MA20.06 Lung Cancer Screening Pilot for People at High Risk: Early Results on Cancer Detection and Staging

Abstract

In June 2017, Cancer Care Ontario initiated organized lung cancer screening for people at high risk of developing lung cancer, using annual low-dose computed tomography (LDCT), at three pilot sites in Ontario. A key indicator of pilot success is detection of lung cancers at early stages. Ontario Cancer Registry (OCR) is used to track lung cancer diagnosis, stage and histology. Patient abstracts were created using Registry Plus CDC abstracting software for pilot participants and patient-level data were collected from hospital data submissions, hospital electronic medical records via remote access, OCR pathology database (eMaRC) and OCR clinical source records (Resolink). Confirmed lung cancer cases were reviewed by a team of cancer staging analysts to achieve consensus on stage group using AJCC TNM 8th edition. A post-staging review was conducted for all staged cases to ensure accuracy and completeness. As of February 2018, 1086 participants received a baseline LDCT scan. 37% (n=404) of participants had Lung-RADS™ scores of 1; 45% (n=487) had Lung-RADS™ scores of 2; 10% (n=112) had Lung-RADS™ scores of 3; and 8% (n=83) had Lung-RADS™ scores of 4A, 4B or 4X, which triggered additional follow-up or diagnostic workup. 18 lung cancers were confirmed and 11 were fully staged. Of the 11 staged cases: 45% (n=5) was stage I; 9% (n=1) stage II; 9% (n=1) stage III; and 36% (n=4) stage IV. This represents a statistically significant increase in the proportion of early stage lung cancers (stage I and II) compared to historical proportions (p<0.05). 73% (n=8) were adenocarcinoma. The median risk score (i.e., PLCOm2012 risk prediction model probability of developing lung cancer in 6 years) was 8.1%, considerably higher than the median risk score of the overall pilot cohort (2.9%). 82% (n=9) had baseline Lung-RADS™ scores of 4X and 18% (n=2) had 4B. The average age at diagnosis was 67. 45% (n=5) were male; 55% (n=6) were current smokers; and 55% (n=6) had high school education or less. In addition, the screening pilot facilitated the successful transition by the OCR from AJCC TNM 7th to TNM 8th edition in lung cancer staging. Results will be updated in the conference presentation. Early pilot results demonstrate success in detecting early stage lung cancers and a statistically significant stage shift to earlier cancer stages. We anticipate a greater proportion of early stage lung cancers on annual recall LDCT scans. The OCR efficiently enabled capturing important incidence, staging and histological pilot data.