Definitive chemo-radiotherapy for squamous cell carcinoma of the pharynx: impact of baseline low hemoglobin level (<12 g/dL) and post-radiation therapy F-18 FDG-PET/CT.

Objective: To identify reliable predictors of overall survival (OS), locoregional control (LC), and metastasis-free survival (MFS) after definitive concurrent chemo-radiotherapy (CCRT) for squamous cell carcinoma (SCC) of the pharynx (nasopharynx, oropharynx and hypopharynx), we examined 16 potential prognostic factors, including pre-treatment hemoglobin level and pre- and post-treatment [(18)F]fluorodeoxyglucose positron emission tomography CT (F-18 FDG-PET/CT) maximum standardized up-take values (SUVmax) of primary sites and lymph node (LN) regions.

Methods: We retrospectively reviewed records of 70 patients treated with definitive CCRT for pharyngeal cancer in our institution during July 2006-April 2012, with particular regard to 16 prognostic factors: age, sex, T stage, N stage, retropharyngeal LN (RPLN) involvement, existence of multiple primary cancer, treatment interruptions, overall treatment time, chemotherapy type, pre-treatment hemoglobin level, pre-treatment body mass index, enteral feeding period, and pre- and post-treatment F-18 FDG-PET/CT SUVmax of primary site and LN region. All patients in our cohort underwent pre- and post-treatment F-18 FDG-PET/CT.

Results: Multivariate analysis associated improved OS with pre-treatment hemoglobin level (≥12 g/dL; hazard ratio [HR] 3.902; 95 % confidence interval [CI] 1.244-12.236; P = 0.020) and post-treatment SUVmax (primary site) (SUVmax <5.00; HR 4.237; 95 % CI 1.072-16.747; P = 0.039). Improved LC was associated with pre-treatment hemoglobin level (≥12 g/dL; HR 2.983; 95 % CI 1.123-7.920; P = 0.028), and post treatment SUVmax (primary site) (SUVmax <5.00; HR 5.233; 95 % CI 1.582-17.309; P = 0.007). No variable was found to be significant for improved MFS.

Conclusions: Significant predictors for outcome in pharyngeal SCC treated with definitive CCRT were pre-treatment baseline hemoglobin level and post-treatment F-18 FDG-PET/CT SUVmax for primary site. Patients who have hemoglobin level lower than 12 g/dL may tend to have dismal prognosis. Additional treatment should be considered in those who have higher SUVmax at primary site in post-treatment F-18 FDG-PET/CT finding.