WAERS: an application for Web-assisted estimation of relative survival

Net cancer survival estimation is usually performed by computing relative survival (RS), which is defined as the ratio between observed and expected survival rates. The mortality of a reference population is required in order to compute the expected survival rate, which can be performed using a variety of statistical packages. A new Web interface to compute RS, called WAERS, has been developed by the Catalan Institute of Oncology. The reference population is first selected, and then the RS of a cohort is computed. A remote server is used for this purpose. A mock example serves to illustrate the use of the tool with a hypothetical cohort, for which RS is estimated based on three different reference populations (a province of Spain, an autonomous community (Region), and the entire Spanish population). At present, only mortality tables for different areas of Spain are available. Future improvements of this application will include mortality tables of Latin American and European Union countries, and stratified (control variable) analysis. This application can be also useful for cohort mortality studies and for registries of several diseases.     

Time trends in incidence and mortality for chronic liver disease and liver cancer in the interval 1980-1997 in Catalonia, Spain

BACKGROUND AND AIMS: It has been reported that the incidence of liver cancer and intrahepatic bile duct tumours might be increasing in some developed countries. The purpose of this study was to examine time trends of incidence and mortality rates of liver cirrhosis and liver cancer for the period 1980-1997 in Catalonia, Spain. METHODS: Data were obtained from the Catalan Mortality Registry and the Tarragona Cancer Registry. Joinpoint analysis was used to detect time-related changes in incidence and mortality of liver diseases. The cohort effect on mortality and incidence rates was explored by an age-period-cohort model. RESULTS: Mortality from liver cirrhosis decreased during the study period for both sexes and all age groups, with the exception of men aged between 25 and 35 years. No changes in incidence or mortality rates were observed for liver cancer. Mortality rates for intrahepatic bile duct tumours increased in men and women, while incidence rates remained stable. CONCLUSIONS: This study identified in Catalonia an increase in mortality due to liver cirrhosis among 25-35-year-old men. Mortality rates for intrahepatic bile duct tumours increased for all age groups and both sexes. The former could be related to hepatitis C or B viruses and human immunodeficiency virus co-infection, while the latter remains unexplained.     

Distribution of HLA genotypes in sibs of patients with acute leukaemia

More unaffected sibs than expected have the same HLA genotypes as their sib with acute leukaemia. This seems not to be due to the restricted heterogeneity in HLA antigens described in the parents of sibs with acute leukaemia.     

Genetic comparison of HIV-1 isolates from Africa, Europe, and North America.

Laboratory scientists used anchored polymerase chain reaction (PCR) and DNA sequencing to compare HIV-1 isolates from countries in Africa (Ivory Coast, Gabon, Zaire, Kenya, and others), Europe (Belgium and other countries), and the US. The US isolates had the most homogenous PCR profile followed by the European pattern. There was considerable PCR primer mispairing for the African isolates, especially those from Kenya, indicating that the range of HIV-1 variation could have been rather extensive. This virus diversity could greatly affect therapy or intervention in sites in Africa with such a complex mix of variants. Nevertheless, the genetic information of these diverse isolates could bring about research leading to an anti-HIV-1 vaccine. For example, the expanded DNA sequence data base could record phylogenetic relationships, thereby, helping researchers choose prototypic variants for vaccine development. More information would allow researchers to generate new PCR primers for better discrimination of variants. They could apply PCR typing to huge sample sizes to adequately document HIV-1 variation in Africa. It could also prove invaluable as a means to determine incidence and prevalence of local variants during vaccine field trials. It can also discern the limiting criteria for HIV-1 genetic variation.     

Rearrangements of immunoglobulin and TCR genes in lymphoid blast crisis of Ph + chronic myeloid leukaemia

Clonal rearrangements of immunoglobulin heavy chain genes as well as both T cell receptor (TCR) delta and gamma genes were found in four cases of blast crisis of Ph+ chronic myeloid leukaemia with unequivocal B cell precursor (common) immunophenotype. In one case, the TCR beta chain gene was also rearranged. Although the developmental sequence of TCR delta, gamma and beta rearrangements in T lymphocytes appeared to be respected, a full phenotypic effect, characteristic of T cell was not observed in these otherwise typical 'common' blast cells. Cytogenetic analysis ruled out the occurrence of TCR rearrangement due to structural chromosome changes. A high incidence of unexpected TCR gene rearrangements has been previously reported in the de novo 'common' acute lymphoblastic leukaemias (ALL). Our cases of chronic myeloid leukaemia (CML) in lymphoid blast crisis show that genotypic similarities may exist between these two haematological entities.     

Trisomy 3q11-q29 is recurrently observed in B-cell non-Hodgkin's lymphomas associated with cold agglutinin syndrome

 Three cases of low-grade B-cell non-Hodgkin's lymphoma associated with cold agglutinin syndrome, cytogenetically characterized by partial trisomy 3, are presented in this report. Our data suggest that the long arm of chromosome 3 might be of particular importance in the pathogenesis of this subgroup of lymphomas. Received: 10 November 1997 / Accepted: 4 February 1998     

Cofactors associated with liver disease mortality in an HBsAg-positive Mediterranean cohort: 20 years of follow-up

The risk of developing liver cancer in hepatitis B virus (HBV) carriers differs across geographical areas, suggesting that exposure to other risk factors may contribute to HBV-linked cancer risk. Our study estimates the mortality due to liver disease and the role of other risk factors in a Spanish HBV cohort. 2,352 hepatitis B surface antigen (HBsAg)-positive and 15,504 HBsAg-negative subjects were identified among blood donors during 1972-1985 and were followed until December 2000 through the Mortality Registry. Clinical examination and an epidemiological questionnaire were performed on 1,000 HBsAg-positive survivors during 1994-1996. In subjects deceased from liver disease, medical records were revised and relatives were interviewed. A nested case-control analysis was conducted comparing both groups. In HBsAg-positive men, an excess mortality from liver cancer [standardized mortality ratio (SMR): 14.1; 7.7-23.6], cirrhosis (SMR: 10.5; 7.0-15.1), haematological neoplasms (SMR: 3.2; 1.2-6.9) and AIDS was detected (SMR: 5.5; 2.2-11.4). In women, an excess was found for cirrhosis (SMR: 7.2; 1.4-21.1). Progression factors to liver disease were alcohol intake [odds ratio (OR): 6.3; 3.1-12.8], diabetes (OR: 3.6; 1.3-9.6), HBV replication (OR: 50.0; 14.9-167.3) and hepatitis C virus (HCV) infection (OR: 27.4; 7.1-107.7). In conclusion, in Spain after 20 years of follow-up, chronic HBV exposure appears as a major risk factor for liver cancer among men and for cirrhosis in both sexes. The risk of death from liver disease among HBV carriers with the presence of HBV replication, HCV, alcohol consumption and diabetes was significantly increased and suggests synergism among these exposures and HBV. Mortality from haematological neoplasms was detected and could be associated to HIV coinfection. These results support screening and adequate follow-up among HBsAg-positive subjects at high risk to develop liver disease, particularly when these risk cofactors are present.