Early recurrence, time-to-recurrence, and recurrence patterns: Assessing their impact on survival outcomes in head and neck squamous cell carcinoma (R/M-HNSCC) patients treated with first line platinum-based chemotherapy

Background: R/M-HNSCC patients typically receive 1L platinum-based chemotherapy with pembrolizumab or cetuximab. However, the outcomes for patients with early recurrence (<6 months) remain unclear due to their exclusion from most 1L studies. This study aimed to assess the impact of time-to-recurrence intervals (TTRI) and recurrence patterns on the survival of R/M-HNSCC patients. Methods: We identified non-curable R/M-HNSCC patients at our institution from 1/2008 through 6/2020. We analyzed the outcomes of early recurrent patients who received 1L systemic treatment, with different TTRIs and recurrence patterns. Results: Our study included 234 eligible patients. The majority (47%) experienced early recurrence (<6 months), while 22%, 20%, and 11% had recurrences at 6-12 months, >12 months, and de novo metastasis, respectively. The platinum-based regimen was the most commonly used chemotherapy (86%), with cetuximab and immunotherapy utilized in 3% and 5% of cases, respectively. Significant differences in PFS and OS were observed among TTRI groups. For patients with early recurrence, both platinum-doublet and monotherapy treatments significantly improved OS. Locoregional recurrence (47%) was the most common, followed by distant metastasis (22%) and both (20%). Recurrence patterns were significantly associated with OS but not with PFS. In multivariate analysis, TTRI >= 12 months significantly correlated with improved PFS (HR 0.51; p = 0.004) and OS (HR 0.58; p = 0.009), whereas recurrent pattern did not. Conclusion: TTRI significantly influenced the survival, while recurrence patterns did not. In our study, the retrospective design limited our ability to definitively establish whether early recurrent R/M-HNSCC patients would benefit more from platinum-doublet. Despite poor prognosis, early recurrent patients benefited from 1L systemic treatments. Given the variation in prognoses, TTRI should be considered a stratification factor in future clinical trials.