Purpose: Evaluate outcome in patients with T1 and T2 laryngeal cancer treated with radiation therapy.
Patients and methods: Retrospective review of 190 patients with SCC of the larynx, stage T1(63%) orT2 (37%), treated with primary radiation therapy from 1/75 through 12/93. Median age was 61 years and median follow-up was 16.6 years. Median field size was 6.0 cm x 6.0 cm with a median fraction size of 2 Gy delivered in 33 daily fractions over 48 days. Energy used was 2 MV (19%), 4 MV (46%), 6 MV (26%), or other (9%). Univariate Cox proportional hazards regression analysis was performed using the following variables: gender, age, T stage, anterior commissure involvement, treatment energy, treatment interruption, alcohol use, smoking history, and tobacco use during treatment.
Results: Overall actuarial 5-year survival was 76%, and 10-year survival was 56%. Actuarial local recurrence free survival (LRFS) at 5 years was 81%, and 10 years LRFS was 79%. Local relapse correlated with T stage (9% T1 versus 28% T2, P = 0.0009) and smoking history (14% for less than 100 pack-year versus 29% for greater than 100 pack-year, P = 0.02). Gender, age, anterior commissure involvement, treatment energy, treatment interruption, alcohol history, alcohol use during treatment, and tobacco use during treatment had no influence on outcomes. Actuarial second malignancies rate at 5 years was 18%.
Conclusion: Heavy tobacco use and T stage appears to correlate with an increase in local relapse rates. Gender, age, anteriorcommissure involvement, treatment energy, treatment interruption, and alcohol use did not significantly correlate with local relapse rates. The risk of second malignancies is comparable to that of local relapse.