Significance of pretreatment hemoglobin level in patients with T1 glottic cancer

Abstract

Recent reports have suggested that pretreatment hemoglobin level (Hgb) is significantly associated with local control (LC) and overall survival (OS) in patients with T1 and T2 squamous cell carcinoma of the glottic larynx. To further evaluate the association of pretreatment Hgb level and other factors with outcome, we performed a retrospective review limited to patients with T1 squamous cell carcinoma of the glottic larynx treated with external beam radiation therapy. One-hundred thirty-nine patients with T1 squamous cell carcinoma of the glottic larynx were analyzed. Median follow-up was 5 years (range 2-22). Median pretreatment Hgb was 14.4 gm/dl (range 8.2-17.2). The following parameters were analyzed for their impact on LC, OS, and disease specific survival (DSS): age; gender; pretreatment Hgb; tumor grade; anterior commissure involvement; field size; total dose; dose per fraction; and overall treatment time. Five-year actuarial LC was 84%. Pretreatment Hgb was not a significant predictor for LC when assessed as a continuous variable (P = 0.38), nor as a dichotomous variable with a cutoff at 13 gm/dl. Local control was 82% for patients with Hgb >13 vs. 92% for Hgb < or = 13 (P= 0.13). No other factor was significant for LC. Five-year actuarial OS was 74%. Univariate analysis revealed that, pretreatment Hgb, total dose, and patient age were significant factors for OS. Overall survival was 78% for patients with pretreatment Hgb > 13 gm/dl vs. 68% for patients with Hgb < or = 13 gm/dl (P = 0.004). Overall survival was 77% for patients treated with > 66 Gy vs. 67% for those treated with < or =66 Gy (P = 0.0013), and 80% for patients < or =61 years as opposed to 69% for patients older than 61 years (P = 0.017). Multivariate analysis revealed that only age (P = 0.014) and Hgb concentration (P = 0.001) retained significance. Five-year actuarial DSS was 92%. Pretreatment Hgb was not a prognostic factor for DSS, nor were any other analyzed factors. Pretreatment Hgb is not a significant prognostic factor for LC in patients with T1 squamous cell carcinoma of the glottic larynx, but it does predict for a poorer OS without affecting DSS. This suggests that patients with lower pretreatment Hgb may have confounding medical problems that detract from their overall survival.