Impact of treatment modalities on oral cancer patients' health-related quality of life over a time trajectory

Background: The aim of this study was to assess the impact of oral cancer and its related treatment on patients' health-related quality of life (HRQoL) and to identify factors associated with HRQoL change over time. Methods: This was a longitudinal observational multi -centre study of a cohort of newly diagnosed oral cancer patients selected using consecutive convenience sampling and followed through over a period of 3 months; from the point of diagnosis (baseline) until 3 months after treatment had commenced. Seven hospital -based oral surgery clinics managing oral cancer patients throughout Malaysia were chosen as sampling points. Data was collected through a face -to -face structured interview in a clinical setting at 3 time points using the translated and cross-culturally adapted and validated FACT-HN (v 4.0) instrument. Six derivatives of FACT summary scores were used to assess HRQoL changes using repeated measures analysis. Multivariate analysis was used to assess the predictors of HRQoL change from baseline to second follow-up visit. Ethics approval was obtained from the Medical Ethics Committee at the Faculty of Dentistry, University of Malaya. Results: A baseline sample of 76 oral cancer patients was recruited. A high attrition rate (19%-first followup; 25%-second follow-up) meant that only a cohort of 42 patients were interviewed from baseline through to the second follow-up at 3 time points (before treatment, 1 month and 3 months after commencing treatment). Oral cancer patients' HRQoL had deteriorated by the first month after commencing treatment and gradually improved, to either close to or better than pre-treatment levels. Surgical intervention produced a greater improvement in patients' overall HRQoL (at 1- and 3-month after commencing treatment) over the other treatment modalities. There was an interaction between tumor size and type of treatment received by patients in respect of their change in HRQoL from baseline to the third month after commencing treatment. Conclusions: Surgery and other treatment modalities impact oral cancer patients' HRQoL differently over time. Notably, interaction between clinical factors, namely tumor size and type of treatment was associated with HRQoL change from pre-treatment till 3 months after commencing treatment. These findings can provide an insight for clinicians in their treatment planning and decision-making for both treatment modalities.