Exercise in Pediatric Oncology: A shift in focus from cure to care.

Over the past 30 years, pediatric cancer survival rates have risen substantially, increasing the number of people living with the debilitating effects of cancer. Notably, the 5-year observed survival rates for children and adolescents from 1999 to 2003 in Canada have improved to 82% from the last estimate of 71% using diagnoses from 1985-1988 [1,2]. For 2012, the Canadian Cancer Society estimated 1,400 new cases of childhood cancer in Canada [3]. In Canada alone, this could mean that around 1,150 children each year are added to the population of cancer survivors. These survivors become suitably “cured” of their disease but are often left to cope with the myriad long-term effects that follow cancer patients throughout their lives.

Children face a series of symptoms that stem directly from their treatment. Children with cancer are commonly treated with intensive multimodal therapy: a set combination of chemotherapy, radiotherapy, immunotherapy and/or surgery. Normally, the areas treated with radiation will often be more prone to effects. These effects can include dry mouth and narrowed esophagus, osteonecrosis, lung damage, and varying heart conditions [4]. Cranial radiation may possibly cause long-term issues with coordination and strength [4]. Common types of chemotherapy drugs are anthracyclines, which can cause side effects such as cardiotoxicity, shortness of breath, anxiety, poor exercise tolerance, fatigue, and an irregular heartbeat [4]. In order to improve and revitalize treatment options, approximately 80% of children are registered in a clinical trial or are receiving treatment based on a recorded protocol. Enrollment in such trials provides a survival advantage [1].

It is simply amazing that a large majority of children are enrolled in a clinical trial to support survivorship. For children with cancer, the problem often lies within their lives after treatment, when they no longer regularly visit the hospital and are dealing with the many problems that arise from being frequently bed-ridden and inactive for a large portion of their childhood. With this resultant shift in survivorship and an emerging knowledge of the late effects of childhood cancer therapy, many have come to shift their focus from cure to care. Experts have specifically been targeting ways to increase health related quality of life (HRQOL) which is defined by Hinds et al. (2004) as an overarching feeling of well-being taken from the ability to continue with usual activities, interactions with and feeling cared for by others, finding meaning in the experience of being ill, and dealing with difficult physical, emotional and cognitive reactions [5]. Studies have indicated a certain number of risk factors that contribute to a diminished HRQOL in childhood cancer populations including fatigue, ethnic status, and being a long-term brain cancer survivor [6].

A sedentary lifestyle is commonly linked to a decreased HRQOL. This lifestyle brings with it an array of potential comorbidities and is commonly adopted in the childhood cancer survivor population [7]. Polgreen et al. (2012) found, in a study of childhood cancer survivors (CCS) under 18 years old, that the CCS had bone deficits upon comparison with a selected healthy control group [8]. Inactivity has been suggested as a potential reason for this bone deficit in the CCS group compared to the healthy group. Another study, capturing the physical activity (PA) behaviors of youth with cancer, has shown that pre-diagnosis levels of PA decline drastically throughout treatment and do not recover post-treatment [9]. Specific treatment options, lessened involvement in school activities, and overprotection from parents and teachers have all been shown to lead to inactivity in pediatric cancer survivors [10-12].

This knowledge allows experts to arrive at a specific and integral question for the future of improved care for pediatric oncology patients: What can alleviate these long-term effects of cancer patients and also improve HRQOL? This article will herein discuss how exercise can be argued as a groundbreaking and effective answer to the above question.

Exercise as a complementary therapy for children facing cancer can be advantageous in many ways as long as it is performed in a controlled and specific manner. Exercise has been linked to alleviating certain side effects of childhood cancer, such as decreased functional capacity and muscular strength, impaired pulmonary function, and reduced physical fitness [13]. With low-moderate exercise being the standard for this population, no damage is seen to immune function [14,15]. Cardiovascular, immune and muscle system overexertion are also unlikely with moderate exercise [16]. Benefits have also included an increase in peak oxygen uptake and anaerobic threshold [17]. An improvement in HRQOL was also seen from a 12-week exercise and cognitive-behavioral therapy [18].

In literature, exercise in a specifically performed manner with expert supervision has rarely been shown to be deleterious to the pediatric oncology population. There are plenty of reported groundbreaking results of positive, advantageous effects for controlled exercise. On a global scale, the knowledge surrounding the benefits of exercise is not translated into practice. A low percentage of hospitals with pediatric oncology clinics offers or supports exercise interventions for children with cancer. Many physicians and nurses know very little about exercise and how to recommend it. This is a problem that is not yet fully understood nor properly discussed. Why would such an evidently advantageous therapy be ignored? Why would health care professionals from around the world not want to encourage improved HRQOL for these children who often miss a large portion of their childhood? Although the answers to these questions are highly unclear, what is certain is that more evidence is emerging to show greater benefits of exercise for children with cancer and survivors of the disease. Someday very soon, the evidence will not possibly be ignored.

