Sigmoidoscopy is a minimally invasive medical examination of the large intestine from the rectum through the last part of the colon. This technique takes only a few minutes and does not require any medication or sedation of the patient. It is used to refer patients to colonoscopy, a more detailed and uncomfortable exploration which requires sedation, based on the premise that distal findings predict the risk of advanced proximal neoplasms.
The COLONPREV (1) study was designed to compare the efficacy of one-time colonoscopy and biennial fecal immunochemical test for reducing colorectal cancer mortality at 10 years. 5059 individuals completed colonoscopy in this large randomized controlled trial. The study was funded by the Asociación Española Contra el Cáncer (AECC) and the Instituto de Salud Carlos III (ISCIII), with the support of public and research institutions from different Spanish regions (Aragón, Canarias, Cataluña, Galicia, Madrid, Murcia, País Vasco and Valencia). The results of the study were published in New England Journal of Medicine.
Based on the lesions in the rectum and final part of the colon detected during the COLONPREV study colonoscopy explorations, researchers estimated how many patients would have been selected using three sets of criteria of colonoscopy referral. These criteria were proposed in the UK Flexible Sigmoidoscopy, Screening for COlon REctum [SCORE], and Norwegian Colorectal Cancer Prevention [NORCCAP] trials.
Advanced proximal neoplasms were found in 255 of 5059 (5.0%) individuals in the COLONPREV study. The prevalence of such lesions was lower in women than in men, as well as in individuals aged 50–59 years than in those aged 60–69 years. Fulfillment of UK (6.2%), SCORE (12.0%), and NORCCAP (17.9%) criteria varied statistically significantly. Although results show that sigmoidoscopy would have detected 35%–43% fewer individuals with advanced neoplasia than colonoscopy, sigmoidoscopy has been demonstrated to reduce colorectal cancer specific mortality and incidence in randomized controlled trials.
The new study published in the Journal of the National Cancer Institute (2) concludes that, whereas the NORCCAP criteria achieved the highest sensitivity for advanced proximal neoplasms detection, the UK recommendations benefited from the lowest number of individuals needed to refer for colonoscopy. Confirmation of these results may contribute to further expansion and tailoring of colorectal cancer screening strategies in average risk populations.
Reference:
(1) Quintero E*, Castells A,* Bujanda L, Cubiella J, Salas D, Lanas Á, Andreu M, Carballo F, Morillas JD, Hernández C, Jover R, Montalvo I, Arenas J, Laredo E, Hernández V, Iglesias F, Cid E, Zubizarreta R, Sala T, Ponce M, Andrés M, Teruel G, Peris A, Roncales MP, Polo-Tomás M, Bessa X, Ferrer-Armengou O, Grau J, Serradesanferm A, Ono A, Cruzado J, Pérez-Riquelme F, Alonso-Abreu I, de la Vega-Prieto M, Reyes-Melian JM, Cacho G, Díaz-Tasende J, Herreros-de-Tejada A, Poves C, Santander C, González-Navarro A; COLONPREV Study Investigators. Colonoscopy versus fecal immunochemical testing in colorectal-cancer screening. N Engl J Med. 2012 Feb 23;366(8):697-706. doi: 10.1056/NEJMoa1108895. *Both authors share first authorship.
(2) Castells A*, Bessa X*, Quintero E, Bujanda L, Cubiella J, Salas D, Lanas A, Carballo F, Morillas JD, Hernández C, Jover R, Montalvo I, Arenas J, Cosme A, Hernández V, Iglesias B, Castro I, Cid L, Sala T, Ponce M, Andrés M, Teruel G, Peris A, Roncales MP, González-Rubio F, Seoane-Urgorri A, Grau J, Serradesanferm A, Pellisé M, Ono A, Cruzado J, Pérez-Riquelme F, Alonso-Abreu I, Carrillo-Palau M, de la Vega-Prieto M, Iglesias R, Amador J, Blanco JM, Sastre R, Ferrándiz J, González-Hernández MJ, Andreu M; for the COLONPREV study investigators. Risk of Advanced Proximal Neoplasms According to Distal Colorectal Findings: Comparison of Sigmoidoscopy-Based Strategies. J Natl Cancer Inst. 2013 Jun 19;105(12):878-886. Epub 2013 May 24. *Both authors share first authorship.