Sequencing of prostate cancers identifies new cancer genes, routes of progression and drug targets.

Prostate cancer represents a substantial clinical challenge because it is difficult to predict outcome and advanced disease is often fatal. We sequenced the whole genomes of 112 primary and metastatic prostate cancer samples. From joint analysis of these cancers with those from previous studies (930 cancers in total), we found evidence for 22 previously unidentified putative driver genes harboring coding mutations, as well as evidence for NEAT1 and FOXA1 acting as drivers through noncoding mutations. Through the temporal dissection of aberrations, we identified driver mutations specifically associated with steps in the progression of prostate cancer, establishing, for example, loss of CHD1 and BRCA2 as early events in cancer development of ETS fusion-negative cancers. Computational chemogenomic (canSAR) analysis of prostate cancer mutations identified 11 targets of approved drugs, 7 targets of investigational drugs, and 62 targets of compounds that may be active and should be considered candidates for future clinical trials.

Appraising the relevance of DNA copy number loss and gain in prostate cancer using whole genome DNA sequence data.

A variety of models have been proposed to explain regions of recurrent somatic copy number alteration (SCNA) in human cancer. Our study employs Whole Genome DNA Sequence (WGS) data from tumor samples (n = 103) to comprehensively assess the role of the Knudson two hit genetic model in SCNA generation in prostate cancer. 64 recurrent regions of loss and gain were detected, of which 28 were novel, including regions of loss with more than 15% frequency at Chr4p15.2-p15.1 (15.53%), Chr6q27 (16.50%) and Chr18q12.3 (17.48%). Comprehensive mutation screens of genes, lincRNA encoding sequences, control regions and conserved domains within SCNAs demonstrated that a two-hit genetic model was supported in only a minor proportion of recurrent SCNA losses examined (15/40). We found that recurrent breakpoints and regions of inversion often occur within Knudson model SCNAs, leading to the identification of ZNF292 as a target gene for the deletion at 6q14.3-q15 and NKX3.1 as a two-hit target at 8p21.3-p21.2. The importance of alterations of lincRNA sequences was illustrated by the identification of a novel mutational hotspot at the KCCAT42, FENDRR, CAT1886 and STCAT2 loci at the 16q23.1-q24.3 loss. Our data confirm that the burden of SCNAs is predictive of biochemical recurrence, define nine individual regions that are associated with relapse, and highlight the possible importance of ion channel and G-protein coupled-receptor (GPCR) pathways in cancer development. We concluded that a two-hit genetic model accounts for about one third of SCNA indicating that mechanisms, such haploinsufficiency and epigenetic inactivation, account for the remaining SCNA losses.

The PROFILE Feasibility Study: Targeted Screening of Men With a Family History of Prostate Cancer.

BACKGROUND: A better assessment of individualized prostate cancer (PrCa) risk is needed to improve screening. The use of the prostate-specific antigen (PSA) level for screening in the general population has limitations and is not currently advocated. Approximately 100 common single nucleotide polymorphisms (SNPs) have been identified that are associated with the risk of developing PrCa. The PROFILE pilot study explored the feasibility of using SNP profiling in men with a family history (FH) of PrCa to investigate the probability of detecting PrCa at prostate biopsy (PB). The primary aim of this pilot study was to determine the safety and feasibility of PrCa screening using transrectal ultrasound-guided PB with or without diffusion-weighted magnetic resonance imaging (DW-MRI) in men with a FH. A secondary aim was to evaluate the potential use of SNP profiling as a screening tool in this population. PATIENTS AND METHODS: A total of 100 men aged 40-69 years with a FH of PrCa underwent PB, regardless of their baseline PSA level. Polygenic risk scores (PRSs) were calculated for each participant using 71 common PrCa susceptibility alleles. We treated the disease outcome at PB as the outcome variable and evaluated its associations with the PRS, PSA level, and DW-MRI findings using univariate logistic regression. RESULTS: Of the 100 men, 25 were diagnosed with PrCa, of whom 12 (48%) had clinically significant disease. Four adverse events occurred and no deaths. The PSA level and age at study entry were associated with PrCa at PB (p = .00037 and p = .00004, respectively). CONCLUSION: The results of the present pilot study have demonstrated that PB is a feasible and safe method of PrCa screening in men with a FH, with a high proportion of PrCa identified requiring radical treatment. It is feasible to collect data on PrCa-risk SNPs to evaluate their combined effect as a potential screening tool. A larger prospective study powered to detect statistical associations is in progress. IMPLICATIONS FOR PRACTICE: Prostate biopsy is a feasible and safe approach to prostate cancer screening in men with a family history and detects a high proportion of prostate cancer that needs radical treatment. Calculating a polygenic risk score using prostate cancer risk single nucleotide polymorphisms could be a potential future screening tool for prostate cancer.