References:

1. Ellison LF, Pogany L, Mery LS. 2007. Childhood and adolescent cancer survival: A period analysis of data from the Canadian Cancer Registry. European Journal of Cancer 43:1967-1975.
2. Villeneuve PJ, Raman S, Leclerc JM, Huchcroft S, Dryer D, Morrison H. 1998. Survival rates among Canadian children and teenagers with cancer diagnosed between 1985 and 1988. Cancer Prevention and Control 2:15-22.
3. Canadian Cancer Society’s Steering Committee on Cancer Statistics. 2012. Canadian Cancer Statistics 2012.
4. Keene N, Hobbie W, Ruccione K. Diseases. 2007. Childhood Cancer Survivors: A Practical Guide to Your Future. McLean, VA: O’Reilley Media, Inc.
5. Hinds PS, Gattuso JS, Fletcher A, Baker E, Coleman B, Jackson T, et al. 2004. Quality of life as conveyed by pediatric patients with cancer. Quality of Life Research 13:766-772.
6. Meeske KA, Patel SK, Palmer SN, Nelson MB, Parow AM. 2007. Factors Associated With Health-Related Quality of Life in Pediatric Cancer Survivors. Pediatric Blood Cancer 49:298-305.
7. Mulhern RK, Tyc VL, Phipps S, Crom D, Barclay D, Greenwald C, et al. 1995. Health-Related Behaviours of Survivors of Childhood Cancer. Medical and Pediatric Oncology 25:159-165.
8. Polgreen LE, Petryk A, Dietz AC, Sinaiko AR, Leisenring W, Goodmand P, et al. 2012. Modifiable risk factors associated with bone deficits in childhood cancer survivors. BioMed Central Pediatrics 12(40):1-9.
9. Keats MR, Culos-Reed SN, Courneya KS, McBride M. 2006. An Examination of Physical Activity Behaviors in a Sample of Adolescent Cancer Survivors. Journal of Pediatric Oncology Nursing 23:135-142.
10. Huang T-, Ness KK. Exercise Interventions in Children with Cancer: A Review. 2011. International Journal of Pediatrics 2011:1-11.
11. Aznar S, Webster AL, San Juan AF, Chamorro-Viña C, Mate-Munoz JL, Moral S, et al. 2006. Physical activity during treatment in children with leukemia: a pilot study. Applied Physiology, Nutrition, and Metabolism 31:407-413.
12. McKenzie DC, Coutts KD, Rogers PC, Jespersen DK, Pretula A. 2002. Aerobic and Anaerobic Capacities of Children and Adolescents Successfully Treated for Solid Tumors. Clinical Exercise Physiology 2(1):39.
13. Takken T, van dT, Zwerink M, Hulzebos EH, Bierings M, Helders PJM, et al. 2009. Development, feasibility and efficacy of a community-based exercise training program in pediatric cancer survivors. Psychooncology 18(4):440-448.
14. Chamorro-Vina C, Ruiz JR, Santan-Sosa E, Gonzalez Vicent M, Madero L, Perez M, et al. 2010. Exercise during hematopoietic stem cell transplant hospitalization in children. Medicine & Science in Sport & Exercise 42(6):1-9.
15. Ladha AB, Courneya KS, Bell GJ, Field CJ, Grundy P. 2006. Effects of acute exercise on neutrophils in pediatric acute lymphoblastic leukemia survivors: a pilot study. Journal of Pediatric Hematology/Oncology 28(10):671- 677.
16. San Juan AF, Wolin K, Lucia A. 2011. Physical Activity and Pediatric Cancer Survivorship. Physical Activity and Cancer 186:319-347.
17. Sharkey AM, Carey AB, Heise CT, Barber G. 1993. Cardiac rehabilitation after cancer therapy in children and young adults. American Journal of Cardiology 71(16):1488-1490.
18. May, Anne M., Irene Korstjens, Ellen van Weert, Bart van den Borne, Josette EHM Hoekstra-Weebers, Cees P. van der Schans, Ilse Mesters, Jan Passchier, Diederick E. Grobbee, and Wynand JG Ros. 2009. Long-term effects on cancer survivors’ quality of life of physical training versus physical training combined with cognitive-behavioral therapy: results from a randomized trial. Supportive care in cancer 17 (6):653-663.

Image Credit: Stone, B.A. 2010. Logistics Specialist Seaman Sergio Torres draws pictures with a child at the Vladivostok children’s cancer ward. Creative Commons. http://commons.wikipedia.org (accessed October 26, 2013).
Image Credit: Nestle. 2011. Nestle Healthy Kids Programme. Creative Commons Attribution-NonCommercial-NoDerivs 2.0 Generic. http://flickr.com (accessed October 26, 2013).

Tynan Wenarchuk is a fourth year Kinesiology student at the University of Calgary majoring in Exercise and Health Physiology, and is the co-founding student of the Pediatric cancer survivors Engaging inExercise for Recovery (PEER) Program. Follow The Triple Helix Online on Twitter and join us on Facebook.