Early glottic cancer: the influence of primary treatment on voice preservation

Retrospective analysis was performed to assess the influence of primary surgical or irradiation treatment on local control, survival, and final preservation of larynx in comparable groups of patients with T1N0 and T2N0 glottic cancer.

Two hundred sixty-three previously untreated patients with invasive squamous cell carcinoma of the glottis (187T1 and 76T2) were treated with primary radiotherapy (159T1 and 60T2) or primary surgery (28T1 and 16T2) between January 1976 and December 1990, at the University of Ljubljana, Slovenia. Conventional one daily fraction of 2 Gy to doses of 60-74 Gy (median: 65 Gy) were used in 98% of primarily irradiated patients through out the observed period. To enable better comparison between the two treatment groups, primarily irradiated patients were retrospectively stratified by the criteria of suitability for primary voice-sparing operation. Several host, tumor, and treatment parameters were analyzed.

Only the stage of the disease significantly influenced both 10-year recurrence-free and disease-specific survival regardless primary treatment modality (p = 0.0002). In all primary irradiated patients local control was significantly better for those with overall treatment time of less than 48 days (p = 0.007). In patients suitable for voice-sparing operation, local control of primarily operated patients was similar to that of patients primarily irradiated with shorter overall treatment time, which was 93 and 88% for T1 and 67 and 64% for T2 tumors, respectively. Ultimate local control in primary surgery and radiotherapy group was 96 and 96% for T1 and 89 and 88% for T2 tumors, respectively. Equal larynx preservation of 100% in T1 and 90% in T2 patients was achieved in finally cured primarily operated patients and those patients primarily irradiated with a shorter overall treatment time. If treatment time was longer than 48 days, significantly worse final larynx preservation of 84% in T1 and 75% in T2 patients was observed (p = 0.003). In patients unsuitable for voice sparing operation, 87% of T1 and 50% of T2 patients in primary radiotherapy group finally had their larynx preserved.

Stratification based on criteria of possibility for initial voice-sparing operation is important when comparing primary surgery with primary radiotherapy treatment in early glottic cancer. The detrimental effect of prolonged treatment time of irradiation resulted not only in inferior local control rate but also in worse final larynx preservation.