Objective

Cancer can be a life-threatening stressor that may evoke pre-existing post-traumatic stress disorder (PTSD). We assessed change in 9/11-related PTSD symptoms following cancer diagnosis in a 9/11-exposed cohort, the World Trade Center Health Registry.

Methods

We examined enrollees who had a first-time post-9/11 invasive cancer diagnosis and at least one pre- and two post-diagnosis 9/11-related PTSD assessments from enrolment through 2015. PTSD symptoms were measured using 17-item PTSD Checklist (PCL, range 17-85). Cancer was identified from New York State Cancer Registry and categorized as localized or advanced stage. We used piecewise spline linear mixed-effects models to examine rate of change in PCL scores from pre- to post-diagnosis periods, and whether the change differed by gender or stage, with time as fixed and random effects, adjusting for baseline age, race, and education.

Results

9/11-related PTSD symptoms were slightly increasing in the pre-diagnosis period, while this trend reversed in the post-diagnosis period (β: −0.38; 95% CI: −0.60, −0.15). This trend was driven by male rescue/recovery workers (RRW), among whom significant decrease in rate of change in PCL scores was observed for those with advanced stage (slope change difference [95% CI]: −1.81 [−2.73, −0.90]). No significant difference in rate of change was observed among non-RRW. Among females, PCL scores tended to decrease slightly, with no significant difference in rate of change between pre- and post-diagnosis periods.

Conclusions

We observed significant reduction in the rate of change in 9/11-related PTSD symptoms among male RRW. The underlying mechanism is unknown, necessitating future research.