I often read stories about cancer patient’s (survivor, warrior, thriver, whatever we want to be called) physical accomplishments before, during, or after treatments – marathons, triathlons, ultras, century rides – all impressive stuff, even outside the realm of cancer. The accomplishments seem understandable too, since exercise has been found to:
- Improve survival in breast (1) and colorectal cancers by 50% (2).
- Brisk walking of 2 1/2 hours per week produced the breast cancer results, but more vigorous exercise of 6 hours per week was needed for colon cancer;
- Other researchers found moderate intensity physical activity to reduce risk of death from all causes by 60% among breast cancer patients (5);
- and, cancer specific mortality from brain (4),andhigh grade, advanced, or fatal prostate cancers (3), were also reduced 43% and 70% respectively.
- running 7.5 to 15.5 miles per week or walking briskly 12 to 23 miles per week for the brain cancer results, and 3 hours per week of vigorous exercise for prostate cancer.
Interestingly, more exercise did not reduce risk any further in the breast (1) or brain cancer studies. However, for their results, the brain cancer subjects had to exceed the recommended physical activity levels (6) of 150 minutes of moderate intensity exercise per week. Walking was also as good as running in the brain cancer study, subjects just had to walk farther.
What does this all mean for those of us affected by cancer? Well, for the cancers mentioned above, if you’re not moving at the levels showing significance, perhaps it is time to get clearance from your physician, and start. Practically, make exercise or physical activity a part of your weekly schedule. It is easy to fill up your calendar with other things and people but forget to plan you into your week. Take a good look at your week, find days and times that work best to accomplish what you want, then write you into those time slots, and keep the appointment. Book others to meet with you if needed, guilt can be the right motivator sometimes.
Hypothetically, what if completing an Ironman Triathlon improved survival by 80%, would cancer patients, the majority of whom are sedentary, start training? I wouldn’t be surprised if many did, determination can be great when faced with a cancer diagnosis. However, even if willing to simply change their lifestyle, or intensely train for an Ironman, are we already hindering patients’ ability to do so by not pre-habilitating (8) them for the insult some treatments inflict on the body? If most cancer patients do not already like to exercise, how are we ever going to convince them to start if we let their physical function decline further prior to or during the treatment process?
For those of us already in the exercise choir, and for cancer types other than those listed above, how much exercise is enough, and what may warrant caution (9) or be too much? Unfortunately, most fitness stories remain just that, stories, unless we happen to be in a study, because, until physical activity is routinely recorded in oncology we will never know to what extent many physical accomplishments affect cancer survivorship (the ‘survivorship beginning at diagnosis’ definition). Most of us in the cancer exercise choir, myself included, are just figuring it out as we go along, sometimes overdoing it (7), or maybe we’re not doing enough, and we share what we’ve learned with others. Ironically, in spite of all the data we generate when training with our consumer fitness tools, there still isn’t the right statistical data to guide many of us.
Missing data …
A physical activity profile (using a short, scientifically validated, questionnaire) is not routinely recorded when extracting biopsy tissue from patients. Is there evidence in tissue samples that could correlate physical activity to cancer treatment response rates and survival? How are tissue samples different, if at all, between those who exercise versus those who don’t? If different, can the differences be exploited to improve cancer treatment outcomes or to develop new drugs? Exercise and physical activity are positively affecting survival for those cancers listed above, but how is this happening? What are the physiological mechanisms, and are we overlooking routine biopsies as sources of evidence? Exercise physiologists sometimes pay study volunteers and take muscle biopsy samples to find out what exercise did. In oncology, other than pathology, how much thought is given to our biopsy samples, which patients pay for, and exorbitantly too?
I wouldn’t limit recording patients’ physical activity to biopsies only, we should be updating fitness profiles at diagnosis, first treatment, scans, and subsequent healthcare visits too. The studies mentioned above were observational ones done over a number of years, some only assessing physical activity every two years (1,3), which doesn’t allow for teasing out information in the weeks specifically surrounding a cancer diagnosis or treatment. Some physical activity questionnaires have gone electronic, but collecting data using paper forms, interviews, and calls to subjects is still done. In today’s electronic world this sounds archaic, but this is how the best observational evidence has been obtained so far.
