(B-172) Comparative Meta-Analysis of the Efficacy and Safety of Targeted Therapy and Immunotherapy Combined with Chemotherapy Versus Conventional Chemotherapy in Recurrent or Metastatic Head and Neck Cancer

Background: Head and neck cancer is the second most prevalent cancer in India, with up to 70% recurrence despite treatment. The EXTREME regimen, though a standard of care, has significant toxicity. While immune checkpoint inhibitors with chemotherapy show promise, conventional chemotherapy remains an option with modest survival benefits. However, no consensus exists on the optimal therapy. This meta-analysis evaluates the efficacy and safety of targeted therapy or immunotherapy combined with chemotherapy versus conventional chemotherapy in recurrent or metastatic head and neck cancer.

Objectives: To evaluate the impact of targeted or immunotherapy-based chemotherapy on overall survival (OS) and progression-free survival (PFS) versus conventional chemotherapy.
To compare the objective response rate (ORR) between the two treatment approaches.
To assess the safety profile by analyzing treatment-related adverse events (TRAEs) and severe adverse events (SAEs).
To explore differences in clinical benefits between first line and second-line treatments.

Methods: A systematic search was conducted in MEDLINE (PubMed), Cochrane Library, and Embase (Elsevier) databases. Studies were included if they were full-text articles published in English that directly compared the specified therapeutic regimens. The primary efficacy outcomes were OS, PFS, and ORR, while the primary safety outcome was the incidence of treatment-related adverse events. Mean differences were calculated for OS and PFS, whereas odds ratios (ORs) were used to assess ORR and safety outcomes, specifically severe adverse events (SAEs). A random-effects model with 95% confidence intervals (CIs) was applied for statistical analysis.

Results: The search identified 704 citations, of which 5 studies met the inclusion criteria, enrolling a total of 753 patients. The meta-analysis showed no statistically significant benefit in objective response rate (ORR: 1.28, 95% CI 0.83–1.95, p=0.26), progression-free survival (PFS: 0.64, 95% CI -0.17–0.44, p=0.12), or overall survival (OS: 1.82, 95% CI -0.76–4.40, p=0.17). Safety outcomes, including treatment-related adverse events (TRAEs, p=0.18), also showed no significant differences, indicating no clear superiority of either treatment approach.

Conclusions: In conclusion, the targeted therapy and immunotherapy in combination with chemotherapy have not shown significant improvement in survival outcomes over conventional chemotherapy, yet there is need for potential therapeutic regimens, overcoming the limitations of small absolute improvements in survival outcomes and substantial toxicity of existing regimens, improving the prognosis of R/M HNSCC patients.