Genomic scan of 254 hereditary prostate cancer families

Hereditary prostate cancer (HPC) is a genetically heterogeneous disease, complicating efforts to map and clone susceptibility loci. We have used stratification of a large dataset of 254 HPC families in an effort to improve power to detect HPC loci and to understand what types of family features may improve locus identification. The strongest result is that of a dominant locus at 6p22.3 (heterogeneity LOD (HLOD) = 2.51), the evidence for which is increased by consideration of the age of PC onset (HLOD = 3.43 in 214 families with median age-of-onset 56-72 years) and co-occurrence of primary brain cancer (HLOD = 2.34 in 21 families) in the families. Additional regions for which we observe modest evidence for linkage include chromosome 7q and 17p. Only weak evidence of several previously implicated HPC regions is detected. These analyses support the existence of multiple HPC loci, whose presence may be best identified by analyses of large, including pooled, datasets which consider locus heterogeneity.     

Genome-wide scan of Swedish families with hereditary prostate cancer: suggestive evidence of linkage at 5q11.2 and 19p13.3

BACKGROUND: Prostate cancer (CaP) is a common disorder with multiple genetic and environmental factors contributing to the disease. CaP susceptibility loci can be identified through genome-wide scans of high-risk families. METHODS: Allele sharing at 405 markers, distributed across the genome, among 50 families with hereditary prostate cancer, ascertained throughout Sweden, was evaluated through linkage analyses. Genotype data were analyzed utilizing multipoint parametric and non-parametric methods. RESULTS: Two regions provided suggestive evidence for linkage: 19p13.3 (marker D19S209, LOD = 2.91, P = 0.0001) and 5q11.2 (marker D5S407, LOD = 2.24, P = 0.0007). Additional regions with moderate evidence for linkage in the complete set of families, or stratified subsets, were observed on chromosome 1, 4, 6, 7, 8, and X. CONCLUSIONS: Our results provide strong confirmatory evidence of linkage at 19q13.3 and 5q11.2. The lack of confirmation of linkage at several loci identified in other genome-wide scans emphasizes the need to combine linkage data between research groups.     

Genome-wide scan for prostate cancer susceptibility genes in the Johns Hopkins hereditary prostate cancer families

BACKGROUND: Although the subject of intensive study, the genetic influences responsible for familial clustering of prostate cancer remain largely unidentified. Genome-wide scans for linkage in prostate cancer families can be used to systematically search for genes capable of affecting risk for the disease. METHODS: All available family members from 188 families, each having at least three first-degree relatives affected with prostate cancer, were genotyped at 406 markers distributed across the genome at average intervals of less than 10 cM. Genotype data was analyzed using primarily a non-parametric, multipoint approach, although parametric analyses were performed as well. RESULTS: The strongest evidence for linkage was observed at D4S1615, at 4q21 (LOD of 2.8, P = 0.0002). Two other regions had LOD scores over 2.0: at 9q34 (marker D9S1826, LOD = 2.17, P = 0.0008) and at 2q23 (marker D2S151, LOD = 2.03, P = 0.001). An additional 12 regions had LOD scores over 1.0, including markers at 1q24-25 and 7q22 having scores >1.6. Stratifying the linkage results by age of diagnosis indicated that the linkages to chromosomes 2 and 4 were strongest in families with early and late ages of diagnosis, respectively. CONCLUSIONS: Our data implicate several new loci as harboring prostate cancer susceptibility genes, and provide confirmatory evidence of linkage at several loci identified previously in other genome-wide scans, including the three regions (4q21, 9q34, and 2q23) with strongest evidence for prostate cancer linkage. These data also emphasize the need to combine linkage data from large numbers of prostate cancer families in efforts to effectively address the extensive heterogeneity that characterizes genetic aspects of this disease.     

