Search

Neuroendocrine tumors are a group of malignancies that arise from primitive neuroectodermal cells. There is, however, considerable variation in the location and clinical behavior of these tumors. They are often difficult to distinguish from other malignancies and difficult to classify. Recent advances in molecular genetics have attempted to resolve some issues regarding accurate diagnosis, classification into prognostic subgroups, and understanding of basic common mechanisms underlying the development of these tumors. Correlation of morphologic changes with molecular changes induced by some potential therapeutic differentiating agents may lead to more rational therapy for these malignancies.

Background: Recent clinical trials establish a beneficial effect for adjuvant chemotherapy after surgical resection of the primary tumor (1) as single treatment for patients with colonic cancer and (2) combined with radiation therapy for patients with rectal cancer. Because adjuvant chemotherapy is not universally effective and is associated with toxicity and some degree of risk, it would be desirable to supplement standard pathologic staging criteria to define more precisely the subset of patients at high risk for tumor recurrence who would benefit most from adjuvant therapy. Tumor cell DNA content and cell proliferation measured by flow cytometry were identified as important and independent prognostic factors for patients undergoing curative resection of colorectal cancer. Basic laboratory investigations show a series of more specific molecular and genetic abnormalities that might provide better prognostic discrimination. Recent molecular studies suggest that the process of tumorigenesis in colorectal cancer proceeds through a series of genetic alterations that include both dominant and recessive protooncogenes. Characterization of these molecular genetic abnormalities may provide valuable prognostic information for use in patient management., Methods: Allelic loss was studied for chromosomes 5, 17, and 18, and immunohistochemical analysis was done of the p53 protein product in tumors from 91 patients with colorectal cancer., Results: Preliminary analysis of disease-free survival after surgical resection in 60 patients with Dukes' B or C tumors suggests a poorer prognosis associated with allelic loss on chromosome 18q (P = 0.08)., Conclusions: Additional studies involving a much larger population of patients with Dukes' B and C colorectal cancer are needed to define the true prognostic significance of these molecular markers.

Data from the Epidemiologic Catchment Area survey were used to examine the relationship between violence and psychiatric disorders among adults living in the community. Psychiatric assessment of survey respondents was based on the Diagnostic Interview Schedule, which also provided self-report information about violent behavior. Those who reported violent behavior within the preceding year tended to be young, male, and of low socioeconomic status, and more than half met DSM-III criteria for one or more psychiatric disorders. Subjects with alcohol or drug use disorders were more than twice as likely as those with schizophrenia to report violent behavior. In a multivariate model of the predictors of violence, a significant interaction effect was found between major mental illness and substance abuse. The risk of violent behavior increased with the number of psychiatric diagnoses for which respondents met DSM-III criteria.