Prevalence and spectrum of pathogenic germline variants in intestinal and pancreatobiliary type of ampullary cancer

[Treatment of Ampullary Adenocarcinoma]

The ampulla of Vater is a small projection formed by the confluence of the main pancreatic duct and common bile duct in the second part of the duodenum. Primary ampullary adenocarcinoma is a rare malignancy, accounting for only 0.2% of gastrointestinal cancers and approximately 7% of all periampullary cancers. Jaundice from a biliary obstruction is the most common symptom of ampullary adenocarcinoma. In the early stages, radical pancreatoduodenectomy is the standard surgical approach. On the other hand, no randomized controlled trial has provided evidence to guide physicians on the choice of adjuvant/palliative chemotherapy because of the rarity of the disease and the paucity of related research. This paper reports the biology, histology, current therapeutic strategies, and potential future therapies of ampullary adenocarcinoma.

Ampulla of Vater carcinoma: advancement in the relationships between histological subtypes, molecular features, and clinical outcomes

The incidence of ampulla of Vater carcinoma, a type of periampullary cancer, has been increasing at an annual percentage rate of 0.9%. However, patients with ampulla of Vater carcinoma have quite different prognoses due to the heterogeneities of the tissue origin of this carcinoma. In addition to TNM staging, histological subtypes and molecular features of ampulla of Vater carcinoma are the key factors for predicting the clinical outcomes of patients. Fortunately, with the development of testing technology, information on the histological subtypes and molecular features of ampulla of Vater carcinoma is increasingly being analyzed in-depth. Patients with the pancreaticobiliary subtype have shorter survival times. In immunohistochemical examination, high cutoff values of positive MUC1 staining can be used to accurately predict the outcome of patients. Mutant KRAS, TP53, negative SMAD4 expression, and microsatellite stability are related to poor prognosis, while the clinical value of BRCA1/BRCA2 mutations is limited for prognosis. Testing the histological subtypes and molecular characteristics of ampulla of Vater carcinoma not only is the key to prognosis analysis but also provides extra information for targeted treatment to improve the clinical outcomes of patients.

Atypical ATMs: Broadening the phenotypic spectrum of ATM-associated hereditary cancer

Heterozygous, loss-of-function germline variants in ATM have been associated with an increased lifetime risk of breast, pancreas, prostate, stomach, ovarian, colorectal, and melanoma cancers. We conducted a retrospective review of thirty-one unrelated patients found to be heterozygous for a germline pathogenic variant in ATM and identified a significant proportion of patients in this cohort with cancers not currently associated with the ATM hereditary cancer syndrome, including carcinomas of the gallbladder, uterus, duodenum, kidney, and lung as well as a vascular sarcoma. A comprehensive review of the literature found 25 relevant studies where 171 individuals with a germline deleterious ATM variant have been diagnosed with the same or similar cancers. The combined data from these studies were then used to estimate the prevalence of germline ATM pathogenic variants in these cancers, which ranged between 0.45% and 2.2%. Analysis of tumor sequencing performed in large cohorts demonstrated that the frequency of deleterious somatic ATM alterations in these atypical cancers equaled or exceeded the alteration frequency in breast cancer and occurred at a significantly higher rate than in other DNA-damage response tumor suppressors, namely BRCA1 and CHEK2. Furthermore, multi-gene analysis of somatic alterations in these atypical cancers demonstrated significant co-occurrence of pathogenic alterations in ATM with BRCA1 and CHEK2, while there was significant mutual exclusivity between pathogenic alterations in ATM and TP53. This indicates that germline ATM pathogenic variants may play a role in cancer initiation and progression in these atypical ATM malignancies, potentially influencing these cancers to be driven toward DNA-damage repair deficiency and away from loss of TP53. As such, these findings provide evidence for broadening of the ATM-cancer susceptibility syndrome phenotype to improve the recognition of affected patients and provide more efficacious, germline-directed therapies.

Beyond BRCA: The Emerging Significance of DNA Damage Response and Personalized Treatment in Pancreatic and Prostate Cancer Patients

The BRCA1/2 germline and/or somatic pathogenic variants (PVs) are key players in the hereditary predisposition and therapeutic response for breast, ovarian and, more recently, pancreatic and prostate cancers. Aberrations in other genes involved in homologous recombination and DNA damage response (DDR) pathways are being investigated as promising targets in ongoing clinical trials. However, DDR genes are not routinely tested worldwide. Due to heterogeneity in cohort selection and dissimilar sequencing approaches across studies, neither the burden of PVs in DDR genes nor the prevalence of PVs in genes in common among pancreatic and prostate cancer can be easily quantified. We aim to contextualize these genes, altered in both pancreatic and prostate cancers, in the DDR process, to summarize their hereditary and somatic burden in different studies and harness their deficiency for cancer treatments in the context of currently ongoing clinical trials. We conclude that the inclusion of DDR genes, other than BRCA1/2, shared by both cancers considerably increases the detection rate of potentially actionable variants, which are triplicated in pancreatic and almost doubled in prostate cancer. Thus, DDR alterations are suitable targets for drug development and to improve the outcome in both pancreatic and prostate cancer patients. Importantly, this will increase the detection of germline pathogenic variants, thereby patient referral to genetic counseling.

Neurological update: COVID-19

Coronavirus Disease 2019 is predominantly a disorder of the respiratory system, but neurological complications have been recognised since early in the pandemic. The major pathophysiological processes leading to neurological damage in COVID-19 are cerebrovascular disease, immunologically mediated neurological disorders and the detrimental effects of critical illness on the nervous system. It is still unclear whether direct invasion of the nervous system by the Severe Acute Respiratory Syndrome Coronavirus 2 occurs; given the vast numbers of people infected at this point, this uncertainty suggests that nervous system infection is unlikely to represent a significant issue if it occurs at all. In this review, we explore what has been learnt about the neurological complications of COVID-19 over the course of the pandemic, and by which mechanisms these complications most commonly occur.