Natural History and Genomic Landscape of Chemotherapy-Resistant Muscle-Invasive Bladder Cancer

PURPOSE

Patients with residual invasive bladder cancer after neoadjuvant chemotherapy (NAC) and radical cystectomy have a poor prognosis. Data on adjuvant therapy for these patients are conflicting. We sought to evaluate the natural history and genomic landscape of chemotherapy-resistant bladder cancer to inform patient management and clinical trials.

METHODS

Data were collected on patients with clinically localized muscle-invasive urothelial bladder cancer treated with NAC and cystectomy at our institution between May 15, 2001, and August 15, 2019, and completed four cycles of gemcitabine and cisplatin NAC, excluding those treated with adjuvant therapies. Survival was estimated using the Kaplan-Meier method, and multivariable Cox proportional hazards models were used to identify predictors of recurrence-free survival (RFS). Genomic alterations were identified in targeted exome sequencing (Memorial Sloan Kettering Integrated Mutation Profiling of Actionable Cancer Targets) data from post-NAC specimens from a subset of patients.

RESULTS

Lymphovascular invasion (LVI) was the strongest predictor of RFS (hazard ratio, 2.15 [95% CI, 1.37 to 3.39]) on multivariable analysis. Patients with ypT2N0 disease without LVI had a significantly prolonged RFS compared with those with LVI (70% RFS at 5 years). Lymph node yield did not affect RFS. Among patients with sequencing data (n = 101), chemotherapy-resistant tumors had fewer alterations in DNA damage response genes compared with tumors from a publicly available chemotherapy-naïve cohort (15% v 29%; P = .021). Alterations in CDKN2A/B were associated with shorter RFS. PIK3CA alterations were associated with LVI. Potentially actionable alterations were identified in more than 75% of tumors.

CONCLUSION

Although chemotherapy-resistant bladder cancer generally portends a poor prognosis, patients with organ-confined disease without LVI may be candidates for close observation without adjuvant therapy. The genomic landscape of chemotherapy-resistant tumors is similar to chemotherapy-naïve tumors. Therapeutic opportunities exist for targeted therapies as adjuvant treatment in chemotherapy-resistant disease.

Final Results of a Phase I Trial of WST-11 (TOOKAD Soluble) Vascular-targeted Photodynamic Therapy for Upper Tract Urothelial Carcinoma

PURPOSE

Vascular-targeted photodynamic therapy with the intravascular photosensitizing agent padeliporfin (WST-11/TOOKAD-Soluble) has demonstrated therapeutic efficacy as an ablative treatment for localized cancer with potential adaptation for endoscopic management of upper tract urothelial carcinoma. This Phase I trial (NCT03617003) evaluated the safety of vascular-targeted photodynamic therapy with WST-11 in upper tract urothelial carcinoma.

MATERIALS AND METHODS

Nineteen patients underwent up to 2 endoscopic vascular-targeted photodynamic therapy treatments, with follow-up for up to 6 months. Patients who had residual or recurrent upper tract urothelial carcinoma (any grade/size) failing prior endoscopic treatment or unable or unwilling to undergo surgical resection were eligible for inclusion. The primary endpoint was to identify the maximally tolerated dose of laser light fluence. A dose escalation model was employed, with increasing light fluence (100-200 mW/cm) using a modified continual reassessment method. The secondary endpoint was treatment efficacy, defined by absence of visible tumor and negative urine cytology 30 days posttreatment.

RESULTS

Fourteen (74%) patients received the maximally tolerated dose of 200 mW/cm, 2 (11%) of whom experienced a dose-limiting toxicity. The initial 30-day treatment response rate was 94% (50% complete, 44% partial). Eight patients underwent a second treatment, with a final observed 68% complete response rate. Leading toxicities were flank pain (79%) and hematuria (84%), which were transient. No ureteral strictures associated with treatment were identified during follow-up.

CONCLUSIONS

Vascular-targeted photodynamic therapy with WST-11 has an acceptable safety profile with strong potential as an effective, kidney-sparing endoscopic management option for upper tract urothelial carcinoma. The recently initiated multicenter Phase 3 ENLIGHTED trial (NCT04620239) is expected to provide further evidence on this therapy.

