931P - Early recurrence, time-to-recurrence, and recurrence patterns: Assessing their impact on survival outcomes in recurrent/metastatic head and neck squamous cell carcinoma (R/M-HNSCC) patients

Background

Patients with recurrent/metastatic head and neck squamous cell carcinoma (R/M-HNSCC) ineligible for curative local therapy typically receive first-line (1L) systemic treatment with platinum-based chemotherapy and pembrolizumab or cetuximab. However, early recurrent patients (<6 months from the last curative local treatment) have been excluded from most 1L systemic treatment studies. Therefore, treatment outcomes for early recurrent patients, the impact of different time-to-recurrence intervals (TTRI), and the influence of recurrence patterns on survival remain unclear.

Methods

We analyzed non-curable R/M-HNSCC patients at our institution between 1/2008 and 6/2020. The study aimed to evaluate outcomes of early recurrent patients receiving 1L systemic treatment and assess TTRIs and recurrent patterns' impact on survival.

Results

234 of 1,281 eligible patients were included. Platinum-based doublet chemotherapy was the predominant 1L treatment. Significant differences in PFS and OS were observed among TTRI groups. In early recurrent patients, those receiving platinum-based doublet and monotherapy showed significantly longer OS compared to best supportive care (BSC). Locoregional recurrence was the most common pattern (47%), followed by distant metastasis (22%) and both (20%). Different R/M-HNSCC patterns were significantly associated with OS (p=0.019), but not PFS (p=0.790). In multivariate analysis, TTRI of ≥12 months correlated with PFS (HR 0.51; p=0.004) and OS (HR 0.58; p=0.009), while recurrence pattern did not. Table: 931P

Conclusions

In our study, R/M-HNSCC patient survival was significantly influenced by TTRI, while recurrence pattern was not. Despite poor prognosis, early recurrent patients benefited from systemic treatments. TTRI should be a stratification factor in future clinical trials, as varying prognoses were observed.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

N. Ngamphaiboon: Financial Interests, Personal, Invited Speaker: Roche, MSD, Merck, Eisai; Financial Interests, Personal, Advisory Board: BeiGene, BMS, Roche, MSD, Eisai, Merck; Financial Interests, Institutional, Research Grant: Pfizer; Financial Interests, Institutional, Principal Investigator: RAPT therapeutics, Boehringer Ingelheim Pharmaceuticals, MSD, Roche, BeiGene, Pfizer; Financial Interests, Institutional, Project Lead: Pfizer. All other authors have declared no conflicts of interest.