Predictors for High Microsatellite Instability in Patients with Colorectal Cancer Fulfilling the Revised Bethesda Guidelines.
BACKGROUND
The revised Bethesda guidelines (rBG) are generally used for screening of Lynch syndrome, and few researchers have investigated the associations between microsatellite instability (MSI) status and each item of the rBG.


PATIENTS AND METHODS
This retrospective study included patients with colorectal cancer who were classified into those fulfilling the rBG (Bethesda group) and those not (control group). The breakdown of each item in the rBG and predictors of high MSI (MSI-H) were determined in the Bethesda group.


RESULTS
Of 809 consecutive patients, 161 (19.9%) were found to fulfil the rBG criteria. As a predictor of MSI-H, items 2 or 5 of the rBG showed a sensitivity of 93.3%. Item 5 and right-sided tumour location were independent predictors of MSI-H in patients fulfilling the rBG (odds ratio(OR)=4.49 and 25.1; p=0.0260 and <0.0001, respectively).


CONCLUSION
Item 5 of the rBG and right-sided tumour location are significant predictors of MSI-H.
['Arakawa|Keiichi|K|', 'Hata|Keisuke|K|', 'Kawai|Kazushige|K|', 'Tanaka|Toshiaki|T|', 'Nishikawa|Takeshi|T|', 'Sasaki|Kazuhito|K|', 'Shuno|Yasutaka|Y|', 'Kaneko|Manabu|M|', 'Hiyoshi|Masaya|M|', 'Emoto|Shigenobu|S|', 'Murono|Koji|K|', 'Nozawa|Hiroaki|H|']
D000328:Adult D000368:Aged D000369:Aged, 80 and over D003123:Colorectal Neoplasms, Hereditary Nonpolyposis D005260:Female D005820:Genetic Testing D017408:Guidelines as Topic D006801:Humans D007564:Japan D008297:Male D053842:Microsatellite Instability D018895:Microsatellite Repeats D008875:Middle Aged D012189:Retrospective Studies
Colorectal cancer Bethesda guidelines Lynch syndrome