Prognosis associated with synchronous or metachronous multiple primary malignancies in patients with completely resected non-small cell lung cancer

To investigate the influence of multiple primary malignancies (MPMs) on the prognosis of patients with completely resected non-small cell lung cancer (NSCLC).

The subjects of this retrospective study were 521 patients who underwent complete curative pulmonary resection for NSCLC. Patients were divided into two groups: those with and those without MPMs.

The 521 NSCLC patients included 184 patients (35.3%) with MPMs and 337 patients without MPMs. The overall 5-year survival rates for patients with vs those without MPMs were 66.1 and 75.6%, respectively (p = 0.0061). According to multivariate analysis, MPMs, age, gender, pathological stage, and interstitial pneumonia were independent predictors of prognosis. The 47 patients with synchronous MPMs and the 82 patients with metachronous MPMs found within the last 5 years had significantly poorer prognoses than patients without MPMs (p = 0.0048 and p = 0.0051, respectively). However, the prognoses of the 55 patients with metachronous MPMs that had been present for over 5 years did not differ from those of the patients without MPMs.

NSCLC patients with synchronous MPMs or metachronous MPMs diagnosed within the last 5 years had poor prognoses. Decisions about the best therapeutic strategies require comprehensive consideration of the organ location, malignant potential, recurrence, and prognosis of the MPMs. In contrast, decisions about the best therapeutic strategies for NSCLC patients with metachronous MPMs present for over 5 years should be based solely on the NSCLC.