Search

Purpose: In patients with metastatic prostate cancer (mPC), ATM and BRCA2 mutations dictate differences in PARPi inhibitor response and other therapies. We interrogated the molecular features of ATM- and BRCA2-mutated mPC to explain the divergent clinical outcomes and inform future treatment decisions. Experimental design: We examined a novel set of 1,187 mPCs after excluding microsatellite-instable (MSI) tumors. We stratified these based on ATM (n = 88) or BRCA2 (n = 98) mutations. As control groups, mPCs with mutations in 12 other homologous recombination repair (HRR) genes were considered non-BRCA2/ATM HRR-deficient (HRDother, n = 193), whereas lack of any HRR mutations were considered HRR-proficient (HRP; n = 808). Gene expression analyses were performed using Limma. Real-world overall survival was determined from insurance claims data. Results: In noncastrate mPCs, only BRCA2-mutated mPCs exhibited worse clinical outcomes to AR-targeted therapies. In castrate mPCs, both ATM and BRCA2 mutations exhibited worse clinical outcomes to AR-targeted therapies. ATM-mutated mPCs had reduced TP53 mutations and harbored coamplification of 11q13 genes, including CCND1 and genes in the FGF family. BRCA2-mutated tumors showed elevated genomic loss-of-heterozygosity scores and were often tumor mutational burden high. BRCA2-mutated mPCs had upregulation of cell-cycle genes and were enriched in cell-cycle signaling programs. This was distinct from ATM-mutated tumors. Conclusions: Tumoral ATM and BRCA2 mutations are associated with differential clinical outcomes when patients are stratified by treatments, including hormonal or taxane therapies. ATM- and BRCA2-mutated tumors exhibited differences in co-occurring molecular features. These unique molecular features may inform therapeutic decisions and development of novel therapies.

The familial aggregation of bladder cancers has been observed, but the incidence and association of familial bladder cancer with germline pathogenic and likely pathogenic (P/LP) variants is unknown.A retrospective analysis was conducted of patients with bladder cancer treated at the Dana-Farber Cancer Institute to identify those with a first-degree relative with bladder cancer. A second cohort of patients referred to DFCI for suspicion of a cancer predisposition syndrome was analyzed for candidate P/LP germline variants. Descriptive statistics were generated.Among 885 patients with bladder cancer, 38 patients (4.3%) had a family history of bladder cancer in a first-degree relative. No significant association of age of diagnosis was observed between patients with and without a first-degree family history of bladder cancer (P = .3). In the second cohort, 27 of 80 (34%) patients with bladder cancer evaluated for cancer predisposition syndromes harbored a P/LP germline variant. P/LP variants were identified most commonly in the following genes: BRCA1 (n = 5), MSH2 (n = 5), MLH1 (n = 4), ATM (n = 3), and CHEK2 (n = 2). Of the 27 patients with identified germline P/LP variants, 20 (74%) had a family history of a tumor component syndrome in a first- or second-degree relative and 3 were subsequently diagnosed with another genetically-linked associated cancer.Familial bladder cancer defined as bladder cancer in the proband and a first-degree relative, was present in 4.3% of patients with bladder cancer and was not associated with age of diagnosis. Additionally, among patients suspected to have a familial cancer syndrome, one-third harbored a germline P/LP variant. Further study of germline variants in patients with familial bladder cancer including somatic testing for loss of heterozygosity may provide insights regarding disease pathogenesis and inform therapy.

Tumor mutation burden (muts/Mb) of ATM and BRCA2 mutant mPCs.

Comparisons of WTS profiles between ATMm and BRCA2m to the HRP group.

AR activities and NEPC signatures in ATM- and BRCA2- mutated tumors.

Overall survival of ATM, BRCA2 mutant, and HRDother mPCs.

Composition and rates of all detectable genomic features detectable through the Caris diagnostic platform.

