Comprehensive genomic profiling (CGP) of chromophobe renal cell carcinoma (chrRCC) compared with clear cell RCC (ccRCC): Impact of FLCN genomic alteration (GA) status

292

Background: FLCN is a tumor suppressor gene associated with cutaneous hair follicle development. FLCN germline mutations are linked to inherited chrRCC in the Birt-Hogg-Dube (BHD) syndrome. We queried whether clinically sporadic chrRCC featured FLCN mutations by comparing the genomic profiles of chrRCC with ccRCC. Methods: 108 chrRCC and 2110 ccRCC underwent hybrid-capture based comprehensive genomic profiling (CGP) to evaluate all classes of genomic alterations (GA). Tumor mutational burden (TMB) was determined on up to 1.1 Mbp of sequenced DNA and microsatellite instability (MSI) was determined on 114 loci. PD-L1 expression was determined by IHC (Dako 22C3). Results: Patients (pts) with chrRCC were more frequently female and younger than pts with ccRCC p <.0001). None of the submitted clinical records in the chrRCC cases listed signs of BHD syndrome. FLCN GA were identified in only 2.3% of the ccRCC cases with 37% of the GA predicted to be germline. chrRCC did not reveal somatic or germline FLCN GA. GA/tumor were slightly higher in ccRCC vs chrRCC (3.6 vs 2.4; NS). GA more frequent in chrRCC included TP53, RB1 and PTEN. GA more frequent in the ccRCC included VHL, BAP1, PBRM1, SETD2, CDKN2A/B, ARID1A, NF2, PIK3CA and TERT. Putative biomarkers of immune checkpoint inhibitor (ICPI) response were infrequent in both groups with only a slightly higher, but still low, mean TMB in ccRCC vs chrRCC cases. IHC revealed moderate PD-L1 expression at low and minimal PD-L1 expression at high staining level, which was slightly increased in the chrRCC group. Conclusions: FLCN mutations that are associated with the familial incidence of chrRCC were not associated with sporadic chrRCC. Sporadic chrRCC has substantially different genomic profile from ccRCC and may harbor a few ‘targetable’ GA. The prediction of response to ICPI in RCC remains challenging with chrRCC featuring slightly higher PD-L1 expression and ccRCC featuring higher PBRM1 GA and higher TMB.[Table: see text]

E-cigarette use and the risk of bladder and lung cancer

443

Background: Electronic cigarette smoking and similar novel smoking modalities have raised questions about their impact on various cancers compared with traditional forms of tobacco smoking. Tobacco smoking has been concretely proven to increase the risk of many cancers, including lung (LCa) and bladder (BCa) cancer. To date, there is little data on how e-cigarette smoking impacts the incidence of these cancers. We investigated whether any disparities exist in the prevalence of LCa and BCa between various smoking histories using a US nationally representative data source. Methods: This cross-sectional survey-based US study included men and women aged 18+ from the National Health Interview Survey (NHIS) database between 2016-2018. Primary endpoint was self-reported occurrence of LCa and BCa diagnosis. Multivariable logistic regression analyses assessed possible association of various covariates with diagnosis of these cancers. Results: Prevalence of BCa and LCa was higher in all smoking histories compared to never smokers. Patients with a history of e-cigarette smoking vs. no history of e-cigarette smoking were significantly younger at BCa diagnosis (56.87 [±9.86] vs. 65.00 [±12.60] years, p=0.001). Multivariable logistic regression models showed that a history of cigarette smoking and e-cigarette smoking individually was associated with increased ORs of 2.476 (p≤0.001) and 1.577 (p≤0.001) for BCa diagnosis, respectively, and 4.589 (p≤0.001) and 1.614 (p=0.007) for LCa diagnosis, respectively. Conclusions: Compared to never smokers, history of e-cigarette smoking was associated with increased risk of LCa and BCa development and earlier BCa diagnosis. Additional studies are needed to better define the public health effects of these novel and unregulated products.

Association of RB1 mutational status with overall genomic landscape in neuroendocrine prostate cancer (NEPC)

156

Background: NEPC is a high-grade aggressive form of prostate cancer. We queried whether RB1 mutation status would impact the genomic features of NEPC. We hypothesized that there would be differences in GA frequencies in RB1 mutated vs non mutated cases. Methods: From a series of 13,496 cases of clinically advanced PC, 415 (3.1%) histologically defined NEPC were sequenced using a hybrid capture-based FDA-approved clinical genomic profiling (CGP) assay to detect all classes of genomic alterations (GA). Tumor mutational burden (TMB) was determined on 0.8 Mbp of sequenced DNA and microsatellite instability (MSI) was determined on 95 loci. PD-L1 expression was determined by IHC (Dako 22C3) with low tumor cell positive staining 1-49% and high staining ≥50% expression. Results: 253 (61%) of NEPC feature GA in RB1 (RB1 mut+). This contrasts with a 5.8% frequency of RB1 GA in the non-NEPC (P <.0001). The RB1 mut+ NEPC featured a slightly greater number of driver GA/tumor than the RB1 mut- NEPC (5.1 vs 4.2). Age and TMPRSS2-ERG fusion frequency were similar between the groups. RB1 Mut- NEPC was associated with significantly higher amplifications (amp) and total GA in AR compared to RB1 mut+ NEPC. RB1 mut+ NEPC featured significantly greater frequency of PTEN GA. GA frequencies in targetable kinases and DNA repair GA including BRCA1/2 and ATM linked to PARP inhibitor (PARPi) response were similar in both groups. For potential immune-oncology (IO) biomarkers, RB1 Mut+ NEPC featured significantly greater frequency of low positive PD-L1 expression and lower frequencies of MDM2 and CDK12 GA. CD274 ( PD-L1) amplification, MSI-high status and cases with TMB ≥10 mut/Mb were very uncommon in both groups. Conclusions: In NEPC, the presence of RB1 mutation is associated with various GA that may have clinical relevance. Limitations include possible selection and confounding biases, and lack of clinical annotation. Further study of RB1 status as a guide of trial designs on therapy selection for men with NEPC is warranted.[Table: see text]

SunRISe-1: Phase 2b study of TAR-200 plus cetrelimab, TAR-200 alone, or cetrelimab alone in participants with high-risk nonmuscle-invasive bladder cancer unresponsive to Bacillus Calmette-Guérin who are ineligible for or decline radical cystectomy

