Human epidermal growth factor receptor 2 (HER2) gene amplification in non-muscle invasive urothelial bladder cancers: Identification of patients for targeted therapy

Objectives

To evaluate human epidermal growth factor receptor 2 (HER2) protein overexpression by immunohistochemistry (IHC) and gene amplification by fluorescent in situ hybridisation (FISH) in urothelial non-muscle-invasive bladder carcinoma (NMIBC), as HER2 is a potential therapeutic target in muscle-invasive bladder carcinoma (MIBC) and HER2 expression and gene amplification in low/high-grade and pTa/pT1 NMIBC is not clear.

Patients and methods

The study included 93 bladder cancers; 25 MIBC and 68 NMIBC (37 low- and 31 high-grade). All HER2 positive (3+) and equivocal (2+) cases were subjected to FISH using a HER2/CEN 17 dual-colour probe kit. IHC and FISH were scored as per the American Society of Clinical Oncology/College of American Pathologists (ASCO/CAP) 2013 Guidelines for breast cancers. Based on the number of signals/nuclei, amplification was categorised as low (≥6–10) and high-level (≥10).

Results

HER2 2–3+ expression was seen in 29% of NMIBCs (10.8% low- and 51.6% high-grade). HER2 3+ expression was seen in high-grade NMIBC (nine of 31; 29%) and MIBC (nine of 25; 36%). In all, 87% of high-grade NMIBCs were lamina invasive (pT1). Gene amplification was found in 45% (eight of 18) of 3+ tumours. None of the HER2 2+ tumours showed gene amplification. IHC and FISH results were in closest agreement when ≥50% of tumour cells showed 3+ expressions. High-level amplification correlated with increased gene expression on reverse transcriptase-polymerase chain reaction. On multivariate analysis, lower  stage, grade, and HER2 expression significantly correlated with progression-free survival. HER2 3+ expression in NMIBC correlated significantly with time to recurrence and progression.

Conclusion

Our present results show that HER2 FISH should not be performed for HER2 2 + and low-grade NMIBC. This contrasts with breast cancers where it is recommended for equivocal 2+ tumours. About 50% of HER2 3+ MIBC and high-grade NMIBC show HER2 gene amplification and can be potential candidates for HER2-targeted therapy.

Abbreviations

ASCO/CAP: American Society of Clinical Oncology/College of American Pathologists; DAB: 3,3ʹ-diaminobenzidine; FISH: fluorescent in situ hybridisation; HER2: human epidermal growth factor receptor 2; IHC: immunohistochemistry;(N)MIBC: (non-) muscle-invasive bladder carcinoma; MPUC: micropapillary variant of urothelial bladder cancer; PFS: progression-free survival; TURBT: transurethral resection of bladder tumour

Oxaliplatin, 5-fluorouracil and leucovorin (FOLFOX) as second-line therapy for patients with advanced urothelial cancer

There is currently no standard treatment for metastatic urothelial cancer after failure of cisplatin-based therapy. The present retrospective study investigated the efficacy and safety of oxaliplatin plus 5-fluorouracil (5-FU) and leucovorin (LV) (FOLFOX) in locally advanced or metastatic urothelial cancer patients following cisplatin-based treatment. Thirty-three patients who had received one or two cisplatin-based regimens were treated with oxaliplatin (85 mg/m²) as a 2-h infusion on day 1, LV (200 mg/m²) as a 2-h infusion followed by bolus 5-FU (400 mg/m²) on day 1, or a 44-h continuous 5-FU (1,200 mg/m²) infusion. Patients were a mean of 67 years old with two involved organs. Metastases were mostly in the lung (43%), lymph nodes (51%) and liver (46%). Based on an intention-to-treat analysis, nine patients achieved a partial response, with an overall response rate of 27%. Eight (24%) patients had stable disease. Mean progression-free survival was 3 months and mean overall survival was 6.1 months. Toxicity was mild to moderate with grade 3 or 4 neutropenia, thrombocytopenia and neuropathy occurring in 5 (15%), 4 (12%) and 2 (6%) patients, respectively. This study demonstrated that oxaliplatin plus 5-FU/LV was a well-tolerated second-line regimen with moderate activity in patients pretreated with cisplatin-based therapeutics.

Society for Immunotherapy of Cancer consensus statement on immunotherapy for the treatment of bladder carcinoma

The standard of care for most patients with non-muscle-invasive bladder cancer (NMIBC) is immunotherapy with intravesical Bacillus Calmette-Guérin (BCG), which activates the immune system to recognize and destroy malignant cells and has demonstrated durable clinical benefit. Urologic best-practice guidelines and consensus reports have been developed and strengthened based on data on the timing, dose, and duration of therapy from randomized clinical trials, as well as by critical evaluation of criteria for progression. However, these reports have not penetrated the community, and many patients do not receive appropriate therapy. Additionally, several immune checkpoint inhibitors have recently been approved for treatment of metastatic disease. The approval of immune checkpoint blockade for patients with platinum-resistant or -ineligible metastatic bladder cancer has led to considerations of expanded use for both advanced and, potentially, localized disease. To address these issues and others surrounding the appropriate use of immunotherapy for the treatment of bladder cancer, the Society for Immunotherapy of Cancer (SITC) convened a Task Force of experts, including physicians, patient advocates, and nurses, to address issues related to patient selection, toxicity management, clinical endpoints, as well as the combination and sequencing of therapies. Following the standard approach established by the Society for other cancers, a systematic literature review and analysis of data, combined with consensus voting was used to generate guidelines. Here, we provide a consensus statement for the use of immunotherapy in patients with bladder cancer, with plans to update these recommendations as the field progresses.