Purpose:In patients with metastatic prostate cancer (mPC), ATM and BRCA2 mutations dictate differences in PARPi inhibitor response and other therapies. We interrogated the molecular features of ATM- and BRCA2-mutated mPC to explain the divergent clinical outcomes and inform future treatment decisions.Experimental design:We examined a novel set of 1,187 mPCs after excluding microsatellite-instable (MSI) tumors. We stratified these based on ATM (n = 88) or BRCA2 (n = 98) mutations. As control groups, mPCs with mutations in 12 other homologous recombination repair (HRR) genes were considered non-BRCA2/ATM HRR-deficient (HRDother, n = 193), whereas lack of any HRR mutations were considered HRR-proficient (HRP; n = 808). Gene expression analyses were performed using Limma. Real-world overall survival was determined from insurance claims data.Results:In noncastrate mPCs, only BRCA2-mutated mPCs exhibited worse clinical outcomes to AR-targeted therapies. In castrate mPCs, both ATM and BRCA2 mutations exhibited worse clinical outcomes to AR-targeted therapies. ATM-mutated mPCs had reduced TP53 mutations and harbored coamplification of 11q13 genes, including CCND1 and genes in the FGF family. BRCA2-mutated tumors showed elevated genomic loss-of-heterozygosity scores and were often tumor mutational burden high. BRCA2-mutated mPCs had upregulation of cell-cycle genes and were enriched in cell-cycle signaling programs. This was distinct from ATM-mutated tumors.Conclusions:Tumoral ATM and BRCA2 mutations are associated with differential clinical outcomes when patients are stratified by treatments, including hormonal or taxane therapies. ATM- and BRCA2-mutated tumors exhibited differences in co-occurring molecular features. These unique molecular features may inform therapeutic decisions and development of novel therapies.

BackgroundAlthough clinical features of multi-parametric magnetic resonance imaging (mpMRI) have been associated with biochemical recurrence in localized prostate cancer, such features are subject to inter-observer variability.ObjectiveTo evaluate whether the volume of the dominant intraprostatic lesion (DIL), as provided by a deep learning segmentation algorithm, could provide prognostic information for patients treated with definitive radiation therapy (RT).Design, Setting, and ParticipantsRetrospective study of 438 patients with localized prostate cancer who underwent an endorectal coil, high B-value, 3-Tesla mpMRI and were treated with RT between 2010 and 2017.InterventionRT.Outcome Measurements and Statistical AnalysisBiochemical recurrence and metastasis risk, assessed with a cause-specific Cox regression and time-dependent receiver operating characteristic analysis.Results and LimitationsThe artificial intelligence (AI) model identified DILs with an area under the receiver operating characteristic curve (AUROC) of 0.827 at the patient level. For the 233 patients with available PI-RADS scores, with a median follow-up of 5.6 years, AI-defined DIL volume was significantly associated with biochemical failure (adjusted hazard ratio 1.54, 95% confidence interval 1.09-2.17, p=0.014) after adjustment for PI-RADS score. Among all 438 patients with a median follow-up of 6.9 years, the AUROC for predicting 7-year biochemical failure for AI volume (0.790) was similar to that for an expanded National Comprehensive Cancer Network (NCCN+) category (p=0.17). The AUROC for predicting 7-year metastasis for AI volume trended towards being higher compared to NCCN+ categories (0.854 vs 0.769, p=0.06).ConclusionsA deep learning algorithm could identify the DIL with good performance. AI-defined DIL volume may be able to provide prognostic information independent of the NCCN+ risk group or other radiologic factors for patients with localized prostate cancer treated with RT.

Supplementary Figure 1. Mutation rates by cohort. Supplementary Figure 2. ERCC2 mutations. Supplementary Figure 3. ERCC2 mutation status and overall survival. Supplementary Figure 4. ERCC2 mutations occur in highly conserved regions.

