Purpose: To study the relationship between the durations of symptoms before the start of radiotherapy and treatment outcome in Stage I-III glottic cancer.
Methods and materials: From 1965 to 1997, 611 glottic cancer patients from the Southern Region of Denmark were treated with primary radiotherapy. A total of 544 patients fulfilled the criteria for inclusion to the study (Stage I-III glottic cancer, a duration of symptoms less than or equal to 36 months, primary radiotherapy with at least 50 Gy and sufficient data for analysis). The total radiation dose ranged from 50.0 to 71.6 Gy in 22 to 42 fractions, and the median dose per fraction was 2.00 Gy (range, 1.56-2.29 Gy). All patients had 5 years of follow-up, and the 5-year recurrence-free survival rate was used as the primary endpoint.
Results: The 5-year recurrence-free survival rate was 74%. In a multivariate Cox regression analysis, duration of symptoms was a significant factor (p < 0.0001) with a hazard ratio of 1.045 (95% CI 1.023, 1.069). Other significant factors included tumor stage and radiation dose, whereas duration of treatment time was borderline significant (p = 0.06).
Conclusions: The duration of symptoms was statistically significantly related to a decrease in recurrence-free survival. One-month delay from onset of symptoms to start of radiotherapy was equivalent to a 4.5% decrease in recurrence-free survival.