Significance of the O6-methylguanine-DNA methyltransferase and glutathione S-transferase activity in the sera of patients with malignant and benign ovarian tumors.

OBJECTIVE: To demonstrate O6-methylguanine-DNA methyltransferase (MGMT) and glutathione S-transferase (GST) activities by analyzing the sera separately obtained from patients with malignant ovarian tumors, benign ovarian tumors, and healthy individuals. STUDY DESIGN: Fourty-nine patients with ovarian cancer, nine patients with benign tumors, and 22 healthy women were included in this study. Blood samples were obtained from all the subjects in the malignant-tumor, benign-tumor, and control groups. Patients with malignant tumors underwent second and third phlebotomies one week following the surgery and after the chemotherapy regimen, respectively. MGMT, GST, and protein levels were measured for each serum sample. GST activity of the samples was measured by the method of Habig et al. using l-chloro-2-4 dinitrobenzene (CDNB) as substrate. MGMT activity was measured by the transfer of radio labelled methyl groups from a prepared MG-DNA substrate to the enzyme fraction of serum. Protein concentration was measured by biuret method. RESULTS: Our work demonstrated that untreated patients with malignant ovarian tumors revealed significantly greater MGMT and GST activities in their sera than did both healthy individuals and patients with benign ovarian tumors, while no significant difference was found between the healthy group and the patients with benign ovarian tumors with respect to their sera MGMT and GST activities. GST activity following chemotherapy was significantly lower than the postoperative values preceding chemotherapy. A relationship between sera MGMT and GST activities, tumor histology and pathology was not found in this study. CONCLUSION: Our work suggests the fact that detection of sera MGMT and GST activities is important in diagnostic and therapeutic approaches during the course of ovarian cancer.

Endometrial mixed Müllerian tumor with heterologous elements following tamoxifen therapy for breast cancer: a case report and literature review.

CASE: A 67-year-old multiparous woman received 20mg tamoxifen daily for four years after surgical treatment of breast cancer. She presented with vaginal bleeding. Uterine curettage revealed a uterine MMT with heterologous elements. She was treated surgically with adjuvant radiotherapy. Tumor cells were found to be estrogen receptor negative and progesterone receptor positive. Uterine MMT may be linked to long term use of tamoxifen. A mechanism in developing MMT other than estrogen receptor pathway may be possible.

Prevalence of endometriosis in malignant epithelial ovary tumours.

OBJECTIVE: To determine the prevalence of ovarian endometriosis in malignant epithelial ovarian tumours. STUDY DESIGN: A retrospective analysis of 160 malignant and 23 borderline ovarian tumours during the period 1995-2001. RESULTS: Fourteen (7.7%) of the tumours contained endometriosis. This affected 22% of the endometrioid and 10.8% of the mixed adenocarcinomas. The mean age of the ovarian endometriosis patients was 43+/-13 range 26-70 years. The incidence in borderline tumours 13% (3/23) was higher than that in ovarian cancer 6.9% (11/160) (P>0.05). Eight (57%) of cases were classified as atypical and six (43%) as typical endometriosis. Nine cases were FIGO (International Federation of Gynaecology and Obstetrics) stage I and 5 stage III. CONCLUSIONS: Both malignant and borderline ovarian tumours are associated with ovarian endometriosis. In addition, atypical endometriosis was found associated with endometrioid and mixed epithelial ovarian tumours.

The role of secondary cytoreductive surgery for recurrent ovarian cancer.

OBJECTIVE: The aim of this study was to assess the survival benefit of salvage surgical cytoreduction in patients with recurrent ovarian cancer and compare the surgical outcome with salvage chemotherapy alone. METHODS: Seventy-five patients with recurrent ovarian cancer were reviewed for possible benefits of salvage therapy. Forty-four had salvage surgery and 31 patients had salvage chemotherapy alone for the treatment of gross recurrent disease. All patients had been clinically free of disease more than 6 months from the completion of primary treatment. RESULTS: A macroscopically complete surgical cytoreduction was obtained in 34 (77%) patients. Survival was significantly longer in patients who had salvage surgery compared to those who had salvage chemotherapy alone (P = 0.03). Moreover, survival was significantly longer in patients who were completely cytoreduced compared to those who were not completely cytoreduced and those who were not operated (P = 0.007 and P = 0.005, respectively). CONCLUSIONS: Macroscopically complete surgical cytoreduction significantly improves further survival of recurrent ovarian cancer patients. However, we remain in need to evaluate the debulkability of tumor before surgery to maximize the survival benefit and minimize the number of ineffective surgeries.