Outcomes of patients with oropharyngeal squamous cell carcinoma treated with induction chemotherapy followed by concurrent chemoradiation compared with those treated with concurrent chemoradiation

Abstract

Background: Induction chemotherapy (IC) has been associated with a decreased risk of distant metastasis in locally advanced head and neck squamous cell carcinoma. However, its role in the treatment of oropharyngeal squamous cell carcinoma (OPSCC) is not well established.

Methods: The outcomes of patients with OPSCC treated with IC followed by concurrent chemoradiation (CRT) were compared with the outcomes of those treated with CRT alone. The primary outcome was overall survival (OS), and the secondary end points were the times to locoregional and distant recurrence.

Results: In an existing database, 585 patients met the inclusion criteria: 137 received IC plus CRT, and 448 received CRT. Most patients were positive for human papillomavirus (HPV; 90.9%). Patients receiving IC were more likely to present with a higher T stage, a higher N stage, and low neck disease. The 3-year OS rate was significantly lower in patients receiving IC (75.7%) versus CRT alone (92.9%). In a multicovariate analysis, receipt of IC (adjusted hazard ratio [aHR], 3.4; P < .001), HPV tumor status (aHR, 0.36; P = .002), and receipt of concurrent cetuximab (aHR, 2.7; P = .002) were independently associated with OS. The risk of distant metastasis was also significantly higher in IC patients (aHR, 2.8; P = .001), whereas an HPV-positive tumor status (aHR, 0.44; P = .032) and completion of therapy (aHR, 0.51; P = .034) were associated with a lower risk of distant metastasis. In HPV-positive patients, IC remained associated with distant metastatic progression (aHR, 2.6; P = .004) but not OS.

Conclusions: In contrast to prior studies, IC was independently associated with worse OS and a higher risk of distant metastasis in patients with OPSCC. Future studies are needed to validate these findings.

Keywords: distant metastasis; induction chemotherapy; oropharyngeal cancer.

Figure 1.

Consort diagram summarizing patient cohort

Figure 2.

A) Overall survival (OS; p<0.001): 2-year OS chemoradiation (CRT) 94.0% (95% CI: 91.2–96.0), induction 84.5% (76.4–90.2); 3-year OS CRT 92.9% (89.4–95.2), induction 75.7% (65.0–83.5) B) Time to progression (TTP; p<0.001): 2-year TTP CRT 89.2% (85.6–92.0), induction 78.2% (69.3–84.8); 3-year TTP CRT 86.6% (82.2–90.0), induction 68.7% (56.9–77.8) C) Time to locoregional (LRP progression (p=0.294): 2-year TTP, LR CRT 93.4% (90.5–95.5), induction 90.9% (83.4–95.1); 3-year TTP, LR CRT 91.9% (88.3–94.4), induction 88.1% (77.9–93.8) D) Time to distant metastatic (DM) progression (p<0.001): 2-year TTP, DM CRT 94.2% (91.2–96.2), induction 84.3% (76.0–89.9); 3-year TTP, DM CRT 92.4% (88.5–95.0), induction 74.7% (63.0–83.2)