Analysis of the genetic phylogeny of multifocal prostate cancer identifies multiple independent clonal expansions in neoplastic and morphologically normal prostate tissue.

Genome-wide DNA sequencing was used to decrypt the phylogeny of multiple samples from distinct areas of cancer and morphologically normal tissue taken from the prostates of three men. Mutations were present at high levels in morphologically normal tissue distant from the cancer, reflecting clonal expansions, and the underlying mutational processes at work in morphologically normal tissue were also at work in cancer. Our observations demonstrate the existence of ongoing abnormal mutational processes, consistent with field effects, underlying carcinogenesis. This mechanism gives rise to extensive branching evolution and cancer clone mixing, as exemplified by the coexistence of multiple cancer lineages harboring distinct ERG fusions within a single cancer nodule. Subsets of mutations were shared either by morphologically normal and malignant tissues or between different ERG lineages, indicating earlier or separate clonal cell expansions. Our observations inform on the origin of multifocal disease and have implications for prostate cancer therapy in individual cases.

Trends in pathologic outcomes after introduction of active surveillance in the UK: implication for focal therapy.

BACKGROUND: We aimed to evaluate the trends in pathologic outcomes of clinically localized prostate cancer treated with radical prostatectomy prior to and after national guidelines placing active surveillance as the primary management in men with low-risk prostate cancer. Further, we examined whether there was a coincident change in the proportion of men potentially suitable for focal therapy. METHODS: All cancer foci in 195 whole mount radical prostatectomy samples during two periods (Period 1: 07/2001-10/2003, n = 100 and Period 2: 01/2007-11/2009, n = 95) were examined. Individual tumor volumes, Gleason grade, and extracapsular extension/positive surgical margins were evaluated. The index lesion was defined as the largest by volume. RESULTS: There was a statistically significant increase in the proportion of Gleason score ≥7 tumors (31-69%; P < 0.001) and pathologically non-organ confined disease (21-37%; P = 0.008), between period 1 and 2, respectively. The proportion of patients with unifocal prostate cancer potentially suitable for focal ablation was stable (14-13.7%; P = 0.9). Although there was a decrease in the proportion of patients potentially suitable for index lesion ablation (51-43%; P = 0.4) and unilateral prostate cancer potentially suitable for hemi-ablation (11-6.3%; P = 0.3), these differences were not statistically significant. CONCLUSION: The increasing use of active surveillance in the UK may be responsible for a trend towards higher grade and stage prostate cancer in whole mount specimens. Despite this, there remain a significant proportion of men who currently undergo radical surgery who may be suitable for focal therapy, if that included index lesion ablation.

Metastatic renal mucinous tubular and spindle cell carcinoma. Atypical behavior of a rare, morphologically bland tumor.

Mucinous tubular and spindle cell carcinoma (MTSCC) is a rare, distinctive renal neoplasm characterized by an admixture of cuboidal cells in tubules and sheets of spindle cells, typically with low-grade nuclei and a myxoid or mucinous background. It is characteristically of low malignant potential, and only rare metastatic cases have been reported. We describe a case in which the patient presented with extensive regional and distant metastases, but both primary and metastatic tumor showed the typical histomorphology of bland cuboidal or spindle cells lacking pleomorphism, mitoses, and necrosis. Almost all previous cases of metastatic MTSCCs have shown nuclear atypia or sarcomatoid morphology of the primary tumor; and metastatic renal MTSCC in which the primary neoplasm does not display atypical features is exceptional, serving to highlight that these rare tumors can behave aggressively even with "indolent" histological appearances.

