Prognostic implications of pathologically determined tumour volume in glottic carcinomas treated by transoral laser microsurgery.

OBJECTIVES: The TNM classification system for squamous cell carcinoma (SCC) of the head and neck neglects to incorporate volumetric analysis of the primary tumour. Tumour volume (TV) has been implicated prognostically in laryngeal SCC treated by primary radiotherapy (RT), but data for patients treated surgically are lacking. We evaluated such for glottic SCCs resected by transoral laser microsurgery (TLM).

DESIGN: Retrospective cohort study utilising TVs calculated as the product of tumour resection dimensions and time-to-event analyses using the Kaplan-Meier method. The prognostic ability of variables was estimated using log-rank statistics, univariate Cox regression and receiver-operating characteristics analysis where appropriate.

SETTING: Tertiary referral head and neck cancer centre.

PARTICIPANTS: Patients undergoing primary TLM for glottic SCC with curative intent (2007-2011) with at least 12 months follow-up data.

MAIN OUTCOME MEASURES: Prognostic impact of TV on local control (LC), overall survival (OS) and disease-specific survival (DSS).

RESULTS: Eligible patients (n = 129) had a median follow-up of 40 months (range 14-79 months). Median TV for all cases was 300 mm(3) (range 2-19800 mm(3)). Three-year LC, OS and DSS were 92%, 92% and 98%, respectively. Tumour volume was not a significant predictor of any oncological outcome measure. Otherwise, a significant influence of pT stage on DSS was observed and of age on OS.

CONCLUSIONS: In contrast to laryngeal SCC treated by RT, TV does not appear to portend oncological outcome in glottic SCC managed specifically by TLM and consequently does not warrant incorporation into current prognostic models for such patients.