Tumor mutation status of Hodgkin lymphoma survivors with secondary lung adenocarcinoma.

Abstract

9600 Background: In a multi-institutional, retrospective study of 1976 patients treated for Hodgkin's lymphoma (HL) from 1969-2007, 55 patients developed second primary lung cancers a median of 19.5 years after treatment. Of these 55 cases, 32 were identified as lung adenocarcinoma (ACA). The development of targeted therapies in recent years has made the detection of specific genomic alterations important for disease prognosis and treatment in lung ACA. The prevalence of certain genomic alterations (EGFR, ALK, and KRAS) is highly correlated with smoking history. We hypothesize that the prevalence of genomic alterations also may differ in patients with a significant exposure to radiation. Methods: This observational retrospective case series includes 6 patients treated with mediastinal radiation for HL who subsequently developed lung ACA. All patients were treated at Ohio State University Wexner Medical Center. Patients were identified by searching billing diagnosis codes in the electronic medical record and by query of the physicians in the department of thoracic oncology at our institution. IRB approval was obtained. Results: The average age at diagnosis of HL was 25 years (range 18-46) and the average age at diagnosis of lung cancer was 58 (range 52-73). All patients were treated with radiation therapy; two patients were treated additionally with chemotherapy. None of the patients received HDT-ASCT. The average time from diagnosis of HL to diagnosis of lung cancer was 33 years. Of our six cases, 2 were positive for EGFR mutations and the other four were triple negative (-EGFR, -ALK, -KRAS). Three were never smokers, one had a 1.5 pack year history, and two had 10 pack year histories. Lung cancer stages at diagnosis were 1B (n=2), 2B (n=1), 3A (n=2), 4 (n=1). Conclusions: To our knowledge, this is the first report of mutational status of second primary lung ACA following radiation therapy for Hodgkin disease. Although the number of patients is small, the higher prevalence of the EGFR mutation in this sample suggests that ACA related to radiation therapy may have a similar mutational profile to that of never smokers. Further investigation is needed to define the disease characteristics of lung ACA in HL survivors.