title: [Effect of chemotherapy in primary tumor of MSI-H colon cancer aged 50 years or younger].
abstract: Microsatellite instability( MSI) in colorectal carcinoma is reportedly associated with resistance to 5-fluorouracil-based chemotherapy. Moreover, colorectal cancer patients aged ≤ 50 years could potentially have Lynch syndrome. In the present study, we examined 11 colorectal cancer patients with unresectable Stage IV disease who underwent resection of the primary tumor between January 2006 and December 2012. The relationship between the MSI status and the efficacy of first- line oxaliplatin-based chemotherapy was retrospectively examined. The MSI status included MSI-H in 1 patient, MSS-L in 2 patients, and MSS in 8 patients. The MSI-H in 1 patient was associated with familial adenomatous polyposis. Following chemotherapy, among 8 MSS patients, 3 showed stable disease (SD) and 1 showed partial response (PR). Moreover 2 MSH-L patients and 1 MSI-H patient showed progressive disease (PD) after chemotherapy. However, additional data collection is required to determine the effect of oxaliplatin-based chemotherapy for MSS-H or MSS-L colorectal patients aged ≤ 59 years.
authors.affiliation: Dept. of Digestive Tract and General Surgery, Saitama Medical Center, Saitama Medical University.
authors.forename: Noriyasu
authors.initials: N
authors.lastname: Chika
authors.forename: Keiichiro
authors.initials: K
authors.lastname: Ishibashi
authors.forename: Kensuke
authors.initials: K
authors.lastname: Kumamoto
authors.forename: Norimichi
authors.initials: N
authors.lastname: Okada
authors.forename: Okihide
authors.initials: O
authors.lastname: Suzuki
authors.forename: Satoshi
authors.initials: S
authors.lastname: Hatano
authors.forename: Kunihiko
authors.initials: K
authors.lastname: Amano
authors.forename: Takeaki
authors.initials: T
authors.lastname: Matsuzawa
authors.forename: Kouki
authors.initials: K
authors.lastname: Kuwabara
authors.forename: Jun
authors.initials: J
authors.lastname: Sobajima
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Kumagai
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Baba
authors.forename: Norihiro
authors.initials: N
authors.lastname: Haga
authors.forename: Takeo
authors.initials: T
authors.lastname: Iwama
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Ishida
authors.forename: Shigehisa
authors.initials: S
authors.lastname: Inokuma
authors.forename: Ikuya
authors.initials: I
authors.lastname: Takeuchi
mesh_terms: D000328:Adult; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D003110:Colonic Neoplasms / Q000188:drug therapy* / Q000235:genetics; D019175:DNA Methylation; D005260:Female; D006801:Humans; D008297:Male; D053842:Microsatellite Instability; D008875:Middle Aged; D011379:Prognosis