Purpose: To investigate the impact of xerostomia on overall quality of life (QoL) outcome and related dimensions among head and neck cancer patients treated with primary radiotherapy.
Methods and materials: A total of 288 patients with Stage I-IV disease without distant metastases were included. Late xerostomia according to the Radiation Therapy Oncology Group (RTOG-xerostomia) and QoL (European Organization for Research and Treatment of Cancer QLC-C30) were assessed at baseline and every 6th month from 6 months to 24 months after radiotherapy.
Results: A significant association was found between RTOG-xerostomia and overall QoL outcome (effect size [ES] 0.07, p < 0.001). A significant relationship with global QoL, all functioning scales, and fatigue and insomnia was observed. A significant interaction term was present between RTOG-xerostomia and gender and between RTOG-xerostomia and age. In terms of gender, RTOG-xerostomia had a larger impact on overall QoL outcome in women (ES 0.13 for women vs. 0.07 for men). Furthermore, in women ES on individual scales were larger, and a marked worsening was observed with increasing RTOG-xerostomia. No different ES according to age was seen (ES 0.10 for 18-65 years vs. 0.08 for >65 years). An analysis of the impact of RTOG-xerostomia on overall QoL outcome over time showed an increase from 0.09 at 6 months to 0.22 at 24 months. With elapsing time, a worsening was found for these individual scales with increasing RTOG-xerostomia.
Conclusions: The results of this prospective study are the first to show a significant impact of radiation-induced xerostomia on QoL. Although the incidence of Grade > or =2 RTOG-xerostomia decreases with time, its impact on QoL increases. This finding emphasizes the importance of prevention of xerostomia.