2 Results
In the present study, 140 consecutive patients were screened for eligibility and 130 patients were enrolled in the clinical trial. Ten patients were excluded (4 were lost to follow-up and 6 were unbearable to side effects during concurrent chemoradiotherapy). Patients were stratified into 3 groups based on the degree of carotid artery involvement: <180º, n=37; 180º≤IG<270º, n=32; and ≥270º, n=61.
Three patients whose primary tumor located in the nasopharyngeal recess and carotid artery invasion ≥270° died of massive neck hemorrhage (Table 3; Fig.2).They were confirmed by repeated nasal endoscopy (gray-white necrotic material) and MRI enhancement of nasopharynx (gray-black necrotic material, non-neoplastic tissue, T1 phase is low signal, T2 phase is slightly high signal) prior to hemorrhage.No radiation-induced carotid pseudoaneurysms were confirmed by DSA.
The median follow-up time was 25 months (range 5-97 months). During the follow-up period, 20 patients died, 22 patients progressed (including 3 patients with recurrence, 2 with cervical lymph node metastasis, 16 with distant metastasis, and 1 with secondary primary cancer). The overall 5-year survival rates were PFS=75.2%, DMFS=76.8%, LNRFS=90.0%, LRFS=93.9%, NRFS=95.8% and OS=87.2% (Fig.3-1).
Univariate analysis showed that gender, age, pathological type and degree of carotid artery involvement were not significantly associated with survival. Clinical stage, induction chemotherapy regimen, concurrent chemotherapy regimen and EGFR inhibitors were significantly associated with PFS and DMFS (P<0.05). Hemoglobin levels during radiotherapy were significantly associated with DMFS, PFS and OS (P<0.05) (Supplementary Table 1).
Multivariate analysis showed that EGFR inhibitor was an independent prognostic factor for DMFS and PFS (P<0.05). Hemoglobin level during radiotherapy was an independent prognostic factor for OS (P<0.05) (Supplementary Table 2; Fig3-2~4).
Comparison of three degrees of the carotid artery invasion (<180°, 180°≤IG<270°, ≥270°) suggested that the 5-year PFS was 82.3%, 72.4% and 59.5%, respectively; 5-year DMFS was 85.8%, 78.0% and 77.1%, respectively; 5-year LNRFS was 95.8%, 90.4% and 77.1%, respectively; 5-year LRFS was 95.8%, 100% and 77.1%, respectively; 5-year NRFS was 100%, 90.4% and 100%, respectively; and 5-year OS was 92.9%, 85.2% and 78.0%, respectively (Supplementary Fig.1-6).