Pattern of practice of radical radiation therapy for oropharyngeal cancers: a retrospective review from January 2009 to December 2012

Abstract

Radiation therapy is a highly effective method of treating oropharyngeal carcinoma, either as a single modality treatment with concurrent chemotherapy or as an adjuvant treatment after surgical resection. There exists an association with human papillomavirus (HPV) and oropharyngeal cancer, dividing oropharyngeal carcinoma into HPV positive oropharyngeal carcinoma and HPV negative oropharyngeal carcinoma. Overall survival has been analysed in these two groups and have been shown to be 80-95% for HPV positive oropharyngeal carcinomas and 57-62% in HPV negative subgroup at 3 years respectively. This retrospective review was intended to analyse patient response to treatment, overall survival, local disease free survival and the difference between HPV positive oropharyngeal carcinoma and HPV negative oropharyngeal carcinoma at Charlotte Maxeke Johannesburg Academic Hospital: Department of Radiation Oncology. Patients and methods A retrospective descriptive study was conducted on patients having received radical radiation therapy, with or without chemotherapy, from January 2009 to December 2012 with a histologically confirmed diagnosis of squamous cell carcinoma involving oropharyngeal sites only. The information obtained from records of forty-eight patients was captured on the prescribed data sheets designed for this study. Results Forty-eight eligible patients were accrued within this retrospective study. The median age of the patient group was 56 years (range 32-78) and comprised of 10 females and 38 males. The performance status was mainly Eastern Cooperative Oncology Group (ECOG) 1 (83%). The radiation therapy dose was within the range 60-70Gy, with majority patients completing 70 Gy (65%). Concurrent chemoradiation was given in 59% of patient group (28 patients). The most common site being the base of tongue (60%), followed by tonsil (36%), soft palate (2%) and posterior pharyngeal wall (2%). Eighty five percent of patients were stage IV oropharyngeal carcinoma. Only 6% of patients were tested for HPV-DNA PCR, and all were HPV positive. A total of 79% patients had a positive smoking history and 50% consumed alcohol regularly. Fifty six percent of patients tested negative for HIV, 14.6% tested positive for HIV and 29.3% had unknown HIV status. At the time of the analyses (March 2014) only 7 (15%) of patients were alive. The 2 year overall survival was 13%, the local disease free survival at 2 years was 59%. None of the prognostic factors were predictive of overall survival using univariate and multivariate analysis. Conclusion Majority of patients present in stage IV lesions with commonest sites of involvement being Base of Tongue. The local disease free survival of 2 years was 59% and the overall survival of 15%. There was no impact of prognostic factors studied on overall survival.