The Cooper Institute
 

Founded in 1970 by the "Father of Aerobics"
Kenneth H. Cooper MD, MPH

 
 

Cardiorespiratory Fitness Levels among Female Cancer Survivors: The Cooper Center Longitudinal Study

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Friday, Apr 27, 2018


Cardiorespiratory fitness (CRF) is defined as the body’s ability to utilize oxygen at the cell level, and is a powerful predictor of all-cause mortality in various populations. Measurement of CRF via maximal treadmill exercise testing is a key component of the comprehensive physical examination offered by Cooper Clinic. It is well-known in the scientific literature that breast cancer survivors have lower CRF when compared to healthy women. The difference in CRF between the two groups is thought to be partly due to the toxic effects of cancer therapy (i.e. chemotherapy and radiation). More specifically, these treatments are associated with anemia, muscle weakness, and muscle pain, as well as damage to the heart muscle and its blood vessels. However, much less is known about the CRF status of women with gynecologic cancers; these include ovarian, endometrial (uterine), and cervical cancers.

Accordingly, a recent issue of Gynecologic Oncology published findings from the Cooper Center Longitudinal Study (CCLS). A total of 89 women with a history of ovarian, endometrial, or cervical cancer were compared with 89 age-matched women with no history of cancer. From this point forward, we will refer to the former as the ‘cancer group’ and the latter as the ‘control group.’ All women underwent a comprehensive physical exam at Cooper Clinic between 1986 and 2011. The average age at the time of the exam in both groups was 51 years. For the cancer group, the average time from cancer diagnosis to the Cooper Clinic exam was 13.5 years. High blood pressure was more common in the cancer group (23%) than in the control group (10%). The average body mass index (BMI)* in the cancer group (24.7 kg/m2) was similar to that of the control group (23.9 kg/m2), however, women with ovarian cancer tended to have higher BMI’s (28.1 kg/m2) than women with endometrial (25.5 kg/m2) or cervical cancer (23.9 kg/m2).



The major focus of this study was to compare CRF levels between the cancer group and the control group. These results are shown below in Figure 1. Before we discuss this Figure, let’s talk first about METs. If you are a sports fan, a MET is a pro baseball player from New York City. However, in the context of the current study, METs are how we quantify CRF. One MET represents how much oxygen the body uses at rest. So, if you were exercising at an intensity of 5 METS, it would mean that your body is using 5 times the amount of oxygen than it would at rest. Based on the final speed and grade achieved during the maximal treadmill exercise test, we can determine the maximal MET level of each patient. The higher the maximal MET level, the higher the level of CRF.

As you seen in Figure 1, the control group had an average value of 10 METs on their treadmill exercise test, while the cancer group had an average value of 9.2 METs. The difference was statistically significant, meaning that these results are very unlikely due to chance alone. This was the first study to show that women with gynecological cancers have significantly lower levels of CRF than women of the same age with no history of cancer. The reason this is important is because lower levels of CRF are associated with a higher risk of cardiovascular disease, which is the leading cause of death among U.S. women. Thus, it is especially important to target female cancer survivors for physical activity programming. Indeed, several studies have shown that meeting current public health guidelines for physical activity** results in significant improvement in CRF among female cancer survivors. As a suggestion, brisk walking represents an inexpensive mode of physical activity that can be done almost anywhere by the ambulatory population.

In Table 1 below, we present some brief statistics on the gynecological cancers mentioned in this blog. These numbers represent the latest data available. To obtain additional information about these cancers, use this link.

Table 1. Annual number of diagnoses and deaths for gynecological cancers in the United States. Source: Centers for Disease Control.
 
Cancer Type Annual number of  diagnoses Annual number of  deaths
Cervical 12,578 4,115
Endometrial (Uterine) 53,028 9,727
Ovarian 21,161 14,195

*BMI is calculated as follows: body weight in pounds x 703 / height in inches / height in inches. If math is not your strong suit, this link from the CDC will automatically calculate your BMI.

**Accumulate at least 150 minutes per week of moderate intensity aerobic activity or at least 75 minutes per week of vigorous intensity aerobic activity. If significant weight loss or higher levels of fitness are the goal, then double these amounts. The guidelines also recommend a minimum of 2 days each week of resistance training in order to maximize health benefits. 

Reference
Peel, A., Barlow, C., Leonard, D., DeFina, L., Jones, L., Lakoski, S. (2015). Cardiorespiratory fitness in survivors of cervical, endometrial, and ovarian cancers: The Cooper Center Longitudinal Study. Gynecologic Oncology, 138(2), 394-397. doi: 10.1016/j.ygyno.2015.05.027


Note: The Cooper Institute has recently published a state of the art textbook titled Principles of Health and Fitness for Fitness Professionals. This book is an absolute must for fitness leaders or anyone in the general population who wants to learn more about health and physical fitness. The book is also a great resource for anyone who is seeking to earn a nationally accredited personal trainer certification! Click on the links above to learn more.