PT - JOURNAL ARTICLE AU - Tsujioka, Hiroshi AU - Hachisuga, Toru AU - Fukuoka, Miyoko AU - Ueda, Taeko AU - Miyahara, Daisuke AU - Horiuchi, Shinji AU - Shirota, Kyoko AU - Yoshizato, Toshiyuki AU - Emoto, Makoto AU - Miyamoto, Shingo AU - Kawarabayashi, Tatsuhiko TI - Monitoring of Endometrial K-<em>ras</em> Mutation in Tamoxifen-Treated Patients With Breast Cancer AID - 10.1111/IGC.0b013e3181a8b0aa DP - 2009 Jul 01 TA - International Journal of Gynecologic Cancer PG - 1052--1056 VI - 19 IP - 6 4099 - http://ijgc.bmj.com/content/19/6/1052.short 4100 - http://ijgc.bmj.com/content/19/6/1052.full SO - Int J Gynecol Cancer2009 Jul 01; 19 AB - Introduction: A high incidence of endometrial K-ras mutations has been reported in tamoxifen (TAM)-treated patients with breast cancer. We examined the changes in the frequency of the endometrial K-ras mutations after the cessation of TAM treatment.Methods: DNA was extracted from fresh cytological or polypectomy samples of the endometrium in 28 patients who had undergone TAM treatment of breast cancer. Mutations were detected by an enriched polymerase chain reaction-enzyme-linked minisequence assay (Sumitomo Metal Industry, Inc, Tokyo, Japan). K-ras codon 12 mutations were monitored in these 28 patients.Results: An initial examination detected endometrial K-ras mutations in 13 of the 28 patients. However, repeated examinations performed after cessation of TAM treatment did not detect endometrial K-ras mutations in any of these 13 patients. No endometrial K-ras mutation has been detected in the repeated examinations performed for these patients for more than 2 years since the cessation of TAM treatment. In addition, the 15 patients who did not have endometrial K-ras mutations in the initial examination did not demonstrate them in repeat examinations.Conclusions: The cessation of TAM treatment may reduce the risk of developing endometrial cancers through K-ras mutations.