Objective: Elucidation of clonal origin of synchronous endometrial and ovarian cancers (SEOs). Methods: We reviewed 852 patients who diagnosed endometrial and/or ovarian cancer. Forty-five (5.3%) patients were diagnosed as SEOs. We evaluated blood and tissue samples from 17 patients. We analyzed the clonal origins of 41 samples from 17 patients by gene sequencing, mismatch microsatellite instability (MSI) polymerase chain reaction assay and immunohistochemical (IHC) staining of 4 repair genes. Results: Sixteen of 17 patients had at least 2 or more trunk mutations shared between endometrial and ovarian cancer suggesting the identical clonal origins. The shared trunk mutation are frequently found in endometrial cancer of the uterus, suggesting the uterine primary. Four out of 17 (24%) SEOs had mismatch repair (MMR) protein deficiency and MSI-high (MSI-H) states. One case was an endometrial carcinoma with local loss of MSH6 protein expression by IHC staining, and the result of MSI analysis using the whole formalin-fixed, paraffin-embedded specimen was microsatellite stable. In contrast, ovarian tissue was deficient MMR and MSI-H in the whole specimen. This indicated that MMR protein deficiency could occur during the progression of disease. Conclusion Most SEOs are likely to be a single tumor with metastasis instead of double primaries, and their origin could be endometrium. In addition, SEOs have a high frequency of MMR gene abnormalities. These findings not only can support the notion of uterine primary, but also can help to expect the benefit for patients with SEOs by immuno-oncology treatment.

Introduction: We report two cases of surgery under general anesthesia during cancer pain management of patients with methadone therapy. Case 1: A 57-year-old woman was started on methadone for pain from right breast cancer with multiple bone metastases, and right mastectomy was performed during the course of chemotherapy. There was no exacerbation of cancer pain due to methadone withdrawal, although analgesics were used temporarily for wound pain. Case 2: A 76-year-old man was placed on methadone for pain from lung cancer. There was concern that lower limb paralysis would develop from a compression fracture of the lumbar spine that had occurred during the course of treatment. Therefore, decompression and fixation surgery was performed. Ketamine was used to control intraoperative pain exacerbation, and fentanyl was used by continuous injection for re-exacerbation of pain after the patient had awakened from anesthesia. Conclusion: Since methadone is available only by mouth in Japan and the equianalgesic ratio between methadone and other opioids has not been established, caution is needed for perioperative pain control while oral methadone cannot be administered. Thus, pain and palliative care specialists prescribing methadone are expected to play an active role in adequate perioperative pain control.