Screen-detected colorectal cancers show improved cancer-specific survival when compared with cancers diagnosed via the 2-week suspected colorectal cancer referral guidelines.

AIM

Biennial screening for colorectal cancer using faecal occult blood testing has been shown to reduce the relative risk of mortality from colorectal cancer. The Norwich screening centre commenced screening in July 2006 and so far has diagnosed over 350 patients with colorectal cancer. We compared the stage at diagnosis and cancer-specific mortality and survival in patients diagnosed through screening with a cohort of symptomatic patients with colorectal cancer within the same age range.

METHOD

A comparative analysis was undertaken of all screen-detected colorectal cancer patients diagnosed between July 2006 and December 2010, with an age-matched group of patients diagnosed in the Norfolk and Norwich Hospital through the 2-week suspected colorectal cancer guidelines.

RESULTS

Three hundred and fifty-six cases of colorectal cancer were diagnosed through the screening programme, in patients with an age range of 60-79 years. In the same time period, 292 patients in the same age range were diagnosed with colorectal cancer through the 2-week suspected colorectal cancer pathway. Sixteen patients in the screening group had evidence of metastatic disease at presentation compared with 62 in the symptomatic group (χ(2) , P<0.001). The proportion of T1/T2 and Dukes A cancers was significantly greater in the screening group (χ(2) , P < 0.001). There were 21 colorectal cancer-related deaths in the screening group compared with 66 in the symptomatic group. Survival analysis curves showed significantly better survival in the screening group (log-rank analysis P<0.001).

CONCLUSION

Screening for colorectal cancer identifies cancers at a significantly earlier stage than in symptomatic patients, with subsequent improvement in cancer-specific survival.