Oncologic manifestations of Klinefelter syndrome

The role and impact of viruses on cancer development

This review focuses on three major aspects of oncoviruses' role in cancer development. To begin, we discuss their geographic distribution, revealing that seven oncoviruses cause 20% of all human cancers worldwide. Second, we investigate the primary carcinogenic mechanisms, looking at how these oncogenic viruses can induce cellular transformation, angiogenesis, and local and systemic inflammation. Finally, we investigate the possibility of SARS-CoV-2 infection reactivating latent oncoviruses, which could increase the risk of further disease. The development of oncovirus vaccines holds great promise for reducing cancer burden. Many unanswered questions about the host and environmental cofactors that contribute to cancer development and prevention remain, which ongoing research is attempting to address.

Mediastinal Germ-cell Tumors Relapse in a Male With Klinefelter Syndrome. Is Longer Surveillance Needed?

Germ cell tumors (GCTs) are a heterogeneous group of pediatric cancers. In up to one-third of male patients, a primary mediastinal location is associated with the presence of Klinefelter syndrome (KS). We describe a case of mediastinal GCT in a patient, with unacknowledged KS, that presented a relapse 7 years from diagnosis, that is, 2 years after the end of the follow-up program usually recommended for patients with GCT. There are no recommendations for screening for KS in patients with mediastinal GCT and there are no specific guidelines for surveillance of GCT in KS patients. Our experience suggests that KS should be suspected in patients with mediastinal GCT, and a longer follow-up plan should be implemented when GCT occurs in patients with KS.

Genetic Disorders with Predisposition to Paediatric Haematopoietic Malignancies—A Review

The view of paediatric cancer as a genetic disease arises as genetic research develops. Germline mutations in cancer predisposition genes have been identified in about 10% of children. Paediatric cancers are characterized by heterogeneity in the types of genetic alterations that drive tumourigenesis. Interactions between germline and somatic mutations are a key determinant of cancer development. In 40% of patients, the family history does not predict the presence of inherited cancer predisposition syndromes and many cases go undetected. Paediatricians should be aware of specific symptoms, which highlight the need of evaluation for cancer syndromes. The quickest possible identification of such syndromes is of key importance, due to the possibility of early detection of neoplasms, followed by presymptomatic genetic testing of relatives, implementation of appropriate clinical procedures (e.g., avoiding radiotherapy), prophylactic surgical resection of organs at risk, or searching for donors of hematopoietic stem cells. Targetable driver mutations and corresponding signalling pathways provide a novel precision medicine strategy.Therefore, there is a need for multi-disciplinary cooperation between a paediatrician, an oncologist, a geneticist, and a psychologist during the surveillance of families with an increased cancer risk. This review aimed to emphasize the role of cancer-predisposition gene diagnostics in the genetic surveillance and medical care in paediatric oncology.

Genetic Landscape of Male Breast Cancer

Male breast cancer (MBC) is now considered molecularly different from female breast cancer (FBC). Evidence from studies indicates that common genetic and epigenetic features of FBC are not shared with those diagnosed in men. Genetic predisposition is likely to play a significant role in the tumorigenesis of this rare disease. Inherited germline variants in BRCA1 and BRCA2 account for around 2% and 10% of MBC cases, respectively, and the lifetime risk of breast cancer for men harboring BRCA1 and BRCA2 mutations is 1.2% and 6.8%. As for FBC, pathogenic mutations in other breast cancer genes have also been recently associated with an increased risk of MBC, such as PALB2 and CHEK2 mutations. However, while multigene germline panels have been extensively performed for BC female patients, the rarity of MBC has resulted in limited data to allow the understanding of the magnitude of risk and the contribution of recently identified moderate penetrance genes of FBC for MBC predisposition. This review gathers available data about the germline genetic landscape of men affected by breast cancer, estimated risk associated with these genetic variants, and current guidelines for clinical management.