Variation in head and neck cancer care in the Netherlands: A retrospective cohort evaluation of incidence, treatment and outcome

Background: To explore variation in numbers and treatment between hospitals that treat head and neck cancer (HNC) in the Netherlands. Material and methods: Patient, tumor and treatment characteristics were collected from the Netherlands Cancer Registry, while histopathological features were obtained by linkage to the national pathology record register PALGA. Inter-hospital variation in volume, stage, treatment, pathologically confirmed loco-regional recurrence and overall survival rate was evaluated by tumor site. Results: In total, 2094 newly diagnosed patients were included, ranging from 65 to 417 patients in participating hospitals treating HNC in 2008. Oral cavity cancer was mainly treated by surgery only, ranging from 46 to 82% per hospital, while the proportion of surgery with (chemo)radiotherapy ranged from 18 to 40%. Increasing age, male sex, and high stage were associated with a higher hazard of dying. In oropharynx cancer, the use of (chemo)radiotherapy varied from 31 to 82% between hospitals. We found an indication that higher volume was associated with a lower overall hazard of dying for the total group, but not by subsite. Low numbers, e.g. for salivary gland, nasopharynx, nasal cavity and paranasal sinus, did not permit all desired analyses. Conclusion: This study revealed significant interhospital variation in numbers and treatment of especially oropharyngeal and oral cavity cancer. This study is limited because we had to rely on data recorded in the past for a different purpose. To understand whether this variation is unwanted, future research should be based on prospectively collected data, including detailed information on recurrences, additional case-mix information and cause of death