TPS593

Background: Treatment options are limited for patients with high-risk non-muscle-invasive bladder cancer (HR-NMIBC) unresponsive to intravesical bacillus Calmette–Guérin (BCG). TAR-200 is an intravesical drug delivery system for local continuous release of gemcitabine within the bladder. The current study will assess the rate of complete response (CR) upon treatment with TAR-200 + systemic cetrelimab (CET [anti–PD-1 antibody]), TAR-200, and CET in BCG-unresponsive participants with HR-NMIBC who are ineligible for or decline radical cystectomy (RC). Methods: SunRISe-1 (NCT04640623) is an open-label, parallel-group, multicenter phase 2b study designed to assess the efficacy and safety of TAR-200 + CET, TAR-200 alone, and CET alone in participants with BCG-unresponsive HR-NMIBC. Eligible participants are aged ≥ 18 years with ECOG PS 0, 1, or 2 and recurrent or persistent histologically confirmed HR-NMIBC (carcinoma in situ) with or without papillary disease (T1, high-grade Ta), who have been diagnosed within 12 months of last BCG treatment and are ineligible for or declined RC. Participants (N≈200) are randomized 2:1:1 to receive TAR-200 + CET (Cohort 1, n≈100), TAR-200 (Cohort 2, n≈50), or CET (Cohort 3, n≈50). In Cohorts 1 and 2, participants receive intravesical TAR-200 every 3 weeks through Week 24, and every 12 weeks thereafter until Week 96. In Cohorts 1 and 3, participants receive CET until Week 78. Primary disease assessments (cystoscopy, urine cytology, transurethral resection of bladder tumor [TURBT], and magnetic resonance imaging/computed tomography) are made at baseline; subsequent cystoscopy and centrally read urine cytology are performed every 12 weeks through Year 2, every 24 weeks until end of Year 3, and in Year 4 and Year 5 in accordance with institutional standards of care. TURBT is conducted at 24 and 48 weeks. The primary end point for the 3 cohorts is overall CR rate at any time point. Secondary end points include duration of response (ie, from time of first CR achieved to first evidence of recurrence, progression, or death [whichever is earlier] for participants who achieve a CR), overall survival, PK immunogenicity of cetrelimab, safety and tolerability, and patient-reported outcomes. Exploratory end points include incidence and time to cystectomy (measured from randomization to date of cystectomy), biomarkers, and health care resource utilization. This study opened in January 2021 and is enrolling participants at ≈165 study sites worldwide. Currently, the study is active in 13 countries with 12 participants enrolled as of September 12, 2021. Clinical trial information: NCT04640623.

Comparison of prostate specific antigen testing in men aged 55 to 69 with and without a history of cancer

230

Background: Prostate specific antigen (PSA) screening remains a controversial issue. However, most urological guidelines recommend PSA testing through a shared decision-making process with the patient. The rate of PSA screening in men with a history of cancer compared to men with no cancer history is not well known. We aimed to compare PSA testing in men aged 55-69 years with and without a history of cancer (excluding prostate cancer patients). Methods: Utilizing the National Health Interview Survey (NHIS) a retrospective cross-sectional study between the years 2015 and 2018 was carried out to analyze and compare PSA testing rates in men aged 55-69 years. Multivariable logistic regression model was implemented do demonstrate potential associations with PSA testing. Results: A total of 13,850 men aged 55-69 years included in the NHIS Survey were analyzed. 1519 (10.9%) men had a history of cancer (non-prostate). On multivariable analysis, men who were previously diagnosed with cancer had a higher rate of PSA testing compared to men with no history of cancer (OR: 1.88, 95% CI 1.39-2.54, p < 0.001). Other factors associated with an increased likelihood of undergoing PSA testing included: age, homosexual orientation, and married men. In contrast, current smokers, American Indians and Alaskan Natives and Asians were less likely to undergo PSA testing. Conclusions: Our data suggest that men aged 55-69 with a history of cancer are more likely to undergo PSA testing than men with no cancer history.[Table: see text]

Association of Race With Cancer-Related Financial Toxicity

PURPOSE

We investigated the association between race and FT among previous patients with cancer. Studies show that patients with cancer experience financial toxicity (FT) because of their cancer treatment.

METHODS

Data on individuals with a cancer history were collected in this cross-sectional study during 2012, 2014, and 2017, from the US Health Information National Trends Survey. This survey is conducted by mail with monetary compensation as an incentive. We specifically assessed responses to two questions: Has cancer hurt you financially? Have you been denied health insurance because of cancer? Multivariable logistic regression analyses were used to assess the associations between these questions and race.

RESULTS

Of 10,592 individuals participating, 1,328 men and women (12.5%) with a cancer history were assessed. Compared with Blacks, Whites were found to have a higher rate of insurance (95.4% v 90.0%), were more likely to receive cancer treatment (93.9% v 85%), and had a higher rate of surgical treatment than Blacks (77% v 60%), Hispanics (55%), and others (77%, 60%, 55%, and 74.2%, respectively, P < .001). On multivariable analysis, Blacks were more than five times as likely to be denied insurance (odds ratio, 5.003; 95% CI, 2.451 to 10.213; P < .001) and more than twice as likely to report being hurt financially because of cancer (odds ratio, 2.448; 95% CI, 1.520 to 3.941; P < .001) than Whites. Of all cancer groups analyzed (genitourinary, gynecologic, gastrointestinal, and breast), genitourinary malignancies were the only group in which the rate of reporting being hurt financially varied in a statistically significant manner (Whites 36.7%, Hispanics 62.5%, and Blacks 59.3%, P = .004).

CONCLUSION

Our data suggest that race is significantly associated with FT because of cancer. Awareness of racial inequality with regards to FT should be raised among health care workers.

The association of sexual orientation with prostate, breast, and cervical cancer screening and diagnosis

129

Background: Data on heterogeneity in cancer screening and diagnosis rates among lesbians/gays and bisexuals is lacking. Recent studies showed that lesbians/gays and bisexuals have decreased healthcare utilization compared to heterosexual counterparts and continue to experience discrimination in healthcare. Few studies have examined how sexual orientation impacts cancer screening and prevalence. We, therefore, investigated the association between sexual orientation and prevalent sex-specific cancer including prostate, breast, and cervical cancer. Methods: This was a cross-sectional survey-based US study, including men and women aged 18+ from the Health Information National Trends Survey (HINTS) database between 2017-2019. The primary endpoint was individual-reported prostate, breast, and cervical cancer screening and prevalence rates among heterosexual and LGB men and women. Multivariable logistic regression analyses assessed association of various covariates with undergoing screening and diagnosis of these cancers. Results: Overall, 4,441 and 6,333 heterosexual men and women, respectively, were compared to 225 and 213 lesbian/gay and bisexual men and women, respectively. Lesbians/gays and bisexuals were younger and less likely to be screened for prostate, breast, and cervical cancer than heterosexuals. A higher proportion of heterosexual women than lesbian and bisexual women were screened for cervical cancer with pap smears (95.36% vs. 90.48% and 86.11%, p = < 0.001) and breast cancer with mammograms (80.74% vs. 63.81% and 45.37%, p = < 0.001). Similarly, a higher proportion of heterosexual men than gay and bisexual men were screened for prostate cancer with PSA blood tests (41.27% vs. 30.53% and 27.58%, p = < 0.001). Conclusions: Lesbians/gays and bisexuals in the US may be less likely to undergo screening of sex-specific prevalent malignancies, including prostate, breast, and cervical cancer. Healthcare professionals should be encouraged to improve cancer screening among lesbians/gays and bisexuals.

