{'fraction_non_alphanumeric': 0.025513033832501388, 'fraction_numerical': 0.02329450915141431, 'mean_word_length': 5.053691275167785, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 1, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
[Diagnosis of colorectal tumours in daily clinical practice: comparison of colonoscopy and sigmoidoscopy].

OBJECTIVE
To map the locations of advanced colorectal neoplasia in patients referred for colonoscopy or sigmoidoscopy and to compare the yield of advanced neoplasia and the distribution of advanced neoplasia per indication for endoscopy.


DESIGN
Observational.


METHOD
In a multicentre survey in North Holland, the Netherlands (n = 18 hospitals), data on all colonoscopies and sigmoidoscopies performed during a three-month period in 2005 were analyzed. The locations and the histological features of all colonic neoplasia and the indications for endoscopy were recorded. Advanced neoplasm was defined as adenoma >or=10 mm in size, an adenoma with any villous features, or high-grade dysplasia or adenocarcinoma.


RESULTS
A total of 4623 patients underwent a total colonoscopy and 3004 patients underwent sigmoidoscopy. The prevalence of advanced neoplasia was 13% on colonoscopy and 6% on sigmoidoscopy. Of the advanced neoplasia found on colonoscopy, 67% were located in the distal colon and 33% in the proximal colon. Of the patients with advanced neoplasia in the proximal colon (n = 228), 51% had no abnormalities in the distal colon. The percentage of advanced neoplasia in the proximal colon varied from 23% in patients younger than 50 years to 41% in patients aged 80 years and older. Depending on the indication for endoscopy, the prevalence of advanced neoplasia in the proximal colon varied from 11-57%.


CONCLUSION
Of the advanced colorectal neoplasms 33% were located in the proximal colon. With increasing age, a shift in tumour localization occurs from distal to proximal in the colon. Colonoscopy is the preferred method for the endoscopic diagnosing of colorectal neoplasia.