Colorectal cancer (CRC) is the fourth most common cancer amongst men and women. Between 3 and 6% of all CRCs are attributed to well-defined inherited syndromes, including Lynch syndrome, familial adenomatous polyposis (FAP), MUTYH-associated polyposis (MAP), and several hamartomatous polyposis conditions. Identification of these patients through family history and appropriate genetic testing can provide estimates of cancer risk that inform appropriate cancer screening, surveillance and/or preventative interventions. This narrative review examines the hereditary colorectal cancer and polyposis syndromes, their genetic basis, clinical management, and evidence supporting cancer screening.

Genetic testing of minors is advised only for conditions in which benefits of early intervention outweigh potential psychological harms. This study investigated whether genetic counseling and test reporting for the CDKN2A/p16 mutation, which confers highly elevated melanoma risk, improved sun protection without inducing distress. Eighteen minors (M = 12.4, SD = 1.9) from melanoma-prone families completed measures of protective behavior and distress at baseline, 1 week (distress only), 1 month, and 1 year following test disclosure. Participants and their mothers were individually interviewed on the psychological and behavioral impact of genetic testing 1 month and 1 year post-disclosure. Carriers (n = 9) and noncarriers (n = 9) reported significantly fewer sunburns and a greater proportion reported sun protection adherence between baseline and 1 year post-disclosure; results did not vary by mutation status. Anxiety symptoms remained low post-disclosure, while depressive symptoms and cancer worry decreased. Child and parent interviews corroborated these findings. Mothers indicated that genetic testing was beneficial (100%) because it promoted risk awareness (90.9%) and sun protection (81.8%) without making their children scared (89.9%); several noted their child's greater independent practice of sun protection (45.4%). In this small initial study, minors undergoing CDKN2A/p16 genetic testing reported behavioral improvements and consistently low distress, suggesting such testing may be safely implemented early in life, allowing greater opportunity for risk-reducing lifestyle changes.

A CDKN2A/p16 mutation confers 28%-67% lifetime melanoma risk, a risk that may be moderated by ultraviolet radiation exposure. The aim of this study was to test whether melanoma genetic counseling and test disclosure conferred unique informational, motivational, or emotional benefits compared to family history-based counseling. Participants included were 114 unaffected members of melanoma-prone families, ages 16-69, 51.8% men, 65.8% with minor children or grandchildren. Carriers (n = 28) and noncarriers (n = 41) from families with a CDKN2A mutation were compared to no-test controls (n = 45) from melanoma-prone families without an identifiable CDKN2A mutation. All participants received equivalent counseling about melanoma risk and management; only CDKN2A participants received genetic test results. Using newly developed inventories, participants rated perceived costs and benefits for managing their own and their children's or grandchildren's melanoma risk 1 month and 1 year after counseling. Propensity scores controlled for baseline family differences. Compared to no-test controls, participants who received test results (carriers and noncarriers) reported feeling significantly more informed and prepared to manage their risk, and carriers reported greater motivation to reduce sun exposure. All groups reported low negative emotions about melanoma risk. Parents reported high levels of preparedness to manage children's risk regardless of group. Carrier parents reported greater (but moderate) worry about their children's risk than no-test control parents. Women, older, and more educated respondents reported greater informational and motivational benefits regardless of group. Genetic test results were perceived as more informative and motivating for personal sun protection efforts than equivalent counseling based on family history alone.

Cowden syndrome (CS) is an often difficult to recognize hereditary cancer predisposition syndrome caused by mutations in phosphatase and tensin homolog deleted on chromosome 10 (PTEN). In addition to conferring increased cancer risks, CS also predisposes individuals to developing hamartomatous growths in many areas of the body. Due to the rarity of CS, estimates vary on the penetrance of certain phenotypic features, such as macrocephaly and skin findings (trichilemmomas, mucocutaneous papules), as well as the conferred lifetime cancer risks. To address this variability, separate clinical diagnostic criteria and PTEN testing guidelines have been created to assist clinicians in the diagnosis of CS. As knowledge of CS increases, making larger studies of affected patients possible, these criteria continue to be refined. Similarly, the management guidelines for cancer screening and risk reduction in patients with CS continue to be updated. This review will summarize the current literature on CS to assist clinicians in staying abreast of recent advances in CS knowledge, diagnostic approaches, and management.

