Comparison of shuttle walk with measured peak oxygen consumption in patients with operable lung cancer

Peak oxygen consumption and long-term all-cause mortality in nonsmall cell lung cancer

BACKGROUND

Identifying strong markers of prognosis is critical to optimize treatment and survival outcomes in patients with nonsmall cell lung cancer (NSCLC). The authors investigated the prognostic significance of preoperative cardiorespiratory fitness (peak oxygen consumption [VO(2peak)]) among operable candidates with NSCLC.

METHODS

By using a prospective design, 398 patients with potentially resectable NSCLC enrolled in Cancer and Leukemia Group B 9238 were recruited between 1993 and 1998. Participants performed a cardiopulmonary exercise test to assess VO(2peak) and were observed until death or June 2008. Cox proportional models were used to estimate the risk of all-cause mortality according to cardiorespiratory fitness category defined by VO(2peak) tertiles (<0.96 of 0.96-1.29/>1.29 L/min⁻¹) with adjustment for age, sex, and performance status.

RESULTS

Median follow-up was 30.8 months; 294 deaths were reported during this period. Compared with patients achieving a VO(2peak) <0.96 L/min⁻¹, the adjusted hazard ratio (HR) for all-cause mortality was 0.64 (95% confidence interval [CI], 0.46-0.88) for a VO(2peak) of 0.96 to 1.29 L/min⁻¹, and 0.56 (95% CI, 0.39-0.80) for a VO(2peak) of >1.29 L/min⁻¹) (P(trend) = .0037). The corresponding HRs for resected patients were 0.66 (95% CI, 0.46-0.95) and 0.59 (95% CI, 0.40-0.89) relative to the lowest VO(2peak) category (P(trend) = .0247), respectively. For nonresected patients, the HRs were 0.78 (95% CI, 0.34-1.79) and 0.39 (95% CI, 0.16-0.94) relative to the lowest category (P(trend) = .0278).

CONCLUSIONS

VO(2peak) is a strong independent predictor of survival in NSCLC that may complement traditional markers of prognosis to improve risk stratification and prognostication.

The lung cancer exercise training study: a randomized trial of aerobic training, resistance training, or both in postsurgical lung cancer patients: rationale and design

Background

The Lung Cancer Exercise Training Study (LUNGEVITY) is a randomized trial to investigate the efficacy of different types of exercise training on cardiorespiratory fitness (VO_2peak), patient-reported outcomes, and the organ components that govern VO_2peak in post-operative non-small cell lung cancer (NSCLC) patients.

Methods/Design

Using a single-center, randomized design, 160 subjects (40 patients/study arm) with histologically confirmed stage I-IIIA NSCLC following curative-intent complete surgical resection at Duke University Medical Center (DUMC) will be potentially eligible for this trial. Following baseline assessments, eligible participants will be randomly assigned to one of four conditions: (1) aerobic training alone, (2) resistance training alone, (3) the combination of aerobic and resistance training, or (4) attention-control (progressive stretching). The ultimate goal for all exercise training groups will be 3 supervised exercise sessions per week an intensity above 70% of the individually determined VO_2peak for aerobic training and an intensity between 60 and 80% of one-repetition maximum for resistance training, for 30-45 minutes/session. Progressive stretching will be matched to the exercise groups in terms of program length (i.e., 16 weeks), social interaction (participants will receive one-on-one instruction), and duration (30-45 mins/session). The primary study endpoint is VO_2peak. Secondary endpoints include: patient-reported outcomes (PROs) (e.g., quality of life, fatigue, depression, etc.) and organ components of the oxygen cascade (i.e., pulmonary function, cardiac function, skeletal muscle function). All endpoints will be assessed at baseline and postintervention (16 weeks). Substudies will include genetic studies regarding individual responses to an exercise stimulus, theoretical determinants of exercise adherence, examination of the psychological mediators of the exercise - PRO relationship, and exercise-induced changes in gene expression.

Discussion

VO_2peak is becoming increasingly recognized as an outcome of major importance in NSCLC. LUNGEVITY will identify the optimal form of exercise training for NSCLC survivors as well as provide insight into the physiological mechanisms underlying this effect. Overall, this study will contribute to the establishment of clinical exercise therapy rehabilitation guidelines for patients across the entire NSCLC continuum.

