Aims: We performed an age-matched case–control study to compare the clinical and pathology outcomes between histologically diagnosed primary malignant mixed műllerian tumour (MMMT) of the uterus and endometrial carcinoma.
Methods: Thirty-two women were treated for primary MMMT at seven tertiary medical centres in Korea from 2000 to 2006. For each woman with MMMT, four women with endometrioid and two with non-endometrioid endometrial carcinoma were selected as age-matched controls for analysis. Medical records were retrospectively reviewed to obtain outcome data.
Results: The incidence of MMMT was 2.57% (32/1244). In comparison with women with endometrioid endometrial cancer, those with MMMT were characterised by large tumour size, higher incidence of adnexal involvement and lymph node metastases, leading to advanced disease stage. Despite the frequent use of adjuvant treatment, the 5-year survival rate of women with MMMT was significantly poorer than those with endometrioid endometrial cancer. However, women with MMMT were not significantly different from those with non-endometrioid endometrial cancer in terms of important pathologic variables, apart from larger tumour size. In addition, the 5-year survival rate of women MMMT was poorer than that those with non-endometrioid endometrial cancer, but the difference was not statistically significant.
Conclusions: Malignant mixed műllerian tumour is characterised by a high incidence of lymph node metastases and advanced stage at diagnosis, leading to poorer overall survival than other subtypes of endometrial carcinoma. Clinical trials for MMMT are critical for improving treatment strategies.