Differences in optimal timing of post-surgical surveillance for limited stage lung cancer patients and associations with outcomes

Elizabeth Colwell, Jalen Benson, Prasha Bhandari, Hao He, Joseph Shrager, Natalie Lui, Mark Berry, Leah Backhus

Abstract

Background: Guidelines for post-operative surveillance for non-small cell lung cancer (NSCLC) are variable. Historically, providers have used a one-size fits all approach, such that surveillance guidelines incorporated few important prognostic indicators for recurrence and survival. The goal of this study was to determine optimal timing for detection of recurrence by CT scan and the association between surveillance CT and overall survival.
Methods: This was a retrospective, single institution series of patients undergoing surgical resection [2008– 2012] with stage I or II disease (AJCC 7th edition) with at least 6 months of follow-up.
Results: Recurrence occurred in 27.2% of patients at a median of 29.5 months following surgery. Recurrences peaked at 2–3 years following surgery for the entire cohort. For those detected on CT scan surveillance, stage I the peak timing for recurrence was at 25–36 months (year 3) whereas stage II peak timing was at 19–24 months (year 2) following resection. Timing of recurrences detected by any means differed significantly based on cancer stage with 81% (n=27) of recurrences occurring more than 24 months following surgery for stage I patients compared to 41% (n=17) of stage II patients (P<0.01). Overall, higher rates of surveillance CT scans were associated with a reduced risk of death [HR 0.14 (95% CI, 0.06–0.36) P<0.01].
Conclusions: The timing of recurrence differs significantly based on stage such that few stage I patients have recurrences within 2 years following surgical resection. Additionally, rates of recurrence detected by surveillance CT scans performed less than 24 months following surgery is significantly lower for stage I patients compared to stage 2 which would favor delaying routine surveillance in this select group. Optimal timing of CT surveillance based on peak recurrence rates has the potential to eliminate unnecessary testing and expense for healthcare systems.