[National quality control of plasma RNA-HCV in the year 2000].
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Biomedical subjects
Publications and source records attributed to P Maisonneuve.
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p27(Kip1) (p27), a cyclin-dependent kinase inhibitor, has an important role in the progression of cells from G(1) into S phase of the cell cycle. p27 may act as a tumor suppressor, and several reports suggest that loss of its expression in breast carcinoma is related to tumor progression and poor prognosis. We evaluated p27 immunohistochemical expression in 512 consecutive cases of breast carcinoma with 9 years of median-term follow-up. p27 expression was heterogeneous and frequently less intense than in normal cells. Low p27 expression (<50% of reacting cells) was associated with grade III tumors, N0 status, estrogen receptor-negative status, and low cyclin D1 expression. In the whole series of cases, p27 expression did not predict outcome. In node-negative cases (249 patients), high p27 expression indicated poor prognosis. p27 was not prognostically relevant in the group of 223 patients with pT1 disease or in the group of 154 patients <50 years of age. We also investigated the prognostic value of the combined expression of p27 and cyclin D1, but no differences in survival were seen in this bivariate analysis.
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beta(1C) integrin is an unspliced form of the integrin beta(1) subfamily, which has been shown to inhibit cell proliferation in vitro. Using an affinity-purified rabbit antibody, we have investigated 283 previously untreated breast carcinomas, with the aim of ascertaining the actual prevalence of beta(1C) expression in these tumors and of defining its pathological correlates. Immunoblotting and reverse transcriptase-polymerase chain reaction experiments have also been performed in selected cases, to confirm the immunocytochemical findings. Overall, beta(1C) immunoreactivity was down-regulated (ie, expressed in < 50% of the neoplastic cells) in 114 cases (40.3%). Down-regulation of beta(1C) expression in breast carcinomas correlated significantly with the tumor grade, the proliferative fraction (as evaluated by Ki-67 immunostaining with the MIB-1 monoclonal antibody), the estrogen and progesterone receptor status, and the tumor size (pT classification) and marginally with the node status. In a multivariate analysis with all available measures fitted simultaneously, tumor grade (P = 0.004), Ki-67 immunolabeling (P = 0.01), and pT categories (P = 0.04) were significantly associated with beta(1C) immunoreactivity. Although the short follow-up time (2-3 years) of the current series of patients does not allow the performance of survival analyses, the correlation of beta(1C) expression with tumor size, grade, and proliferative fraction and its alleged role as an upstream regulator of p27(kip1) make this integrin variant a likely novel prognostic parameter for invasive carcinomas of the breast.
The global cancer burden in women appears to have stabilized according to the most recent estimates available although the distribution of cancer types appears to be changing with a sharp contrast between the increase in the absolute numbers of breast cancers and a decline in cervix cancers. Prospects for cancer control in women appear to be good within our current knowledge and deserve close attention. Rates of lung cancer in women are increasing substantially in many countries and seem set to overtake breast cancer as the commonest form of cancer death in women in many parts of the world. These changes are due to the effects of cigarette smoking, a habit which women widely embraced during the second half of the last century. The high levels of smoking currently in young women, which have yet to have their full impact on death rates, constitute an important hazard not only for future cancer risks but for several other important causes of death. There is strong and consistent evidence that increased consumption levels of fruit and vegetables is associated with reduced risks of many common forms of cancer including breast cancer. Although the breast is the commonest form of cancer in women in most western countries, the etiology of this disease remains elusive and preventable causes remain to be identified. Endogenous hormones also appear to have a role in cancer risk in women: oral contraceptives seem to increase slightly the risk of breast cancer in users in the use and in the immediate post-use period, but 10 years after cessation the risk again returns to that of never users. Oral contraceptive usage also appears to be protective against ovarian and endometrial cancer. The use of hormonal replacement therapy (HRT) appears to increase the risk of endometrial cancer and a positive association with breast cancer risk appears to exist. Within our current knowledge of the epidemiology of cancer in women, the most important preventive strategies would appear to be the prevention of cigarette smoking and increased dietary intake of vegetables and fruits. Screening has also shown to be effective in reducing incidence and mortality of cervix cancer and mortality from breast cancer. Although more work is needed, it is becoming clear that there could be an important role of HPV testing to further enhance cervix cancer screening. There are important variations in survival from a variety of cancers which are due to factors unrelated to the tumor behavior and that there are significant variations in survival from cancer. Reduction of these gaps could lead to a reduction in cancer mortality and contribute towards increased prospects for cancer control in women.
