Search

Malignant PEComas are an extremely rare subtype of soft tissue sarcomas. Here, we report the case of a man presenting with a perirectal PEComa and liver metastasis. Since the tumor harbored a tumor mutational burden of 23/Mb and a programmed death-ligand 1 tumor positivity score of 50%, the patient was treated with pembrolizumab as a second line of systemic therapy, in combination with everolimus. This combined therapy led to a near-complete response of the primary tumor and a partial response of the metastasis. Radioembolization of the liver metastasis was performed due to isolated liver progression, and the pelvic tumor was treated by radiotherapy because of pelvic symptoms. The disease is still stable after 13 months of pembrolizumab plus everolimus and multimodal treatment. This case shows that malignant PEComas can display molecular features associated with sensitivity to checkpoint inhibitors. The use of checkpoint inhibitors may be a relevant therapeutic strategy in these patients. It is also the first report on selective internal radiation therapy in PEComas. Plain language summary: A case of a patient with metastatic PEComa of the rectum, a very rare tumor type, treated by immunotherapy in combination with local treatments This article reports the case of a patient presenting with a very rare tumor type called "PEComa". The tumor originated from the rectum and had disseminated to the liver. Since this tumor is very rare, there is a lack of knowledge on which treatments to use, and every case reporting the use of new treatments in PEComas is helpful. Here, the tumor displayed molecular alterations that suggested that it would respond to immunotherapy, such as a high number of mutations. Therefore, the patient was treated with an immunotherapy called pembrolizumab, in combination with another medication (everolimus). The rectal tumor nearly disappeared under treatment, and the liver metastasis decreased in size. The patient had radiotherapy of the rectum because of rectal bleeding. For the liver metastasis we used another technique called radioembolization, that consists in delivering radioactive compounds directly in the metastasis through the bloodstream. Now, he has received immunotherapy for 13 months and the disease is still under control. This case shows that immunotherapy can be a good treatment option in PEComas. It is also the first time that a medical team reports the using radioembolization to treat a PEComa. [ABSTRACT FROM AUTHOR]

Résumé: Les adénocarcinomes de l'intestin grêle (AIG) sont des tumeurs rares mais leur incidence est en augmentation. La localisation primitive la plus fréquente est le duodénum. Même si les AIG sont le plus souvent sporadiques, certaines maladies sont des facteurs de risque comme la maladie de Crohn, et il existe des prédispositions génétiques à ce cancer comme le syndrome de Lynch et la polypose adénomateuse familiale. Le phénotypage moléculaire révèle des différences entre les AIG et les adénocarcinomes colorectaux. Le diagnostic précoce des AIG reste difficile malgré des progrès de l'endoscopie et des examens radiologiques. Après résection chirurgicale R0, un envahissement ganglionnaire est le principal facteur pronostique. Un essai randomisé international (essai BALLAD) est en cours pour évaluer l'intérêt d'une chimiothérapie adjuvante. Pour les maladies métastatiques, des études rétrospectives ont suggéré que les schémas de chimiothérapie à base de sels de platines étaient les plus efficaces mais aucun progrès notable n'a été réalisé depuis des décennies. Un effet spectaculaire de l'immunothérapie est rapporté en cas de tumeur avec un défaut de réparation de l'ADN. D'autres thérapies ciblées pourraient être efficaces en cas d'altérations moléculaires spécifiques. Small bowel adenocarcinomas (SBA) are rare tumors, but their incidence is increasing. The commonest primary location is the duodenum. Even though SBA are more often sporadic, some diseases are risk factors, such as Crohn's disease and some genetic predispositions to cancer as Lynch syndrome or familial adenomatous polyposis. Molecular phenotyping revealed some differences between SBA and colorectal cancer. Early diagnosis of small bowel adenocarcinoma remains difficult, despite significant radiological and endoscopic progresses. After R0 surgical resection, the main prognostic factor is lymph node invasion. An international randomized trial (BALLAD study) is ongoing to evaluate the benefit of adjuvant chemotherapy. For metastatic disease, retrospective studies suggest that platinum-based chemotherapy is the most effective treatment, but no significant improvement has been achieved since decades. A dramatic effect has been reported with immunotherapy in tumor with deficient mismatch repair system. Phase II studies are ongoing to evaluate targeted therapy in metastatic SBA. Other targeted therapies may be efficient in case of specific molecular alterations. [ABSTRACT FROM AUTHOR]