The relation between hypoxia and proliferation biomarkers with radiosensitivity in locally advanced laryngeal cancer.

Purpose: Treatment decision-making in advanced-stage laryngeal squamous cell carcinoma (LSCC) is difficult due to the high recurrence rates and the desire to preserve laryngeal functions. New predictive markers for radiosensitivity are needed to facilitate treatment choices. In early stage glottic LSCC treated with primary radiotherapy, expression of hypoxia (HIF-1α and CA-IX) and proliferation (Ki-67) tumour markers showed prognostic value for local control. The objective of this study is to examine the prognostic value of tumour markers for hypoxia and proliferation on locoregional recurrent disease and disease-specific mortality in a well-defined cohort of patients with locally advanced LSCC treated with primary, curatively intended radiotherapy.

Methods: In pre-treatment biopsy tissues from a homogeneous cohort of 61 patients with advanced stage (T3-T4, M0) LSCC primarily treated with radiotherapy, expression of HIF-1α, CA-IX and Ki-67 was evaluated with immunohistochemistry. Demographic data (age and sex) and clinical data (T- and N-status) were retrospectively collected from the medical records. Cox regression analysis was performed to assess the relation between marker expression, demographic and clinical data, and locoregional recurrence and disease-specific mortality.

Results: Patients with high expression of HIF-1α developed significantly more often a locoregional recurrence (39%) compared to patients with a low expression (21%) (p = 0.002). The expression of CA-IX and Ki-67 showed no association with locoregional recurrent disease. HIF-1α, CA-IX and Ki-67 were not significantly related to disease-specific mortality. Clinical N-status was an independent predictor of recurrent disease (p < 0.001) and disease-specific mortality (p = 0.003). Age, sex and T-status were not related to locoregional recurrent disease or disease-specific mortality.

Conclusion: HIF-1α overexpression and the presence of regional lymph node metastases at diagnosis were independent predictors of locoregional recurrent disease after primary treatment with curatively intended radiotherapy in patients with locally advanced LSCC.