Genomic scan of 12 hereditary prostate cancer families having an occurrence of pancreas cancer

BACKGROUND: Prostate cancer is a genetically heterogeneous disease. Using the occurrence of other cancers in hereditary prostate cancer (HPC) families is a promising strategy for developing genetically homogeneous data sets that can enhance the ability to identify susceptibility loci using linkage analysis. METHODS: Twelve HPC families with the co-occurrence of adenocarcinoma of the pancreas were selected from the Prostate Cancer Genetic Research Study (PROGRESS). Non-parametric linkage analysis for a prostate/pancreas cancer susceptibility phenotype was performed using 441 genome-wide microsatellite markers. RESULTS: No statistically significant linkage signal was detected in this analysis. The strongest linkage signals, as measured by Kong and Cox LOD score (KC LOD), were observed on chromosomes 2q37.2-q37.3 (KC LOD = 1.01; P = 0.02) and 16q23.2 (KC LOC = 1.05; P = 0.01). CONCLUSIONS: Despite the lack of statistically significant findings, four chromosomal regions, three of which (2q, 16q, 17q) were previously noted as harboring potential susceptibility loci, showed suggestive linkage results in this scan.     

Suggestive genetic linkage to chromosome 11p11.2-q12.2 in hereditary prostate cancer families with primary kidney cancer

BACKGROUND: The Seattle-based PROGRESS study was started in 1995 to ascertain hereditary prostate cancer (HPC) families for studies of genetic susceptibility. Subsequent studies by several research groups, including our own, suggest that HPC is a genetically heterogeneous disease. To be successful in mapping loci for such a complex disease, one must consider ways of grouping families into subsets that likely share the same genetic origin. Towards that end, we analyzed a genome-wide scan of HPC families with primary kidney cancer. METHODS: An 8.1 cM genome-wide scan including 441 microsatellite markers was analyzed by both parametric and non-parametric linkage approaches in fifteen HPC families with the co-occurrence of kidney cancer. RESULTS: There was no evidence for significant linkage in the initial findings. However, two regions of suggestive linkage were observed at 11q12 and 4q21, with HLOD scores of 2.59 and 2.10, respectively. The primary result on chromosome 11 was strengthened after excluding two families with members who had rare transitional cell carcinoma (TCC). Specifically, we observed a non-parametric Kong and Cox P-value of 0.004 for marker D11S1290 at 11p11.2. The 8 cM region between 11p11.2 and 11q12.2 was refined by the addition of 16 new markers. The subset of HPC families with a median age of diagnosis >65 years demonstrated the strongest evidence for linkage, with an HLOD = 2.50. The P-values associated with non-parametric analysis ranged from 0.004 to 0.05 across five contiguous markers. CONCLUSIONS: Analysis of HPC families with members diagnosed with primary renal cell carcinoma demonstrates suggestive linkage to chromosome 11p11.2-q12.2.     

Worry and attitude of men in at-risk families for prostate cancer about genetic susceptibility and genetic testing

BACKGROUND: The aim of this study was to evaluate worry about genetic susceptibility and the attitude of men with family history of prostate cancer (CaP) toward genetic testing. METHODS: Three hundred seventy-five eligible first-degree relatives (FDR) of men with CaP, were asked to participate in a screening and to fill out a survey covering the worry about genetic susceptibility and interest in genetic testing. RESULTS: Of the 375 candidates contacted, 277 completed the survey, and had undergone PSA measurement. Sixty-four percent worried a little or not at all about inherited predisposition to CaP, while the remainder worried a lot or extremely. The candidates who worried a lot or extremely were men with high levels of durable anxiety disposition (STAI trait), who had undergone a previous screening procedure and men with sons. Ninety-eight percent of men expressed their interest in undergoing genetic testing. The most motivated candidates to have the test done were men with several relatives with CaP. CONCLUSIONS: The level of worry about genetic susceptibility was low and there was a concrete interest in genetic testing in FDR of men with CaP. This interest increased with the number of CaP in the family.     

Genome-wide scan for prostate cancer susceptibility genes using families from the University of Michigan prostate cancer genetics project finds evidence for linkage on chromosome 17 near BRCA1