The incidence of anal squamous cell carcinoma (ASCC) has been increasing, particularly in populations with HIV. Human papillomavirus (HPV) is the causal factor in 85% to 90% of ASCCs, but few studies evaluated HPV genotypes and integrations in relation to genomic alterations in ASCC. Using whole-exome sequence data for primary (n = 56) and recurrent (n = 31) ASCC from 72 patients, we detected HPV DNA in 87.5% of ASCC, of which HPV-16, HPV-18, and HPV-6 were detected in 56%, 22%, and 33% of HIV-positive (n = 9) compared with 83%, 3.2%, and 1.6% of HIV-negative cases (n = 63), respectively. Recurrent copy-number variations (CNV) involving genes with documented roles in cancer included amplification of PI3KCA and deletion of APC in primary and recurrent tumors; amplifications of CCND1, MYC, and NOTCH1 and deletions of BRCA2 and RB1 in primary tumors; and deletions of ATR, FANCD2, and FHIT in recurrent tumors. DNA damage response genes were enriched among recurrently deleted genes in recurrent ASCCs (P = 0.001). HPV integrations were detected in 29 of 76 (38%) ASCCs and were more frequent in stage III–IV versus stage I–II tumors. HPV integrations were detected near MYC and CCND1 amplifications and recurrent targets included NFI and MUC genes. These results suggest HPV genotypes in ASCC differ by HIV status, HPV integration is associated with ASCC progression, and DNA damage response genes are commonly disrupted in recurrent ASCCs.Implications:These data provide the largest whole-exome sequencing study of the ASCC genomic landscape to date and identify HPV genotypes, integrations, and recurrent CNVs in primary or recurrent ASCCs.

Significantly altered genes in clinical subsets. MutSigCV ranked lists for significantly mutated genes in the non-responders only (n = 25), the responders only (n = 25), and the ERCC2WT responders only (n = 16).

All alterations in responders and non-responders. All somatic mutations and short insertion/deletions are listed, with additional annotations regarding genomic coordinates, protein change, allelic fractions, and validation status (if available).

Damaging scores for alterations. This table shows the damaging scores (Methods) for nonsynonymous alterations (missense, nonsense, splice site, frame shift) studied in this cohort. The damaging score was derived as follows: missense mutations were scored using the Polyphen2 score(41) for the amino acid substitution. Nonsense mutations, splice site mutations, and short insertion/deletions were automatically assigned a damaging score of 1. "Unavailable" damaging scores are those that are missense mutations without a PolyPhen2 score.

Supplemental Table S1. Clinical characteristics and outcomes by HIV status. Supplemental Table S2. HPV integration sites detected in patient WXS data. Supplemental Table S3. Curated list of 981 cancer-related genes considered in this study.

Supplemental Table S4. Functional ontology enrichment of genes within recurrent CNVs in all ASCC tumors, primary ASCC tumors, and recurrent or metastatic ASCC tumors

Treatment information and sequencing metrics for all patients The treatment information and raw sequencing metrics, including mean target coverage, for each case is listed here. In addition, the mutation rate data referred to in the Results and represented in Supplementary Figure 1 is listed here by synonymous rate, non-synonymous rate, and total number of mutations per patient. *Cases that were included in the TCGA effort (UC-0296 and UC-0234). (dd = dose dense, GC = gemcitabine/cisplatin, MVAC = methotrexate, vinblastine, doxorubicin, cisplatin). Unavailable cases for Fluidigm Validation (due to inadequate remaining DNA or technical failure) are also denoted (n = 15).

Supplemental Figure S1. HPV-18 genome coverage in ASCC. Supplemental Figure S2. Copy number variation in 81 ASCCs.

Selective alteration enrichment. This table shows the results of applying Fisher's Exact Test to a tabulated set of predicted damaging somatically altered genes in responders compared to non-responders. A Benjamini-Hochberg/FDR q-value is reported for genes with the minimum number of events necessary to be considered for a theoretically significant p-value of {less than or equal to} 0.01 (n = 6). The results are sorted by p-value (lowest to highest).

