title: Redistribution of resistance and sensitivity to platinum during the observation period following treatment of epithelial ovarian cancer.
abstract: The standard postoperative chemotherapy for epithelial ovarian cancer is a combination therapy including platinum and taxanes. The aim this study was to investigate the degree of platinum sensitivity in patients with relapsed epithelial ovarian cancer according to the treatment-free interval (TFI) and the histological tumor type. The medical records of 405 patients diagnosed with stage III/IV ovarian cancer, including 107 patients who relapsed after attaining a clinical complete response with first-line treatment, were retrospectively reviewed. The degree of platinum sensitivity was assessed by comparing the progression-free survival (PFS) following the second-line treatment. In patients with serous/endometrioid adenocarcinoma who were treated with platinum following relapse, there were significant differences in the PFS between the following groups of patients: those who relapsed within 6 months and those who relapsed between 6 and 12 months; those who relapsed between 6 and 12 months and those who relapsed between 12 and 18 months; and those who relapsed between 12 and 18 months and those who relapsed after 18 months. By contrast, in patients with clear cell/mucinous adenocarcinoma who were treated with platinum following a relapse, there were no significant differences in the PFS between patients who relapsed within 6 months and those who relapsed between 6 and 12 months, while there were significant differences in the PFS between those who relapsed between 6 and 12 months and those who relapsed after 12 months. With regard to the patients who relapsed after 12 months, the PFS of those with clear cell/mucinous adenocarcinoma was significantly shorter compared with the PFS of those with serous/endometrioid adenocarcinoma. Therefore, we considered it justified to classify patients with clear cell/mucinous adenocarcinoma who relapsed within 12 months as platinum-resistant and those who relapsed after 12 months as platinum-sensitive.
authors.affiliation: Department of Obstetrics and Gynecology, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori 0368562, Japan.
authors.forename: Yoshihito
authors.initials: Y
authors.lastname: Yokoyama
authors.affiliation: Department of Obstetrics and Gynecology, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori 0368562, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Futagami
authors.affiliation: Department of Pathologic Analysis, Hirosaki University Graduate School of Health Sciences, Hirosaki, Aomori 0368564, Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Watanabe
authors.affiliation: Department of Obstetrics and Gynecology, Akita University School of Medicine, Akita, Akita 0108543, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Sato
authors.affiliation: Department of Obstetrics and Gynecology, Akita University School of Medicine, Akita, Akita 0108543, Japan.
authors.forename: Yukihiro
authors.initials: Y
authors.lastname: Terada
authors.affiliation: Department of Obstetrics and Gynecology, Iwate Medical University School of Medicine, Morioka, Iwate 0208505, Japan.
authors.forename: Fumiharu
authors.initials: F
authors.lastname: Miura
authors.affiliation: Department of Obstetrics and Gynecology, Iwate Medical University School of Medicine, Morioka, Iwate 0208505, Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Sugiyama
authors.affiliation: Department of Obstetrics and Gynecology, Tohoku University School of Medicine, Sendai, Miyagi 9808574, Japan.
authors.forename: Tadao
authors.initials: T
authors.lastname: Takano
authors.affiliation: Department of Obstetrics and Gynecology, Tohoku University School of Medicine, Sendai, Miyagi 9808574, Japan.
authors.forename: Nobuo
authors.initials: N
authors.lastname: Yaegashi
authors.affiliation: Department of Obstetrics and Gynecology, Yamagata University School of Medicine, Yamagata, Yamagata 9909585, Japan.
authors.forename: Takanobu
authors.initials: T
authors.lastname: Kojimahara
authors.affiliation: Department of Obstetrics and Gynecology, Yamagata University School of Medicine, Yamagata, Yamagata 9909585, Japan.
authors.forename: Hirohisa
authors.initials: H
authors.lastname: Kurachi
authors.affiliation: Department of Obstetrics and Gynecology, Fukushima Medical University, Fukushima, Fukushima 9601295, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nishiyama
authors.affiliation: Department of Obstetrics and Gynecology, Fukushima Medical University, Fukushima, Fukushima 9601295, Japan.
authors.forename: Keiya
authors.initials: K
authors.lastname: Fujimori
authors.affiliation: Department of Gynecology, Miyagi Cancer Center, Natori, Miyagi 9811293, Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Tase
authors.affiliation: Department of Obstetrics and Gynecology, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori 0368562, Japan.
authors.forename: Hideki
authors.initials: H
authors.lastname: Mizunuma
keywords: histological type; platinum sensitivity; progression-free interval; relapsed epithelial ovarian cancer; treatment-free interval