High Growth Rate of Pancreatic Ductal Adenocarcinoma in CDKN2A-p16-Leiden Mutation Carriers

Two Japanese families with familial pancreatic cancer with suspected pathogenic variants of CDKN2A: a case report

BACKGROUND

Germline mutations in CDKN2A result in Familial Atypical Multiple Mole Melanoma Syndrome (FAMMM) (OMIM #155,601), which is associated with an increased risk of pancreatic ductal adenocarcinoma and melanoma. FAMMM has been reported globally, but it is quite rare in Japan. We report two families with familial pancreatic cancer with suspected pathogenic variants of CDKN2A that were incidentally identified through comprehensive genomic profiling.

CASE PRESENTATION

The first case is a 74-year-old woman with a diagnosis of pancreatic carcinoma with multiple liver metastases. She had family histories of pancreatic cancer, but no personal or family history of malignant melanoma. Whole exon sequencing detected a germline CDKN2A variant evaluated as likely pathogenic. The results were disclosed to her daughters after she died, and the same CDKN2A variant was detected in one of the daughter. The daughter was referred to a nearby hospital for her clinical management. The second case is a 65-year-old man with pancreatic ductal adenocarcinoma. He had family histories of pancreatic cancer, but no personal or family history of malignant melanoma. He underwent a comprehensive genomic profiling test using pancreatic cancer tissue, and detected a presumed germline pathogenic variant of CDKN2A. Germline testing confirmed the same CDKN2A variant. Genetic analysis of his relatives produced negative results. Other blood relatives are scheduled for genetic analysis in the future. We report two families with familial pancreatic cancer with suspected pathogenic variants of CDKN2A that were incidentally identified through comprehensive genomic profiling.

CONCLUSIONS

In current Japanese precision medicine, comprehensive genetic analysis can reveal rare genetic syndromes and offer us the opportunity to provide health management for patients and their relatives. However, gene-specific issues are raised in terms of the evaluation of a variant's pathogenicity and the extent of surveillance of the at-risk organs due to a lack of genetic and clinical data concerning CDKN2A variant carriers in Japan.

Familial Predisposition and Genetic Risk Factors Associated with Pancreatic Cancer

Pancreatic cancer (PC) is a highly lethal cancer and projected to be the second leading cause of cancer death by 2030. Multigene panel testing has facilitated the identification of germline variants associated with an increased risk of PC. Precision treatment has led to improved outcomes for patients with these findings. Because of these improved outcomes as well as the implications for at-risk family members who may benefit from additional cancer screening, the NCCN recommends universal genetic testing for newly diagnosed PC patients. This review describes the most common heritable conditions associated with PC and those who may benefit from screening.

Inherited predisposition to pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is projected to be the second leading cause of cancer death in the US by 2030. There are multiple germline pathogenic variants and cancer syndromes associated with an increased risk of PDAC. Precision treatment, informed by germline genetic testing and molecular tumor analysis, can optimize therapeutic regimens and outcomes for those diagnosed with PDAC. As a result, the National Comprehensive Cancer Network currently recommends genetic testing for all newly diagnosed PDAC patients given the clinical implications for treatment but also for the identification of at-risk family members who can benefit from pancreatic cancer screening and other cancer prevention strategies. This article reviews inherited risk factors for the development of PDAC and current screening strategies for the early detection of PDAC in high-risk populations.

LMNA functions as an oncogene in hepatocellular carcinoma by regulating the proliferation and migration ability

The role of the LMNA gene in the development and progression of hepatocellular carcinoma (HCC) and the associated molecular mechanism is not yet clear. Therefore, the purpose of this study was to evaluate the relationship between LMNA and HCC. LMNA gene expression in normal tissues and corresponding tumours was evaluated and the Kaplan-Meier survival analysis was performed. Next, the LMNA gene was knocked out in the 293T and HepG2 cell lines using the CRISPR/Cas9 technique. Subsequently, the proliferation, migration and colony formation rate of the two LMNA knockout cell lines were analysed. Finally, the molecular mechanism affecting the tumorigenesis due to the loss of the LMNA gene was evaluated. The results showed that the LMNA gene was abnormally expressed in many tumours, and the survival rate of the HCC patients with a high expression of the LMNA gene was significantly reduced compared with the rate in patients with a low LMNA expression. The knockout of the LMNA gene in the HCC cell line HepG2 resulted in a decreased tumorigenicity, up-regulation of the P16 expression and down-regulation of the CDK1 expression. These findings suggested that LMNA might function as an oncogene in HCC and provided a potential new target for the diagnosis and treatment of HCC.