Lynch Syndrome and Gynecologic Tumors: Incidence, Prophylaxis, and Management of Patients with Cancer

SIMPLE SUMMARY: Lynch syndrome (LS) is a genetic condition predisposing to a variety of tumors, including endometrial (EC) and ovarian cancers (OC), with cancer lifetime risk depending on the specific LS-mutation involved. Universal Screening is the standard for LS detection. Prophylactic surgery is a risk-reducing option that may be considered, and the age at hysterectomy and recommendation for bilateral oophorectomy depend on the mutated variant and offspring desire. Besides surgery, chemoprevention via contraceptives combination or progestin-alone is a viable option, and vaccination with tumor-specific antigens has shown promising results in mouse models. LS patients requiring adjuvant radiotherapy or systemic treatment for EC or OC are managed according to international standard of care. However, when conservative treatment for EC is considered, worse oncologic and obstetric outcomes are reported for patients with mismatch repair deficiency or LS. Moreover, LS-related tumors are characterized by a highly immunogenic tumor-environment that can be targeted by specific immune checkpoint inhibitors. ABSTRACT: This review provides a comprehensive update on recent evidence regarding gynecologic tumors associated with Lynch Syndrome (LS). Endometrial cancer (EC) and ovarian cancer (OC) are the first and second most common gynecologic malignancies in developed countries, respectively, and LS is estimated to be the hereditary cause in 3% of both EC and OC. Despite the increasing evidence on LS-related tumors, few studies have analyzed the outcomes of LS-related EC and OC stratified by mutational variant. This review aims to provide a comprehensive overview of the literature and comparison between updated international guidelines, to help outline a shared pathway for the diagnosis, prevention, and management of LS. Through the widespread adoption of the immunohistochemistry-based Universal Screening, LS diagnosis and identification of mutational variants could be standardized and recognized by international guidelines as a feasible, reproducible, and cost-effective method. Furthermore, the development of a better understanding of LS and its mutational variants will support our ability to better tailor EC and OC management in terms of prophylactic surgery and systemic treatment in the light of the promising results shown by immunotherapy.