Monitoring of endometrial K-ras mutation in tamoxifen-treated patients with breast cancer.
BACKGROUND
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.
Tsujioka
Hiroshi
H
Department of Obstetrics and Gynecology, Faculty of Medicine, Fukuoka University, Nanakuma, Jonan-ku, Fukuoka, Japan. tsujioka@fukuoka-u.ac.jp
Hachisuga
Toru
T
Fukuoka
Miyoko
M
Ueda
Taeko
T
Miyahara
Daisuke
D
Horiuchi
Shinji
S
Shirota
Kyoko
K
Yoshizato
Toshiyuki
T
Emoto
Makoto
M
Miyamoto
Shingo
S
Kawarabayashi
Tatsuhiko
T
D000328:Adult; D000368:Aged; D018931:Antineoplastic Agents, Hormonal / Q000009:adverse effects / Q000627:therapeutic use; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000235:genetics / Q000473:pathology; D002277:Carcinoma / Q000188:drug therapy* / Q000235:genetics / Q000473:pathology; D004252:DNA Mutational Analysis; D016889:Endometrial Neoplasms / Q000139:chemically induced / Q000453:epidemiology / Q000235:genetics / Q000473:pathology; D004717:Endometrium / Q000378:metabolism* / Q000473:pathology; D005260:Female; D005787:Gene Frequency; D011905:Genes, ras; D006801:Humans; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000379:methods; D009154:Mutation / Q000502:physiology; D016609:Neoplasms, Second Primary / Q000453:epidemiology / Q000235:genetics / Q000473:pathology; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism; D016283:Proto-Oncogene Proteins p21(ras); D012189:Retrospective Studies; D013629:Tamoxifen / Q000009:adverse effects / Q000627:therapeutic use*; D028761:Withholding Treatment; D018631:ras Proteins / Q000235:genetics / Q000378:metabolism
D018931:Antineoplastic Agents, Hormonal; C117307:KRAS protein, human; D011518:Proto-Oncogene Proteins; D013629:Tamoxifen; D016283:Proto-Oncogene Proteins p21(ras); D018631:ras Proteins