Or … data to nowhere
With all the new consumer fitness products available we are still unable to get much of the data they generate into our electronic health records (EHRs). My Garmin data, Moves data, and the information I type into my training and treatment log, all just sit there in electronic form somewhere in cyberspace. My information cannot be pooled with the fitness data from others to search for statistical significance. You can be sure the consumer fitness developers know a lot of things about me, but the products they have developed are generating data that goes nowhere – lots of data rather than ‘Big Data’ – my cancer and fitness story has no statistical power even though plenty of Information Technology (IT) is attached to it.
Recent announcements regarding consumer fitness and IT may change this and move us closer to continuously updated physical activity profiles by using data automatically uploaded through privacy ensured patient portals (EPIC’s ‘MyChart’ would be a good example). Physical activity information could then be accessible when needed by clinicians from EHRs, and more importantly, tied to pathology, treatment, and other information within EHRs. Apple’s collaboration with The Mayo Clinic, Nike, and the prominent EHR system, EPIC, appears to be headed in this direction. However, without the broad use of internationally standardized exercise and physical activity codes for the common measures most exercise stakeholders are recording – steps, calories, heart rate, etc. – integrating the fitness data into EHRs will remain problematic. Medicine wants valid standardized data and evidence before they will change clinical practice. Our fitness stories, with isolated data on only one person, will not change clinical practice.
There is interest among cancer patients in allowing their data to be shared for research purposes, 87% reporting a willingness to do so (10) as long as privacy was adequately addressed. How many of them have stories on the extreme ends of the physical activity spectrum and how is cancer survivorship going for them out there? Fitness stories may motivate or guide others, but we also need statistical significance in order to impact clinical practice.
1. Holmes MD, et al., Physical activity and survival after breast cancer diagnosis. JAMA. 2005;393:2479-86.
2. Meyerhardt JA, et al., Impact of physical activity on cancer recurrence and survival in patients with stage III colon cancer: findings from CALGB 89803. J. Clin Oncol. 2006: 24:3535-41.
3. Giovannucci EL, et al., A prospective study of physical activity and incident and fatal prostate cancer. Arch. Intern. Med. 2005:165:1005-10.
4. Williams PT, Reduced risk of brain cancer mortality from walking and running. Med. Sci. Sports Exerc. 2014 May;46(5):927-32.
5. Irwin ML, et al., Influence of pre and postdiagnosis physical activity on mortality in breast cancer survivors: the health, eating, activity, and lifestyle study. J. Clin. Oncol. 2008:26:3958-64.
6. Schmitz K.H, et al., American College of Sports Medicine Roundtable on Exercise Guidelines for Cancer Survivors. Med Sci Sports Exerc. 2010 Jul;42(7):1409-26.
7. Kano S, et al., [A case with myositis as a manifestation of chronic graft-vs-host-disease (GVHD) with severe muscle swelling developed after aggressive muscular exercise.] Rinsho Shinkeigaku. 2003 Mar;43(3):93-7.
8. Julie K. Silver, MD and Jennifer Baima, M.D. Cancer Prehabilitation: An opportunity to Decrease Treatment-Related Morbidity, Increase Cancer Treatment Options, and Improve Physical and Psychological Health Outcomes. Am J Phys Med Rehabil. 2013 Aug;92(8):715-27.
9. Stan, D, et al., Pilates for Breast Cancer Survivors: Impact of Physical Parameters and Quality of Life After Mastectomy. Clinical Journal of Oncology Nursing. Volume 16, Number 2; pp:131-141.
10. Rechis, R, et al., The Promise of Electronic Health Information Exchange: A LIVESTONG Report.
The Future of Medicine Is in your Smartphone. Eric J. Topol, MD. The Wall Street Journal, 1/9/2015.