In Yogyakarta, nasopharyngeal carcinoma (NPC) shows a poor response to radiotherapy treatment. Previous study
showed a prolonged overall treatment time (OTT), due to interruptions during treatment. This study explores the association
between clinical outcome and OTT. Secondary, the relation between clinical outcome and disease stage, waiting time to radiation
(WT) and chemotherapy schedule was explored.
In this retrospective cohort, 142 patients who started curative
intent radiotherapy for NPC between March 2009 and May 2014, with or without chemotherapy, were included. The median follow
up time was 1.9 years. Data was collected on WT, OTT, disease stage, and chemotherapy schedule. Time factors were log-transformed.
Clinical outcome was defined as therapy response, loco-regional control (LRC), disease free survival (DFS) and overall survival
The median WT was 117 days (range 12–581) and OTT was 58 days (43–142). OTT and disease stage were
not associated to any of the clinical outcome parameters. The log- WT was associated to poor therapy outcome (HR 1.68; 95%
ci: 1.09–2.61), LRC (HR 1.66; 95% ci: 1.15–2.39), and DFS (HR 1.4; 95% ci: 1.09–1.81). In the multivariable analysis, significant
hazard risk for poor therapy response, LRC, DFS and OS were seen for patients who didn’t received concurrent chemotherapy.
receiving concurrent chemotherapy showed the strongest risk for poor outcome. Since the choice of chemotherapy is related
to a variety of factors, like the WT and patient’s physical condition when radiation can start, careful interpretation is
needed. Reason for not finding a relation between OTT and clinical outcome might be the low number of patients who finished
radiotherapy within 7 weeks, or by a stronger detrimental effect of other factors.