Oligometastatic non-small cell lung cancer: a significant entity outside of specialized cancer centers?

To report the incidence, patterns of care, and outcomes of oligometastatic non-small cell lung cancer (NSCLC) in a rural practice setting in Norway.

A retrospective analysis was conducted of all patients with stage IV NSCLC at the initial diagnosis who received active treatment in the central part of Nordland, a rural county in northern Norway, during the period of 2006-2012. We analyzed overall survival and prognostic factors.

The initial study population included 113 patients with stage IV disease who received active therapy; of these, 23 (20%) had oligometastatic spread (a maximum of 3 metastases to 1 organ). The median age was 71 years. Of the 23 patients, 16 (70%) did not receive radical or at least moderately aggressive local treatment for their thoracic disease. Of the remaining 7 patients, 4 (17.4%) did not receive systemic therapy. The median actuarial survival was 5.6 months in patients with more advanced metastases and 11.7 months in those with oligometastases (p = 0.03). Significant differences were also seen between the 2 oligometastatic patient groups with and without more intense thoracic treatment (median 19.7 vs. 7.6 months, p = 0.004). Further significant predictors of survival in patients with oligometastases were nodal stage (p = 0.028) and weight loss (p = 0.045). Trends were seen for T stage (p = 0.058) and performance status (p = 0.07).

Oligometastatic NSCLC was diagnosed in a relevant proportion of patients; therefore, warranting prospective studies are recommended. Such studies are also needed to confirm the treatment-dependent survival differences observed in our patient population.