Second-line treatment options in metastatic castration-resistant prostate cancer: a comparison of key trials with recently approved agents

Standard first-line treatment for metastatic castration-resistant prostate cancer (mCRPC) is docetaxel plus prednisone; however, patients will usually experience disease progression during or after docetaxel treatment due to inherent or acquired resistance. Before 2010, second-line options for mCRPC were limited. However, cabazitaxel, abiraterone acetate and enzalutamide have since been approved for patients with mCRPC whose disease has progressed during or after receiving docetaxel, based on the Phase III trials TROPIC, COU-AA-301 and AFFIRM. In all three trials, an overall survival benefit (primary endpoint) was seen in the experimental arm compared with the control arm: 15.1 vs. 12.7months for cabazitaxel plus prednisone compared with mitoxantrone plus prednisone in TROPIC (hazard ratio [HR] 0.70; P<0.0001); 14.8 vs. 10.9months for abiraterone acetateplus prednisone compared with placebo plus prednisone in COU-AA-301 (HR 0.65; P<0.001); and 18.4 vs. 13.6months for enzalutamide compared with placebo alone in AFFIRM (0.63; P<0.001). However, differences in patient populations, comparators, and selection and/or definition of secondary endpoints make it difficult to draw direct cross-trial comparisons. Radium-223 dichloride has also been approved for patients with mCRPC with metastases to bone but not other organs. To date, no comparative trials or sequencing studies with newer agents have been performed. Without such data, treatment decisions must be based on evaluation of the existing evidence. This commentary compares and contrasts study designs and key data from each of these Phase III trials, and also discusses recent and ongoing clinical trials with new agents in the first- and second-line settings in mCRPC.

Neoadjuvant paradigm for accelerated drug development: an ideal model in bladder cancer

Neoadjuvant cisplatin-based combination chemotherapy for muscle-invasive bladder cancer (MIBC) has been shown to confer a survival advantage in two randomized clinical trials and a meta-analysis. Despite level 1 evidence supporting its benefit, utilization remains dismal with nearly one-half of patients ineligible for cisplatin-based therapy because of renal dysfunction, impaired performance status, and/or coexisting medical problems. This situation highlights the need for the development of novel therapies for the management of MIBC, a disease with a lethal phenotype. The neoadjuvant paradigm in bladder cancer offers many advantages for accelerated drug development. First, there is a greater likelihood of successful therapy at an earlier disease state that may be characterized by less genomic instability compared with the metastatic setting, with an early readout of activity with results determined in months rather than years. Second, pre- and post-treatment tumor tissue collection in patients with MIBC is performed as the standard of care without the need for research-directed biopsies, allowing for the ability to perform important correlative studies and to monitor tumor response to therapy in "real time." Third, pathological complete response (pT0) predicts for improved outcome in patients with MIBC. Fourth, there is a strong biological rationale with rapidly accumulating evidence for actionable targets in bladder cancer. This review focuses on the neoadjuvant paradigm for accelerated drug development using bladder cancer as the ideal model.

Critical analysis of contemporary clinical research in muscle-invasive and metastatic urothelial cancer: a report from the Bladder Cancer Advocacy Network Clinical Trials Working Group

BACKGROUND

There have been no improvements in the treatment of metastatic urothelial cancer in the past several decades. A census of contemporary clinical research in this disease was performed to identify potential barriers and opportunities.

METHODS

These authors performed a search for clinical trials exploring interventions in muscle-invasive and metastatic urothelial cancer, using the ClinicalTrials.gov registry. Data extracted from the registry included title, recruitment status, interventions, sponsor, phase, enrollment, study design, and study sites.

RESULTS

Among 120 eligible trials exploring interventions in muscle-invasive and metastatic urothelial cancer, 73% were phase 2 and 73% were nonrandomized. The majority (63%) involved treatment in the metastatic disease state. The median planned enrollment size per trial was 45 patients (interquartile range, 47 patients). The majority of trials (55%) involved ≤ 3 study sites. Trials most commonly explored interventions in the first-line metastatic (30%) or second-line metastatic (37%) settings. Targeted therapeutics were studied in 58% of the trials. Among 56 trials that completed enrollment, the median time to complete accrual was 50 months (range, 10-109 months), and these trials enrolled a median of 40 patients per trial (interquartile range, 44 patients).

CONCLUSIONS

The majority of contemporary clinical trials in muscle-invasive and metastatic urothelial cancer are small, nonrandomized, phase 2 trials involving 1 to 3 study sites. Enhanced communication and collaboration among the urothelial cancer community, and other stakeholders, is needed to facilitate the design and conduct of trials capable of expediting progress in this disease.