Survival after subsequent non-Hodgkin's lymphoma and non-small cell lung cancer in patients with malignant thymoma.
BACKGROUND
Survivors of malignant thymoma (MT) are at an increased risk of developing subsequent neoplasms. We compare overall survival (OS) between MT survivors who developed non-Hodgkin's lymphoma (NHL) or non-small cell lung cancer (NSCLC), and patients with first primary NHL (NHL-1) or NSCLC (NSCLC-1), respectively.


METHODS
Using the population-based Surveillance, Epidemiology, and End Results (SEER) database for 1973 through 2013, 273,313 patients who had NHL-1, 21 patients with MT-NHL, 566,819 patients with NSCLC-1, and 38 patients with MT-NSCLC were identified. Univariate and multivariate models were used to assess the impact of various factors on OS.


RESULTS
The observed-to-expected ratio among MT patients was 2.63 [95% confidence interval (95% CI), 1.40-4.49; P<0.05] for NHL and 1.90 (95% CI, 1.33-3.63; P<0.05) for lung cancer. On univariate analysis, MT history did not worsen OS for NHL [hazard ratio (HR), 1.46; 95% CI, 0.87-2.47; P=0.16] or NSCLC (HR, 0.89; 95% CI, 0.61-1.29; P=0.53). On multivariate analysis, MT history was found to be an adverse prognostic indicator on OS for NHL (HR, 2.03; 95% CI, 1.20-3.42; P=0.008), but not NSCLC (HR, 0.87; 95% CI, 0.60-1.25; P=0.45).


CONCLUSIONS
Patients who develop NHL after MT have inferior survival than those with first primary NHL. A history of MT does not have an adverse prognostic impact on subsequent NSCLC. Clinicians must be aware of the intrinsic risk for subsequent malignancies after MT and the potential adverse impact of MT history on NHL prognosis but not NSCLC.
Department of Radiation Oncology, University of Rochester Medical Center, Rochester, NY, USA.
Jacob S
JS
Parzen
Department of Radiation Oncology, University of Florida, Gainesville, FL, USA.
James E
JE
Bates
Department of Radiation Oncology, University of Rochester Medical Center, Rochester, NY, USA.
Michael T
MT
Milano
Department of Radiation Oncology, University of Rochester Medical Center, Rochester, NY, USA.
Sughosh
S
Dhakal
Thymoma; cancer survivorship; non-Hodgkin’s lymphoma (NHL); non-small cell lung cancer (NSCLC)