Exercise as it relates to Disease/Effect of Exercise on Patients Diagnosed with Colorectal Cancer

This is an anlysis of the journal article "Impact of Physical Activity on Cancer Recurrence and Survival in Patients With Stage III Colon Cancer" by Jeffrey A. Meyerhardt et al (2006).

What is the background to this research?
Colorectal or Bowel cancer is a type of cancer that takes place in the colon or rectum, which are components of the large intestine. Current research suggests that people who are physically active have a lower risk of developing colon cancer. In fact, physical inactivity is now widely considered to be a risk factor for developing the disease, however, a healthy lifestyle does not guarantee developing clorectal cancer as there are other many risk factors involving this type of cancer.

Current medicine has a way to treat this type of cancer by surgically removing the tumor and undertaking chemotherapy to prevent the cancer to grow back. The treatment is successful most times although cancer recurrence still occurs among patients.

Very little is known about the effect that exercise might have on people who are already diagnosed with the disease. Consequently, this study was developed to uncover how exercise can influence cancer recurrence and survival after patients are successfully treated with surgery and chemotherapy.

Where is the research from?
This research was a collaborative effort of twelve Doctors of Medicine from the Division of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA; Cancer and Leukemia Group B Statistical Center, Duke University, Durham, NC; Memorial Sloan-Kettering Cancer Center, New York, NY; Division of Medical Oncology, Ohio State University, Columbus, OH; Division of Colon and Rectal Surgery, Mayo Clinic Foundation, Rochester MN; Hôpital du Sacré-Coeur de Montréal, Montreal, Ontario, Canada; Department of Medicine, Loyola University, Maywood; and Section of Hematology/Oncology, University of Chicago, Chicago, IL.

The American Society of Clinical Oncology published this Journal in 2006.

What kind of research was this?
This was an observational study of patients with stage III colon cancer. Patients reported on various recreational physical activities six months after they finished their medical therapy and were observed for cancer recurrence.

What did the research involve?
The purpose of this study was to find out if regular physical activity could reduce the risk of cancer to grow back on patients who have had the cancer removed and been through chemotherapy after colorectal cancer diagnosis.

The patients on this cohort study were participants in the NCI-sponsored Cancer and Leukemia Group B supplementary therapy trial for stage III colon cancer. They were chosen according to the results of a self-administered questionnaire targeting diet and lifestyle habits, 832 patients were apt for the study.

Six months after patients completed the therapy, they took a physical activity assessment, in which they would record the average hours they spent a week in activities such as walking, jogging, bicycling, swimming, racket sports or other vigorous exercises. The final stage of the assessment period was determined as disease-free survival (DFS), the time patients spent from the physical assessment questionnaire to tumor recurrence. DFS would basically be a unit to measure how long physically active patients live after treatment without cancer recurrence.

What were the basic results?
Patients who exercised for more than 18 hours per week had a higher DFS, which means that they present lower risk of cancer recurrence, showing almost 50% improvement in DFS. That means that if a patient walked 6 hours per week, they would double the time before the tumor grows back.

How did the researches interpret the results?
Researches claim that "beyond surgical resection and postoperative adjuvant chemotherapy for stage III colon cancer, for patients who survive and are recurrence free approximately 6 months after adjuvant chemotherapy, physical activity appears to reduce the risk of cancer recurrence and mortality." Accordingly, if you or you know of someone who has had surgery and chemotherapy from colon cancer, exercise will be a good advice if a fear of recurrence is present.

What conclusions should be taken away from this research?
People who have been diagnosed with colorectal cancer and have gone through therapy, have now a way to enhance their lifestyle by reducing the risk of cancer recurrence.

The researches Based their conclusions on self-reports of the number of times patients exercised a week. This data could therefore be over estimated as people are often prone to over estimate their exercise intensity. To avoid this in future studies, there could be someone to record the hours of exercise for the patients. However, regardless of the exact number of hours spent exercising, it was clear in the results that those patients who spent greater time exercising, had less risk of cancer recurrence.

What are the implications of this research?
This research implies that now patients with colorectal cancer will be exercising more as the public becomes more aware of the benefits that exercise has to the disease. This might emerge more questions about the matter such as; how safe is it for patients who have undertaken surgery and chemotherapy to exercise? and how long to waith for patients to exercise, and how much is it too long to start a new exercise plan? Research has already answered some of these questions.

It may be quite hard for patients who have just had surgery and chemotherapy to get up and exercise as they might find themselves unwell, tired etc. Also, they might fear that exercise might make extra damage to their delicate bodies. Exercise however is scientifically proven to not cause any harm to the body after this kind of therapy, therefore exercise after an event such as surgery and chemotherapy treatment is totally safe and harmless.[4]

This research has already suggests a time of margin since treatment and exercise; they waited six months before patients started their exercise programs. Through the study, six months is safe and no patients suffered any complications, however the study never discusses if they set six months because they had previously studied that it was the most scientifically accurate time to wait or it was just mere guess. To answer this question further research is needed.