Synopsis: Pembrolizumab is an immune checkpoint inhibitor that uses anti-programmed cell death 1 antibody, and its indications have been expanding in the field of gynecology in recent years. Endometrial cancer cases that have microsatellite instability (MSI) are often high in tumor mutational burden (TMB-H), and microsatellite stable (MSS) cases are very rarely TMB-H. Herein, we report a case where pembrolizumab was highly effective against MSS and TMB-H.Key words: endometrial carcinoma, MS-Stable, TMB-High, pembrolizumab, cancer multi-gene panel testing

Pembrolizumab has a higher success rate with TMB-H compared to low TMB even in MSS cases, thus knowing the TMB status in addition to MSI is clinically important for predicting treatment efficacy.

Combination therapy with pembrolizumab and lenvatinib mesylate without companion diagnostics is covered by insurance for uterine body cancer, and opportunities to investigate MSI/TMB are expected to decrease. However, determining the MSI/TMB status through MSI testing or cancer gene panel testing is clinically useful.

Synopsis: Recurrence of carcinoma in situ (CIS) of uterine cervix in the form of invasive cancer is extremely rare. We report a case of repeated recurrence after total hysterectomy for CIS. The patient underwent cervical conization for CIS at 48-years-old. At 57-years-old, the patient had a recurrence of CIS and underwent extended hysterectomy. At 59-years-old, the patient had an abnormal vaginal stump cytological diagnosis and the histological diagnosis was CIS. The patient was referred to our hospital because a recurrent tumor was found on the vaginal stump. A recurrent lesion was found on the vaginal wall and a 2 cm-sized tumor was palpated on the left side of the vaginal stump. The vaginal wall histology showed SCC and the lesion disappeared after CCRT. 9 months after, a recurrence was found in the vaginal stump, and radiotherapy was performed again, but 4 months later, a recurrence in the vaginal stump and metastasis in the external iliac lymph node were found and chemotherapy was performed. 3 months later, a recurrence in the external iliac and obturator lymph node was found, and the patient underwent resection of the recurrent tumor and pelvic lymph node dissection. 15 months after surgery, the patient underwent resection of recurrent tumor and vagina and colostomy.17 months after surgery, para-aortic lymph node metastasis was detected and radiotherapy was administered. She has had recurrences and repeated chemotherapy since then and is still undergoing chemotherapy.