Trial Registration

NCT00018255

Patient-related risk factors for postoperative adverse events

PURPOSE OF REVIEW

The risk of adverse outcome in patients undergoing major surgery is affected both by cardiorespiratory fitness, and the presence and severity of comorbidities. Accurate risk stratification is essential for the identification of patients who may benefit from specific perioperative management strategies or from an augmented level of perioperative care. Risk stratification techniques include risk prediction models, assessment of functional capacity and novel biochemical markers. This review examines the evidence for the use of these different techniques in perioperative patients.

RECENT FINDINGS

There remains considerable variation in the predictive ability of risk stratification models, in part due to the subjective nature of some of the component variables. Whereas a basic assessment of functional capacity using structured questionnaires may be helpful, in patients thought to be at high risk, the most accurate technique may be cardiopulmonary exercise testing, although the strength of the hypothesized relationship between functional capacity and perioperative outcome has not been fully defined. There have been advances in the identification and refinement of biochemical markers for risk prediction, in particular, brain natriuretic peptide and C-reactive protein. Currently, few centres routinely systematically utilize these strategies to risk stratify perioperative patients.

SUMMARY

The development of improved risk stratification techniques would be assisted by large-scale epidemiological studies. Improvements to currently used risk prediction models are likely to result from the use of variables which more objectively measure patient health and fitness than current tools, and may use a combination of all the above techniques to improve predictive accuracy.

Oxygen consumption, shuttle walking test and the evaluation of lung resection

BACKGROUND

Assessment of peak oxygen uptake (VO(2)) is recommended in the evaluation of patients with borderline pulmonary function as VO(2) is the strongest independent predictor of postoperative pulmonary complications. However, the measurement of VO(2) requires expensive equipment not available in many medical facilities. The shuttle walking test (SWT) has been proposed to be used as a screening tool prior to performing a cardiopulmonary exercise test. Although an association exists between SWT distance and VO(2), only one small study directly measured VO(2) during the SWT.

OBJECTIVES

The aim of this study was to further validate the VO(2)-SWT association by directly measuring VO(2) during SWT in a larger cohort of patients with stable chronic obstructive pulmonary disease (COPD).

METHODS

Fifty stable COPD patients with mild/severe disease were studied. Each patient performed an SWT while wearing a validated portable metabolic monitor.

RESULTS

Mean VO(2) (ml/kg/min) measured after each finalized minute of the SWT was (95% confidence interval): 6 (5-7), 9 (8-10), 11 (10-12), 13 (11-14), 15 (14-16), 18 (16-20) and 21 (18-26) for minutes 1-7, respectively. Patients that completed the British Thoracic Society-recommended 25 shuttles (5 min or 250 m) in the SWT had a mean VO(2) of 15 (14-16). The positive predictive value for walking 25 shuttles (predicting a VO(2) of >or=15ml/kg/min) was 90% and the negative predictive value was 90%.

CONCLUSIONS

Our findings validate the association between VO(2) and SWT distance and facilitate the interpretation of the test in general practice, particularly when deciding the candidacy of a patient for surgical resection.

Assessment of physical functioning in recurrent glioma: preliminary comparison of performance status to functional capacity testing

BACKGROUND

Performance status (PS) scoring systems are tools of immense clinical importance in the management of patients with malignant disease but these tools are subjective and do not provide an objective evaluation of physical functioning. We conducted a pilot study to explore the feasibility and clinical utility of functional capacity testing to assess physical functioning in recurrent primary malignant glioma patients.

PATIENTS AND METHODS

Using a cross-sectional design, consecutive patients with recurrent glioma performed a six minute walk (6MW) test to assess functional capacity. Performance status was assessed using Karnofsky Performance Status (KPS) scoring system. QOL was assessed by the Functional Assessment of Cancer Therapy-Brain scale. Self-reported exercise behavior was assessed using the Godin Leisure Time Exercise Questionnaire (GLTEQ).

