Final Overall Survival Analysis of Gemcitabine and Cisplatin Induction Chemotherapy in Nasopharyngeal Carcinoma: A Multicenter, Randomized Phase III Trial

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically on the based on the primary end point, may be published when key planned co-primary or secondary analyses are not yet available. Clinical Trial Updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported.We previously reported significantly improved failure-free survival using gemcitabine plus cisplatin induction chemotherapy in locoregionally advanced nasopharyngeal carcinoma. Here, we present the final overall survival (OS) analysis. In this multicenter, randomized trial, patients were assigned to be treated with concurrent chemoradiotherapy alone (standard therapy, n = 238) or gemcitabine and cisplatin induction chemotherapy before concurrent chemoradiotherapy (n = 242). With a median follow-up of 69.8 months, the induction chemotherapy group had a significantly higher 5-year OS (87.9% v 78.8%, hazard ratio, 0.51 [95% CI 0.34 to 0.78]; P = .001) and a comparable risk of late toxicities (≥ grade 3, 11.3% v 11.4%). Notably, the depth of the tumor response to induction chemotherapy correlated significantly and positively with survival (complete response v partial response v stable/progressive disease, 5-year OS, 100% v 88.4% v 61.5%, P = .005). Besides, patients with a low pretreatment cell-free Epstein-Barr virus DNA load (< 4,000 copies/mL) might not benefit from induction chemotherapy (5-year OS, 90.6% v 91.4%, P = .77). In conclusion, induction chemotherapy before concurrent chemoradiotherapy improved OS significantly in patients with locally advanced nasopharyngeal carcinoma, without increasing the risk of late toxicities. Tumor response to induction chemotherapy and pretreatment cell-free Epstein-Barr virus DNA might be useful to guide individualized treatment.

Gemcitabine and Cisplatin Induction Chemotherapy in Nasopharyngeal Carcinoma

BACKGROUND

Platinum-based concurrent chemoradiotherapy is the standard of care for patients with locoregionally advanced nasopharyngeal carcinoma. Additional gemcitabine and cisplatin induction chemotherapy has shown promising efficacy in phase 2 trials.

METHODS

In a parallel-group, multicenter, randomized, controlled, phase 3 trial, we compared gemcitabine and cisplatin as induction chemotherapy plus concurrent chemoradiotherapy with concurrent chemoradiotherapy alone. Patients with locoregionally advanced nasopharyngeal carcinoma were randomly assigned in a 1:1 ratio to receive gemcitabine (at a dose of 1 g per square meter of body-surface area on days 1 and 8) plus cisplatin (80 mg per square meter on day 1), administered every 3 weeks for three cycles, plus chemoradiotherapy (concurrent cisplatin at a dose of 100 mg per square meter every 3 weeks for three cycles plus intensity-modulated radiotherapy) or chemoradiotherapy alone. The primary end point was recurrence-free survival (i.e., freedom from disease recurrence [distant metastasis or locoregional recurrence] or death from any cause) in the intention-to-treat population. Secondary end points included overall survival, treatment adherence, and safety.

RESULTS

A total of 480 patients were included in the trial (242 patients in the induction chemotherapy group and 238 in the standard-therapy group). At a median follow-up of 42.7 months, the 3-year recurrence-free survival was 85.3% in the induction chemotherapy group and 76.5% in the standard-therapy group (stratified hazard ratio for recurrence or death, 0.51; 95% confidence interval [CI], 0.34 to 0.77; P = 0.001). Overall survival at 3 years was 94.6% and 90.3%, respectively (stratified hazard ratio for death, 0.43; 95% CI, 0.24 to 0.77). A total of 96.7% of the patients completed three cycles of induction chemotherapy. The incidence of acute adverse events of grade 3 or 4 was 75.7% in the induction chemotherapy group and 55.7% in the standard-therapy group, with a higher incidence of neutropenia, thrombocytopenia, anemia, nausea, and vomiting in the induction chemotherapy group. The incidence of grade 3 or 4 late toxic effects was 9.2% in the induction chemotherapy group and 11.4% in the standard-therapy group.

CONCLUSIONS

Induction chemotherapy added to chemoradiotherapy significantly improved recurrence-free survival and overall survival, as compared with chemoradiotherapy alone, among patients with locoregionally advanced nasopharyngeal carcinoma. (Funded by the Innovation Team Development Plan of the Ministry of Education and others; ClinicalTrials.gov number, NCT01872962.).