It is unknown whether or why genetic test reporting confers benefits in the understanding and management of cancer risk beyond what patients learn from counseling based on family history. A prospective nonexperimental control group study compared participants from melanoma-prone families who underwent CDKN2A/p16 (p16) genetic testing (27 carriers, 38 noncarriers) to participants from equivalently melanoma-prone families known not to carry a deleterious p16 mutation (31 no-test controls). All participants received equivalent counseling concerning elevated lifetime melanoma risk and corresponding recommendations for prevention and screening. Both immediately and one month after counseling, participants receiving a genetic test result reported greater understanding of their risk, decreased derogation of the risk information, and greater personal applicability of prevention recommendations than no-test controls. Decreased derogation of risk information after test reporting predicted further increases in understanding of melanoma risk and applicability of prevention recommendations one month later. Results suggest unique benefits of genetic test reporting in promoting understanding and acceptance of information about hereditary cancer risk and its management.

This study investigated whether genetic counseling and test reporting for the highlypenetrant CDKN2A melanoma predisposition gene promoted decreases in sun exposure. Method: A prospective, non-equivalent control group design compared unaffected participants (N=128, M age =35.24, 52% men) from: 1) families known to carry a CDKN2A mutation, who received counseling about management recommendations and a positive or negative genetic test result, and 2) "no-test control" families known not to carry a CDKN2A mutation, who received equivalent counseling based on their comparable family history. Changes in daily UVR exposure (joules/m 2), skin pigmentation (Melanin Index), and sunburns between baseline and one year following counseling were compared among carriers (n=32), noncarriers (n=46), and no-test control participants (n=50). Results: Both carriers and no-test control participants exhibited a decrease one year later in daily UVR dose (Bs=−.52, −.33, ps<.01). Only carriers exhibited a significant decrease in skin pigmentation at the wrist one year later (B=−.11, p< .001), and both carriers and no-test control participants reported fewer sunburns than noncarriers (ps<.05). Facial pigmentation did not change for any group. Noncarriers did not change on any measure of UVR exposure. Conclusions: These findings support the clinical utility of disclosing CDKN2A test results and providing risk-management education to high-risk individuals. Users may view, print, copy, and download text and data-mine the content in such documents, for the purposes of academic research, subject always to the full Conditions of use:

Leptomeningeal dissemination of paraganglioma is rare, with only 2 prior cases in the literature. The authors present the case of a metastatic low-grade lumbar paraganglioma via leptomeningeal dissemination. This report emphasizes the utility of 3,4-dihydroxy-6-18F-fluoro-l-phenylalanine (18F-FDOPA) PET scanning for diagnosis, as well as the combination of radiation therapy and alkylating chemotherapeutic agents for the treatment of this rare phenomenon. The patient was a 61-year-old woman who presented with low-back pain and was found to have an isolated L-3 intrathecal tumor on MRI. Sixteen months after gross-total en bloc resection of the paraganglioma, the patient again became symptomatic with new neurological symptoms. MRI findings revealed enhancing leptomeningeal nodules throughout the spine. 18F-FDOPA PET/CT scanning was used to confirm the diagnosis of disseminated paraganglioma. Intrathecal thiotepa, radiation therapy, and systemic therapy with capecitabine and temozolomide have been used sequentially over a 2-year period, with each able to stabilize tumor growth for several months. The authors also summarize the 2 other reports of leptomeningeal dissemination of paragangliomas in the literature and compare the course and management of the 3 cases.

INTRODUCTION PARAGRAPHMultiple large COVID-19 genome-wide association studies (GWAS) have identified reproducible genetic associations indicating that some infection susceptibility and severity risk is heritable.1-5 Most of these studies ascertained COVID-19 cases in medical clinics and hospitals, which can lead to an overrepresentation of cases with severe outcomes, such as hospitalization, intensive care unit admission, or ventilation. Here, we demonstrate the utility and validity of deep phenotyping with self-reported outcomes in a population with a large proportion of mild and subclinical cases. Using these data, we defined eight different phenotypes related to COVID-19 outcomes: four that align with previously studied COVID-19 definitions and four novel definitions that focus on susceptibility given exposure, mild clinical manifestations, and an aggregate score of symptom severity. We assessed replication of 13 previously identified COVID-19 genetic associations with all eight phenotypes and found distinct patterns of association, most notably related to the chr3/SLC6A20/LZTFL1 and chr9/ABO regions. We then performed a discovery GWAS, which suggested some novel phenotypes may better capture protective associations and also identified a novel association in chr11/GALNT18 that reproduced in two fully independent populations.