RESULTS

A total of 171 patients were recruited and tested. Seventy percent were diagnosed with glioblastoma multiforme (WHO grade IV) and 85% were undergoing therapy. Median KPS was 90% (range, 70-100%). Median 6MW distance was 400 m (range, 102-630 m), equivalent to 56 +/- 13% (range, 14-87%) of that predicted for age and sex. KPS, self-reported exercise, and QOL increased across 6MW distance quartiles (P < 0.05) although there was considerable variation within each category. 6MW distance and KPS were significantly correlated with each other (r = 0.34, P < 0.01) and several QOL domains (range, r = -0.43 to 0.46, P < 0.05).

CONCLUSIONS

6MW distance is a clinically feasible tool that provides an objective measure of physical functioning in select patients with recurrent glioma. Further research is required to investigate the prognostic value of these tests in patients with advanced malignancy.

Effects of presurgical exercise training on cardiorespiratory fitness among patients undergoing thoracic surgery for malignant lung lesions

BACKGROUND

To determine the effects of preoperative exercise training on cardiorespiratory fitness in patients undergoing thoracic surgery for malignant lung lesions.

METHODS

Using a single-group design, 25 patients with suspected operable lung cancer were provided with structured exercise training until surgical resection. Exercise training consisted of 5 endurance cycle ergometry sessions per week at intensities varying from 60% to 100% of baseline peak oxygen consumption (VO(2 peak)). Participants underwent cardiopulmonary exercise testing, 6-minute walk (6 MW), and pulmonary function testing at baseline, immediately before, and 30 days after surgical resection.

RESULTS

Five patients were deemed ineligible before surgical resection and were removed from the analysis. Of the remaining 20 patients follow-up assessments were obtained for 18 (90%) before resection and 13 (65%) patients postresection. The overall adherence rate was 72%. Intention-to-treat analysis indicated that mean VO(2peak) increased by 2.4 mL . kg(-1) . min(-1)(95% confidence interval [CI], 1.0-3.8; P = .002) and 6MW distance increased 40 m (95% CI, 16-64; P = .003) baseline to presurgery. Per protocol analyses indicated that patients who attended >or=80% of prescribed sessions increased VO(2peak) and 6 MWD by 3.3 mL.kg(-1).min(-1) (95% CI, 1.1-5.4; P = .006) and 49 meters (95% CI, 12-85; P = .013), respectively. Exploratory analyses indicated that presurgical exercise capacity decreased postsurgery, but did not decrease beyond baseline values.

CONCLUSIONS

Preoperative exercise training is a beneficial intervention to improve cardiorespiratory fitness in patients undergoing pulmonary resection. This benefit may have important implications for surgical outcome and postsurgical recovery in this population. Larger randomized controlled trials are warranted.

Safety and feasibility of cardiopulmonary exercise testing in patients with advanced cancer

PURPOSE

The use of cardiopulmonary exercise testing (CPET) is increasing in many areas of disease management, the clinical utility of this procedure in patients with advanced cancer remains to be determined. Accordingly, we conducted a pilot study to comprehensively evaluate the safety and feasibility of CPET in 85 patients diagnosed with inoperable non-small cell lung cancer (NSCLC) or metastatic breast cancer (MBC).

METHODS

Using a cross-sectional design, consecutive patients with histologically or cytologically confirmed inoperable NSCLC or MBC were screened for eligibility by their attending oncologist. All consenting patients performed complete pulmonary function tests (NSCLC only) and a symptom-limited CPET on a cycle ergometer with gas exchange analysis.

RESULTS

A total of 85 patients (NSCLC, n=46; MBC, n=39) were recruited and tested. Overall, there were a total of three (3.5%) positive exercise tests [NSCLC, n=2 (4.3%); MBC, n=1 (2.6%)]; 68 (80.0%) negative tests [NSCLC, n=33 (71.7%); MBC, n=35 (89.7%)]; and 14 (16.5%) indeterminate tests [NSCLC, n=11 (23.3%); MBC, n=3 (7.7%)]. Two patients experienced an adverse event during exercise testing. Mean VO(2peak) was 17.0mlkg(-1)min(-1) and 16.5mlkg(-1)min(-1) for NSCLC and MBC patients, respectively. The mean percentage of age and sex-predicted VO(2peak) maximum for both groups was 67%.

CONCLUSION

A symptom-limited, individualized CPET appears to be a relatively safe and feasible assessment tool to objectively evaluate physical functioning in selected patients with advanced cancer. This study provides important information to future investigations examining the potential role of exercise training in this patient population.