Prognostic Impact of Tumor Growth Velocity in Head and Neck Squamous Cell Carcinoma Treated by Radio(Chemo)Therapy

The purpose of this study is to determine the impact of tumor growth velocity on the survival of patients with hea and neck squamous cell carcinoma treated by (chemo-)radiotherapy. Patients with stages I to IV oropharyngeal primary squamous cell carcinoma (OPSCC) elected for radiotherapy or radiochemotherapy with curative intent will be selected. Tumor volume and number and size of pathological neck lymph nodes (small diameter \> 1 cm) will be assessed on diagnostic CT-scan (DiCT) and treatment planning CT-scan (RtCT) using the summation of areas technique. Tumor progression and tumor doubling time will be calculated based on DiCT and RtCT. Tumor proliferation will be assessed on biopsy specimens by Ki67 immunohistochemistry and mitotic index. HPV status will be evaluated by PCR and p16 immunohistochemistry. Ulcerative or exophytic aspect will be noticed. Tumoral kinetics patterns will be correlated with disease free survival and overall survival of patients with HNSCC. These patterns will be compared to HPV status and proliferation markers in order to study their clinical signification \[time frame: 5 years\] and develop predictive markers of tumor progression for head and neck cancers.