Gene-based Confirmatory Germline Testing Following Tumor-only Sequencing of Prostate Cancer

BACKGROUND

Tumor-only genomic profiling is an important tool in therapeutic management of men with prostate cancer. Since clinically actionable germline variants may be reflected in tumor profiling, it is critical to identify which variants have a higher risk of being germline in origin to better counsel patients and prioritize genetic testing.

OBJECTIVE

To determine when variants found on tumor-only sequencing of prostate cancers should prompt confirmatory germline testing.

DESIGN, SETTING, AND PARTICIPANTS

Men with prostate cancer who underwent both tumor and germline sequencing at Memorial Sloan Kettering Cancer Center from January 1, 2015 to January 31, 2020 were evaluated.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Tumor and germline profiles were analyzed for pathogenic and likely pathogenic ("pathogenic") variants in 60 moderate- or high-penetrance genes associated with cancer predisposition. The germline probability (germline/germline + somatic) of a variant was calculated for each gene. Clinical and pathologic factors were analyzed as potential modifiers of germline probability.

RESULTS AND LIMITATIONS

Of the 1883 patients identified, 1084 (58%) had a somatic or germline pathogenic variant in one of 60 cancer susceptibility genes, and of them, 240 (22%) had at least one germline variant. Overall, the most frequent variants were in TP53, PTEN, APC, BRCA2, RB1, ATM, and CHEK2. Variants in TP53, PTEN, or RB1 were identified in 746 (40%) patients and were exclusively somatic. Variants with the highest germline probabilities were in PALB2 (69%), MITF (62%), HOXB13 (60%), CHEK2 (55%), BRCA1 (55%), and BRCA2 (47%), and the overall germline probability of a variant in any DNA damage repair gene was 40%. Limitations were that most of the men included in the cohort had metastatic disease, and different thresholds for pathogenicity exist for somatic and germline variants.

CONCLUSIONS

Of patients with pathogenic variants found on prostate tumor sequencing, 22% had clinically actionable germline variants, for which the germline probabilities varied widely by gene. Our results provide an evidenced-based clinical framework to prioritize referral to genetic counseling following tumor-only sequencing.

PATIENT SUMMARY

Patients with advanced prostate cancer are recommended to have germline genetic testing. Genetic sequencing of a patient's prostate tumor may also identify certain gene variants that are inherited. We found that patients who had variants in certain genes, such as ones that function in DNA damage repair, identified in their prostate tumor sequencing, had a high risk for having an inherited cancer syndrome.

Targeted Therapies in Advanced and Metastatic Urothelial Carcinoma

This review describes the current landscape of targeted therapies in urothelial carcinoma. The standard of care for advanced urothelial carcinoma patients remains platinum-based combination chemotherapy followed by immunotherapy. However, median overall survival for these patients is still <1 year and there is an urgent need for alternative therapies. The advent of next-generation sequencing has allowed widespread comprehensive molecular characterization of urothelial tumors and, subsequently, the development of therapies targeting specific molecular pathways implicated in carcinogenesis such as FGFR inhibition, Nectin-4, Trop-2, and HER2 targeting. As these therapies are demonstrated to be effective in the second-line setting, they will be advanced in the treatment paradigm to localized and even non-muscle invasive disease.

Germline Variants Identified in Patients with Early-onset Renal Cell Carcinoma Referred for Germline Genetic Testing

BACKGROUND

Despite guidelines recommending genetic counseling for patients with early-onset renal cell carcinoma (RCC), studies interrogating the spectrum of germline mutations and clinical associations in patients with early-onset RCC are lacking.

OBJECTIVE

To define the germline genetic spectrum and clinical associations for patients with early-onset RCC diagnosed at age ≤46 yr who underwent genetic testing.

DESIGN, SETTING, AND PARTICIPANTS

We retrospectively identified patients with early-onset RCC who underwent germline testing at our institution from February 2003 to June 2020.

