Outcomes of lung cancer screening among cancer survivors: An NCCN institution experience.

Abstract

1595 Background: In 2013, the USPTF recommended low-dose CT (LDCT) screening for individuals at high risk of lung cancer based on data from the National Lung Screening Trial. However, the trial excluded participants with cancer diagnosis < 5 years except for non-melanoma skin cancer, making it unclear whether the data will be generalizable to cancer survivors. This population, while at increased risk of secondary lung cancer, may be prone to false positive results due to anatomic defects or recurrent cancers. Our NCCN institution serves a large number of cancer survivors. We evaluated the outcomes of LDCT screening and the adherence to annual screening among cancer survivors, compared with individuals without cancer history (IWC). Methods: Prospectively maintained database of LDCT screening participants was analyzed. Eligibility was per NCCN criteria and cancer survivors needing regular chest CT were not offered LDCT. Participants were asked to complete a self-administered questionnaire on risk factors. Positive result was defined as Lung-RADS ≥3, corresponding to nodule ≥6 mm. Adherence to LDCT screening was defined as having T1 screening, excluding those < 18 months from T0 at time of analysis. Predicted risk of lung cancer was calculated per PLCOm2012 model. Results: To date, 454 subjects have undergone LDCT screening. Positive results occurred in 60 subjects (13.2%) at T0; lung cancer was diagnosed in 10 subjects (2.2%); and other cancers were diagnosed in 5 subjects (1.1%). There were 152 cancer survivors, including survivors of breast (52), prostate (26), bladder or kidney (19), lung (14), and head and neck cancer (13). The median time from cancer treatment to LDCT screening was 6 years (range 0-55). Cancer survivors were older than IWC: median age 67.4 vs. 63.5 years ( p< 0.001) and more likely to be active smokers: 37.5% vs. 29.5%, ( p= 0.09). The median predicted risk of lung cancer at 6 year was 5.5% vs. 3.2%, ( p= 0.15). No significant difference in the screening outcomes was found between groups. Among cancer survivors (N = 152), positive screening occurred in 15 (9.9%); lung cancer was diagnosed in 1 (0.7%); and other cancers were diagnosed in 3 subjects (1.9%). Non-adherence to LDCT screening occurred in 31 out of 152 cancer survivors (20.4%), compared with 81 out of 262 (30.9%) IWC, ( p= 0.02). Conclusions: About one-third of LDCT screenings at this NCCN institution occurred among cancer survivors. We found no evidence of increased false positive results. However, a higher rate of adherence to annual screening was observed among cancer survivors than IWC.