Multiresolution Application of Artificial Intelligence in Digital Pathology for Prediction of Positive Lymph Nodes From Primary Tumors in Bladder Cancer

PURPOSE

To develop an artificial intelligence (AI)-based model for identifying patients with lymph node (LN) metastasis based on digital evaluation of primary tumors and train the model using cystectomy specimens available from The Cancer Genome Atlas (TCGA) Project; patients from our institution were included for validation of the leave-out test cohort.

METHODS

In all, 307 patients were identified for inclusion in the study (TCGA, n = 294; in-house, n = 13). Deep learning models were trained from image patches at 2.5×, 5×, 10×, and 20× magnifications, and spatially resolved prediction maps were combined with microenvironment (lymphocyte infiltration) features to derive a final patient-level AI score (probability of LN metastasis). Training and validation included 219 patients (training, n = 146; validation, n = 73); 89 patients (TCGA, n = 75; in-house, n = 13) were reserved as an independent testing set. Multivariable logistic regression models for predicting LN status based on clinicopathologic features alone and a combined model with AI score were fit to training and validation sets.

RESULTS

Several patients were determined to have positive LN metastasis in TCGA (n = 105; 35.7%) and in-house (n = 3; 23.1%) cohorts. A clinicopathologic model that considered using factors such as age, T stage, and lymphovascular invasion demonstrated an area under the curve (AUC) of 0.755 (95% CI, 0.680 to 0.831) in the training and validation cohorts compared with the cross validation of the AI score (likelihood of positive LNs), which achieved an AUC of 0.866 (95% CI, 0.812 to 0.920; P = .021). Performance in the test cohort was similar, with a clinicopathologic model AUC of 0.678 (95% CI, 0.554 to 0.802) and an AI score of 0.784 (95% CI, 0.702 to 0.896; P = .21). In addition, the AI score remained significant after adjusting for clinicopathologic variables (P = 1.08 × 10^-9), and the combined model significantly outperformed clinicopathologic features alone in the test cohort with an AUC of 0.807 (95% CI, 0.702 to 0.912; P = .047).

CONCLUSION

Patients who are at higher risk of having positive LNs during cystectomy can be identified on primary tumor samples using novel AI-based methodologies applied to digital hematoxylin and eosin-stained slides.

The association of sexual orientation with cancer screening and diagnosis

6506

Background: Data on heterogeneity in cancer screening and diagnosis rates among sexual minorities (SMs) is lacking. Recent studies have shown SMs are more likely to engage in risky health behavior and have decreased healthcare utilization compared to heterosexual counterparts. However, few studies have examined how sexual orientation (SO) impacts cancer screening and prevalence. We therefore investigated whether SO affects prevalent gender-specific cancer screening and prevalence, including prostate (PCa), breast (BC), and cervical cancer (CC). Methods: This was a cross-sectional survey-based US study, including men and women aged 18+ from the Health Information National Trends Survey (HINTS) database (part of the National Cancer Institute’s division of cancer control and population sciences) between 2017-2019. The primary endpoint was individual-reported PCa, BC, and CC screening and prevalence rates among heterosexual and SM men and women. Multivariable logistic regression analyses assessed association of various covariates with undergoing screening and diagnosis of these cancers. Results: Overall, 4,441 (95.18%) men and 6,333 (96.75%) women reported a SO of heterosexual whereas 167 (3.6%) and 58 (1.2%) men and 105 (1.6%) and 108 (1.6%) women reported a SO of gay and bisexual, respectively. Mean age was higher in the heterosexual group compared to the gay and bisexual groups in both men (57.7 [±16.0] vs. 52.4 [±14.5] and 51.9 [±18.0] years, p = < 0.001) and women (56.2 [±16.7] vs. 49.0 [±17.1] and 40.0 [±14.8] years, p = < 0.001). Homosexuals and bisexuals were less likely to be screened for PCa (30.53% and 27.58% vs 41.27%, p = < 0.001), BC (63.81% and 45.37% vs 80.74%, p = < 0.001), and CC (90.48% and 86.11% vs 95.36%, p = < 0.001) than their heterosexual counterparts. While rates of PCa and BC diagnoses were similar across SO, more homosexual and bisexual women were diagnosed with CC compared to their heterosexual counterparts (4.76% and 3.70% vs 1.85%, p = 0.039). Multivariable logistic regression models showed that SMs were less likely to be screened for cancer with ORs of 0.61 (95% CI 0.39-0.95, p = 0.030) for PCa, 0.52 (95% CI 0.30-0.92, p = 0.025) for BC, and 0.21 (95% CI 0.09-0.46, p = < 0.001) for CC. Although multivariable models did not show that SMs were more likely to be diagnosed with PC, BC, or CC, SMs were more likely to be diagnosed with any cancer with ORs of 1.64 (95% CI 1.06-2.54, p = 0.026) in women only and 1.50 (95% CI 1.11-2.03, p = 0.009) in men and women combined. Conclusions: These data suggest that in addition to other established and known specific socio-economic risk factors, SMs may be less likely to undergo screening of prevalent malignancies such as PCa, BC, and CC. This provides more evidence of ongoing healthcare inequality, urging our healthcare system to invest more in cancer screening of this vulnerable population.

The influence of race on financial toxicity among cancer patients

1525

Background: Studies show that cancer patients and survivors are likely to endure financial toxicity long after being diagnosed. Methods: To examine the influence of race on financial toxicity among individuals with a history of cancer, a US based cross sectional study was conducted using data on 1,328 cancer patients collected from the Health Information National Trends Survey. Multivariable logistic regression analyses were used to analyze the relationship between race and financial toxicity, adjusting for known confounders. Results: Blacks, Hispanics and other races were shown to have a lower rate of insurance compared to Whites. Whites were also more likely to receive cancer treatment than other races (6.1% received no treatment vs 15.0% of Blacks, 17.8% of Hispanics, and 9.7% of other races, p<0.001). Considerably more Whites underwent surgical treatment of their cancer (77%) vs. 60% of Blacks, 55% of Hispanics and 74.2% of other races, p<0.001. Blacks were found to be over 5 times more likely to be denied insurance (OR 5.003, 95% CI 2.451-10.213, p<0.001) and more than twice as likely to be hurt financially than Whites (OR 2.448, 95% CI 1.520-3.941, p<0.001). Other racial minorities were also more than twice as likely to be hurt financially than Whites (OR 2.421, 95% CI 1.248-4.698, p=0.009) (Table). Conclusions: These data suggest that race is significantly associated with increased rates of being hurt financially and being denied insurance due to cancer. Awareness of race inequality should be raised so that equal cancer treatment can be provided, irrespective of race, gender or socioeconomic status.[Table: see text]

