J Korean Cancer Assoc.
1997 Dec;29(6):984-991.
Prognostic Factors for Local Control and Survival in T1-T2 Glottic Cancer
- Affiliations
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- 1Department of Therapeutic Radiology, Seoul National University College of Medicine, Seoul, Korea.
- 2Department of Otolaryngology, Seoul National University College of Medicine, Seoul, Korea.
Abstract
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PURPOSE: To evaluate the efficacy of radiotherapy as the first treatment of T1-T2 golttic cancers, we analyzed survival rates, local control rates, and voice preservation rates retrospectively. Furthermore, prognostic factors potentially influencing local control and incidence of second primary tumors were analyzed.
MATERIALS AND METHODS
One hundred patients with T1-T2 glottic cancer were irradiated between February 1989 and July 1991. Median follow-up time was 80 months. 1) Factors analyzed for each patient included age, stage, anterior commissure involvement, fraction size, field size, total dose and treatment time. 2) Survival analysis methods were employed to assess the effects of these factors in local control and survival rates. All patients received Co-60 irradiation, one daily fraction of 1.75~2.0 Gy to doses of 60~72 Gy.
RESULTS
The overall survival rate, disease free survival rate and cause specific survival rates for all patients at 5 year were 80.7%, 78.6% and 87.3%, respectively. The 5-year overall survival rates for patients with T1, 2 were 82.8% and 76.9%, respectively. Overall treatment time of 50 days or less was uniquely found to have superior impact on local control rate to that of more than 50 days in univariate prognostic factor analysis (p=0.0494), and showed statistical trend in multivariate analysis (p=0.0577). Fourteen patients who had showed relapse after radiotherapy underwent salvage operation, among whom nine patients were cured. The 5-year local control rate for all patients after radiotherapy was 79% and ultimate local control rate was 87%. Voice preservation rate after radiotherapy and salvage operation was 87.6%. The second primary cancer developed in 9 patients (9%).
CONCLUSION
Radiotherapy which showed high survival rates and voice preservation rate proved to be the optimal initial treatment for patients with T1-T2 glottic cancer. Prolongation of overall treatment should be avoided as the overall treatment was found to have a significant impact on the local control of tumor. The close follow-up and prevention should be needed to decrease the death rate by second primary tumor.
