Synopsis: Objective: To examine adverse events related to different PARP inhibitor maintenance therapies in patients with advanced or recurrent ovarian cancer.Key words: ovary, retrospective observational study, PARP inhibitors, maintenance therapy, adverse event

Methods: This study targeted patients treated with PARP inhibitor maintenance therapies from 2019 to 2022. The therapies included olaparib (O group), niraparib (N group), and a combination of olaparib and bevacizumab (P group). We evaluated the rates of treatment interruption, dose reduction, and discontinuation, as well as the incidence of grade 3 or higher hematotoxicity.

Results: A total of 319 cases were examined. The rates (%) of interruption, dose reduction, and discontinuation for initial treatment in the O, N, and P groups were 60/72/69 (NS: not significant), 42/47/51 (NS), and 6/7/2 (NS) respectively. Grade 3 or higher adverse events were anemia 15/12/12 (NS) and neutropenia 15/16/10 (NS). Thrombocytopenia was 0/10/0 (p＝0.009), showing a significant difference between the three groups.

Conclusion: No significant difference was found in the rates of interruption, dose reduction, or discontinuation among the three groups. A significant difference was observed in grade 3 or higher thrombocytopenia. All PARP inhibitor maintenance therapies were considered to be safely administered.

Synopsis: Platinum drugs are key drugs for gynecological malignancies, but as the frequency of administration increases, hypersensitivity, especially to carboplatin (CBDCA), increases. In the present study, we compared the safety of CBDCA and CDDP desensitization therapy in patients with a history of hypersensitivity to CBDCA. All 14 patients with a history of CBDCA hypersensitivity were treated with 38 CBDCA desensitization sessions and 30 CDDP desensitization session, with completion rates of 86.8%and 100%, respectively. No recurrent hypersensitivity was observed after CDDP desensitization therapy. In gynecologic malignancies, limitation of platinum dosing due to CBDCA hypersensitivity may lead to markedly worse prognosis. Although safety precautions must be taken, the pharmacologic mechanism of action suggests that CDDP desensitization therapy may be useful in the treatment of CBDCA hypersensitivity.Key words: cisplatin, carboplatin, desensitization, hypersensitivity

Synopsis: Mesonephric-like adenocarcinoma (MLA) is a rare tumor of the uterine corpus and ovaries. It is difficult to obtain a true diagnosis because MLAs have several configurations. We report a case of MLA of the uterine corpus, implying divergence from endometrioid adenocarcinoma, including morphological and immunohistochemical considerations.Key words: uterine corpus, mesonephric-like adenocarcinoma, case report

Case: A 71-year-old woman (gravida 6, para 1) presented with heavy genital bleeding and was admitted to our hospital. Examination revealed a suspected carcinoma measuring 45 mm × 35 mm in the uterine cavity. Endometrial cytology revealed an endometrioid carcinoma. She was diagnosed with stage IA uterine corpus carcinoma (Stage IA) and underwent a total laparoscopic hysterectomy and bilateral salpingo-oophorectomy. A pathological examination revealed several atypical cell configurations. Staining for TTF1, GATA3, and CD10 was positive; staining for ER was focally positive; and staining for PR was negative. The partial area implies that the MLA originated from endometrioid carcinoma because the MLA and endometrioid carcinoma were consecutive.

Conclusion: MLA is a rare tumor, and its origin remains unknown. The accumulation of more information and further reports is required.

Synopsis: Lazarus-type response refers to drastic and significant improvement with immunotherapy in advanced cancer patients with poor general condition. We report a case of Lazarus-type response to pembrolizumab in endometrial cancer.

A 43-year-old nulliparous woman with no relevant past medical history was referred to our hospital due to hypermenorrhea and dysmenorrhea. Imaging analyses revealed a tumor of the corpus uteri extending to the cervix with metastases in the pelvic and paraaortic lymph nodes above the renal vein. Tumor biopsy revealed grade 3 endometrioid carcinoma, and a diagnosis of FIGO clinical stage IIIC2 was made.

The tumor progressed rapidly after four courses of carboplatin and paclitaxel chemotherapy. Radical hysterectomy and ileal conduit diversion were performed for tumor reduction. The residual tumor continued to progress during 2nd line chemotherapy, and she was classified as PS 4 because of uncontrollable cancer pain with opioid administration. As she wished to continue treatment, pembrolizumab was administered based on genetic analysis of the tumor indicating microsatellite instability-high.

The patient showed drastic improvement after three courses of pembrolizumab. After treatment with 20 cycles of pembrolizumab for 2 years, computed tomography and analyses of tumor markers indicated no tumor progression and she maintained PS 0.

Synopsis: Carcinosarcoma is a rare malignant tumor comprising both carcinoma and sarcoma components. We describe a case in which serous tubal intraepithelial carcinoma (STIC) occurred along with omental carcinosarcoma. We ascertained that the STIC had become the primary lesion and metastasized to the omentum. The patient was a carrier of the BRCA2 pathological variant. After adjuvant chemotherapy with docetaxel and carboplatin, maintenance therapy with olaparib was administered. The patient has continued with the maintenance therapy with olaparib for 24 months, and has not had a recurrence. Olaparib may be effective in the treatment of BRCA pathological variant-positive carcinosarcoma.

Synopsis: Malignant struma ovarii (MSO) is a rarely detected tumor, due to which its standard treatment has not been established.Key words: Malignant struma ovarii, intraperitoneal dissemination, peritoneal strumosis, radioactive iodine treatment, recurrence

We encountered a 39-year-old patient with MSO and intraperitoneal dissemination. At the age of 34 years, a histological examination of the left ovarian cyst during cesarean section revealed a struma ovarii. She was referred to our hospital because transvaginal ultrasound revealed a solid component within the ovarian cyst. Magnetic resonance imaging revealed a polycystic tumor with solid component within ovary. Blood test results demonstrated an elevated thyroglobulin level of 878 ng/mL; therefore, we suspected MSO. We performed a simple hysterectomy, bilateral salpingo-oophorectomy, omentectomy, and disseminated lesion resection. Surgery was performed without residual tumor. Histopathology revealed struma ovarii in the left ovary and papillary thyroid carcinoma in the right ovary, and struma ovarii in the omentum, surface of rectum, sigmoid mesentery, and ileal mesentery. After postoperative 1 year and 5 months, the patient was diagnosed with recurrent MSO using radioiodine scintigraphy and underwent thyroidectomy and radioactive iodine treatment. The recurrent tumor remarkably shrank after the treatment in computed tomography.

This study suggests that radioactive iodine may be useful in treating recurrent MSO and peritoneal strumosis.

Synopsis: In the treatment of cervical cancer, there are many opportunities to choose radiotherapy as primary treatment or adjuvant therapy to surgery. Therefore, when cervical cancer recurs, whether the recurrence site is inside or outside of the irradiation field is important for treatment selection and prognosis. Recurrence within the radiation field cannot be re-irradiated to the same site realistically. Therefore, re-irradiation for recurrence within the irradiation field is limited due to complications, and other effective treatments are limited, resulting in short survival times. Chemotherapy and molecular-targeted drugs are the main treatments for recurrence. As a limited surgical therapy, although pelvic exenteration is guaranteed to be curative to some extent, it is only applicable to very limited cases in terms of invasiveness to the patient and loss of function. We performed a surgical intervention aimed at excision of the tumor for lymph node recurrence within the radiation field of cervical cancer. We report 5 cases in which the invasiveness to the patient was reduced and good results were obtained.Key words: uterine cervix, cytoreduction, cervical cancer, previously irradiated field, recurrence