Genomic landscape of MSH6-mutated clinically advanced castrate-resistant prostate cancer (mCRPC)

5062

Background: Loss-of-function genomic alterations (GAs) in MSH6 have been associated with a unique subtype of hypermutated mCRPC that is often microsatellite stable (MSS) and may occur in either a sporadic or familial Lynch Syndrome-like clinical setting. Methods: 5,617 mCRPC cases were sequenced to evaluate all classes of GA using a hybrid capture-based FDA-approved comprehensive genomic profiling (CGP) assay. Tumor mutational burden (TMB) was determined on 0.8 Mb of sequenced DNA and microsatellite instability high (MSI-High) was determined on 95 loci. MSI-low status was not assessed. Results: 78 (1.4%) mCRPC were MSH6mut (Table). MSH6mut mCRPC included 73.1% short variant mutations, 23.1% biallelic deletions, 2.6% genomic rearrangements, and 1.3% multiple GAs/sample. Co-mutation of MSH2 was found in 28% of MSH6mut cases vs. 2% in MSH6wt cases (P <.0001) and was most frequently caused by biallelic co-deletion of both genes (73% of co-mutated cases). MSI-High status was present in 46% of MSH6mut mCRPC, which was significantly greater than the 2% seen in MSH6wt cases (P <.0001). An MMR single nucleotide mutational signature was observed in 65% of MSH6mut cases, compared to 3% MSH6wt cases (P <.0001). Among MSH6mut cases with neither MSI-High nor MMR mutational signature, 87% did not have biallelic loss of MSH6 or any other MMR gene, confirming that monoallelic pathogenic mutations are insufficient to cause the MMR-D phenotype. For subjects whose variants could be classified, 45% (19/42) of pathogenic MSH6 alleles were germline; of these, 58% (11/19) had neither MSI-High nor an MMR single nucleotide signature. MSH6mut cases had fewer TMPRSS2: ERG fusions (P =.01), but harbored significantly higher frequencies of GAs in AR (P =.0002), ATM (P =.04), PIK3CA (P =.0003), APC (P =.005), ERBB2 (P =.001), and CDK6 (p =.046), likely at least partially attributable to the higher TMB in MSH6mutcases (P <.0001). Conclusions: MSH6mut mCRPC is a unique disease that often features a hypermutated genomic signature, although only 46% of cases exhibited MSI-high status. This complex phenotype highlights the potential utility of multiple rather than single biomarkers to understand tumor biology and determine patients who may benefit from immunotherapy.[Table: see text]

Clinically advanced pelvic squamous cell carcinomas (pSCC) in men and women: A comprehensive genomic profiling (CGP) study

3130

Background: Given that the clinical manifestations, disease course, and treatment options for pSCC differ between tumor types, we performed CGP to examine possible genomic differences. Methods: 1,741 clinically advanced pSCCs including 230 penile (penSCC), 17 male urethral (murthSCC), 125 male anal (manSCC), 7 female urethral (furthSCC), 263 vulvar (vulSCC), 822 cervical (crvSCC), and 277 female anal SCCs (fanSCC) underwent hybrid capture-based CGP to evaluate all classes of genomic alterations (GAs). Tumor mutational burden (TMB) was determined on up to 1.1 Mb of sequenced DNA and microsatellite instability (MSI) was determined on up to 114 loci. PD-L1 expression was determined by IHC (Dako 22C3). Results: HPV-16/18 detection was lowest in murthSCC and vulSCC and highest in manSCC, fanSCC, and crvSCC. TP53 GAs were inversely associated with HPV status. PIK3CA GA frequency varied (22-43%). DNA-damage response (DDR) GAs (e.g., BRCA1/2, ATM, others) were low ( < 1-3%) throughout. Cell-cycle GAs were most frequent in external cases (penSCC, furthSCC, vulSCC). MTOR pathway GAs ( PTEN, FBXW7) were the most frequently identified “actionable” GAs. FGFR3 GA were present in >5% of murthSCC, crvSCC, and fanSCC; other receptor-tyrosine kinase (RTK) targeted options were 1% in BRAF/ ERBB2. NOTCH1 GAs were present in > 15% of penSCC and vulvSCC. TMB ≥10 mut/Mb was >15% in manSCC, fanSCC, and crvSCC. PD-L1 low expression was > 25% in all pSCC except crvSCC and high expression was > 18% in all pSCC except urthSCC and manSCC. Conclusions: Despite similar histology, pSCC differ widely in GAs and HPV status. PIK3CA is the most frequent “targetable” GA followed by MTOR pathway and cell cycle; RTK targets are extremely rare. PARP inhibitor options appear low given the infrequent finding of DDR GAs. Anti-PD(L)1 could be considered in a number of cases based on TMB>10 mut/Mb and PD-L1 expression.[Table: see text]

Comprehensive genomic profiling of metastatic collecting duct carcinoma, renal medullary carcinoma, and clear cell renal cell carcinoma

INTRODUCTION AND OBJECTIVE

Unlike clear cell renal cell carcinoma (CCRCC), collecting duct carcinoma (CDC) and renal medullary carcinoma (RMC) are rare tumors that progress rapidly and appear resistant to current systemic therapies. We queried comprehensive genomic profiling to uncover opportunities for targeted therapy and immunotherapy.

MATERIAL AND METHODS

DNA was extracted from 40 microns of formalin-fixed, paraffin-embedded specimen from relapsed, mCDC (n = 46), mRMC (n = 24), and refractory and metastatic (m) mCCRCC (n = 626). Comprehensive genomic profiling was performed, and Tumor mutational burden (TMB) and microsatellite instability (MSI) were calculated. We analyzed all classes of genomic alterations.

RESULTS

mCDC had 1.7 versus 2.7 genomic alterations/tumor in mCCRCC ( = 0.04). Mutations in VHL (P < 0.0001) and TSC1 (P = 0.04) were more frequent in mCCRCC. SMARCB1 (P < 0.0001), NF2 (P = 0.0007), RB1 (P = 0.02) and RET (P = 0.0003) alterations were more frequent in mCDC versus mCCRCC. No VHL alterations in mRMC and mCDC were identified. SMARCB1 genomic alterations were significantly more frequent in mRMC than mCDC (P = 0.0002), but were the most common alterations in both subtypes. Mutations to EGFR, RET, NF2, and TSC2 were more frequently identified in mCDC versus mRMC. The median TMB and MSI-High status was low with <1% of mCCRC, mCDC, and mRMC having ≥ 20 mut/Mb.

CONCLUSION

Genomic alteration patterns in mCDC and mRMC differ significantly from mCCRCC. Targeted therapies for mCDC and mRMC appear limited with rare opportunities to target alterations in receptor tyrosine kinase and MTOR pathways. Similarly, TMB and absence of MSI-High status in mCDC and mRMC suggest resistance to immunotherapies.

