The Evolving Landscape of Treatment for Bladder Cancer: From Understaging Risk Factors to Immunotherapy's Role

The Evolving Landscape of Treatment for Bladder Cancer: From Understaging Risk Factors to Immunotherapy's Role

Introduction:
Bladder cancer is a complex disease that requires careful evaluation and treatment planning. In recent years, research has shed light on various aspects of the disease, from factors influencing understaging to the emergence of immunotherapy as a potential alternative to chemotherapy. This article aims to explore these topics and provide actionable advice for clinicians.

Factors Influencing Understaging at the Time of Radical Cystectomy:
A study focusing on non-muscle invasive high-grade urothelial carcinoma of the bladder identified several risk factors that can increase the risk of understaging. These factors include deep lamina propria and microscopic vascular invasion, multiple tumors, tumor size larger than 6 cm, tumor location in the trigone and dome, and the presence of residual tumor. Understanding and considering these risk factors is crucial to ensure accurate staging and appropriate treatment planning.

Immunotherapy vs. Chemotherapy in the Neoadjuvant Setting:
Another significant development in the field of bladder cancer treatment is the rise of immunotherapy as a potential replacement for chemotherapy in the neoadjuvant setting. Research presented at EAU 2020 suggests that PD-1/PD-L1 inhibitors may replace chemotherapy in the cisplatin-ineligible population. In the cisplatin-eligible population, combining immunotherapy with chemotherapy is a probable approach. However, the question of whether immunotherapy combination therapy will outperform chemotherapy, particularly in the locally advanced/induction setting, remains open for debate.

Key Takeaways from Dr. Boormans' Presentation:
During the EAU 2020 conference, Dr. Boormans presented several key take-home messages regarding neoadjuvant treatment with immunotherapy in muscle-invasive bladder cancer patients undergoing radical cystectomy. Firstly, neoadjuvant immunotherapy is feasible and has a favorable toxicity profile compared to chemotherapy. Early studies indicate that the delay in time to surgery is limited, and postoperative complications are not higher than those associated with neoadjuvant chemotherapy. Furthermore, the rates of complete pathological response are similar to those observed with neoadjuvant chemotherapy.

Safety Profile and Biomarkers:
Comparing the safety profiles of pembrolizumab and atezolizumab, pembrolizumab was generally better tolerated. Responders to immunotherapy showed higher levels of CD8+ T-cells, and the 8-gene T-cell signature was associated with a positive response. However, in the ABACUS study, PDL1 expression, tumor mutation burden, and DDR gene mutations did not correlate with a pathologic complete response, contradicting their predictive ability in the metastatic setting. These findings highlight the complexity of identifying biomarkers for response to immunotherapy.

Considerations for Adjuvant Chemotherapy:
While there is no level 1 evidence in favor of adjuvant chemotherapy, it is important to acknowledge that many patients do not respond to chemotherapy. Non-responders may experience delays in curative surgery, increased toxicity rates, and higher rates of pN+/M+ disease. The use of neoadjuvant radiotherapy has significantly decreased, while neoadjuvant chemotherapy has seen an increase in clinical practice. However, it is worth noting that while clinical trials report downstaging rates of 30-40% to ypT0N0, real-world clinical practice typically achieves ypT0N0 rates of only 25%.

Actionable Advice:

1. Consider the identified risk factors for understaging when evaluating patients with high-grade non-muscle invasive bladder cancer. This will help ensure accurate staging and appropriate treatment planning.
2. Stay updated with the latest research on immunotherapy in the neoadjuvant setting. Understanding the potential benefits and limitations of immunotherapy compared to chemotherapy will aid in making informed treatment decisions.
3. Explore the use of biomarkers to predict response to immunotherapy. While the current evidence is conflicting, ongoing research may provide valuable insights into identifying patients who are most likely to benefit from immunotherapy.

Conclusion:
The field of bladder cancer treatment is constantly evolving, with new findings and advancements shaping the way we approach the disease. From identifying risk factors for understaging to the potential role of immunotherapy in the neoadjuvant setting, these developments have the potential to improve outcomes for patients. By incorporating the actionable advice provided, clinicians can stay at the forefront of bladder cancer treatment and provide optimal care for their patients.