Supplementary Table 2

Histogram showing the distribution of alterations in KDM6A in males and females for 4 subtypes of urothelial carcinoma. Red bars are scaled to show the frequency (%) of female samples with an alteration in KDM6A; Gray bars are scaled to show the frequency of bi-allelic mutation in KDM6A in female samples; and blue bars show the frequency of KDM6A mutation in males. The numbers above each bar indicate the number of samples with each category of alteration; the numbers below show the total number of samples for each sex and UC subtype.

Supplemental Tables

siRNA and sgRNA sequences

Purpose:Cisplatin-based chemotherapy is a first-line treatment for muscle-invasive and metastatic urothelial cancer. Approximately 10% of bladder urothelial tumors have a somatic missense mutation in the nucleotide excision repair (NER) gene, ERCC2, which confers increased sensitivity to cisplatin-based chemotherapy. However, a significant subset of patients is ineligible to receive cisplatin-based therapy due to medical contraindications, and no NER-targeted approaches are available for platinum-ineligible or platinum-refractory ERCC2-mutant cases.Experimental Design:We used a series of NER-proficient and NER-deficient preclinical tumor models to test sensitivity to irofulven, an abandoned anticancer agent. In addition, we used available clinical and sequencing data from multiple urothelial tumor cohorts to develop and validate a composite mutational signature of ERCC2 deficiency and cisplatin sensitivity.Results:We identified a novel synthetic lethal relationship between tumor NER deficiency and sensitivity to irofulven. Irofulven specifically targets cells with inactivation of the transcription-coupled NER (TC-NER) pathway and leads to robust responses in vitro and in vivo, including in models with acquired cisplatin resistance, while having minimal effect on cells with intact NER. We also found that a composite mutational signature of ERCC2 deficiency was strongly associated with cisplatin response in patients and was also associated with cisplatin and irofulven sensitivity in preclinical models.Conclusions:Tumor NER deficiency confers sensitivity to irofulven, a previously abandoned anticancer agent, with minimal activity in NER-proficient cells. A composite mutational signature of NER deficiency may be useful in identifying patients likely to respond to NER-targeting agents, including cisplatin and irofulven.See related commentary by Jiang and Greenberg, p. 1833

Supplementary Methods

Description of supplementary materials and methods.

Purpose:DNA-damaging agents comprise the backbone of systemic treatment for many tumor types; however, few reliable predictive biomarkers are available to guide use of these agents. In muscle-invasive bladder cancer (MIBC), cisplatin-based chemotherapy improves survival, yet response varies widely among patients. Here, we sought to define the role of the nucleotide excision repair (NER) gene ERCC2 as a biomarker predictive of response to cisplatin in MIBC.Experimental Design:Somatic missense mutations in ERCC2 are associated with improved response to cisplatin-based chemotherapy; however, clinically identified ERCC2 mutations are distributed throughout the gene, and the impact of individual ERCC2 variants on NER capacity and cisplatin sensitivity is unknown. We developed a microscopy-based NER assay to profile ERCC2 mutations observed retrospectively in prior studies and prospectively within the context of an institution-wide tumor profiling initiative. In addition, we created the first ERCC2-deficient bladder cancer preclinical model for studying the impact of ERCC2 loss of function.Results:We used our functional assay to test the NER capacity of clinically observed ERCC2 mutations and found that most ERCC2 helicase domain mutations cannot support NER. Furthermore, we show that introducing an ERCC2 mutation into a bladder cancer cell line abrogates NER activity and is sufficient to drive cisplatin sensitivity in an orthotopic xenograft model.Conclusions:Our data support a direct role for ERCC2 mutations in driving cisplatin response, define the functional landscape of ERCC2 mutations in bladder cancer, and provide an opportunity to apply combined genomic and functional approaches to prospectively guide therapy decisions in bladder cancer.See related commentary by Grivas, p. 907

