be effective in oropharyngeal cancer of early stage, especially such as soft palate, uvular or tonsillar cancer which did not extend to adjacent tissue. But in order to improve the survival of patients of most advanced oropharyngeal caner, other altered fractionated radiotherapy such as hyperfractionation rather than conventional fractionation or multimodel approach combining radiotherapy and accessible surgery or concurrent chemotherapy might be beneficial.