Sequential Versus Concurrent Chemotherapy for Locally Advanced Nasopharyngeal Carcinoma: A US-Based Study

Purpose/Objective(s): Concurrent chemotherapy is the standard of care for locally advanced nasopharyngeal carcinoma (NPC). Distant metastasis (DM) is the main pattern of failure in patients with this regimen. Results of the ongoing phase 3 trial in Asia comparing sequential to concurrent chemoradiation will define the role of induction chemotherapy in endemic areas. The purpose of this study was to examine the role of induction chemotherapy in non-endemic regions. Materials/Methods: Between 1997 and 2013, 73 patients with locally advanced non-metastatic NPC received sequential (induction+concurrent) (n Z 53) or concurrent chemotherapy (n Z 20). Tumor stage distribution was Tx:T1:T2:T3:T4 2:8:10:15:38. Nodal stage distribution was N0:N1:N2:N3 17:14:34:8. Stage distribution was Stage II (n Z 7), Stage III (n Z 24), Stage IVA (n Z 34), and Stage IVB (n Z 8). Median age was 49.7 years. The median dose to the GTV was 70 Gy (range: 69.96-76.8). The median age for those in the sequential vs concurrent groups were 47 and 57.8 years, respectively. Ninety percent in the sequential group and 45% in the concurrent group had Stage IVA/B disease. Eighty-five percent of patients in the sequential group received 3 cycles of docetaxel, cisplatin and 5-FU (TPF). Seventy percent of patients in the concurrent group received cisplatin 100 mg/m every 3 weeks. Results: At a median follow up of 53 months, there were 3 local, 1 regional and 7 distant failures. The overall local control (LC) and regional control (RC) rates at 4 years was 94.6% (95% CI, 83.9-98.2%) and 98.4% (95% CI, 88.9-99.8%), respectively. The overall DM-free rate at 4 years was 88.2% (95% CI, 76.7-94.3%). The OS at 4 years was 88.6% (95% CI, 76.7-94.3%). The LC rates at 4 years for sequential and concurrent groups were 100% and 93.1% (95% CI, 80-97.7%), respectively (p Z 0.35). The RC rates at 4 years for sequential and concurrent groups were 100% and 97.8% (95% CI, 85.6-99.7%), respectively (p Z 0.57). The DM free survival rates at 4 years for sequential and concurrent groups were 87.7% (95% CI, 58.1-96.9%) and 88.7% (95% CI, 74.9-95.2%), respectively (p Z 0.77). The disease-free survival (DFS) rates at 4 years for sequential and concurrent groups were 87.7% (95% CI, 58.1-96.9%) and 76.9% (95% CI, 61.9-86.5%), respectively (p Z 0.56). The OS rates for sequential and concurrent groups were not significantly different at 4 years (95% [95% CI, 69.5-99.3%] vs 86.8% [95% CI, 72.7-93.9%]), respectively (pZ 0.54). In a subset analysis of Stage IVA/B patients, there was a trend towards improved DFS with sequential compared to concurrent chemotherapy at 4 years (85.9% [95% CI, 52.9-96.4%] and 64.9% [95% CI, 41.8-80.7%], p Z 0.19). Conclusions: Our data suggest that treatment with sequential or concurrent chemotherapy result in similar locoregional and distant metastasis rates in non-endemic, US populations. Patients with Stage IVA/B may benefit from sequential chemotherapy. Author Disclosure:M. Kim: None. A.A. Aizer: None. E. Weyman: None. S.M. McBride: None. L. Wirth: None. J. Clark: None. S.M. Rothenberg: None. P.M. Busse: None. A.W. Chan: None.