Objective: To compare survival rates of concurrent chemo-radiation (CRT) and radiation (RT) alone in locally, advanced
unresectable head and neck cancers and to assess factors associated with survival.
Material and Method: A retrospective cohort study was conducted of 165 patients treated for locally advanced unresectable head and neck cancers (Stage III, IV) at the Department of Radiation Oncology, Rajavithi Hospital, from 1 January 2011 to 31 December 2013. Patients were divided into two groups: in the first group, 68 patients received CRT, and in the second, 97 patients received RT alone. The Cox proportional hazards model was used to assess the factors which had an impact on survival while controlling for known prognostic factors. The ethics committee of Rajavithi Hospital reviewed and approved this study.
Results: There was an overall survival (OS) rate of 1 year (1 year OS) in 27% of cases, and 2 years (2 years OS) in 15.4%
of cases with a median overall survival rate of 7.63 months (7.63 OS) (95% CI 6.99-8.27). The mean follow-up time was 7.34 months with maximal follow-up time of 41.77 months and minimal follow-up time of 0.2 months (6 days). Patients who
received chemotherapy had better overall survival rates than those who had no chemotherapy with 1 year OS of 52% vs.
9.5%, 2 years OS of 36.7% vs. 1.5%, and median OS of 13.17 vs. 5.4 months, p<0.001. However, no significant difference
for median survival was observed among three different chemotherapy regimens with median OS of 11-13 months but
chemotherapy group had significant difference from no chemotherapy group with median OS of 5.40 months (4.59-6.21).
Conclusion: Concurrent chemo-radiation (CRT) should be used as the standard treatment in patients who are medically fit.
A Cisplatin or Carboplatin weekly regimen can be used as an alternative to a Cisplatin three-weekly regimen. Site of primary
tumor, N-stage, recurrent tumor, low RT dose (below 70 Gy), and co-morbidity (with impaired renal or liver function) are
significant predictors of overall survival.

Keywords: Chemoradiation, Radiation oncology, Survival rate, Head and Neck cancer