BACKGROUND: Previous linkage studies have suggested prostate cancer susceptibility genes located on chromosomes 1, 20, and X. Several putative prostate cancer candidate genes have also been identified including RNASEL, MSR1, and ELAC2. Presently, these linkage regions and candidate genes appear to explain only a small proportion of hereditary prostate cancer cases suggesting the need for additional whole genome analyses. METHODS: A genome-wide mode-of-inheritance-free linkage scan, using 405 genetic markers, was conducted on 175 pedigrees, the majority containing three or more affected individuals diagnosed with prostate cancer. Stratified linkage analyses were performed based on previously established criteria. RESULTS: Results based on the entire set of 175 pedigrees showed strong suggestive evidence for linkage on chromosome 17q (LOD = 2.36), with strongest evidence coming from the subset of pedigrees with four or more affected individuals (LOD = 3.27). Race specific analyses revealed strong suggestive evidence for linkage in our African-American pedigrees on chromosome 22q (LOD = 2.35). CONCLUSIONS: Genome-wide analysis of a large set of prostate cancer families indicates new areas of the genome that may harbor prostate cancer susceptibility genes. Specifically, our linkage results suggest that there is a prostate cancer susceptibility gene on chromosome 17 that is independent of ELAC2. Further research including combined analyses of independent genome-wide scan data may clarify the most important regions for future investigation.     

Genome-wide linkage scan for prostate cancer aggressiveness loci using families from the University of Michigan Prostate Cancer Genetics Project

BACKGROUND: Prostate cancer (PC) is a complex disease that displays variable disease outcome, ranging from a relatively indolent disease to forms that result in death from the disease. One measure of disease severity is the Gleason score. Using the Gleason score as a measure of tumor aggressiveness, several independent genome scans have reported evidence of linkage. As of yet, however, no genes have been implicated. METHODS: We report an independent genome scan using the Gleason score as a quantitative trait. We genotyped 405 highly polymorphic microsatellite markers in 175 brother pairs from 103 families. RESULTS: Our strongest evidence of linkage is to 6q23 at 137 cM (D6S292, P = 0.0009). Other interesting regions (P < 0.005) were on chromosome 1p13-q21 and on chromosome 5p13-q11. CONCLUSIONS: Our results provide further evidence that tumor aggressiveness has a genetic component, and that this genetic component may be influenced by several independent genes.     

Genome linkage screen for prostate cancer susceptibility loci: results from the Mayo Clinic Familial Prostate Cancer Study

Prostate cancer is one of the most common cancers among men and has long been recognized to occur in familial clusters. Brothers and sons of affected men have a twofold to threefold increased risk of developing prostate cancer. However, identification of genetic susceptibility loci for prostate cancer has been extremely difficult. Several putative loci identified by genetic linkage have been reported to exist on chromosomes 1 (HPC1, PCAP, and CAPB), X (HPCX), 17 (HPC2), and 20 (HPC20), with genes RNASEL (HPC1) and ELAC2 (HPC2) tentatively defined. In this study, we report our genome linkage scan in 160 prostate cancer families, using the ABI Prism Linkage Mapping Set Version 2 with 402 microsatellite markers. The most significant linkage was found for chromosome 20, with a recessive model heterogeneity LOD score (HLOD) of 4.77, and a model-free LOD score (LOD - ZLR) of 3.46 for the entire group of pedigrees. Linkage for chromosome 20 was most prominent among families with a late age of diagnosis (average age at diagnosis >/= 66 years; maximum LOD - ZLR = 2.82), with <5 affected family members (LOD - ZLR = 3.02), with presence of hereditary prostate cancer (LOD - ZLR = 2.81), or with no male-to-male transmission of disease (LOD - ZLR = 3.84). No other chromosome showed significant evidence for linkage. However, chromosomes 6 and X showed suggestive results, with maximum LOD - ZLR values of 1.38 and 1.36, respectively. Subset analyses suggest additional chromosomal regions worth further follow-up.     

Population-based risk assessment for other cancers in relatives of hereditary prostate cancer (HPC) cases

BACKGROUND: To identify associations of other cancers with hereditary prostate cancer (HPC) we estimated relative risks (RRs) of 36 different cancers in relatives of prostate cancer cases in the Utah Population Data Base (UPDB), which combines genealogical and cancer data for Utah. METHODS: We utilized known genetic relationships between prostate cancer cases and their relatives with cancer, combined with age- and sex-specific cancer rates calculated internally from the UPDB, to estimate RRs for cancer in relatives of prostate cancer cases. RESULTS: Multiple other cancers were observed in excess in both first- and second-degree relatives of HPC cases including colon cancer, non-Hodgkins lymphoma, multiple myeloma, rectal cancer, cancer of the gallbladder, and melanoma (skin). CONCLUSIONS: This analysis supports the existence of heritable prostate cancer syndromes that include other cancers. We hypothesize that the study of homogeneous pedigrees co-segregating prostate cancer and another cancer could allow more straightforward localization and identification of the gene(s) responsible.     

