International Agency for Research on Cancer

About: International Agency for Research on Cancer is a government organization based out in Lyon, France. It is known for research contribution in the topics: Population & Cancer. The organization has 2989 authors who have published 9010 publications receiving 929752 citations. The organization is also known as: IARC.

Validity of Free Testosterone and Free Estradiol Determinations in Serum Samples from Postmenopausal Women by Theoretical Calculations

Abstract: In this study, we validated measurements of free testosterone (fT) and free estradiol (fE(2)) concentrations calculated from total serum concentrations of testosterone (T), estradiol (E(2)), and sex hormone-binding globulin (SHBG), measured by direct, commercial radioimmunoassays, by comparison with reference measurements obtained by dialysis plus an in-house radioimmunoassay after extraction and chromatographic purification. The study was conducted in serum samples from 19 postmenopausal women who were part of an ongoing prospective cohort study. We also performed sensitivity analyses to examine the robustness of the theoretical calculations. Sensitivity analyses showed that in this population, competitive binding of dihydrotestosterone and total T could be ignored in the calculation of fE(2), and competitive binding by dihydrotestosterone does not need to be taken into account for calculation of fT. Furthermore, variations in albumin and SHBG concentrations had negligible effects on fT and fE(2) calculations. Values of fT and fE(2), calculated from total T and E(2) concentrations obtained by the same in-house radioimmunoassay used for the dialysis method, correlated highly with the measurements by dialysis (Pearson's coefficients of correlation above 0.97). When calculating fT and fE(2) using total T and total E(2) concentrations obtained by different direct radioimmunoassays, almost all kits gave good correlations with the reference method for fT (Pearson's r > 0.83), but only a few gave good correlations for fE(2) (Diagnostic System Laboratories and DiaSorin; r > 0.80). The direct radioimmunoassays giving the best correlation for fT and fE(2) with the dialysis method were those that best measured total concentrations of T and E(2). Furthermore, mean values of fT and fE(2) corresponded well to mean values by the reference method if SHBG measurements were also well calibrated. We conclude that in postmenopausal women, theoretical calculations are valid for the determination of fT and fE(2) concentrations and can give reliable estimation of cancer risk in epidemiological studies when the total concentrations of T, E(2), and SHBG are measured accurately.

A population-based study of the incidence and survival rates in patients with pilocytic astrocytoma

Abstract: Object. The incidence of pilocytic astrocytomas and the rate of patient survival were analyzed in a population-based study in the canton of Zurich, Switzerland. Methods. Between 1980 and 1994, 987 astrocytic and oligodendroglial tumors were diagnosed, of which 55 (5.5%) were pilocytic astrocytomas. The incidence rate, adjusted to the World Standard Population, was 4.8 per 1 million per year. The mean age at clinical diagnosis was 19.6 ± 12.7 years, and the male/female ratio was 1.12. The most frequent tumor sites were the cerebellum (40%), followed by supratentorial locations (35%), the optic pathway and hypothalamus (11%), and the brainstem (9%). The mean follow-up period was 12 years. Observed survival rates were 100% at 5 years and 95.8% at 10 years after diagnosis (relative survival rate at 10 years: 96.8%). Seven patients (13%) received postoperative radiotherapy, but this did not significantly affect survival. In all patients the tumors were histologically classified as WHO Grade I, except in two pa...

ΔN-p53, a natural isoform of p53 lacking the first transactivation domain, counteracts growth suppression by wild-type p53

Abstract: The tumor suppressor protein p53 is ubiquitously expressed as a major isoform of 53 kD, but several forms of lower molecular weight have been observed. Here, we describe a new isoform, DeltaN-p53, produced by internal initiation of translation at codon 40 and lacking the N-terminal first transactivation domain. This isoform has impaired transcriptional activation capacity, and does not complex with the p53 regulatory protein Mdm2. Furthermore, DeltaN-p53 oligomerizes with full-length p53 (FL-p53) and negatively regulates its transcriptional and growth-suppressive activities. Consistent with the lack of Mdm2 binding, DeltaN-p53 does not accumulate in response to DNA-damage, suggesting that this isoform is not involved in the response to genotoxic stress. However, in serum-starved cells expressing wild-type p53, DeltaN-p53 becomes the predominant p53 form during the synchronous progression into S phase after serum stimulation. These results suggest that DeltaN-p53 may play a role as a transient, negative regulator of p53 during cell cycle progression.

Classic kaposi sarcoma: epidemiology and risk factors.

Abstract: BACKGROUND Although Kaposi sarcoma (KS) initially was described over a century ago, its biology remains enigmatic and conflicting. Whereas the classic type occurs mainly in older men of Mediterranean or Eastern European backgrounds and is not linked to impairment of the host immune response, iatrogenic and human immunodeficiency virus (HIV)-associated KS are linked to such conditions. A recently discovered pathogen, KS-associated herpesvirus (KSHV) (also known as human herpesvirus 8 [HHV8]), is found in tissues from all four forms of KS (classic, iatrogenic, endemic [African], and HIV-associated). This universal detection of KSHV/HHV8 suggests a central role for the virus in the development of KS and a common etiology for all KS types. The epidemiology and risk factors of classic KS, along with the biology of KSHV/HHV8 and the prevalence of the virus among different populations, is presented. METHODS The current review is based on multiple information sources, electronic health data in all languages from 1966 onward, and previously published scientific reports from the Americas, Europe, and Africa. RESULTS Nearly 5000 cases of morphologically characterized classic KS have been reported in Europe, Mediterranean countries, and the Americas up to 1998. Geographic location, ethnicity, time interval, age, and gender heavily influence the incidence rate of classic KS. The rate of incidence of nonacquired immunodeficiency syndrome-associated KS correlates with the KSHV/HHV8 seroprevalence in the general population. CONCLUSIONS Many contributory factors undoubtedly have etiologic and pathogenic significance in the development of classic KS; however, the interplay between these factors has complicated the understanding of the induction and development of the disease as well as the significance of each factor. As with other cell-transforming human DNA viruses, infection with KSHV/HHV8 alone is not sufficient for the development of KS and additional cofactors are required. Cancer 2000;88:500–17. © 2000 American Cancer Society.