Exercise Testing for Early Stage Breast Cancer Patients Receiving Radiation Treatment

Inclusion Criteria:

Female
ECOG performance status 0 or 1
Medical clearance from attending radiation oncologist or medical oncologist to undergo a symptom-limited CPET
Currently undergoing intact breast radiotherapy for early stage breast cancer (including TisN0, T1N0, T2N0) or has completed intact breast RT in the last 3 months.
Receiving or received a prescribed dose of 4240 cGy in 16 fractions to the whole breast without treatment directed at nodal basins. Patients may also be receiving or have received a boost to the lumpectomy bed at the discretion of the treating physician.
Subjects may be treated in the supine or prone position at the discretion of the treating physician.
Subjects may be treated with or without a deep inspiratory breath hold technique at the discretion of the treating physician.
Identified by the treating radiation oncologist as having significant treatment-related fatigue or minimal treatment-related fatigue and not simply baseline fatigue. A score of "0" on the RTOG fatigue scale will be considered minimal fatigue, while a score of "2" or greater will be considered significant fatigue (moderate fatigue causing difficulty performing some ADLs).

Exclusion Criteria:

Currently undergoing post-mastectomy radiation
Has received chemotherapy previously or has a plan to receive chemotherapy during the timeframe of study assessment.

Any of the following absolute contraindications to CPET, as per American Thoracic Society (ATS) recommendations

Acute myocardial infarction (within 3-5 days of any planned study procedures)
Unstable angina
Uncontrolled arrhythmia causing symptoms or hemodynamic compromise
Recurrent syncope
Active endocarditis
Acute myocarditis or pericarditis
Symptomatic severe aortic stenosis
Uncontrolled heart failure
Acute pulmonary embolus or pulmonary infarction within 3 months of any planned study procedures
Thrombosis of lower extremities
Suspected dissecting aneurysm
Uncontrolled asthma
Pulmonary edema
Room air desaturation at rest ≤ 85%
Respiratory failure
Acute non-cardiopulmonary disorders that may affect exercise performance or be aggravated by exercise (i.e. infection, renal failure, thyrotoxicosis)
Mental impairment leading to inability to cooperate