e-Poster Presentation Clinical Oncology Society of Australia Annual Scientific Meeting 2020

The utility of surveillance CT scans in a cohort of survivors of colorectal cancer (#211)

Jorja Braden 1 2 , Natalie Southi 1 2 , Kim Kerin-Ayres 1 2 , Ashanya Malalasekera 1 2 , Janette Vardy 1 2 , Prunella Blinman 2
  1. Sydney Cancer Survivorship Centre, Concord Hospital , Concord, NSW, Australia
  2. Concord Cancer Care Centre, Concord Hospital, Concord, NSW

Aims: Previous trials have shown a survival benefit for annual computed tomography (CT) surveillance in survivors of colorectal cancer (CRC). We aimed to quantify CRC recurrences and incidental findings detected by surveillance CT-scans in a CRC survivorship cohort.

Methods: Eligible patients had high-risk stage II or stage III CRC and underwent at least one surveillance CT-scan and initial visit to the Sydney Cancer Survivorship Centre (SCSC) clinic between September 2013 and January 2020.  Patients whose CT scan/s were unavailable for review were excluded (n=29). Abnormal CT results were classified as suspected CRC recurrence or incidental finding. Suspected CRC recurrence was further classified into confirmed recurrence or benign depending on subsequent investigations. Incidental findings were further classified into those requiring further investigation/management or not clinically significant. This interim analysis reports results from the first 121 eligible patients.

Results: Of the 121 patients, the median age was 69 years (range: 35-92 years), 51% male, and 81% had stage III CRC. These 121 patients had 307 surveillance CTs. In total 13/121 (9.9%) recurrences were detected. Of the 307 surveillance scans, 43/307 (14%) showed possible recurrence of CRC, of which 8/307 (2.6%) were confirmed recurrences. 4/8 of these confirmed CRC recurrences also had a concurrent rise in CEA. A further 5/121 (4.1%) confirmed recurrences of CRC were detected by rising CEA. 104/307 (33.8%) incidental findings were identified: most were lung nodules (29/104), hepatic lesions (28/104) and thyroid nodules (12/104). Thirty incidental findings (30/307, 9.7%) required further investigations or management.

Conclusion: The rate of detection of recurrence of CRC by surveillance CT-scans alone in survivors of CRC was low, at the cost of more incidental findings requiring further investigation and management.