The role of embolization in the management of tumour recurrence after radical nephrectomy.

This article presents the case of a 56-year-old woman who developed a tumour recurrence following radical nephrectomy. This was invading the descending colon and causing severe gastrointestinal haemorrhage. Angiography revealed neovascularization from T11 and T12 intercostal arteries, which were successfully embolized percutaneously.

Case report: PET/CT, a cautionary tale.

BACKGROUND: The use of combined positron emission tomography/computerised tomography (PET/CT) scanners in oncology has been shown to improve the staging of tumours and the detection of relapses. However, mis-registration errors are increasingly recognised to be a common pitfall of PET/CT studies. CASE PRESENTATION: We report a patient with a germ cell tumour of the testis, who underwent a PET/CT scan to detect the site of relapse with a view to surgical removal. However, the PET/CT scan mislocalised the tumour site to be within the T2 vertebral body. A subsequent endoscopic ultrasound scan however showed the tumour to be anterior to the vertebral body, which was confirmed at surgery. CONCLUSION: In this report, we highlight the artefactual mislocalisation errors which may occur with PET/CT imaging, and the need to review and verify these scans.

Characteristics of incidental prostatic adenocarcinoma in contemporary radical cystoprostatectomy specimens.

OBJECTIVES: To investigate the relationship between prostate-specific antigen (PSA) level and tumour volume for incidental adenocarcinoma of the prostate found in cystoprostatectomy (CP) specimens, and to analyse the incidence of clinically significant prostate cancers in CP specimens and the biochemical recurrence of incidental prostate cancers on short-term follow up. PATIENTS AND METHODS: Complete data from 97 of 105 prostates from CP specimens were available. Prostates were thoroughly analysed and sectioned at 2 mm intervals. PSA levels and the findings at digital rectal examination before surgery were obtained prospectively. None of the patients had any evidence of prostate cancer before CP. RESULTS: Incidental prostate cancer was detected in 58 of 97 (60%) of the CP specimens; of these, 31 (53%) were significant according to the definition of Stamey et al. There was a weak correlation between tumour volume and PSA level, weighted solely by the four larger-volume cancers. The median PSA level for patients with and without prostate cancer was not significantly different (3.1 vs 1.1 ng/mL, P = 0.06). The follow-up of the 35 patients alive with prostate cancer showed four PSA recurrences (PSA >0.02 ng/mL) with one distant metastasis after a median follow-up of 3 years. None of the patients with insignificant tumours developed biochemical recurrence. CONCLUSIONS: The weak correlation between PSA level and tumour volume in these patients supports the argument that PSA is largely produced by benign prostatic hyperplasia and is therefore a poor screening tool for asymptomatic healthy men. Most incidental prostate cancers in CP specimens are significant, contrary to previous analyses, but have little practical importance in terms of oncological outcome.

The role of transbronchial fine needle aspiration in an integrated care pathway for the assessment of patients with suspected lung cancer.

Transbronchial fine needle aspiration (TBNA) is a simple technique for sampling mediastinal lymph nodes and may provide additional information in patients with suspected lung cancer. However, the technique is still under-utilized, and the objective of this study was to evaluate the value of TBNA as part of an integrated pathway for the assessment of patients with suspected lung cancer. All patients referred to the lung cancer services of our institutions were prospectively evaluated. TBNA was performed in all patients with evidence of mediastinal lymphadenopathy. TBNA of one or more lymph node sites were performed in 129 of these patients. TBNA was the sole diagnostic modality in 23% of patients and provided positive staging information for 49% of patients, with adequate sampling in 71% of patients. Among patients with mediastinal adenopathy, the number of patients who required a TBNA performed to diagnose one patient with malignancy in patients suspected with lung cancer (number needed to diagnose) was 1.47 (95% confidence interval, 1.47-1.76). No complications were observed in patients who underwent TBNA. TBNA improves the diagnostic yield and staging of patients with lung cancer. Moreover, it is a simple, low-cost, and safe test, which should be incorporated into the diagnostic pathway of patients with suspected lung cancer.