Outcomes of a Highly Selective Surgical Approach to Oligometastatic Lung Cancer

A highly selected subset of patients with oligometastatic non-small cell lung cancer (NSCLC) will be cured after all sites of established disease (primary and metastases) have been eliminated by surgery or radiation (ie, "curative intent" approach). Mediastinal lymph node metastases (N2) have been found retrospectively to predict a poor prognosis in this setting (5-year survival of 4% for N2-positive versus 31% for N2-negative). Hence, our institution has programmatically limited the use of curative intent local therapy to oligometastatic NSCLC patients confirmed to be free of N2 disease. However, it is unclear whether the exclusion of N2-positive patients is an effective prospective selection step to aggressively treat oligometastatic NSCLC.

A prospectively maintained institutional tumor registry was reviewed for oligometastatic stage IV NSCLC patients evaluated for curative intent treatment from 2005 to 2014.

All synchronous oligometastatic NSCLC cases were evaluated by invasive mediastinal staging before treatment. Twenty-two patients without N2 disease underwent curative intent treatment, and 13 patients with N2 disease were treated palliatively. The groups were similar by bivariate analyses. The N2-negative patients treated with curative intent had a superior 5-year survival compared with N2-positive patients treated palliatively (58% versus 0%, respectively; p = 0.028).

Using invasive mediastinal staging to exclude N2 disease has a role in surgical decision making and achieving long-term survival among oligometastatic NSCLC patients. Further study is warranted to determine whether a subset of patients with N2 disease also have the potential for long-term survival with local therapy.