Purpose: Regular surveillance decreases the risk of recurrent cancer in colorectal cancer (CRC) survivors. However, studies suggest that receipt of follow-up tests is not consistent with guidelines. This systematic review aimed to: (1) examine receipt of recommended post-treatment surveillance tests and procedures among CRC survivors, including adherence to established guidelines, and (2) identify correlates of CRC surveillance.
Methods: Systematic searches of Medline, PubMed, PsycINFO, CINAHL Plus, and Scopus databases were conducted using terms adapted for each database's keywords and subject headings. Studies were screened for inclusion using a three-step process: (1) lead author reviewed abstracts of all eligible studies; (2) coauthors reviewed random 5 % samples of abstracts; and (3) two sets of coauthors reviewed all "maybe" abstracts. Discrepancies were adjudicated through discussion.
Results: Thirty-four studies are included in the review. Overall adherence ranged from 12 to 87 %. Within the initial 12 to 18 months post-treatment, adherence to recommended office visits was 93 %. Adherence ranged from 78 to 98 % for physical exams, 18-61 % for colonoscopy, and 17-71 % for carcinoembryonic antigen (CEA) testing. By 2 to 3 years post-treatment, cumulative adherence ranged from 70 to 88 % for office visits, 89-93 % for physical exams, 49-94 % for colonoscopy, and 7-79 % for CEA testing. Between 18 and 28 % of CRC survivors received greater than recommended overall surveillance; overuse of physical exams (42 %), colonoscopy (24-76 %), and metastatic disease testing (1-29 %) was also prevalent. Studies of correlates of CRC surveillance focused on sociodemographic and disease/treatment characteristics, and patterns of association were inconsistent across studies.
Conclusions: Deviation from surveillance recommendations includes both under- and overuse. Examination of modifiable determinants is needed to inform interventions targeting appropriate and timely receipt of recommended surveillance.
Implications for cancer survivors: Among CRC survivors, it remains unclear what modifiable psychosocial factors are associated with the observed under- and overuse of surveillance. Understanding and intervening with these psychosocial factors is critical to improving adherence to guideline-recommended surveillance and thereby reducing mortality among this group of survivors.