Hereditary pancreatitis is a rare form of pancreatitis, accounting for approximately 1% of all types of pancreatitis. It is inherited as an autosomal dominant disease, with incomplete penetrance. The genetic defect is believed to be caused by mutations in the trypsinogen gene. Patients who inherit the disorder suffer from a form of pancreatitis that resembles other types of pancreatitis, but the age of onset is much earlier. Sixteen biopsy-proven pancreatic cancers have developed in a cohort of 412 patients with a median follow-up period of 18 years (interquartile range, 7 to 30 years) since the onset of symptoms. Compared with the background population, the risk of pancreatic cancer is approximately 50 to 60 times greater than expected. Smoking appears to be an additional risk factor in these patients: Smoking increases the risk of developing pancreatic cancer and lowers the age of onset by approximately 20 years. Patients with hereditary pancreatitis are urged to avoid smoking because it greatly increases the risk of pancreatic cancer and to avoid alcohol, a known risk factor for all forms of pancreatitis.
This report notes the differences in the classification of the primary renal disease (PRD) used in different renal dialysis and transplant registries worldwide. The heterogeneity of coding systems complicates the comparative analysis of end-stage renal disease from different regions. Using data collected over two decades in the United States, Europe, and Australia/New Zealand, we present a method for reorganization of the classes of PRD that allows a straightforward comparison of retrospective data from these registries.
BACKGROUND: Exposure to GB virus type C/HGV (GBV-C/HGV) could be determined by detection either of RNA by RT-PCR or of antibodies of the envelope protein E2. STUDY DESIGN AND METHODS: The aim of the study was to determine the proportion of the GBV-C/HGV markers of infection in a blood donor population infected with HCV and to identify GBV-C/HGV routes of transmission that are associated with HCV genotypes and risk factors. RESULTS: Among 306 HCV RNA-positive blood donors, the proportion of GBV-C/HGV RNA-positive donors and anti-E2-positive donors was 19.3 percent (95% CI = 15.0-24.2%) and 42.1 percent (95% CI = 36.6-47.9%), respectively. Exposure to GBV-C/HGV (RNA or anti-E2) was significantly associated with the risk factor of IV drug use. There was a trend toward association with HCV subtypes 1a and 3a, probably because these HCV subtypes are the most frequent in IV drug users. No correlation was observed between ALT elevation and the presence of GBV-C/HGV RNA. CONCLUSION: In persons with HCV infection, IV drug use seems to be a major route of GBV-C/HGV transmission. Precautions taken to avoid HCV infection will probably also decrease GBV-C/HGV transmission.
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Insulin-like growth factor 1 (IGF-1) likely is involved in thyrocyte proliferation via autocrine mechanisms, but limited data are available on its in vivo expression in thyroid neoplasms. This prompted us to explore IGF-1 expression at the protein and mRNA levels and IGF-1 receptor (IGF-1rec) immunoreactivity in normal and neoplastic thyroids (50 adenomas and 53 carcinomas). We documented increased IGF-1 and IGF-1rec immunoreactivity in adenomas (31 of 50 and 40 of 50 cases, respectively) and carcinomas (38 of 53 and 42 of 53 cases) compared with normal thyroid, which only showed minimal immunoreactivity for the ligand and its receptor. A corresponding up-regulation of IGF-1 mRNA was documented in carcinomas, whereas adenomas exhibited down-regulated expression of IGF-1 mRNA. Immunoreactivity for IGF-1 and cognate receptor positively correlated with tumor diameter and wide intrathyroidal extension but not with patients' gender and age or with the stage of the tumors and the occurrence of lymph node metastases. These data emphasize a possible role of the IGF-1 system in thyroid tumorigenesis, as indicated by in vitro studies. In addition, the evaluation of IGF-1 and IGF-1rec immunoreactivity might have clinical implications, because it positively correlates with the aggressiveness of these tumors.
