Discussion
OPSCC, head and neck cancers, toxicity, stroke, AJCC
STROKE, RECURRENCE, CARDIOVASCULAR DISEASE, HEAD AND NECK CANCER
According to the NCCN guidelines [Most previous studies have investigated both p16-positive and p16-negative OPSCC [Many studies have reported that PET–CT can be used for determining the response to treatments, including CCRT, or for the detection of recurrence in head and neck cancers [Compared with the control group, more patients in the case group had advanced AJCC stages, advanced cN stages, and poor differentiation, which were identified as poor prognostic factors for OS. Despite the presence of more poor prognostic factors for survival in the PET–CT group, the crude mortality rates of the pre-CCRT PET–CT and non-pre-CCRT PET–CT groups were 61.0% and 64.5%, respectively (Table In the multivariable analysis, we observed that age > 70 years [As shown in Table The strength of our study is that it is the first largest homogenous modality study on PET–CT including a long-term follow-up cohort to examine the survival outcomes of pre-CCRT This study has some limitations. First, because all the patients with p16-negative OPSCC were enrolled from an Asian population, the corresponding ethnic susceptibility compared with that of a non-Asian population remains unclear; hence, our results should be cautiously extrapolated to non-Asian populations. However, no evidence indicates differences in the survival outcomes of patients with p16-negative OPSCC receiving CCRT between Asian and non-Asian populations. Second, the toxicity scores have not been available in the TCRD. Third, the diagnoses of all comorbidities were based on ICD-10-CM codes. However, the combination of the TCRD and National Health Insurance Research Database in Taiwan appears to be a valid resource for population research on cardiovascular disease, stroke, or chronic comobidities [