The association between sexual orientation and screening of prevalent gender-specific cancers

198

Background: Data on heterogeneity in cancer screening and diagnosis rates among sexual minorities (SMs) is lacking. Recent studies have shown SMs are more likely to engage in risky health behavior and have decreased healthcare utilization. However, few studies have examined how sexual orientation impacts cancer screening and prevalence. We therefore investigated whether sexual orientation affects prevalent gender-specific cancer including prostate (PCa), breast (BC), and cervical cancer (CC). Methods: This was a cross-sectional survey-based US study, including men and women aged 18+ from the Health Information National Trends Survey (HINTS) database (part of the National Cancer Institute’s division of cancer control and population sciences) between 2017-2019. The primary endpoint was individual-reported PCa, BC, and CC screening and prevalence rates among heterosexuals and homosexuals/bisexuals. Multivariable logistic regression analyses assessed association of various covariates with undergoing screening and diagnosis of these cancers. Results: Overall, 4,441 and 6,333 heterosexual men and women, respectively, were compared to 225 and 213 homosexual/bisexual men and women, respectively. Homosexuals/bisexuals were younger and less likely to be screened for PCa (34.7% vs 41.3%, p=0.013), BC (54.5% vs 80.7%, p=<0.001), and CC (88.3% vs 95.4%, p=<0.001). While rates of PCa and BC diagnosis were similar, more than twice as many homosexual/bisexual women were diagnosed with CC (4.2% vs 1.9%, p=0.023). Multivariable logistic regression models (Table) showed homosexuals/bisexuals were less likely to be screened for cancer with ORs of 0.61 (95% CI 0.39-0.95) for PCa, 0.52 (95% CI 0.30-0.92) for BC, and 0.21 (95% CI 0.09-0.46) for CC. Homosexuals/bisexuals were more likely to be diagnosed with any cancer with ORs of 1.64 (95% CI 1.06-2.54) in women only and 1.50 (95% CI 1.11-2.03) in men and women combined. Conclusions: Homosexuals/bisexuals in the US may be less likely to undergo screening of gender-specific prevalent malignancies, including PCa, BC, and CC. The implementation of cancer screening among SMs should be improved. [Table: see text]

Sarcomatoid (srcRCC) versus clear cell (ccRCC) renal cell carcinoma: A comparative comprehensive genomic profiling (CGP) study

349

Background: srcRCC is a well-described histologic entity often featuring rapid progression and aggressive clinical course when compared with classic ccRCC. We queried whether CGP would uncover opportunities for targeted and immunotherapy (IO) for srcRCC patients that could individualize their treatment and entry into clinical trials. Methods: Using a hybrid capture-based CGP assay to evaluate all classes of genomic alterations (GA), 160 cases of srcRCC and 1,664 cases of ccRCC were sequenced from FFPE tissue samples. Tumor mutational burden (TMB) was determined on up to 1.1 Mbp of sequenced DNA and microsatellite instability (MSI) was determined on up to 114 loci. PD-L1 expression was determined by IHC (Dako 22C3) with low tumor cell positive staining set at 1-49% and high staining >50% expression. Results: Gender and age distributions for both tumor types were similar. srcRCC featured significantly higher GA/tumor than ccRCC (P < .0001). CGP revealed major differences with ccRCC associated more frequently with tumor suppressor gene (TSG) losses in VHL, PBRM1, TSC2 and SETD2 (all P < .0001). In contrast, srcRCC is associated with cell proliferation with increased inactivation of cell cycle regulatory genes including TP53, CDKN2A/B, MDM2 and TERT (all P < .0001). RB1 GA in srcRCC may reflect neuroendocrine differentiation occasionally found in these tumors. NF2 GA were more frequent in srcRCC (P < .0001). Conclusions: CGP reveals striking differences between srcRCC and ccRCC which may in part explain the differing histologic appearances and typical clinical course of these 2 aggressive malignancies. ccRCC is driven more by TSG loss and srcRCC is driven more by cell cycle dysregulation. Targeted therapy opportunities were uncommon for both tumor types although each featured biomarkers potentially predictive of mTOR inhibitor responses ( TSC2 in ccRCC and NF2 in srcRCC). Although the higher PBRM1 GA frequency in ccRCC may explain the IO benefit well-known for this tumor type, the srcRCC group features significantly increased TMB, CD274 amplification and PD-L1 staining which may also create IO opportunities for srcRCC patients. [Table: see text]

Novel synthetic lethality (SL) anti-cancer drug target in urothelial bladder cancer (UCB) based on MTAP genomic loss: Incidence and correlations in standard of care (SOC)

485

Background: When UCB presents or progresses to chemorefractory metastatic disease, the search for new therapy targets is paramount. Targeting PRMT5 arginine methyltransferase accumulation in tumors with MTAP (methylthioadenosine Phosphorylase) genomic loss has been proposed as a new SL based anti-tumor strategy and under consideration for development for UCB. We sought to evaluate the incidence of patients with candidate SL and correlate to treatment-guiding biomarkers currently evaluated in SOC. Methods: 2,683 cases of clinically advanced UCB underwent hybrid-capture based comprehensive genomic profiling in a standard of care setting using the F1CDx FDA-approved assay to evaluate all classes of genomic alterations (GA) among 324 genes. Tumor mutational burden (TMB) was determined on 0.8 Mbp of sequenced DNA and microsatellite instability (MSI) was determined on 95 loci. PD-L1 expression was determined by IHC (Dako 22C3). Results: 650 (24%) of UCB feature MTAP loss (MTAP-) (Table). The gene and age distributions were similar MTAP intact (MTAP+) and MTAP- UCB. The GA/tumor was higher in MTAP- UCB likely reflecting the significant GA co-deletions of CDKN2A/ B at the 9p21 locus. Of potential therapeutic targets, FGFR3 and PTEN GA were more frequent in the MTAP- UCB. In contrast, biomarkers of immunotherapy (IO) response included higher frequencies of high TMB and high PD-L1 IHC staining in the MTAP+ UCB. Conclusions: When compared with MATP+ UCB, MTAP- UCB differs in genomic signatures including an increase in potential for targeted therapies but a lower potential for IO drug benefit. Thus, the genomic landscape in MTAP- UCB may play a significant role in the design of clinical trials incorporating SL strategies when targeting PRMT5 in MTAP deficient tumors. [Table: see text]

Clinically advanced penile (pSCC) and male urethral (uSCC) squamous cell carcinoma: A comparative genomic profiling (CGP) study