OUTCOME MEASUREMENT AND STATISTICAL ANALYSIS

The frequency and spectrum of pathogenic/likely pathogenic (P/LP) variants were determined. Clinical characteristics associated with mutation status were analyzed using two-sample comparison (Fisher's exact or χ2 test).

RESULTS AND LIMITATIONS

Of 232 patients with early-onset RCC, 50% had non-clear-cell histology, including unclassified RCC (12.1%), chromophobe RCC (9.7%), FH-deficient RCC (7.0%), papillary RCC (6.6%), and translocation-associated RCC (4.3%). Overall, 43.5% had metastatic disease. Germline P/LP variants were identified in 41 patients (17.7%), of which 21 (9.1%) were in an RCC-associated gene and 20 (8.6%) in a non-RCC-associated gene, including 17 (7.3%) in DNA damage repair genes such as BRCA1/2, ATM, and CHEK2. Factors associated with RCC P/LP variants include bilateral/multifocal renal tumors, non-clear-cell histology, and additional extrarenal primary malignancies. In patients with only a solitary clear-cell RCC, the prevalence of P/LP variants in RCC-associated and non-RCC-associated genes was 0% and 9.9%, respectively.

CONCLUSIONS

Patients with early-onset RCC had high frequencies of germline P/LP variants in genes associated with both hereditary RCC and other cancer predispositions. Germline RCC panel testing has the highest yield when patients have clinical phenotypes suggestive of underlying RCC gene mutations. Patients with early-onset RCC should undergo comprehensive assessment of personal and family history to guide appropriate genetic testing.

PATIENT SUMMARY

In this study of 232 patients with early-onset kidney cancer who underwent genetic testing, we found a high prevalence of mutations in genes that increase the risk of cancer in both kidneys and other organs for patients and their at-risk family members. Our study suggests that patients with early-onset kidney cancer should undergo comprehensive genetic risk assessment.

Management of High-grade T1 Urothelial Carcinoma

PURPOSE OF REVIEW

The optimal management of high-grade T1 (HGT1) urothelial carcinoma (UC) is complex given its high rate of recurrence, progression, and cancer-specific mortality as well as its clinical variability. Our current treatment paradigm has been supplemented by recent data describing the expanding options for salvage intravesical therapy, bladder preservation, and the promising role of molecular epidemiology. In the current review, we attempt to summarize and critically analyze these studies.

RECENT FINDINGS

Evidence describing new intravesical therapies has demonstrated an adequate safety profile and some efficacy in BCG-unresponsive patients who desire bladder preservation. However, response rates are still poor in this high-risk patient population, and it is important to keep these data in perspective when counseling patients. Concomitantly, the continued molecular characterization of non-muscle-invasive bladder cancer may suggest potential therapeutic targets as well as predictors of treatment response in the future. The integration of new intravesical therapies and molecular data into the current treatment paradigm for HGT1 urothelial carcinoma will be critical to improving oncologic outcomes in this particularly high-risk population.

Fibromyxoid Nephrogenic Adenoma in the Ureter

Background: Nephrogenic adenoma is a benign lesion found in the genitourinary tract, often at sites of prior inflammation, and is characterized by tubular, papillary, or tubulopapillary structures. It is thought to arise from distal migration and implantation of renal tubular cells into the renal pelvis, ureter, bladder, or urethra. These tumors often resemble malignant neoplasms. Morphologic variants include small tubules, signet ring-like pattern, papillary formations, flat pattern, and vessel-like structures. A fibromyxoid variant was first described in 2007. Here, we present the first known cases of fibromyxoid nephrogenic adenoma of the ureter.

Case Presentations: A 79-year-old white man presented with asymptomatic right hydroureteronephrosis to the level of the mid-ureter with associated right ureteral wall thickening found on surveillance CT scan for lymphoma. A 59-year-old white man presented with a right ureteral stricture after ureteroscopic ureteral injury and underwent effective robotic ureteroureterostomy. Pathology analysis in both cases revealed fibromyxoid nephrogenic adenoma.

Conclusion: Fibromyxoid nephrogenic adenoma may occur in the ureter. Knowledge of this rare tumor is important for urologists and pathologists to prevent misdiagnosis and overtreatment of a typically benign process.