Tumor characteristics in screening for prostate cancer with and without rectal examination as an initial screening test at low PSA (0.0-3.9 ng/ml)

BACKGROUND: The value of rectal examination as initial screening test for prostate cancer at low PSA values (0.0-3.9 ng/ml) was determined by evaluating the number and tumor characteristics of the cancers detected. METHODS: Two study populations were subjected to screening with (n = 10,226) and without (n = 10,753) rectal examination as initial screening test. The number of cancers detected at low PSA values for both screening regimens, the corresponding biopsy and radical prostatectomy tumor characteristics were assessed. Possibly harmless cancers were defined as small (< 0.5 ml) organ-confined tumors without Gleason growth-patterns 4/5. RESULTS: At low PSA, 26.6% (117/440) of screen-detected cancers were detected after the evaluation of a suspicious rectal examination. The number of cancers and tumor aggressiveness features were highly associated with serum-PSA level. The proportion of possibly harmless disease steadily declined from 100% (PSA 0.0-0.9 ng/ml) to 15.4% (PSA 3.0-3.9 ng/ml). Rectal examinations were performed unnecessarily in 94.7-100% of cases, when detection of clinically significant disease was aimed at. Using PSA (and a cut-off of 3.0 ng/ml) as the only screening tool, 24.3% (121/498) of screen-detected cancers were in the PSA range 3.0-3.9 ng/ml, and 60.0% were assessed as clinically significant. CONCLUSIONS: Rectal examination as initial screening test for prostate cancer at low PSA values may be replaced by screening using serum-PSA only. At PSA levels below 3.0 ng/ml, 289 rectal examinations are required to find one case of clinically significant disease, and 96 rectal examinations are needed to diagnose prostate cancer of any size, grade, or stage.     

Early versus delayed endocrine treatment of T2-T3 pN1-3 M0 prostate cancer without local treatment of the primary tumour: final results of European Organisation for the Research and Treatment of Cancer protocol 30846 after 13 years of follow-up (a randomised controlled trial)

Background

The timing of endocrine treatment (ET) for prostate cancer (PCa) remains controversial. The issue is addressed in European Organisation for the Research and Treatment of Cancer (EORTC) protocol 30846 for patients with lymph node–positive (pN1-3) cancer without local treatment of the primary tumour.

Objective

To evaluate the effect of early versus delayed treatment in pN1-3 PCa.

Design, setting, and participants

Two hundred thirty-four patients with histologically proven PCa and nodal metastases (pN1-3) were randomized to immediate versus delayed ET without treatment of the primary tumour. ET consisted of a depot luteinising hormone-releasing hormone (LHRH) agonist and 1 mo of an anti-androgen or surgical castration. The trial's main objective was to show non-inferiority of delayed ET to immediate ET by ruling out a hazard ratio (HR) of 1.50 for overall survival (OS), with 85% power at one-sided α = 5%.

Measurements

All but three patients were treated as randomized. The median follow-up is 13 yr. The median protocol treatment duration was 2.7 yr in the delayed and 3.2 yr in the immediate ET groups.

Results and limitations

Overall, 193 patients (82.5%) have died (97 on delayed ET and 96 on immediate ET), 59.4% of them as a result of PCa. The intention-to-treat analysis shows a 22% increase in the hazard of death of those randomized to delayed treatment (HR = 1.22, 95% confidence interval [CI]: 0.92, 1.62). The difference is not statistically significant, but non-inferiority is also not proved.The median OS on immediate ET is 7.6 yr (95% CI, 6.3–8.3 yr) versus 6.1 yr (95% CI, 5.7–7.3 yr) in the delayed ET group. The 10-yr cumulative incidence of death resulting from PCa was 55.6% in the delayed ET group versus 52.1% with immediate ET group. Similar conclusions hold for PCa-specific survival.

Conclusions

After 13 years of follow-up, survival or PCa-specific survival between immediate and delayed ET appear similar, but the trial is underpowered to reach its goal of showing non-inferiority.