2

Background: Although SCC of the penile skin (pSCC) and the male urethral surface epithelium (uSCC) arise in nearby locations and can feature similar histology, their clinical manifestations, disease course, and surgical and medical treatment options are distinct. We performed CGP on pSCC and uSCC to examine genomic profiles differences. Methods: Tissues obtained from men with clinically advanced pSCC (n = 230) and uSCC (n = 17) underwent hybrid capture-based CGP to evaluate all classes of genomic alterations (GAs). Tumor mutational burden (TMB) was determined on up to 1.1 Mb of sequenced DNA and microsatellite instability (MSI) was determined on up to 114 loci. PD-L1 expression was determined by IHC (Dako 22C3). Results: The median ages were similar in both groups. pSCC exhibited a slightly higher frequency of HPV-16/18 infection (29% vs. 12%, P = .16), although the TP53 mutation frequencies were nearly identical (55% vs. 59%, NS). CDKN2A inactivation (P = .08), CCND1 amplification trending higher and TERT promoter mutations (P = .01) were more frequent in pSCC, potentially indicating prior HPV infection. GAs in NOTCH1 were exclusively identified in pSCC. Potentially actionable GAs identified in both groups included PIK3CA activating mutations (TKIs) as well as pathogenic alterations in FBXW7 and PTEN (MTOR inhibitors). Rare BRCA1 and BRCA2 inactivation (PARP inhibitors) was seen in pSCC only. High-positive PD-L1 staining was elevated in pSCC (34 vs. 14%, P = .06). Although average TMB was similar in both groups, pSCC exhibited an elevated frequency of cases with CD274 ( PD-L1) amplification as well as TMB >10 mut/Mb which are on label for immune checkpoint inhibitor (ICPI) treatment. Conclusions: CGP of pSCC and uSCC identifies opportunities for both targeted and ICPI therapies. Compared to uSCC, pSCC had genomic features more similar to head and neck SCC including slightly increased cell-cycle perturbation, HPV infection, and NOTCH pathway signaling alterations. Further use of CGP in the treatment planning for pSCC and uSCC may be warranted. [Table: see text]

HHV-8 positive clinically advanced castrate-resistant prostate cancer (mCRPC): A potentially distinct molecular subset

163

Background: Herpesvirus HHV-8 has been detected in normal prostate tissue and has been linked to the acquisition of androgen-independent growth of prostate cancer cells in vitro, early development of anti-androgen therapy resistance, and more aggressive disease in a subset of patients with mCRPC. We used comprehensive genomic profiling (CGP) to test the hypothesis that HHV-8 associated mCRPC is a distinct molecular subset of mCRPC featuring altered AR signaling compared to HHV-8 negative mCRPC. Methods: Using a hybrid capture-based FDA-approved CGP assay, a series of 4,918 mCRPC were sequenced to evaluate all classes of genomic alterations (GAs). Tumor mutational burden (TMB) was determined on up to 1.1 Mb of sequenced DNA and microsatellite instability (MSI) was determined on 114 loci. PD-L1 expression was determined by IHC (Dako 22C3). HHV-8 status was determined by CGP-based identification of unique viral reads. Results: Overall, 128 (2.6%) of the mCRPC cases harbored HHV-8 sequences (Table). The patient age distribution was similar in the HHV-8+ and HHV-8− groups. GAs in AR, predominantly amplifications, and RAD21 were slightly reduced in HHV-8+ mCRPC cases (P = .01 for both). The frequencies of GAs in genes associated with mCRPC including PTEN, BRCA2, ATM, CDK12, and the TMPRSS2: ERG fusion were similar in the two groups. HHV-8+ patients were less likely to be of European ancestry (P = 0.001). Putative biomarkers associated with immunotherapy response (MSI status, TMB, and PD-L1 expression) were also similar in the two groups. Conclusions: HHV-8+ mCRPC is a rare sub-type of mCRPC with lower frequency of AR GAs compared to HHV-8− mCRPC cases, suggesting a potential role of HHV-8 in inducing androgen-independent prostate cancer growth. Additional alterations associated with potentially enhanced PARP inhibitor response seen in HHV-8+ mCRPC (e.g., RAD21) suggest that early performance of CGP may inform precision treatment strategies to be tested in clinical trials. [Table: see text]

HPV-16 positive clinically advanced squamous cell carcinoma of the urinary bladder (mBSCC): A comprehensive genomic profiling (CGP) study

481

Background: mBSCC is an uncommon form of urinary bladder malignancy when compared with the much higher urothelial carcinoma incidence. We studied the genomic alteration (GA) landscape in a series of mBSCC based on the association with HPV-16 to determine if differences would be observed between the positive and negative groups. Methods: Using a hybrid capture-based FDA-approved CGP assay, a series of 171 mBSCC were sequenced to evaluate all classes of GA. Tumor mutational burden (TMB) was determined on up to 1.1 Mbp of sequenced DNA and microsatellite instability (MSI) was determined on 114 loci. PD-L1 expression was determined by IHC (Dako 22C3) with low tumor cell positive staining set at 1-49% and high staining at ≥50% expression. Results: Overall, 11 (6.4%) of the mBSCC were found to harbor HPV-16 sequences (Table). HPV-16+ status was identified slightly more often in women (NS) and in younger patients (P = .04); 2 female patients with mBSCC had prior history of SCC including 1 anal SCC and 1 vaginal SCC. HPV-16+ mBSCC had fewer GA/tumor (P < .0001), and fewer inactivating GA in CDKN2A (P < .0001), CDKN2B (P = .05), TERT promoter (P = .0004) and TP53 (P < .0001). GA in genes associated with urothelial carcinoma including FGFR2 and FGFR3 were similar in both HPV-16+ and HPV-16- mBSCC groups. MTOR and PIK3CA pathway GA were not significantly different in the 2 groups. MSI and TMB were also similar in the 2 groups. The 3 HPV-16+ mBSCC cases showed high positive PD-L1 IHC staining. Conclusions: HPV-16+ mBSCC tends to occur more often in women and younger patients. As reported in other HPV-associated squamous cell carcinomas, HPV-16+ mBSCC demonstrates significantly reduced frequencies of inactivating mutations in cell cycle regulatory genes with similar GA in MTOR and PIK3CA pathways. The implication of HPV in the pathogenesis of bladder cancer remains unknown but warrants further exploration and clinical validation. [Table: see text]

Comprehensive genomic profiling (CGP) in patients with relapsed/refractory germ cell tumors (GCT)

