Trends in treatment patterns associated with small cell lung cancer in a U.S. Medicare population.

Abstract

8584 Background: Characterizing changes in the incident small cell lung cancer (SCLC) patient population and SCLC treatment landscape is essential for understanding drivers of outcomes among patients diagnosed with SCLC. The objective of this study was to examine trends in patient characteristics and treatment patterns for SCLC in a Medicare population. Methods: A retrospective analysis was conducted using the Surveillance, Epidemiology, and End Results (SEER)–Medicare linked data. Patients were included if they had a record with a diagnosis of SCLC in the database from 1/1/2007 – 12/31/2017 and were ≥65 years of age at diagnosis. Patients also had continuous enrollment for ≥180 days pre-SCLC diagnosis. Characteristics and treatment patterns were stratified by year of SCLC diagnosis. Results: 13,516 patients met the study criteria. Overall, 57.7% were female, mean age was 74 years, 89.5% were white, and 45.6% had a history of tobacco use. The majority (73.1%) were diagnosed with stage IV disease. Just over half (55.4%) of patients initiated first line (1L) treatment and mean time from diagnosis to 1L treatment was 6 weeks. Only 36.7% of those initiating 1L went on to second line (2L). Platinum-based chemotherapy (carboplatin or cisplatin + etoposide) was by far the most common 1L regimen (91.3%). 44.7% of patients received monotherapy in 2L, with topotecan being the most common (28.4%) regimen. Carboplatin + etoposide was used for approximately 20% of 2L patients. Over time, the demographic characteristics of patients diagnosed with SCLC was fairly stable with the exception of patients reporting a history of tobacco use, which more than tripled, increasing from 19.3% to 67.7% between 2007 and 2017. Between 2007 and 2017 the share of SCLC patients initiating 1L treatment increased 8.2% from 53.8% to 58.2% and the share initiating 2L fluctuated between 35% and 39%. Platinum-based chemotherapy was consistently used by the vast majority (88.7%–96.6%) of patients in 1L during the study period. Other chemo monotherapy (e.g., topotecan) and platinum-based chemotherapy with or without irinotecan were the most common 2L regimens from 2007-2014. Use of checkpoint inhibitors (CPIs) in 2L began in 2015 and became the most common 2L treatment following platinum-based chemotherapy by 2017 with 41.5% of patients receiving a CPI in 2L. Conclusions: While an increasing share of SCLC patients are pursuing treatment, less than 60% of SCLC patients receive any anticancer therapy. Fewer still receive more than one line of treatment, highlighting the ongoing need for effective therapies for SCLC.