Hereditary cancer syndrome diagnosis: molecular genetic clues and cancer control

Proposed Terminology and Classification of Pre-Malignant Neoplastic Conditions: A Consensus Proposal

Cancer evolution is a step-wise non-linear process that may start early in life or later in adulthood, and includes pre-malignant (indolent) and malignant phases. Early somatic changes may not be detectable or are found by chance in apparently healthy individuals. The same lesions may be detected in pre-malignant clonal conditions. In some patients, these lesions may never become relevant clinically whereas in others, they act together with additional pro-oncogenic hits and thereby contribute to the formation of an overt malignancy. Although some pre-malignant stages of a malignancy have been characterized, no global system to define and to classify these conditions is available. To discuss open issues related to pre-malignant phases of neoplastic disorders, a working conference was organized in Vienna in August 2015. The outcomes of this conference are summarized herein and include a basic proposal for a nomenclature and classification of pre-malignant conditions. This proposal should assist in the communication among patients, physicians and scientists, which is critical as genome-sequencing will soon be offered widely for early cancer-detection.

Signs and genetics of rare cancer syndromes with gastroenterological features

Although the genetic bases of most hereditary cancer syndromes are known, and genetic tests are available for them, the incidence of the most rare of these syndromes is likely underestimated, partially because the clinical expression is neither fully understood nor easily diagnosed due to the variable and complex expressivity. The clinical features of a small pool of rare cancer syndromes include gastroenterological signs, though not necessarily tumors, that could require the intervention of a gastroenterologist during any of the phases of the clinical management. Herein we will attempt to spread the knowledge on these rare syndromes by summarizing the phenotype and genetic basis, and revising the peculiar gastroenterological signs whose underlying role in these rare hereditary cancer syndromes is often neglected. Close collaboration between geneticists and gastroenterologists could facilitate both the early identification of patients or relatives at-risk and the planning of multidisciplinary and tailored management of these subjects.

Individuals at high-risk for pancreatic cancer development: management options and the role of surgery

Pancreatic cancer (PC) is a highly lethal disease. Despite advances regarding the safety and long-term results of pancreatectomies, early diagnosis remains the only hope for cure. This necessitates the implementation of an intensive screening program (based mainly on modern imaging), which - given the incidence of PC - is not cost effective for the general population. However, this screening program is recommended for individuals at high-risk for PC development. Indications for screening include the following three clinical settings: hereditary cancer predisposition syndromes associated with PC, hereditary pancreatitis and familial pancreatic cancer syndrome. The aim of this strategy is to identify pre-invasive (precursor) lesions, which are curable. Surgery is recommended in the presence of recognizable lesion on imaging lesions. Partial (anatomic) pancreatectomy - depending on the location of the suspicious lesion - is the most widely accepted type of surgical intervention in this setting; occasionally, however, total pancreatectomy may be required, in carefully selected patients. Despite that experience still remains limited, there is evidence that this aggressive strategy allows early detection of neoplastic lesions, thereby improving the effectiveness of surgery and prognosis.

Management of melanoma families

In this review we have aimed to focus on the clinical management of familial melanoma patients and their relatives. Along this line three major topics will be discussed: (1) management/screening of familial melanoma families: what is advised and what is the evidence thereof; (2) variability of families worldwide with regard to clinical phenotype, including cancer spectrum and likelihood of finding germline mutations and (3) background information for clinicians on the molecular biology of familial melanoma and recent developments in this field.

The recognition and surgical management of heritable lesions of the pancreas

Our knowledge regarding the inherited factors that lead to the development of lesions within the pancreas is clearly incomplete. This article addresses clinical issues in patients at moderate-to-high risk for pancreatic malignancy, with special emphasis on the recognition and diagnosis of known genetic syndromes. Using the current available information, the authors attempt to equip the practicing surgeon with critical information to increase clinical suspicion for heritable syndromes and inform specific surgical management. Additionally, this article is meant to encourage the practicing surgeon to participate in the genetic testing/screening, cancer surveillance, and prevention activities of patients who have heritable cancer syndromes and associated pancreatic lesions that require surgery.

Landmarks in the history of cancer epidemiology

The application of epidemiology to cancer prevention is relatively new, although observations of the potential causes of cancer have been reported for more than 2,000 years. Cancer was generally considered incurable until the late 19th century. Only with a refined understanding of the nature of cancer and strategies for cancer treatment could a systematic approach to cancer prevention emerge. The 20th century saw the elucidation of clues to cancer causation from observed associations with population exposures to tobacco, diet, environmental chemicals, and other exogenous factors. With repeated confirmation of such associations, researchers entertained for the first time the possibility that cancer, like many of the infectious diseases of the time, might be prevented. By the mid-20th century, with antibiotics successfully addressing the majority of infectious diseases and high blood pressure treatment beginning to affect the prevalence of heart disease in a favorable direction, the focus of much of epidemiology shifted to cancer. The early emphasis was on exploring, in greater depth, the environmental, dietary, hormonal, and other exogenous exposures for their potential associations with increased cancer risk. The first major breakthrough in identifying a modifiable cancer risk factor was the documentation of an association between tobacco smoking and lung cancer. During the past four decades, epidemiologic studies have generated population data identifying risk factors for cancers at almost every body site, with many cancers having multiple risk factors. The development of technologies to identify biological molecules has facilitated the incorporation of these molecular manifestations of biological variation into epidemiologic studies, as markers of exposure as well as putative surrogate markers of cancer outcome. This technological trend has, during the past two decades, culminated in emphasis on the identification of genetic variants and their products as correlates of cancer risk, in turn, creating opportunities to incorporate the discipline of molecular/genetic epidemiology into the study of cancer prevention. Epidemiology will undoubtedly continue contributing to cancer prevention by using traditional epidemiologic study designs to address broad candidate areas of interest, with molecular/genetic epidemiology investigations honing in on promising areas to identify specific factors that can be modified with the goal of reducing risk.

Will knowledge of gene-based colorectal cancer disease risk influence quality of life and screening behavior? Findings from a population-based study

BACKGROUND

Several gene variants conveying a modestly increased risk for disease have been described for colorectal cancer. Patient acceptance of gene variant testing in clinical practice is not known. We evaluated the potential impact of hypothetical colorectal-cancer-associated gene variant testing on quality of life, health habits and cancer screening behavior.

METHODS

First-degree relatives of colorectal cancer patients and controls from the Seattle Colorectal Cancer Familial Registry were invited to participate in a web-based survey regarding testing for gene variants associated with colorectal cancer risk.

RESULTS

310 relatives and 170 controls completed the questionnaire. Quality of life for the hypothetical carrier state was modestly and nonsignificantly lower than current health after adjustment for sociodemographic and health factors. In the positive test scenario, 30% of respondents expressed willingness to change their diet, 25% to increase exercise, and 43% to start colorectal cancer screening. The proportions willing to modify these habits did not differ between groups.

CONCLUSIONS

Testing for gene variants associated with colorectal cancer risk may not influence quality of life, but may impact health habits and screening adherence. Changing behaviors as a result of testing may help to reduce cancer incidence and mortality, particularly among those at higher risk for colorectal cancer.