Repetitive hypoxia followed by persistently increased ventilatory motor output is referred to as long-term facilitation (LTF). LTF is activated during sleep after repetitive hypoxia in snorers. We hypothesized that LTF is activated in obstructive sleep apnea (OSA) patients. Eleven subjects with OSA (apnea/hypopnea index = 43.6 +/- 18.7/h) were included. Every subject had a baseline polysomnographic study on the appropriate continuous positive airway pressure (CPAP). CPAP was retitrated to eliminate apnea/hypopnea but to maintain inspiratory flow limitation (sham night). Each subject was studied on 2 separate nights. These two studies are separated by 1 mo of optimal nasal CPAP treatment for a minimum of 4-6 h/night. The device was capable of covert pressure monitoring. During night 1 (N1), study subjects used nasal CPAP at suboptimal pressure to have significant air flow limitation (>60% breaths) without apneas/hypopneas. After stable sleep was reached, we induced brief isocapnic hypoxia [inspired O(2) fraction (FI(O(2))) = 8%] (3 min) followed by 5 min of room air. This sequence was repeated 10 times. Measurements were obtained during control, hypoxia, and at 5, 20, and 40 min of recovery for ventilation, timing (n = 11), and supraglottic pressure (n = 6). Upper airway resistance (Rua) was calculated at peak inspiratory flow. During the recovery period, there was no change in minute ventilation (99 +/- 8% of control), despite decreased Rua to 58 +/- 24% of control (P < 0.05). There was a reduction in the ratio of inspiratory time to total time for a breath (duty cycle) (0.5 to 0.45, P < 0.05) but no effect on inspiratory time. During night 2 (N2), the protocol of N1 was repeated. N2 revealed no changes compared with N1 during the recovery period. In conclusion, 1) reduced Rua in the recovery period indicates LTF of upper airway dilators; 2) lack of hyperpnea in the recovery period suggests that thoracic pump muscles do not demonstrate LTF; 3) we speculate that LTF may temporarily stabilize respiration in OSA patients after repeated apneas/hypopneas; and 4) nasal CPAP did not alter the ability of OSA patients to elicit LTF at the thoracic pump muscle.

Objectives: To analyze the response of neck disease to treatment with primary chemoradiation. Methods: Retrospective review of patients with head and neck cancer treated with chemoradiation with curative intent at a Veterans hospital. Results: Thirty-four patients were identified who received concomitant chemotherapy and radiation: 7 patients with N1, 22 with N2, and 7 with N3 disease. 78% of patients had complete clinical and radiographic response of their neck disease following treatment. Eleven patients underwent neck dissection post treatment. 33% of the neck specimens had pathologically positive nodes. 81% of patients were alive without evidence of recurrent disease in the primary site or neck at last follow-up. Conclusions: The majority of HNSCC patients treated with chemoradiation have complete response in the neck. Patients with clinical and radiographic evidence of complete response in the neck may not require neck dissection, even with N2 or greater disease.

6511 Background: The United States Food and Drug Administration (USFDA) advocates blinded independent central review (BICR) of radiographic exams for oncology registration studies when the primary study endpoint is based on tumor measurements, such as progression-free survival, time to progression or objective response rate. However, a proportion of subjects progress clinically prior to radiographic evidence of disease progression and in certain indications, measurement of cutaneous lesions may be incorporated into response criteria calculations. Methods: BICR data from 4,183 subjects in the following indications: lymphoma, melanoma, breast cancer, and colorectal cancer, was blinded, pooled, and reviewed to determine the impact of clinical review on best response and date of progression following BICR of radiographic images. Results: Inclusion of clinical data and/or clinical photography impacted 27% (47/171) of lymphoma subjects, affecting the assessment of the best response (13%), best response date (16%) and/or the date of progression (19%); 12% (13/107) of melanoma subjects, affecting the assessment of the best response (6%), best response date (5%), and/or the date of progression (8%); 10% (308/2,947) of breast cancer subjects, affecting the assessment of the best response (4%), best response date (4%), and/or the date of progression (9%); 3% (32/958) of colorectal cancer subjects, affecting the assessment of the best response (2%), best response date (2%), and/or the date of progression (2%). Conclusions: When using BICR to determine endpoints in oncology clinical trials, inclusion of a clinical review may be relevant in 27% of subjects for lymphoma, 12% for melanoma, 10% for breast cancer, and 3% for colorectal cancer. [Table: see text]

6603 Background: RECIST suggests progression of non-target disease is rare in patients with stable or responding target disease. We reviewed outcomes by RECIST to determine the rate of non-target (NT) progressive disease (PD). Methods: Outcomes of RECIST-based blinded independent central review (BICR) of 962 breast and colon cancer patients were used to identify 514 patients that had a progression event in order to determine the incidence of NT-PD. The radiographs of the 55 patients that had NT-PD were further reviewed by the authors (KB, RF) to confirm the NT-PD was “unequivocal.” To be considered unequivocal, there had to be a definite, substantial increase in the size of one or more metastatic NT lesions that was clearly not related to differences in imaging technique. To confirm the subjective nature of the “unequivocal progression,” the lesion(s) upon which PD was assessed was measured and a 20% increase in the lesion(s) since nadir was required. Results: Of the patients with PD, 11% (55/514) progressed only on worsening of NT disease. In 82% (45/55) of cases where the NT-PD was unequivocal, either the target disease was increasing but had not met the quantitative requirement for progression or the increase in NT disease would have resulted in target progression had the NT site(s) of disease been included with the baseline target lesions. Of the remaining 18% (10/55) where the two criteria described above did not apply, and an additional evaluation was performed, the next evaluation confirmed PD. Conclusions: Progression on the basis of NT disease can be reliably assessed if the target disease has started to increase from the nadir or if the increase in NT disease is significant enough to have resulted in target disease progression if classified as such. If one of the above criteria is not met, it is recommended that treatment continue until progression can be confirmed at the next evaluation. No significant financial relationships to disclose.

OBJECTIVE: 1. To analyze the response of neck disease to treatment with primary chemoradiation. 2. To determine when neck dissection should be done following chemoradiation. METHODS: Retrospective review of patients with head and neck cancer (HNSCC) treated with chemoradiation with curative intent at a Veterans' Administration hospital, with specific attention given to the response of the neck disease to the treatment. RESULTS: Thirty-two patients were identified who received concomitant chemotherapy and radiation: 8 patients with N1, 19 with N2, and 5 with N3 disease; 63% of patients had complete clinical and radiographic response of their neck disease following treatment. One additional patient had radiographic evidence of neck disease post-treatment that continued to diminish in size on subsequent CT scans over the following year. Eleven patients underwent neck dissection post-treatment (two patients with N1, six patients with N2, and three patients with N3 disease); 36% of the neck specimens had pathologically positive nodes. One of the N1, 2 of the N2, and one of the N3 neck dissections had positive nodes. Two patients who had complete clinical and radiographic response in the neck went on to recur at their primary site and die of their disease. Seventy-eight percent of patients were alive without evidence of recurrent disease in the primary site or neck at last followup. CONCLUSIONS: The majority of HNSCC patients treated with chemoradiation have complete response in the neck. Patients with clinical and radiographic evidence of complete response in the neck may not require neck dissection, even with N2 or greater disease.