Supplementary Table 3

Table 1

High-grade T1 (HGT1) bladder cancer is the highest risk subtype of non–muscle-invasive bladder cancer with unpredictable outcome and poorly understood risk factors. Here, we examined the association of somatic mutation profiles with nonrecurrent disease (GO, good outcome), recurrence (R), or progression (PD) in a cohort of HGT1 patients. Exome sequencing was performed on 62 HGT1 and 15 matched normal tissue samples. Both tumor only (TO) and paired analyses were performed, focusing on 95 genes known to be mutated in bladder cancer. Somatic mutations, copy-number alterations, mutation load, and mutation signatures were studied. Thirty-three GO, 10 R, 18 PD, and 1 unknown outcome patients were analyzed. Tumor mutational burden (TMB) was similar to muscle-invasive disease and was highest in GO, intermediate in PD, and lowest in R patients (P = 0.017). DNA damage response gene mutations were associated with higher TMB (P < 0.0001) and GO (P = 0.003). ERCC2 and BRCA2 mutations were associated with GO. TP53, ATM, ARID1A, AHR, and SMARCB1 mutations were more frequent in PD. Focal copy-number gain in CCNE1 and CDKN2A deletion was enriched in PD or R (P = 0.047; P = 0.06). APOBEC (46%) and COSMIC5 (34%) signatures were most frequent. APOBEC-A and ERCC2 mutant tumors (COSMIC5) were associated with GO (P = 0.047; P = 0.0002). pT1b microstaging was associated with a genomic cluster (P = 0.05) with focal amplifications of E2F3/SOX4, PVRL4, CCNE1, and TP53 mutations. Findings were validated using external public datasets. These findings require confirmation but suggest that management of HGT1 bladder cancer may be improved via molecular characterization to predict outcome.Significance:Detailed genetic analyses of HGT1 bladder tumors identify features that correlate with outcome, e.g., high mutational burden, ERCC2 mutations, and high APOBEC-A/ERCC2 mutation signatures were associated with good outcome.

Supplemental figures and box plots

Supplementary Figures and Methods // Supplementary Figure 1: The DDB2 proteo-probe assay measures cellular nucleotide excision repair (NER) capacity. Low magnification (20X) images of wild-type (WT) or mutant ERCC2-complemented XP cells before, 5 minutes after, and 150 minutes after UV exposure (see Figure 1 for high magnification [63X] images). DDB2 proteoprobe binding to UV-induced (6,4)-photoproducts is visualized using an anti-FLAG antibody (red). Nuclei are stained with DAPI (blue). ERCC2 expression is confirmed with an anti-Myc antibody (green). R683W is a common germline pathogenic allele, D312N is a common non-pathogenic germline allele, and G607A is a mutation identified in a cisplatin responsive tumor. Supplementary Figure 2: Sensitivity profiles for WT and mutant ERCC2-complemented cells for non-cisplatin agents. A. Carboplatin. B. Doxorubicin (Adriamycin) is a DNA intercalating agents that results in creation of double-strand DNA breaks. C. Rucaparib is a poly(ADP-ribose) polymerase inhibitor that demonstrates enhanced toxicity in homologous recombination (HR)-deficient cells. D. Ionizing radiation (IR). R683W is a common pathogenic germline allele in patients with the xeroderma pigmentosum complementation group D (XPD). D312N is a common, non-pathogenic germline ERCC2 allele in the general population. Y14C and G607A are helicase domain mutations identified in cisplatin responsive patients and are associated with NER loss and cisplatin sensitivity (Figure 2). Supplementary Figure 3: ERCC2 mutations identified in cisplatin non-responders are functionally deleterious. A. Cisplatin sensitivity curves for WT or mutant ERCC2-complemented cells. Whereas WT ERCC2 rescues cisplatin sensitivity, the sensitivity profiles for S44L and S246F, identified in two cisplatin non-responders from the FCCC cohort, are similar to mock-infected cells. B. The S44L and S246F mutants also fail to rescue sensitivity to UV sensitivity. C. Immunoblot showing expression of FLAG-tagged WT or mutant ERCC2. Supplementary Figure 4: Identification of an ERCC2 E86Q mutation in matched pre- and post-treatment tumor samples. The E86Q mutation was not identified in the pre-treatment sample by the standard mutation-calling algorithm due to the low number of reads, but was later identified by "force-calling" after the E86Q mutation was identified in the post-treatment sample. Correcting for tumor purity, the E86Q mutation was inferred to be clonal in both the pre- and post-treatment samples. Supplementary Figure 5: Phylogenetic tree showing relationship between pre- and post-chemotherapy tumors from a patient with an ERCC2 E86Q mutation. The pre- and post-chemotherapy tumors share several mutations, indicating a common ancestor. Shared mutations in other select cancer genes are noted. Supplementary Figure 6: CRISPR/Cas9 technology was used to create a KU19-19 cell line harboring an in-frame deletion at the endogenous ERCC2 allele. A. An sgRNA guide was designed to target the region near T484, a common site of ERCC2 mutations in MIBC tumors. B. Integrated Genomics Viewer (IGV) screenshot showing sequence of WT ERCC2 allele in KU19-19 parental cell line. C. The CRISPR-edited cell line KE1 harbors an in-frame deletion at T484. Supplementary Figure 7: An ERCC2 mutation confers an NER defect in a bladder cancer cell line. Low magnification (20X) images from a DDB2 proteoprobe assay comparing KU19-19 (WT ERCC2) and KE1 (mutant ERCC2) cell lines (see Figure 4 for high magnification [63X] images). Whereas the KU19-19 cell line efficiently resolves DDB2 foci, the foci persist in NER-deficient KE1 cells. Supplementary Figure 8: KU19-19 (WT ERCC2) and KE1 (mutant ERCC2) cell lines have similar sensitivity to the PARP inhibitor olaparib. Supplementary Figure 9: Overall survival for patients with ERCC2 wild-type (blue) versus mutant (red) tumors in the updated TCGA bladder tumor cohort (Robertson et al. Cell 2017; 171:1-17). There was no significant difference in survival between the groups (P=0.095). This figure was created using cBioPortal (Gao et al. Sci Signaling 2013; 6(269):pl1 and Cerami et al. Cancer Discov 2012; 2(5):401).

