For people with advanced esophageal cancer, a new first-line treatment combining immunotherapy (called a PD-1 inhibitor) with chemotherapy is a significant step forward. This analysis of over 4,700 patients from eight major trials shows the combination is clearly more effective than chemotherapy alone. It helps patients live longer, delays the cancer's progression, and is more than twice as likely to shrink tumors. Importantly, the risk of serious treatment-related side effects was not statistically higher than with chemo alone. The benefits were widespread. Older patients and those whose cancer had spread, even to the liver, saw similar improvements. But there's one important exception: patients whose tumors have very low levels of a protein called PD-L1 (specifically, a combined positive score of less than 1) may get only a limited benefit from adding the immunotherapy. This means that while this combo is a powerful new option for most, doctors need better tests to identify everyone who will respond, so no one misses out on the right treatment.
Who benefits most from new esophageal cancer treatment? Most patients do, except one group.
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A new immunotherapy-chemo combo helps most with advanced esophageal cancer, but a protein test can show who might benefit less. What this means for you:
A new immunotherapy-chemo combo helps most with advanced esophageal cancer, but a protein test can show who might benefit less. View Original Abstract ↓
BACKGROUND: Esophageal cancer exhibits peak incidence in Asia and Africa, representing the sixth most common malignancy and seventh leading cause of global cancer mortality. Esophageal squamous cell carcinoma (ESCC) constitutes 90% of esophageal cancer cases. The European Medicines Agency approved programmed death 1 (PD-1) inhibitors plus chemotherapy as a first-line treatment for high PD-1-expressing ESCC.
METHODS: We systematically searched randomized controlled trials of PD-1 or PD-L1 inhibitors as first-line treatment from PubMed, Embase, and Cochrane Library. The following outcomes were combined: overall survival, progression-free survival, objective response rate, and treatment-related adverse events (TRAEs). Bias risk was rigorously evaluated using the Cochrane Risk of Bias Tool. RevMan 5.3 and R Studio (Boston) were utilized for data synthesis in this meta-analysis, with sensitivity analyses comparing fixed- and random-effects models to reinforce findings.
RESULTS: A total of 4702 patients (PD-1 inhibitors plus chemotherapy: 2529; chemotherapy: 2173) were enrolled in 8 randomized controlled trials. Compared with conventional chemotherapy, first-line PD-1 inhibitors plus chemotherapy significantly improved the overall survival (hazard ratio = 0.68, 95% confidence interval (CI): 0.63-0.74; P < .00001) and objective response rate (relative risk [RR] = 2.03, 95% CI: 1.80-2.29; P < .00001) of advanced ESCC patients. Moreover, PD-1 inhibitor-based therapy provided benefits in progression-free survival (hazard ratio = 0.62, 95% CI: 0.58-0.66; P < .00001). But PD-1 inhibitors were not associated with statistically lower incidences of TRAEs and grade 3 to 5 TRAEs. In subgroup analyses, except the limited benefit observed in the programmed death-ligand 1 (PD-L1) combined positive score < 1 subgroup, none of the following factors significantly influenced the efficacy of PD-1 inhibitor therapy: advanced age, metastatic status, number of metastatic organs, or presence of liver metastases.
CONCLUSION: The combination of PD-1 inhibitors with chemotherapy demonstrates superior efficacy as first-line therapy for advanced esophageal squamous cell carcinoma. Both elderly patients and those with metastatic involvement derive universal benefit without increased adverse risks. However, patients with PD-L1 combined positive score < 1 may experience restricted clinical benefits. Thus, more precise predictive markers are required to stratify potential responders, enabling broader patient populations to derive benefits from PD-1 inhibitor-chemotherapy regimens.