Malignant transformation arising from mature cystic teratoma of the ovary: a retrospective study of 20 cases.
OBJECTIVE
Mature cystic teratoma (MCT) of the ovary rarely undergoes malignant transformation (MT). Malignant transformation carries a significantly worse prognosis than epithelial ovarian cancer, regardless of whether postoperative chemotherapy or radiotherapy is applied. The rarity of this tumor has posed a significant challenge to developing standardized postoperative management protocols. The aim of this study was to review our experience with MT and to describe our current treatment practices.


METHODS
A retrospective chart review of these patients was performed that identified 20 women treated for MT of MCT at our centers between 1988 and 2008.


RESULTS
The median age was 52.5 (range, 29-77) years. Fifteen patients had squamous cell carcinoma (SCC), and 5 patients had other histological subtypes. The International Federation of Gynecology and Obstetrics stage distribution was as follows: 11 were stage I, 4 were stage II, 4 were stage III, and 1 was stage IV. All patients underwent an initial laparotomy. Eleven patients received adjuvant treatment: 8 were treated with chemotherapy, 2 with concurrent chemoradiation therapy, and 1 with radiation therapy. Platinum-based chemotherapy was the first-line regimen. The overall 1-year survival rate was 70%. Significant correlations between overall survival and age, stage, and residual tumor were presented (P = 0.044, P = 0.0107, P < 0.0001, respectively). Eight patients with advanced stage died of their disease. Four patients, however, were treated with adjuvant chemotherapy or concurrent chemoradiation therapy and survived more than 1 year. One stage III patient had a disease-free interval of 2 years. Two cases of SCC treated with combination platinum/taxane chemotherapy temporarily responded. In the other 2 cases of SCC, concurrent chemoradiation therapy with nedaplatin also resulted in tumor regression.


CONCLUSIONS
The prognosis of MT is highly dependent on age, stage, and optimal cytoreduction. Adjuvant treatment has not been standardized, although our experience supports the use of combination platinum/taxane chemotherapy.
Department of Obstetrics and Gynecology, Tohoku University Graduate School of Medicine, 1-1 Seiryo machi, Aoba ku, Sendai 9808574, Japan. smichiko@m.tains.tohoku.ac.jp
Michiko
M
Sakuma
Takeo
T
Otsuki
Kosuke
K
Yoshinaga
Hiroki
H
Utsunomiya
Satoru
S
Nagase
Tadao
T
Takano
Hitoshi
H
Niikura
Kiyoshi
K
Ito
Keiko
K
Otomo
Toru
T
Tase
Yoh
Y
Watanabe
Nobuo
N
Yaegashi
D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents / Q000627:therapeutic use; D002294:Carcinoma, Squamous Cell / Q000473:pathology* / Q000628:therapy; D002471:Cell Transformation, Neoplastic; D005260:Female; D006801:Humans; D008875:Middle Aged; D010051:Ovarian Neoplasms / Q000473:pathology* / Q000628:therapy; D011379:Prognosis; D012189:Retrospective Studies; D013724:Teratoma / Q000473:pathology* / Q000628:therapy
D000970:Antineoplastic Agents