Supplementary figures, tables, material & methods and results

Purpose:Poly (ADP ribose)-polymerase (PARP) inhibitors are approved for use in breast, ovarian, prostate, and pancreatic cancers, which are the solid tumor types that most frequently have alterations in key homologous recombination (HR) genes, such as BRCA1/2. However, the frequency of HR deficiency (HRD) in other solid tumor types, including bladder cancer, is less well characterized.Experimental Design:Specific DNA aberration profiles (mutational signatures) are induced by HRD, and the presence of these “genomic scars” can be used to assess the presence or absence of HRD in a given tumor biopsy even in the absence of an observed alteration of an HR gene. Using whole-exome and whole-genome data, we measured various HRD-associated mutational signatures in bladder cancer.Results:We found that a subset of bladder tumors have evidence of HRD. In addition to a small number of tumors with biallelic BRCA1/2 events, approximately 10% of bladder tumors had significant evidence of HRD-associated mutational signatures. Increased levels of HRD signatures were associated with promoter methylation of RBBP8, which encodes CtIP, a key protein involved in HR.Conclusions:A subset of bladder tumors have genomic features suggestive of HRD and therefore may be more likely to benefit from therapies such as platinum agents and PARP inhibitors that target tumor HRD.

Purpose:The purpose of this study is to characterize the mutational landscape across the spectrum of urothelial carcinoma (UC) to identify mutational features and potential therapeutic targets.Experimental Design:Using targeted exome sequencing (n = 237 genes), we analyzed the mutation spectra of 82 low-grade nonmuscle-invasive bladder cancers (LG-NMIBC), 126 high-grade (HG) NMIBC, 199 muscle-invasive bladder cancers (MIBC), 10 LG-upper tract urothelial cancers (LG-UTUC), and 55 HG-UTUC.Results:FGFR3 and KDM6A mutations were significantly more common in LG-NMIBC (72% and 44%, respectively) versus other bladder subtypes. FGFR3 alterations were also enriched in LG-UTUC versus HG-UTUC tumors (80% vs. 16%). In contrast, TP53 and RB1 mutations were significantly more frequent in all 3 HG urothelial carcinoma subtypes than in LG-NIMBC (45%–58% vs. 4%; 9%–22% vs. 0; respectively). Among LG-NMIBC tumors, KDM6A mutations were more common in women than in men (71% vs. 38%). HG-NMIBC and MIBC had higher tumor mutational burden (TMB) than LG-NMIBC (P = 0.001 and P < 0.01, respectively). DNA-damage repair (DDR) alterations were associated with a higher TMB in HG-NMIBC and MIBC tumors, and these two tumor types were also enriched for an APOBEC mutational signature compared with LG-NMIBC and HG-UTUC. Alterations in FGFR3, PIK3CA, and EP300 correlated with worse overall survival in HG-UTUC and occurred concurrently.Conclusions:Our analysis suggests that a fraction of MIBCs likely arise from precursor lesions other than LG-NMIBC. KDM6A mutations are twice as common in women with LG-NIMBC than those in men. DDR gene mutations and APOBEC mutagenesis drive mutations in HG-NMIBC and MIBC. UTUC has a distinct mutation profile from bladder cancer.

Supplementary Methods, Tables, and Figures

