RESUMEN
BACKGROUND AND AIMS: Subsite-specific incidence rates of colorectal cancer (CRC) and adenomas may vary considerably by race, sex and age as well as due to different screening strategies. We assessed variations in the anatomical distribution of adenomas according to age and sex in an average-risk screening cohort testing positive at immunological faecal occult blood test (i-FOBT) in northern Italy. METHODS: Data from 2,281 consecutive asymptomatic i-FOBT-positive subjects ageing 50-70 years undergone colonoscopy were reviewed. Size, number, macroscopic and histological features of all adenomas found as well as their proximal or distal location in relation to the splenic flexure were examined. Odds ratios (OR) of proximal neoplasms, according to the presence of distal neoplasms and other selected covariates were assessed by multiple logistic regression analysis. RESULTS: A total of 2,599 neoplasms were found in 1,396 patients. Of these, 116 (5 %) were colorectal cancers, diagnosed in 106 patients. Out of 2,483 adenomas found, 1,564 (63 %) were sessile, 795 (32 %) were peduncolated and 124 (5 %) were flat-type; 54 % of all adenomas were tubular, 36 % were tubulovillous or villous, and 10 % were serrated adenomas. The majority of neoplasms (66 %) were located in the distal colon. Tumour subsite distribution was consistent in both sexes, whereas significant proximal migration of neoplasms occurred in the older age cohort. Indeed, the rate of proximal neoplasms in patients aged ≥60 years was 37 % as compared with 29 % in those ageing 50-59 years. Male gender (OR 1.84), age of 60 years or older (OR 1.44), having a family history of colorectal neoplasms (OR 1.47) and presence of at least 1 distal advanced adenoma (OR 1.63) were all significant predictors of advanced proximal neoplasms. CONCLUSIONS: A left to right shift of colorectal adenomas with increasing age is evident in northern Italian asymptomatic i-FOBT-positive population. Advanced proximal neoplasms are not uncommon in subjects with or without distal adenomas, especially after 60 years of age. This should be carefully considered when implementing public screening strategies for CRC since the use of flexible sigmoidoscopy as a screening tool, particularly in older age groups, appears to be less effective.
Asunto(s)
Adenoma/patología , Neoplasias Colorrectales/patología , Detección Precoz del Cáncer/métodos , Pruebas Hematológicas/métodos , Sangre Oculta , Caracteres Sexuales , Adenoma/sangre , Adenoma/diagnóstico , Adenoma/epidemiología , Factores de Edad , Anciano , Estudios de Cohortes , Colonoscopía , Neoplasias Colorrectales/sangre , Neoplasias Colorrectales/diagnóstico , Neoplasias Colorrectales/epidemiología , Femenino , Humanos , Italia/epidemiología , Masculino , Persona de Mediana Edad , Factores de RiesgoRESUMEN
BACKGROUND AND STUDY AIMS: Colorectal cancer (CRC) screening aims to reduce mortality by detecting cancers at an early stage and removing adenomatous polyps at an acceptable cost. The aim of the current study were to assess the outcomes and costs of the first two biennial rounds of a population-based CRC screening program using the immunochemical fecal occult blood test (i-FOBT) in a northern Italian province. METHODS: All residents aged 50â-â69 years were invited to take part in a biennial screening program using a 1-day i-FOBT, followed by colonoscopy in positive individuals. The i-FOBT uptake, compliance to colonoscopy, detection rate for cancer or advanced adenomas according to age and sex, and direct cost analysis were carried out separately for the 1st and 2nd rounds of screening. RESULTS: In 78â083 (1st round) and 81â619 (2nd round) individuals who were invited to screening, the participation rates were 49.7â% and 54.4â% and i-FOBT positivity rates were 6.2â% and 5.8â%, respectively. Detection rates for cancer and advanced adenomas were lower in the 2nd screening compared with the 1st one (1.6 vs. 2.5 for cancers and 15.8 vs. 17.9 for advanced adenomas, respectively), whereas positive predictive values for cancer and advanced adenoma were similar in both rounds. In 165 adenocarcinomas detected, 52â% were Dukes' stage A and 21â% were stage B. All cost indicators were slightly higher in the 1st round of screening compared with the 2nd. The direct cost per cancer or advanced adenoma detection was similar in the two rounds (â1252 and â1260, respectively). CONCLUSIONS: Compliance and diagnostic yield of i-FOBT screening were satisfactory. Most detected cancers were at a very early stage. Program costs were reasonable and did not increase with repeat screening. Screening could contribute to decreasing the cost of CRC care by improving the stage at diagnosis.