Lee J, et al. - Researchers here aimed to determine the timing and patterns of recurrence after the treatment of stage IIIA (N2) non-small cell lung cancer via neoadjuvant concurrent chemoradiotherapy followed by surgery. They realized that the dynamics of recurrence after trimodality therapy was organ-specific and varied in accordance to pathologic factors. Outcomes provided data on selection patients with risk of recurrence and timing of surveillance study.

Methods

• Researchers reviewed an institutional database retrospectively between 1997 and 2013 (N = 570).
• They included patients having pathologically proven N2 disease.
• The planned trimodality therapy was completed by the patients with curative intent.
• They used the hazard rate function and competing risk analysis to assess the recurrence dynamics.

Results

• In this study, 76% of the included patients had single station N2 involvement and 95% had complete resection.
• The 5-year overall survival rate was 47% and recurrence-free survival rate was 29%.
• Recurrence was evident in 290 patients; 25 (8.4%) of these experienced loco-regional recurrence, whereas 238 (80.4%) had distant metastases.
• For overall recurrence, the hazard rate function revealed a peak at approximately 8 months after surgery and a marked decline after 2 years.
• Researchers observed differences in the peak recurrence frequency of distant metastasis with respect to each site; isolated brain metastases exhibited the earliest peak (6 months) and a narrow recurrence interval (15 months).
• A higher recurrence hazard rate for adenocarcinoma than for squamous cell carcinoma but similar pattern of recurrences were evident in histological comparison.
• A lower cumulative incidence rate of recurrence but a slightly earlier peak of recurrence was observed among patients with complete responses.
• As per nodal responses to induction therapy, patients with ypN0 had the lowest recurrence risk, whereas patients with ypN1 and ypN2 had similar hazard rates and cumulative incidence rates of recurrence.