Purpose: Squamous cell carcinoma of the anal canal (ASCC) accounts for 2% to 4% of gastrointestinal malignancies in the United States and is increasing in incidence; however, genomic features of ASCC are incompletely characterized. Primary treatment of ASCC involves concurrent chemotherapy and radiation (CRT), but the mutational landscape of resistance to CRT is unknown. Here, we aim to compare mutational features of ASCC in the pre- and post-CRT setting.Experimental Design: We perform whole-exome sequencing of primary (n = 31) and recurrent (n = 30) ASCCs and correlate findings with clinical data. We compare genomic features of matched pre- and post-CRT tumors to identify genomic features of CRT response. Finally, we investigate the mutational underpinnings of an extraordinary ASCC response to immunotherapy.Results: We find that both primary and recurrent ASCC tumors harbor mutations in genes, such as PIK3CA and FBXW7, that are also mutated in other HPV-associated cancers. Overall mutational burden was not significantly different in pre- versus post-CRT tumors, and several examples of shared clonal driver mutations were identified. In two cases, clonally related pre- and post-CRT tumors harbored distinct oncogenic driver mutations in the same cancer gene (KRAS or FBXW7). A patient with recurrent disease achieved an exceptional response to anti-programmed death (PD-1) therapy, and genomic dissection revealed high mutational burden and predicted neoantigen load.Conclusions: We perform comprehensive mutational analysis of ASCC and characterize mutational features associated with CRT. Although many primary and recurrent tumors share driver events, we identify several unique examples of clonal evolution in response to treatment. Clin Cancer Res; 23(12); 3214–22. ©2016 AACR.

Purpose:Neuroendocrine (NE) bladder carcinoma is a rare and aggressive variant. Molecular subtyping studies have found that 5% to 15% of muscle-invasive bladder cancer (MIBC) have transcriptomic patterns consistent with NE bladder cancer in the absence of NE histology. The clinical implications of this NE-like subtype have not been explored in depth.Experimental Design:Transcriptome-wide expression profiles were generated for MIBC collected from 7 institutions and clinical-use of Decipher Bladder. Using unsupervised clustering, we generated a clustering solution on a prospective training cohort (PTC; n = 175), developed single-sample classifiers to predict NE tumors, and evaluated the resultant models on a testing radical cystectomy (RC) cohort (n = 225). A random forest model was finalized and applied to 5 validation cohorts (n = 1302). Uni- and multivariable survival analyses were used to characterize clinical outcomes.Results:In the training cohort (PTC), hierarchical clustering using an 84-gene panel showed a cluster of 8 patients (4.6%) with highly heterogeneous expression of NE markers in the absence of basal or luminal marker expression. NE-like tumors were identified in 1% to 6.6% of cases in validation cohorts. Patients with NE-like tumors had significantly worse 1-year progression-free survival (65% NE-like vs. 82% overall; P = 0.046) and, after adjusting for clinical and pathologic factors, had a 6.4-fold increased risk of all-cause mortality (P = 0.001). IHC confirmed the neuronal character of these tumors.Conclusions:A single-patient classifier was developed that identifies patients with histologic urothelial cancer harboring a NE transcriptomic profile. These tumors represent a high-risk subgroup of MIBC, which may require different treatment.

