The goal of this clinical research study is to compare the 6-minute walk test with the exercise stress test, in patients who may have lung surgery. Researchers want to find out if the 6-minute walk test is as good as the exercise stress test at predicting possible complications that may occur after lung surgery.

Description of the Study Tests:

The exercise stress test is commonly used for predicting possible complications that may occur after lung surgery. The 6-minute walk test is a simpler test that does not require as much equipment.

6-Minute Walk Test: If you agree to take part in this research study, you will be asked to perform two 6-minute walk tests along with your routine exercise stress test. Both 6-minute walk tests will be done within 15 Days of the already scheduled exercise stress test if your clinical condition does not change during that time period. The 6-minute walk tests should be done at least 2 hours before or 1 hour after the exercise stress test. The second 6-minute walk test may be done 20 minutes after the first one. If you had a 6-minute walk test done within 15 Days before enrolling in the study, it can be used for the study.

To perform the 6-minute walk tests, you will walk as far as possible around cones on a flat indoor course that is about 40 yards long. You will walk at your own pace and can take breaks at any time if necessary. After the 6 minutes, the study staff will tell you the total distance you have walked.

Researchers will compare the distances you walked for the two 6-minute walk tests with the results of the exercise stress test. The walk test results will not affect your treatment plan.

Other Study Procedures:

Before and after the walk tests, the following procedures will be performed. Your blood pressure will be measured. You will be asked about any shortness of breath and/or fatigue you may have.

Before, during, and for about 1 minute after the walk tests, your heart rate will be measured. A device that looks like a clothespin will be placed on your finger to wear during this time, and it will measure the amount of oxygen in your blood.

Length of Study:

You will be considered off-study after the second walk test.

If you do have lung surgery, researchers will monitor your health status by checking your medical records until you are discharged from the hospital or for 30 days after the lung surgery, whichever comes first.

This is an investigational study. Using the 6-minute walk test for this study's purpose is considered experimental. Up to 101 patients will take part in this study. All will be enrolled at M. D. Anderson.

Inclusion Criteria:

1. Patient's age is between 18-90.
2. Patient has been referred for an oxygen consumption exercise test because they are considered high risk for morbidity and/or mortality post lung resection
3. Patient must be able to read, understand and provide informed consent.

Exclusion Criteria:

1. Patients diagnosed with angina pectoris
2. Patients diagnosed with critical aortic stenosis
3. Patients with unstable gait that persists with use of assistive device
4. Patients unable to walk

Patients at high risk for complications from lung resection.