Unraveling the Mystery: PD-L1 CPS and Gastric Cancer Treatment
In a captivating discussion led by Dr. Yelena Y. Janjigian, the role of PD-L1 CPS in frontline gastric cancer treatment was explored, leaving many with intriguing questions.
The NCCN guidelines suggest incorporating immune checkpoint inhibitors for advanced esophageal and gastric cancers, but only with a strong preference when PD-L1 CPS reaches 5 or higher. However, the grey area lies between CPS scores of 1 and 5, sparking a lively debate among experts.
The PD-L1 CPS Conundrum
Dr. Janjigian, a renowned expert in gastrointestinal oncology, delved into the reliability of PD-L1 scores and the importance of seizing the opportunity for immunotherapy in the initial stages of treatment. She emphasized that while level 1 evidence from phase 3 studies provides a controlled perspective, real-world practice presents a different scenario.
But here's where it gets controversial...
The quality of samples and testing can vary significantly, leading to discrepancies in PD-L1 testing results. Dr. Janjigian shared a compelling case where a patient's PD-L1 status changed dramatically between tests, highlighting the unreliability of the test. This raises the question: Should we rely solely on PD-L1 CPS for treatment decisions?
And this is the part most people miss...
The experts discussed the impact of PD-L1 CPS on treatment selection and the potential benefits for patients with low CPS scores. Dr. Fayez Estefan emphasized the importance of shared decision-making with patients, especially when considering immunotherapy as a first-line option.
A Tale of Two Perspectives
Dr. Haiyun Wang and Dr. Estefan shared their approaches, with Dr. Wang using a CPS of 1 as a cutoff, while Dr. Estefan discussed the potential benefits and adverse events with patients, considering CPS scores between 1 and 5.
The Real-World Challenge
Dr. Janjigian's experience with retesting PD-L1 status and the variability in sample quality underscores the challenges of relying solely on PD-L1 CPS. She believes that, in practice, the situation is vastly different from controlled clinical trials, and thus, a more cautious approach with anti-PD-1 treatment is warranted, especially given the difficulties associated with Claudin18.2 inhibition.
A Thought-Provoking Question
Dr. Bolanle Adepoju presented a case where a patient, initially treated with FOLFOX and trastuzumab, was never started on PD-L1 therapy. Dr. Janjigian suggested adding anti-PD-1 therapy, considering the patient's fitness and the potential benefits of improving survival in the first-line setting.
The Heterogeneity Factor
Dr. Yanyan Lou brought up an interesting point regarding the heterogeneity of PD-L1 expression in lung adenocarcinoma. Dr. Janjigian suggested retesting or consulting with pathologists to ensure the quality of the sample and the accuracy of the scoring method.
Long-Term Survival and Beyond
Dr. Sheila Donnelly inquired about long-term survivors with nivolumab plus chemotherapy, particularly in cases with liver metastases. Dr. Janjigian shared that, unlike colon cancer, liver metastases are not a negative predictor of outcome for these agents. Instead, the focus shifts to peritoneal disease as the primary challenge.
First-Line Treatment Options
The experts discussed the use of nivolumab plus ipilimumab in squamous histology, with Dr. Estefan favoring chemotherapy plus single-agent IO for a quick response. Dr. Janjigian expressed her concerns about chemotherapy-free backbones, given the sick nature of these patients.
Second-Line Strategies
The panel explored treatment options for patients who are chemotherapy/IO failures. Dr. Estefan suggested a taxane with ramucirumab, while Dr. Ike Onwere typically uses carboplatin/paclitaxel or paclitaxel for squamous cases. Dr. Muhammad Masab shared his experience with T-DXd, highlighting the frailty of some patients and the potential deterioration in performance status.
Final Thoughts
The discussion on PD-L1 CPS and gastric cancer treatment highlights the complexity of decision-making in oncology. While guidelines provide a framework, real-world practice demands a nuanced approach, considering the variability in testing, sample quality, and patient-specific factors. The experts' insights offer a valuable perspective on navigating these challenges.
Join the conversation and share your thoughts on this intriguing topic! Do you agree with the experts' approaches? What factors do you consider when making treatment decisions for gastric cancer patients? Let's continue the discussion and learn from each other's experiences.