Alterations in DNA damage response (DDR) genes are common in advanced prostate tumors and are associated with unique genomic and clinical features. ATM is a DDR kinase that has a central role in coordinating DNA repair and cell-cycle response following DNA damage, and ATM alterations are present in approximately 5% of advanced prostate tumors. Recently, inhibitors of PARP have demonstrated activity in advanced prostate tumors harboring DDR gene alterations, particularly in tumors with BRCA1/2 alterations. However, the role of alterations in DDR genes beyond BRCA1/2 in mediating PARP inhibitor sensitivity is poorly understood. To define the role of ATM loss in prostate tumor DDR function and sensitivity to DDR-directed agents, we created a series of ATM-deficient preclinical prostate cancer models and tested the impact of ATM loss on DNA repair function and therapeutic sensitivities. ATM loss altered DDR signaling, but did not directly impact homologous recombination function. Furthermore, ATM loss did not significantly impact sensitivity to PARP inhibition but robustly sensitized to inhibitors of the related DDR kinase ATR. These results have important implications for planned and ongoing prostate cancer clinical trials and suggest that patients with tumor ATM alterations may be more likely to benefit from ATR inhibitor than PARP inhibitor therapy.Significance:ATM loss occurs in a subset of prostate tumors. This study shows that deleting ATM in prostate cancer models does not significantly increase sensitivity to PARP inhibition but does sensitize to ATR inhibition.See related commentary by Setton and Powell, p. 2085

Immunofluorescence and IR survival data; additional methods

The morbidity associated with radical cystectomy (RC) for muscle-invasive bladder cancer (MIBC) has fueled investigations into the feasibility of bladder preservation strategies after a favorable clinical response to neoadjuvant therapy (NAT). Identifying optimal candidates for bladder preservation is predicated on our ability to identify tumors with inherent cisplatin sensitivity and accurately stage patients before and after NAT. In the present review, we evaluate the accuracy and limitations of contemporary staging modalities and investigate clinical outcomes in patients with MIBC who were managed with bladder preservation after NAT. Lastly, we discuss the predictive role of cisplatin-sensitizing DNA damage response (DDR) gene alterations as a foundational component to current prospective clinical trials evaluating bladder preservation in the setting of MIBC.

Tumor molecular profiling of single gene-variant (‘first-order’) genomic alterations informs potential therapeutic approaches. Interactions between such first-order events and global molecular features (for example, mutational signatures) are increasingly associated with clinical outcomes, but these ‘second-order’ alterations are not yet accounted for in clinical interpretation algorithms and knowledge bases. We introduce the Molecular Oncology Almanac (MOAlmanac), a paired clinical interpretation algorithm and knowledge base to enable integrative interpretation of multimodal genomic data for point-of-care decision making and translational-hypothesis generation. We benchmarked MOAlmanac to a first-order interpretation method across multiple retrospective cohorts and observed an increased number of clinical hypotheses from evaluation of molecular features and profile-to-cell line matchmaking. When applied to a prospective precision oncology trial cohort, MOAlmanac nominated a median of two therapies per patient and identified therapeutic strategies administered in 47% of patients. Overall, we present an open-source computational method for integrative clinical interpretation of individualized molecular profiles. Van Allen and colleagues develop a data-integration framework with an underlying knowledge base supporting clinical decision making and also serving as a hypothesis-generating platform, which the authors benchmark and validate across several retrospective cohorts and a prospective precision oncology trial.