388

Background: Understanding the genetic alterations in patients with relapsed/refractory GCT (rrGCT) could delineate the pathogenesis of cisplatin resistance. Our study uses CGP to characterize genomic alterations (GA) in refractory GCT and correlate with clinical outcomes. Methods: 432 patients with rrGCT were seen at Indiana University between Jan 2016 to Sep 2019 of whom 52 patients underwent CGP using a hybrid-capture based commercial assay to evaluate all classes of GA. Tumor mutational burden (TMB) was determined on 1.1 Mbp of sequenced DNA and reported as mutations/Mb and microsatellite instability (MSI) was determined on 114 loci. PDL1 expression was determined by IHC (DAKO 22C3 antibody). Results: All patients relapsed after first-line cisplatin-based combination chemotherapy. Median age at diagnosis was 33 (range 15-68). Primary site of GCT was testicular in 85% and mediastinum in 8%. 6 patients had pure seminoma and 46 had non-seminoma. Platinum refractory disease, defined as serologic or radiographic progression within 4 weeks of first-line chemotherapy comprised 23% of patients. The primary tumor was used for sequencing in 6 cases (12%) and non-primary tumor metastatic site (lymph node, lung, liver, brain, omentum) in 46 cases (88%). The most common GA in the entire cohort were FGF6 (27%), FGF23 (27%), KDM5A (27%), CCND2 (27%), KRAS (18%), TP53 (14%), KIT (8%), APC (8%), ZNF217 (6%), MUTYH (6%), AURKA (6%), NRAS (6%), EGFR (6%), CTNNB1 (6%), GNAS (6%). Most common alterations for testicular primary tumors were FGF6, FGF23, KDM5A, CCND2, KRAS, TP53, KIT. For non-testicular primary GCT, most common GA were APC, TP53, EGFR. Most common GA for non-seminoma were FGF6, FGF23, KDM5A, CCND2, KRAS, TP53, APC. Most common GA for pure seminoma was KIT. Potentially targetable genomic alterations were found in 17 patients (33%). 10 of 17 patients (59%) tested had PDL1 score ≥1% and 3 patients had PDL1 ≥50%. Median TMB was 3.5 mutations/MB. There were 4 patients (8%) with TMB ≥ 10 mutations/Mb and 2 patients (4%) with TMB ≥ 20 mutations/Mb. 1 of 48 patients (2%) evaluated for MSI had MSI-High status. Isochromosome 12p was detected in the majority of samples where it was tested. Outcomes with GA-directed therapy will be presented at the conference. Conclusions: CGP can reveal potential therapeutic targets in patients with rrGCT including EGFR, ERBB3, KIT, and MET. Consistent with reported clinical trials in rrGCT, biomarkers predicting response to immune checkpoint blockade are uncommon with most patients having low TMB, absence of MSI-H status, and low expression of PDL1.

Genomic landscape of CDK12 mutated metastatic castrate-resistant prostate cancer (mCRPC)

165

Background: Identifying prostate cancer patients likely to benefit from immune checkpoint inhibitors (ICPI) remains an unmet need. Specific loss-of-function genomic alterations (GA) in CDK12 are associated with focal tandem duplications linked to fusion-induced production of neoantigens and are a promising candidate biomarker for ICPI. Using comprehensive genomic profiling (CGP) we compared the GA landscape of CDK12 altered (CDK12mut+) and unaltered (CDK12mut-) tumors. Methods: 4,918 mCRPC tumors were sequenced using a hybrid capture-based FDA-approved CGP assay. Tumor mutational burden (TMB) was determined on 0.8 Mbp of sequenced DNA and microsatellite instability (MSI) was determined on 95 loci. PD-L1 expression was determined by IHC (Dako 22C3) with low tumor cell positive staining -49% and high staining ≥50% expression. Results: Overall, 315 (6.4%) of the mCRPC cases were CDK12mut+ (Table). CDKmut+ cases had significantly fewer GA in TMPRSS2: ERG (P < .0001), TP53 (P < .0001), PTEN (P < .0001), ATM (P = .001), PIK3CA (P = .003), RB1 (P = .02), BRCA2 (P < .0001) and APC (P = .002). CDK12mut+ cases featured higher frequencies only in CCND1 (P < .0001), BRAF (P = .007) and ERBB2 (P < .001) as well as in cell cycle regulatory genes including MDM2/4 (P < .0001), CDK4 (P < .0001) and CDK6 (P = .002). CDK12mut+ cases featured more frequent MSI-H status (P = .007), significantly higher median TMB (P < .001) and more frequent low positive (1-49% staining) PD-L1 expression (P = .02). High (≥50%) PD-L1 expression was rarely identified in either cohort. Conclusions: CDK12mut+ mCRPC demonstrates a unique genomic profile with significant differences compared with CDK12mut- mCRPC. Lower frequencies of GA associated with homologous recombination defect and mTOR pathway may impact the use of platinum agents, as well as PARPi and PIK3CA/Akt/mTOR inhibitors. Opportunities for targeted therapies for BRAF and ERBB2 driven mCRPC may be enriched in the CDK12mut+ tumors and raise the possibility of combination therapy strategies although the numbers of patients are small and validation is needed. The slightly higher MSI High status, median TMB and PD-L1 staining may be associated with additional benefit from ICPI and warrants further prospective investigation. [Table: see text]

Contrasting genomic profiles in post-systemic treatment metastatic sites (MET), pretreatment primary tumors (PT), and liquid biopsies (LB) of clinically advanced prostate cancer (PC)

5534

Background: Comprehensive genomic profiling (CGP) was done on pre-systemic treatment (pre) PT, post-treatment (post) MET sites and LB in PC to uncover differences in genomic alterations (GA) and potential impact on therapy selection. Methods: 1,294 PC tissues and 782 LB underwent hybrid-capture based CGP. PT biopsies and resections were compared with post-treatment MET biopsies from bone (BO), liver (LIV), lung (LU), brain (BN), lymph node (LN) and soft tissue (ST) sites and LB. TMB was determined on up to 1.1 Mbp of sequenced DNA for tumor samples. Tumor cell PD-L1 IHC was measured (Dako 22C3). Results: Differences in alteration frequencies between PT, MET and LB for selected genes are shown in the Table. TMPRSS2:ERG fusion frequencies were similar between PT and MET (35% vs 33%) but varied between MET sites (27% in BO and ST to 40% in LN). GA in AR were lowest in pre PT (2%) and highest in MET (24% in LU to 50% in LIV). BN had the highest GA/tumor (8) and the most PTEN GA. BRCA2 GA frequency varied from 0% in BN to 15% in LI. Potential predictors of IO response included CDK12 GA (16% in LU) and MSI high status (29% in BN). High PD-L1 expression was found in only two cases (LN) and low PD-L1 expression was relatively uncommon. ERBB2 amplifications were increased in MET compared with PT. RB1 GA were increased in LIV cases. LB GA had a similar increase in AR and TP53 GA to MET and appeared to be a blend of MET site biopsies across alteration frequencies. Conclusions: CGP of PT, MET and LB in PC demonstrates differences most likely associated with exposure to systemic therapies. Differences identified in the MET GA landscape suggest that liquid biopsies may capture a broader range of therapeutic opportunities for PC patients. [Table: see text]

