Screening vs. non-screening detected colorectal cancer: Differences in pre-therapeutic work up and treatment

Objectives: To compare preoperative staging, multidisciplinary team-assessment, and treatment in patients with screening detected and non-screening detected colorectal cancer. Methods: Data on patient and tumour characteristics, staging, multidisciplinary team-assessment and treatment in patients with screening and non-screening detected colorectal cancer from 2008 to 2012 were collected from the Stockholm-Gotland screening register and the Swedish Colorectal Cancer Registry. Results: The screening group had a higher proportion of stage I disease (41 vs. 15%; p< 0.001), a more complete staging of primary tumour and metastases and were more frequently multidisciplinary team-assessed than the non-screening group (p< 0.001). In both groups, patients with endoscopically resected cancers were less completely staged and multidisciplinary team-assessed than patients with surgically resected cancers (p< 0.001). No statistically significant differences were observed between the screening and non-screening groups in the use of neoadjuvant treatment in rectal cancer (68 vs. 76%), surgical treatment with local excision techniques in stage I rectal cancer (6 vs. 9%) or adjuvant chemotherapy in stages II and III disease (46 vs. 52%). Emergency interventions for colorectal cancer occurred in 4% of screening participants vs. 11% of non-compliers. Conclusions: Screening detected cancer patients were staged and multidisciplinary team assessed more extensively than patients with non-screening detected cancers. Staging and multidisciplinary team assessment prior to endoscopic resection was less complete compared with surgical resection. Extensive surgical and (neo) adjuvant treatment was given in stage I disease. Participation in screening reduced the risk of emergency surgery for colorectal cancer.