Significance of imaging-detected extranodal extension in locally advanced squamous cell carcinoma of the head and neck treated with induction chemotherapy followed by chemoradiotherapy.

BACKGROUND

Prognosis of locally advanced squamous cell carcinoma of the head and neck (LA-HNSCC) is poor, particularly in cases with extranodal extension. The Head and Neck Cancer International Group (HNCIG) recently published criteria for imaging-detected extranodal extension (iENE). Here, we aimed to clarify the significance of iENE in induction chemotherapy followed by chemoradiotherapy.

METHODS

We retrospectively investigated patients with LA-HNSCC scheduled to receive induction chemotherapy followed by chemoradiotherapy between 2013 and 2022 at the National Cancer Center Hospital East, Japan. Two radiologists blindly annotated the grading of iENE for pretreatment computed tomography scans according to the HNCIG criteria.

RESULTS

Eighty-eight patients were identified, of whom 21 were categorized as iENE-negative and 67 as iENE-positive. The iENE-positive group showed a significantly poorer prognosis than the negative group for event-free survival (EFS) (hazard ratio [HR]; 2.92, 95% confidence interval [CI]; 1.15-7.43, log-rank p-value; 0.02) and overall survival (OS) (HR; 9.34, 95%CI; 1.26-69.3, log-rank p-value; 0.03). In multivariate analysis of variables at pretreatment and after induction chemotherapy, iENE positivity and non-response to induction chemotherapy were independently associated with adverse prognosis for EFS (iENE-positive: HR; 2.57, 95%CI; 1.01-6.57, p-value; 0.04. Non-response to induction chemotherapy: HR; 2.40, 95%CI; 1.31-4.40, p-value; 0.005) and OS (iENE-positive: HR; 8.17, 95%CI; 1.10-60.0, p-value; 0.04, non-response to induction chemotherapy: HR; 3.40, 95%CI; 1.46-8.28, p-value; 0.004).

CONCLUSION

The presence of iENE and non-response to induction chemotherapy were independently associated with poor prognosis for LA-HNSCC treated with induction chemotherapy followed by chemoradiotherapy.