Comprehensive genomic profiling (CGP) in patients with relapsed/refractory germ cell tumors (GCT)

e17053

Background: Understanding the genetic alterations in patients with relapsed/refractory GCT (rrGCT) could delineate the pathogenesis of cisplatin resistance. Our study uses CGP to characterize genomic alterations (GA) in refractory GCT and correlate with clinical outcomes. Methods: 432 patients with rrGCT were seen at Indiana University between Jan 2016 to Sep 2019 of whom 52 patients underwent CGP using a hybrid-capture based commercial assay to evaluate all classes of GA. Tumor mutational burden (TMB) was determined on 1.1 Mbp of sequenced DNA and reported as mutations/Mb and microsatellite instability (MSI) was determined on 114 loci. PDL1 expression was determined by IHC (DAKO 22C3 antibody). Results: All patients relapsed after first-line cisplatin-based combination chemotherapy. Median age at diagnosis was 33 (range 15-68). Primary site of GCT was testicular in 85% and mediastinum in 8%. 6 patients had pure seminoma and 46 had non-seminoma. Platinum refractory disease, defined as serologic or radiographic progression within 4 weeks of first-line chemotherapy comprised 23% of patients. The primary tumor was used for sequencing in 6 cases (12%) and non-primary tumor metastatic site (lymph node, lung, liver, brain, omentum) in 46 cases (88%). The most common GA in the entire cohort were FGF6 (27%), FGF23 (27%), KDM5A (27%), CCND2 (27%), KRAS (18%), TP53 (14%), KIT (8%), APC (8%), ZNF217 (6%), MUTYH (6%), AURKA (6%), NRAS (6%), EGFR (6%), CTNNB1 (6%), GNAS (6%). Most common alterations for testicular primary tumors were FGF6, FGF23, KDM5A, CCND2, KRAS, TP53, KIT. For non-testicular primary GCT, most common GA were APC, TP53, EGFR. Most common GA for non-seminoma were FGF6, FGF23, KDM5A, CCND2, KRAS, TP53, APC. Most common GA for pure seminoma was KIT. Potentially targetable genomic alterations were found in 17 patients (33%). 10 of 17 patients (59%) tested had PDL1 score ≥1% and 3 patients had PDL1 ≥50%. Median TMB was 3.5 mutations/MB. There were 4 patients (8%) with TMB ≥ 10 mutations/Mb and 2 patients (4%) with TMB ≥ 20 mutations/Mb. 1 of 48 patients (2%) evaluated for MSI had MSI-High status. Isochromosome 12p was detected in the majority of samples where it was tested. Outcomes with GA-directed therapy will be presented at the conference. Conclusions: CGP can reveal potential therapeutic targets in patients with rrGCT including EGFR, ERBB3, KIT, and MET. Consistent with reported clinical trials in rrGCT, biomarkers predicting response to immune checkpoint blockade are uncommon with most patients having low TMB, absence of MSI-H status, and low expression of PDL1.

Comprehensive genomic profiling (CGP) of histologic subtypes of urethral carcinomas (UrthCa)

5087

Background: UrthCa is an uncommon GU malignancy that can progress to advanced metastatic disease. Methods: 127 metastatic UrthCa underwent hybrid-capture based CGP to evaluate all classes of genomic alterations (GA). Tumor mutational burden (TMB) was determined on up to 1.1 Mbp of sequenced DNA and microsatellite instability (MSI) was determined on 114 loci. PD-L1 expression was determined by IHC (Dako 22C3). Results: 49 (39%) urothelial (UrthUC), 31 (24%) squamous (UrthSCC), 34 (19%) adenocarcinomas (UrthAC) and 13 (9%) clear cell (UrthCC) were evaluated along with a control cohort of 2,130 bladderUC cases. UrthUC and UrthSCC were more common in men; UrthAC and UrthCC more common in women. Age was similar in all 4 groups. GA in PIK3CA were the most frequent potentially targetable GA; MTOR pathway GA in PTEN also identified. GA in other potentially targetable genes were also identified including ERBB2(6% in UrthUC, 3% in UrthSCC and 12% in UrthAC), FGFR1-3 (3% in UrthSCC), BRAF (3% in UrthAC), PTCH1 (8% in UrthCC) and MET (8% in UrthCC). Higher TMB was seen in UrthUC and UrthCC compared to UrthAC and UrthSCC, possibly reflecting their higher GA/tumor status and suggesting potential for immunotherapy benefit. MSI high status was absent throughout. The bladderUC cases had similar genomic pattern as UrthUC with significantly lower frequency of HPV16/18 positive cases. Conclusions: CGP reveals GA that may be predictive of both targeted and immunotherapy benefit in patients with advanced UrthCa and that could potentially be used in future adjuvant, neoadjuvant and metastatic disease trials. [Table: see text]

Clinically advanced renal cell carcinoma (RCC) and renal sarcoma (RSC) in young patients: A comprehensive genomic profiling (CGP) study

5066

Background: We queried whether the landscape of genomic alterations (GA) would differ in patients with metastatic RCC under 40 years of age (under40) and patients 40 years of age or older (over40). Methods: FFPE tissues from 2,128 clinically advanced RCC and 25 RSC underwent hybrid-capture based CGP to evaluate all classes of GA. Samples were classified at time of sequencing as the following RCC subtypes: clear cell (ccRCC), papillary (papRCC), chromophobe (chrRCC), medullary (medRCC), collecting duct (cdRC), sarcomatoid (sarcRCC) and NOS (nosRCC). Tumor mutational burden (TMB) was determined on up to 1.1 Mbp of sequenced DNA. Tumor cell PD-L1 expression was determined by IHC (Dako 22C3). Results: The male preponderance increased in the over40 patients. The GA/tumor increased in the over40 cohorts except for medRCC. Similarly, TMB was consistently higher in over40 groups. MSI high status was virtually absent. PD-L1 expression, available only in small subsets, was generally absent although 44% high positive staining in sarcRCC was noteworthy. Differences in GA in under40 vs over40 RCC were seen and included increased PBRM1 and SETD2 GA in over40 vs under40 ccRCC; increased C DKN2A/B and TERT and decreased FH GA in over40 vs under40 papRCC; increased TP53 and decreased VHL, BAP1, SETD2 and PTEN in over40 vs under40 chrRCC; increased TP53, PTEN and TERT GA with decreased NF2 GA in over40 vs under 40 sarcRCC; and increased TP53, VHL and TERT in over40 vs under40 nosRCC. Changes in GA in under40 vs over40 medRCC, cdRCC and RSC were noted but insufficient cases prevented further evaluation. Conclusions: When separately evaluated by under/over 40 years of age, CGP of clinically advanced RCC demonstrates differences in genomic landscapes with over40 cases featuring increasing male preponderance, higher GA/tumor, higher TMB and increases in a variety of GA. These findings may play important roles in the planning of future clinical trials designed to personalize the treatment of metastatic RCC. [Table: see text]