BACKGROUND: We evaluated and analysed risk factors of HCV-infected blood donors according to HCV genotypes in order to improve the transfusion policy and safety of blood supply. MATERIALS AND METHODS: HCV-RNA was analysed in sera from 518 anti-HCV-positive blood donors, who were invited to medical consultation and interview as to risk factors by means of an extensive questionnaire. HCV genotyping was done on all samples positive for HCV-RNA. RESULTS: Of the 518 sera, 399 (77%) were HCV-RNA positive, and 394 of 399 HCV genotypes were identified. Major genotypes were 1b (34.3%), 3a (24%), 1a (19.5%) and 2 (11.4%). Of the donors, 289 (55.8%) were interviewed regarding their risk behaviour: 27% were former intravenous drug users (IVDUs), 26% had been transfused, 8% had a history of invasive diagnostic procedures, and 13% a history of surgery. Among the 224 interviewed donors, genotypes 1a and 3a were mainly associated with IVDU (51 and 45% respectively) and genotype 1b, with transfusion and nosocomial infections (40 and 25%, respectively). CONCLUSION: In this population of anti-HCV-positive blood donors, nosocomial infection may be a route of HCV spread, but the main risk factor remains IVDU, particularly in young men. The transfusion policy will improve if predonation interviews of such young men are done with a specific and sensitive questionnaire.
This review addresses the history of the ras oncogene, the techniques used to detect molecular alterations in the ras oncogene, and the application of polymerase chain reaction (PCR)-based methods to determine point mutations in clinical samples of patients with pancreatic diseases, namely pancreatic carcinoma and chronic pancreatitis. The frequency of ras mutations in pancreatic carcinoma is high, ranging from 70 to almost 100%. The frequence of ras mutations in chronic pancreatitis, either in pancreatic tissue or pancreatic secretions, vary between 0 and 100%. This wide range in part may be owing to differences in sampling, DNA extraction, or PCR method. The meaning of a k-ras mutation is under debate. Taking into account the positivity of ductal hyperplasias in normal pancreas and ras mutations in normal appearing duct cells, this molecular finding may not mean anything. In contrast, ras mutations are associated with smoking, one acknowledged risk factor for pancreatic carcinoma. The need for large prospective cohort studies is emphasized.
To study the possible role of dietary and supplementary selenium intake in the etiology of cancer, we carried out a case-control study of breast, colon, and prostate cancer in Montreal between 1989 and 1993. In this study, we were able to interview a total of 1,048 incidence cases of colon (402), breast (414) and prostate (232) cancer subjects and 688 population-based controls matched for age and gender. Of these, a total of 501 cancer cases and 202 controls produced toenail samples for their selenium concentrations, which were determined by neutron activation analysis. We found no association between toenail selenium and breast cancer (odds ratio [OR], 0.72; 95% confidence interval [CI], 0.4-1.31) or prostate cancer (OR, 1.14; 95% CI, 0.46-2.83), though we did observe a statistically significant inverse association between toenail selenium level and the risk of colon cancer for both genders combined (OR, 0.42; 95% CI, 0.19-0.93; P = .009) and for female subjects (P = .050). We also found that nonsmoker case and control subjects had higher selenium in their toenail samples. This could be due either to the nature of tobacco, which reduces selenium absorption, or to smokers' consumption of certain foods containing less selenium. Further epidemiologic studies are required to clarify the role of selenium in the etiology of certain cancers.
