Development of colorectal tumors in colonoscopic surveillance in Lynch syndrome.
OBJECTIVE
Mutation carriers in Lynch syndrome families have a high risk for developing colorectal cancer during their lifetime. This study was designed to assess the cumulative risk for the development of colorectal adenoma or carcinoma in prospective colonoscopic surveillance.


METHODS
Data from the Finnish Hereditary Colorectal Cancer Registry electronic database on 420 Lynch syndrome mutation carriers without previous colorectal tumors were reviewed. Between March 1982 and May 2005 the mutation carriers underwent a total of 1252 colonoscopies. The total follow-up time was 3150 years (mean, 6.7 y/patient).


RESULTS
The cumulative risk of adenoma by age 60 was estimated as 68% (95% confidence interval [CI], 50%-80%) in men and 48% (95% CI, 29%-62%) in women. The estimated cumulative risk up to age 60 years for the development of cancer found as a result of surveillance at an interval of 2-3 years was 35% (95% CI, 16%-49%) in men and 22% (95% CI, 7%-34%) in women. Half of the adenomas were located proximal to the splenic flexure. Extracolonic cancer was diagnosed in 73 patients (18%).


CONCLUSIONS
Adenoma would appear to be the most important lesion preceding cancer formation in Lynch syndrome and removal of adenomas decreases the risk for colorectal cancer (CRC). The Finnish surveillance protocol of colonoscopies at 2- to 3-year intervals facilitates patient adherence but includes an essential risk for CRC up to 60 years of age, but without CRC-related mortality when the surveillance instructions are followed.
Mecklin
Jukka-Pekka
JP
Department of Surgery, Jyväskylä Central Hospital, Jyväskylä, Finland. jukka-pekka.mecklin@ksshp.fi
Aarnio
Markku
M
Läärä
Esa
E
Kairaluoma
Matti V
MV
Pylvänäinen
Kirsi
K
Peltomäki
Päivi
P
Aaltonen
Lauri A
LA
Järvinen
Heikki J
HJ
D000236:Adenoma / Q000175:diagnosis* / Q000235:genetics / Q000401:mortality / Q000473:pathology; D000328:Adult; D000367:Age Factors; D002277:Carcinoma / Q000175:diagnosis* / Q000235:genetics / Q000401:mortality / Q000473:pathology; D003113:Colonoscopy; D003123:Colorectal Neoplasms, Hereditary Nonpolyposis / Q000175:diagnosis* / Q000235:genetics / Q000401:mortality / Q000473:pathology; D018450:Disease Progression; D005260:Female; D005387:Finland / Q000453:epidemiology; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D053208:Kaplan-Meier Estimate; D008297:Male; D008403:Mass Screening / Q000379:methods*; D008875:Middle Aged; D009154:Mutation; D017410:Practice Guidelines as Topic; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012042:Registries; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors