Outcomes of a universal germline screening program in a community urology practice

The role of germline genetic testing in urologic oncology has expanded in recent years. However, implementation of genetic testing in community practices remains a challenge, often due to limited access to qualified genetics trained providers. In this study, we report outcomes of a universal germline screening program in a community urology practice. Between November 2021 and September 2022, all patients referred for urology clinic visits at Frederick Health (Frederick, MD, USA) were provided an online genetics screening questionnaire prior to the visit. Responses were compared against National Comprehensive Cancer Network (NCCN) criteria for germline testing. Those who met criteria were provided educational materials at the end of the questionnaire, and then counseled by a trained urologic oncologist (HC) in the clinic or referred to a genetic counselor prior to testing. Testing was performed with a 36-gene pan-cancer panel (CancerNext) or a 14-gene targeted prostate cancer panel (ProstateNext), with or without additional RNA analysis (RNAinsight) (Ambry Genetics, CA, USA). Demographic and clinical parameters, as well as genetic testing results, were retrospectively collected under IRB approval. In the study period, 765 patients were seen over 1370 clinic visits. Of these, 505 patients (66.0%) completed the screening questionnaire. The majority were completed via email (54.5%) with the remainder (45.5%) via text message. Of the patients who completed screening, 125/505 (24.7%) met NCCN criteria for germline testing. 58/125 patients (46.4%) who met criteria underwent germline testing, of whom 5/58 (8.6%) had distinct pathogenic mutations identified. These included actionable mutations in BRCA1, BRCA2, and CHEK2, as well as an additional pathogenic mutation in NBN. Variants of unknown significance were identified in 8/58 patients (13.8%) in 11 total genes. Challenges to implementation of this program included meeting institutional requirements for genetic testing consent, facilitating specimen collection in clinic, and integration of results into the electronic health record. Genetic risk assessment for high-risk individuals is feasible as part of a universal screening program in a community urology practice. Approximately 8% of tested patients were found to have pathogenic germline mutations, which is consistent with contemporary tertiary referral cohorts.

Comparison of germline mutations in African American and Caucasian men with metastatic prostate cancer

BACKGROUND

The goal of this study is to evaluate germline genetic variants in African American men with metastatic prostate cancer as compared to those in Caucasian men with metastatic prostate cancer in an effort to understand the role of genetic factors in these populations.

METHODS

African American and Caucasian men with metastatic prostate cancer who had germline testing using multigene panels were used to generate comparisons. Germline genetic results, clinical parameters, and family histories between the two populations were analyzed.

RESULTS

A total of 867 patients were included in this retrospective study, including 188 African American and 669 Caucasian patients. There was no significant difference in the likelihood of a pathogenic or likely-pathogenic variants (PV/LPVs) between African American and Caucasian patients (p = .09). African American patients were more likely to have a variant of unknown significance than Caucasians (odds ratio [OR] = 1.95; p < .0001). BRCA1 PV/LPVs were higher in African Americans (OR = 4.86; p = .04). African American patients were less likely to have a PV/LPV in non-BRCA DNA repair genes (OR = 0.30; p = .008). Family history of breast (OR = 2.09; p = .002) or ovarian cancer (OR = 2.33; p = .04) predicted PV/LPVs in Caucasians but not African-Americans. This underscores the limitations of family history in AA men and the importance of personal history to guide germline testing in AA men.

CONCLUSIONS

In metastatic prostate cancer patients, PV/LPVs of tested genes did not vary by race, BRCA1 PV/LPVs were more common in the African American subset. However, PV/LPVs in non-BRCA DNA repair genes were less likely to be encountered in African Americans. Family history associated with genetic testing results in Caucasians only.

Family history and pathogenic/likely pathogenic germline variants in prostate cancer patients

BACKGROUND

Recent literature highlights the importance of germline genetic testing in prostate cancer (PCa) patients. Surprisingly, a literature review indicates that family history (FH) records are incomplete in the major published studies from prostate cancer patients.

METHODS

Prospective family history data were gathered from 496 men in a single institution with a personal history of PCa who underwent germline genetic testing using a panel of at least 79 genes. Comprehensive first degree FH were obtained in all PCa of patients and analysis of prevalent FH was assessed at the time of sample collection.

RESULTS

Pathogenic/likely pathogenic variants (PV/LPVs) were not associated with age at diagnosis, race, or presence of metastasis. One or more first degree relatives (FDR) with any cancer was not predictive for germline PV/LPVs for men with PCa (p = .96). Separate analysis of patients with one or more FDR with breast, prostate, ovarian, or pancreatic cancer revealed that only FDR with breast or ovarian cancer was predictive for PV/LPVs (p = .028, p = .015 respectively). Patients with a FDR with breast cancer had 1.8 increased risk of PV/LPVs, and patients with a FDR with ovarian cancer had 2.9 increased risk of PV/LPV.

CONCLUSION

In men with a personal history of PCa, germline PV/LPVs were associated with a FDR with breast or ovarian cancer. Notably having FDRs with PCa does not predict for PV/LPVs. These data emphasize the contribution of FH in a data set with complete ascertainment of FH.

Outcomes With First-Line PD-1/PD-L1 Inhibitor Monotherapy for Metastatic Renal Cell Carcinoma (mRCC): A Multi-Institutional Cohort

Introduction: The treatment landscape of metastatic renal cell carcinoma has advanced significantly with the approval of combination regimens containing an immune checkpoint inhibitor (ICI) for patients with treatment-naïve disease. Little information is available regarding the activity of single-agent ICIs for patients with previously untreated mRCC not enrolled in clinical trials. Methods: This retrospective, multicenter cohort included consecutive treatment-naïve mRCC patients from six institutions in the United States who received ≥1 dose of an ICI outside a clinical trial, between June 2017 and October 2019. Descriptive statistics were used to analyze outcomes including objective best response rate (ORR), progression-free survival (PFS), and tolerability. Results: The final analysis included 27 patients, 70% men, median age 64 years (range 42-92), 67% Caucasian, and 33% with ECOG 2 or 3 at baseline. Most patients had intermediate risk (85%, IMDC) with clear cell (56%), papillary (26%), unclassified (11%), chromophobe (4%), and translocation (4%) RCC. All patients had evidence of metastatic disease involving the lungs (59%), lymph node (41%), CNS (19%), liver (11%), adrenal gland (11%), and bone (11%). The median time on ICI was 3.1 (0.1-26.8) months, and the median PFS was 6.3 (95% CI, 0-18.6) months. Among the 21 patients with an evaluable response, the best ORR was 33%, including two complete responses and five partial responses. The ORR was 29% (n = 1 complete response, n = 5 partial response) in clear cell and 5% (n = 1 complete response) in non-clear cell RCC. Adverse events (AEs) of any cause were reported in 37% and included fatigue (11%), dermatitis (11%), diarrhea (7%), and shortness of breath (7%). Significant AEs (30%) included shortness of breath (7%), acute kidney injury (4%), dermatitis (4%), Clostridium difficile infection (4%), cerebrovascular accident (4%), and fatigue (7%). Three patients discontinued therapy due to grade 4 AEs. Conclusions: In this multi-institutional case series, single-agent ICI demonstrated objective responses and was well tolerated in a heterogeneous treatment-naïve mRCC cohort. ICI monotherapy is not the standard of care for patients with mRCC, and further investigation is necessary to explore predictive biomarkers for optimal treatment selection in this setting.

Clinical activity of pembrolizumab in metastatic prostate cancer with microsatellite instability high (MSI-H) detected by circulating tumor DNA

To report a multi-institutional case series of patients with advanced microsatellite instability high (MSI-H) prostate adenocarcinoma identified with clinical cell-free DNA (cfDNA) next-generation sequencing (NGS) testing and treated with immune checkpoint inhibitors. Retrospective analysis of patients with metastatic castration-resistant prostate cancer (mCRPC) and MSI-H tumor detected by a commercially available cfDNA NGS assay Guardant360 (G360, Guardant Health) at eight different Academic Institutions in the USA, from September 2018 to April 2020. From a total of 14 MSI-H metastatic prostate cancer patients at participating centers, nine patients with mCRPC with 56% bone, 33% nodal, 11% liver and 11% soft-tissue metastases and a median PSA of 29.3 ng/dL, were treated with pembrolizumab after 2 lines of therapy for CRPC. The estimated median time on pembrolizumab was 9.9 (95% CI 1.0 to 18.8) months. Four patients (44%) achieved PSA50 after a median of 4 (3–12) weeks after treatment initiation including three patients with >99% PSA decline. Among the patients evaluable for radiographic response (n=5), the response rate was 60% with one complete response and two partial responses. Best response was observed after a median of 3.3 (1.4–7.6) months. At time of cut-off, four patients were still on pembrolizumab while four patients discontinued therapy due to progressive disease and one due to COVID-19 infection. Half of the patients with PSA50 had both MSI-H and pathogenic alterations in BRCA1 and BRCA2 in their G360 assays. The use of liquid biopsy to identify metastatic prostate cancer patients with MSI-H is feasible in clinical practice and may overcome some of the obstacles associated with prostate cancer tumor tissue testing. The robust activity of pembrolizumab in selected patients supports the generalized testing for MSI-H.

First-line PD-1/PD-L1 inhibitor monotherapy for advanced renal cell carcinoma (aRCC): A multi-institutional cohort

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Background: Combination regimens containing a programmed cell death protein 1 (PD-1) or a programmed cell death ligand 1 (PD-L1) inhibitor improve the clinical outcomes of previously untreated aRCC. These regimens are clinically active but are associated with adverse events (AEs). One prospective study (KEYNOTE-427) has shown clinical activity of pembrolizumab monotherapy in aRCC. We aimed to describe the utilization and outcomes of single-agent PD-1/PD-L1 in previously untreated aRCC patients (pts). Methods: Consecutive pts treated with front-line PD-1/PD-L1 monotherapy for aRCC were included. Descriptive statistics were used to analyze outcomes including overall response rate (ORR), progression-free survival (PFS) and safety. Results: A total of 28 pts (median age 60; 32% ECOG 2/3; intermediate/poor risk 86%/14%; 35% non-clear cell aRCC) were identified. Common sites of metastases included lung (57%), lymph nodes (39%), bone (21%) and brain (21%). Pts received pembrolizumab (n = 9), avelumab (n = 1) or nivolumab (n = 18) due to pt/physician’s decision (46%), poor performance status (29%) or clinical trial (21%). In evaluable pts (n = 24), the ORR was 33% in ccRCC and 30% in nccRCC. With a median follow up of 13 months (mo), the median PFS was 6.3 mo (CI 95%, 1.5-11.1) and 16 pts progressed on therapy. Frequent AEs (57%) included fatigue (21%), myalgias/arthralgias (11%) and hypothyroidism (7%). No significant grade AEs (G3+) were noted. After progression on PD-1/PD-L1 (n = 16), 39% received a subsequent anti-VEGF (cabozantinib n = 6; sunitinib n = 4; pazopanib n = 1), 42% went to hospice or died and 21% were lost to follow up. Conclusions: First-line single-agent treatment with PD-1/PD-L1 inhibitors showed a favorable safety profile and clinical activity in patients with clear cell and non-clear cell aRCC who were not considered for a combination regimen. [Table: see text]

Comparison of germline mutations in African American and Caucasian men with metastatic prostate cancer

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Background: The relevance of germline mutations in metastatic prostate cancer is well established; however, comparison of germline genetics in African American (AA) versus Caucasian (CA) men with metastatic prostate cancer (PCa) is limited. Methods: Germline data from self-identified AA and CA metastatic PCa patients (pts) were collected from 5 academic cancer centers. Various commercial cancer-specific germline testing panels were used to evaluate 12-86 genes. Pathogenic (P) or likely pathogenic (LP) mutations, and variants of unknown significance (VUS), were reported according to ACMG guidelines. Self-reported family history (FH) was annotated for 99% of pts. Statistical analyses included Chi-squared and Fischer’s exact tests. Results: A total of 821 metastatic PCa pts were assessed: 152 AAs and 669 CAs. For P/LP alterations, AAs had a frequency of 11.2% (17/152) as compared to a frequency of 14.6% (98/669) in CAs (p = 0.302). AA pts were more likely to have a VUS than CA pts, 61% vs 43% respectively (OR = 2.09, 95%CI [1.45, 2.99], p < 0.001). BRCA mutations were similar between races, but AA were more likely to have a BRCA1 P/LP alteration (OR = 6.00, 95% CI [1.33, 27.09], p = 0.025). AA pts were less likely to have a P/LP alteration in a non-BRCA gene (OR = 0.34, 95% CI [0.15, 0.80], p = 0.013). Among DNA repair genes, there were no significant difference between AA and CA pts (p = 0.574); however, there was a trend toward AA pts having fewer P/LP alteration in a non-BRCA DNA repair genes (OR = 0.26, 95% CI [0.06, 1.08], p = 0.071). In pts with >1 first degree relative (FDR) with ovarian cancer, P/LP germline alterations were more likely in CAs (OR = 2.33, 95% CI [1.05, 5.17], p = 0.043); but there were no significant differences in AAs (p = 0.098). Those with >2 FDRs with PCa were more likely to have a P/LP change in CAs (OR = 2.32, 95% CI [1.04, 5.15], p = 0.043), but there were no difference in AAs (p = 0.700). In pts with ≥2 FDRs with breast cancer, P/LP germline alterations were more likely in both AAs (OR = 9.36, 95% CI [1.72, 50.84], p = 0.019) and CAs (OR = 3.92, 95% CI [1.79, 8.59], p = 0.001). Conclusions: We did not observe a difference in the overall frequency of germline P/LP alterations between AA and CA men with metastatic PCa but VUSs were more common in AA men. These AA men have an overall frequency of BRCA mutations similar to CA men; however, BRCA1 mutations were more prevalent in these AAs. Non-BRCA P/LP mutations are significantly less frequent in AA pts. A positive family history of >2 FDRs with breast cancer was associated with P/LP alterations in both AA and CA pts.

Family history and germline alterations in metastatic prostate cancer patients

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Background: Recent literature has highlighted the importance of germline genetic testing in metastatic prostate cancer (PCa)patients (pts). This retrospective study evaluated family history (FH), evaluate treatment outcomes in metastatic patients with pathogenic germline mutations, and compared family history in Caucasian (CA) and Africans Americans (AA). Methods: At Tulane Cancer Center, 428 metastatic PCa pts had germline testing in at least 79 genes. Comprehensive family histories were obtained in all. Analysis of prevalent FH, including breast, ovarian, prostate, and pancreatic cancers was assessed for all metastatic pts. Statistical analyses including chi square were performed. Results: 64 (64/428; 14.9%) pts had at least one or more pathogenic mutations, while 166 (166/428; 38.7%) had were normal. The remaining 199 (199/428; 46.4%) of pts had a variant of uncertain significance (VUS). Pts with a DNA repair pathogenic mutation were more likely to have >2 family members affected by cancer, regardless of cancer type or degree of relationship (p=0.0047); 6 pts without any family history of cancer had a pathogenic mutation. In CA, the presence of either a breast or PCa family history was associated with pathogenic germline findings (p=.022/.0367) However, in AAs neither breast nor prostate cancer predicted pathogenic germline alterations. Conclusions: The correlation between family history of breast and PCa cancer in CA pts with pathogenic mutations is notable as is the finding of >2 family members with cancer predicting germline pathogenic alterations. With AA pathogenic pts, there was no correlation of family history of breast and PCa, which highlights the need to learn more about the genetic factors which influence AA prostate cancer risk.[Table: see text]

Circulating tumor DNA (ctDNA) landscape in metastatic castrate-resistant prostate cancer patients with germline alterations

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Background: Circulating tumor-DNA (ctDNA) in mCRPC patients (pts) provides a viable approach for examining the genetic landscape of prostate cancer. In this follow-up, we report ctDNA variants in germline tested mCRPC pts. Methods: ctDNA alterations in 73 genes were detected using Guardant360 (G360) assays. Alteration types assessed were missense, frameshift, insertions, splice variants, truncations, amplifications (amp), deletions, and other. Pts included in the analysis received germline genetic testing (Invitae Corporation, San Francisco, CA) and ctDNA assays at various treatment timepoints. Statistical analyses were performed using chi-square and fisher exact test with p-value <0.05 for significance. Results: Germline and ctDNA testing was completed in 270 mCRPC pts. 13% (35/270) of pts had pathogenic germline alterations. Germline alterations detected were BRCA2 (43%, n=15), ATM (8.5%, n=3), CHEK2 (8.5%, n=3), and BRCA1 (6%, n=2). Of the 673 alterations detected in G360 assays, TP53 (25%, n=167) and AR (17%, n=117) were most commonly observed. ctDNA alteration breakdown for germline negative/positive pts is summarized in Tables A/B. Germline negative pts had more AR alterations compared to germline positive (p = 0.023). Also, germline negative pts presented with more amps (p < 0.001) and germline positive pts with more frameshift alterations (p = 0.005). The association of ctDNA alteration to clinical outcomes in germline positive/negative pts was also assessed and is ongoing. Conclusions: Pts with germline positive alterations had few somatic AR alterations and higher frequency of deleterious mutation in comparison to their germline negative counterparts.[Table: see text][Table: see text]

Comparison of Caucasian and African-American DNA repair alterations in men with metastatic prostate cancer

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Background: Data on germline DNA repair defects and VUS rates are sparse in African American (AA) men with metastatic prostate cancer (PCa). Methods: Germline testing data from two centers with a significant percentage of metastatic AA PCa patients were combined and compared to Caucasian American (CA) with metastatic PCa. Fourteen canonical DNA repair genes (ATM, BARD1, BRCA1, BRCA2, BRIP1, CHEK2, MLH1, MSH2, MSH6, NBN, PALB2, PMS2, RAD51C, RAD51D) were assessed in all tested patients (pts) using a pathogenic/likely pathogenic (P/LP) classification. Variants of unknown significance (VUS) were assessed in an Invitae-derived dataset with consistent VUS reporting. Results: A total of 105 AA men with metastatic disease were evaluated and 7/105 of these men (6.67%) had P/LP alteration. Among the AA pt alterations, there were 4 pts with BRCA2, 2 pts with BRCA1, and 1 pt with PALB2. A total of 39/417 (9.3%) of CA metastatic patients had P/LP alterations in the canonical 14 genes. No differences were detected in the AA vs CA metastatic comparison (p=0.39). A total of 1/105 (0.95%) AA pts and 23/418 (5.5%) CA had non-BRCA P/LP mutations. The number of non-BRCA P/LP mutations were lower in the AA as compared to the CA men (p=0.045). When evaluating VUS calls in the metastatic AAs using Invitae multi-gene panels, 28/92 (30.43%) pts had a VUS in the canonical 14 genes as compared to 67/366 (18.31%) of the CA men. AAs were more likely than CA to have a VUS (p=0.010). These data indicate that metastatic AA pts and CA are not significantly distinct in the P/LP alterations in 14 canonical DNA repair genes but that there were lower percentages of P/LP in the AA non-BRCA gene subset. Further, when assessing these genes, it is clear that a VUS is more likely to be called in the AA men. Conclusions: Among men with metastatic PCa, AAs have similar rates of inherited P/LP alterations in 14 well accepted DNA repair genes as compared to CA men, however the non-BRCA gene P/LP alterations were less frequent among the AAs. Variants classified as a VUS were clearly higher in these AA pts as compared to the CA pts.

Androgen receptor cfDNA longitudinal mutational analysis in metastatic castrate-resistant prostate cancer

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Background: Androgen receptor (AR) mutations commonly occur in metastatic castrate resistant prostate cancer (mCRPC). Methods: Circulating tumor DNA (ctDNA) data were obtained from Guardant 360 assays throughout the clinical course of mCRPC patients (pts). Retrospective analysis for any pt with ≥ 3 Guardant assays at least 4 weeks apart were reviewed. Patients must have at least 1 AR mutation or amplification to qualify for inclusion. Statistical analyses, including chi-sq and longitudinal analyses, were conducted. Results: Of the 259 patients with Guardant testing, a total of 88 patients had at least 3 Guardant tests; of these, 59 (67%) had at least one AR alteration. Patients had a median of 4 Guardant assays (range 3-10). Patients with AR amplification, AR mutation or both were identified (23, 20, 16 respectively). The most common and clinically relevant AR mutations found alone or in combination with amplification were T878A (22%), L702H(19%), W742C (19%), and H875Y (10%). These particular functional AR mutations occurred alone in 16 patients. Only 3 patients had neither amplification nor common AR mutation. 17/59 patients were found to have at least one common AR mutation and amplification at some point (on same or different Guardant). One patient had seven different AR mutations with no amplification and two other patients had 3 AR mutations. Remainder of patients had either AR amplification or ≤ 2 alternative mutations. Patients with an AR amplification were 0.1138x (95% Cl 0.0289 - 0.4491) significantly less likely of having a common known functional mutation (p <0.002) at any point. Conclusions: Patients with the most frequently identified known functional AR mutations are less likely to have AR amplification in pts with mCRPC; these common AR mutations have been shown to be associated with resistance to 2nd generation androgen deprivation. Further clinical correlation between treatment regimen and %cfDNA of these and other non-AR driver mutations is planned.

Neurocristopathy resembling neurofibromatosis type 1 in an NGF-SV40 transgenic line

BACKGROUND

Animal models of carcinogenesis have been produced in transgenic mice by directing the expression of oncogenes such as SV40 T antigen and myc to different tissues by creating fusions with promoter/enhancer elements of various mammalian or viral genes.

RESULTS

A transgenic mouse line was created in which SV40 T antigen is under the control of the mouse nerve growth factor (NGF) promoter. While the oncogene is expressed in a wide range of NGF producing tissues, it specifically causes the development of either neurofibromas or neurofibrosarcomas similar to those found in the human disease neurofibromatosis type 1 (NF1). These tumours are completely penetrant and appear after a mean latency of about 8 months. In contrast to the previously reported neurofibromatosis mouse model HTLV-1 tax, the tumours in these transgenic mice arise in Schwann cells rather than perineural fibroblasts and have a very restricted tissue distribution. In a cell line cloned from a neurofibroma from these mice, NGF was detected in the culture medium at levels similar to those produced by cultured primary Schwann cells.

CONCLUSION

As all animal model for a heritable neurocristopathy resembling NF1, this mouse should allow study of the pathology and treatment of this disease.