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BACKGROUND: Previous studies have suggested that the frequency of cancer is higher in patients with end-stage renal disease (ESRD) than in the general population, but have not established whether this increase is confined to certain cancers or to certain categories of ESRD patients. The aim of this study was to examine the risk of cancer in a large cohort of patients treated by dialysis but not transplantation. METHODS: We assembled a cohort of 831,804 patients who received dialysis during the period 1980-94 for ESRD in the USA, Europe, Australia, or New Zealand. We compared the observed frequency of cancer among these patients during 2,045,035 person-years of follow-up with the frequency of cancer in the respective background populations. FINDINGS: During average follow-up of 2.5 years, 25,044 (3%) of 831,804 patients developed cancer compared with an expected number of 21,185 (standardised incidence ratio 1.18 [95% CI 1.17-1.20]). We observed a higher risk of cancer in patients younger than 35 years (3.68 [3.39-3.99]), and the risk gradually decreased with increasing age. High risks were observed for cancer of the kidney (3.60 [3.45-3.76]), bladder (1.50 [1.42-1.57]), and thyroid and other endocrine organs (2.28 [2.03-2.54]). Excess cancers appeared in several organs for which viruses have been suspected as causative agents, whereas cancers of the lung, colorectum, prostate, breast, and stomach were not consistently increased. INTERPRETATION: The overall risk of cancer is increased in patients with ESRD, and the distribution of tumour types resembles the pattern seen after transplantation (although we have no data to make the comparison with skin cancer). The excess risk can largely be ascribed to effects of underlying renal or urinary-tract disease, or of loss of renal function, on the kidney and bladder, and to increased susceptibility to viral carcinogenesis. The relative risk, which is especially high in younger patients, gradually diminishes with age.
Our knowledge of the etiology of all forms of cancer including pancreatic cancer has improved dramatically in the second half of this century. The current model describes a gradual change from a normal pancreatic cell to a fully malignant cell requiring several stages with gradual and progressive alterations appearing at the genetic and the tissue level. Although there are many germ line diseases that are associated with pancreatic cancer it is probable that inherited diseases account for only about 10% of the total burden of pancreatic cancer. Avoidance of smoking and dietary modification are the current best strategies for reducing the risk of this tumor. In addition, newer molecular techniques and imaging procedures should provide clinicians with the ability to detect pancreatic cancer at an early, potentially curable stage.
BACKGROUND: Radioiodine is used increasingly as first-line treatment for hyperthyroidism, but concerns remain about subsequent risk of cancer, especially in those treated at a young age. We investigated cancer incidence and mortality in patients treated with radioiodine for hyperthyroidism. METHODS: We did a population-based study in 7417 patients treated in Birmingham, UK, between 1950 and 1991. We compared details of all cancer diagnoses and deaths in 1971-91 from the UK Office for National Statistics with data on cancer incidence and mortality for England and Wales specific for age, sex, and period. FINDINGS: During 72,073 person-years of follow-up, 634 cancer diagnoses were made, compared with an expected number of 761 (standardised incidence ratio [SIR] 0.83 [95% CI 0.77-0.90]). The relative risk of cancer mortality was also decreased (observed cancer deaths 448, expected 499; standardised mortality ratio [SMR] 0.90 [0.82-0.98]). Incidence of cancers of the pancreas, bronchus, trachea, bladder, and lymphatic and haemopoietic systems was lowered. Mortality from cancers at all these sites was also reduced but findings were significant only for bronchus and trachea. There were significant increases in incidence and mortality for cancers of the small bowel (SIR 4.81 [2.16-10.72], SMR 7.03 [3.16-15.66]) and thyroid (SIR 3.25 [1.69-6.25], SMR 2.78 [1.16-6.67]), although absolute risk of these cancers was small. INTERPRETATION: The decrease in overall cancer incidence and mortality in those treated for hyperthyroidism with radioiodine is reassuring. The absolute risk of cancers of the small bowel and thyroid remain low, but the increased relative risk shows the need for long-term vigilance in those receiving radioiodine.