[Neural structural relations between the chemosensitive areas of the ventrolateral medulllary surface and the medullary nuclei in rats]

Experiments were done on 30 chloralose-urethane anesthetized Sprague-Dawley strain rats. The ventrolateral medullary surface was exposed and a small millipore filter paper soaked with horseradish peroxidase (HRP) was applied locally to different parts of the underlying chemosensitive areas separately, trying to identify location of the HRP-stained cells. (1) After HRP application to the rostral area (n = 10), quite a number of labelled cells were distributed at the ventrolateral part of the nucleus of trapezoid body (Tz), the lateroventral periolivary nucleus (LVPO) and the retrotrapezoid nucleus (NRT). (2) After HRP application to the caudal area (n = 10), HRP labelled cells were mainly located at the lateral reticular nucleus (LRt) and the ventral part of at the lateral paragigantocellular nucleus LPGi. (3) After HRP application to the intermediate area (n = 6), only 8 HRP labelled cells were observed at the (LPGi) in 6 rats. (4) After HRP application to the control area (n = 4), only 6 HRP labelled cells were found at the rostral ventrolateral reticular nucleus (RVL). The above findings demonstrated the existence of the neural structural relations between the chemosensitive areas of the ventrolateral medullary surface and Tz, LVPO, NRT, LPGi, LRt, which supports that all these nuclei might participate in the central chemoreception of respiration.

[Role of the lateroventral periolivary nucleus in the central chemoreception of respiration in rats]

Using the methods of microinjection, microiontophoresis, electrolytic destruction and electric stimulation, the present work was undertaken to investigate whether the lateroventral periolivary nucleus (LVPO) might play a role in the central mechanism of chemoreception on respiration. Experiments were performed on 38 chloralose-urethane anesthetized Sprague-Dawley rats. The results were as follows: (1) Bilateral microinjection of acidified mock CSF into the LVPO region, evoked an enhancement in respiratory activities. (2) Microiontophoretic application of H+ caused mainly excitatory effects on the spontaneously discharging units in LVPO region, and some of the excitatory units were also responsible to microinjection of acidified mock CSF to the ventrolateral medullary surface. (3) After the electrolytic destruction of bilateral LVPO region in carotid body denervated rats, respiratory response to inhaled CO2 was attenuated significantly. (4) Electric stimulation of LVPO region caused an increase in discharging frequency of some units in the NTS and NRA regions. The above results indicate that LVPO plays a significant role in the central mechanism of chemoreception.

Effects of alloxan on electric activity of mouse pancreatic B cells in vitro

Microelectrode method for recording membrane potentials was used. It was observed that alloxan possessed stimulative and toxic dual effects on the electric activity of pancreatic B cells. A 10-min exposure to alloxan 14 mmol.L-1 in the perfusion medium without glucose caused a significant depolarization of B cells from -44 +/- 13 mV to -36 +/- 12 mV (n = 7, P < 0.05) and evoked spikes in B cells. But the spikes disappeared at 24 +/- 12 min (n = 8). In the presence of glucose 5.5 mmol.L-1 or 11.0 mmol.L-1, the dual effects became weaker or not obvious. After 10-min exposure to diazoxide (an ATP sensitive K+ channel opener) 0.8 mmol.L-1 in the perfusion medium with alloxan 14 mmol.L-1 but devoid of glucose, the amplitude of membrane potential went up from -31 +/- 11 mV to -48 +/- 21 mV and the mean value of spikes dropped from 31 +/- 24 spikes.min-1 to 5 +/- 5 spikes.min-1. It was suggested that the stimulative effect of alloxan was due to blocking of ATP sensitive K+ channel and a higher concentration of glucose could prevent B cells from alloxan injury.

[Analysis of the acetylcholine action on the electrical activities of pancreatic islet B-cells in mice]

Intracellular potential recording and extracellular microiontophoretic techniques were used to study the acetylcholine (ACh) action on the electrical activities of pancreatic islet B-cells in mice. The B cell membrane potential was decreased (5-10 mV) and the spikes were increased (11-17/30 s) by the ACh microinotophoresis. These effects were dependent on glucose and completely blocked by atropine. However, pirenzepine could attenuate the electrical activity by approximately 70%. The ACh-induced membrane depolarization was Ca(2+)-independent and blocked by TTX. But the effect of ACh on spikes was Ca(2+)-dependent and not blocked by verapamil. The results showed that ACh action in the enhancement of glucose-dependent electrical activities of B-cell were mediated by muscarinic receptor, mainly by subtype M1. Then TTX-sensitive Na channel and verapamil-insensitive Ca channel were activated by M1 receptors. Na+ influx resulted in membrane depolarization and Ca2+ influx enhanced spike discharges.

Effects of substance P on electric activity of mouse pancreatic islet cells in vitro

The effects of substance P (SP), [D-Pro2, D-Trp7,9]SP and verapamil on the electric activity of B cells of Langerhans islets of mice were investigated. Addition of SP 100 nmol.L-1 to the perfusion medium stimulated spontaneous electric activity induced by glucose 5.5 mmol.L-1 with an increase in frequency and amplitude of the spikes. [D-Pro2, D-Trp7,9]SP 50 nmol.L-1 reversed the stimulative effect of SP. There was no evidence for an enhancing interaction between SP and acetylcholine 1 mumol.L-1. Verapamil 60 mumol.L-1 blocked the stimulative effect of SP. These results suggest that the stimulative effect of SP on the electric activity of B cells may be due to the increase in Ca2+ influx through the voltage-dependent Ca2+ channels.