385P - The prognostic factors of induction chemotherapy followed by concurrent chemoradiotherapy in patients with HPV associated with oropharyngeal cancer

Background

Although systemic chemotherapy or concurrent chemoradiotherapy (CRT) are effective for HPV-positive oropharyngeal squamous carcinoma (OPSCC), for these reasons, de-escalation therapy can be suggested as an optional therapy. However, in clinical practice, de-escalation therapy for HPV-positive OPSCC is insufficient to apply to all patients considering risk factors such as smoking. Thus, we investigated the high-risk factors associated with the treatment outcomes.

Methods

Patients with stage III-IVA OPSCC (AJCC 8^th) who were treated for induction chemotherapy followed by CRT between 2004 and 2020 were enrolled. We analyzed the overall response rate, 3-year disease-free survival (3Y DFS), and 5-year overall survival (5Y OS) which were associated with clinical factors, by univariate and multivariate analyses.

Results

In a total of 105 patients, HPV-negative patients accounted for 38.1% (40/105) and HPV-positive patients for 61.9% (65/105). The median age at diagnosis was 60 years (range, 40 to 76). In multivariate analysis, a poor prognosis was revealed by a statistically significant difference in the 3Y DFS estimate for the subset of patients with ≥60 years and T4 compared with those with <60 years and T0-T3. In HPV- negative OPSCC, N2c was a strong and independent factor for poor DFS (HR 6.01, 95% CI 1.209-29.871, p=0.028). Unlike HPV-negative OPSCC, in HPV-positive OPSCC, age≥60 (HR 2.802, 95% CI 1.113-7.051, p=0.029) and T4 (HR 3.531, 95% CI 1.300-9.589, p=0.013) were independent prognostic factors for poor DFS. Additionally, T4 was independent factors for poor OS (HR 4.587, 95% CI 1.334-15.772, p=0.016). In the context of risk factors, we observed that T4 was a strong and independent predictor of poor DFS and OS in patients with HPV-positive OPSCC.

Conclusions

In conclusion, our analysis represents independent poor prognosis factors with T4 in p16 -positive OPSCC. Therefore, de-escalation therapy should be carefully determined for HPV-positive OPSCC patients with risk factors, and additional therapeutic approaches such as induction chemotherapy could be considered.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.