Key points

Introduction

Alternative exercise traditions (AETs), such as Pilates, yoga, Tai Chi Chuan, Qigong, and various forms of dance, have been extensively promoted as methods of rehabilitation after cancer treatment. There are compelling reasons for this trend, as the putative and empirical benefits of these traditions are extensive. However, many remain underresearched, and the attributes assumed to mediate their beneficial effects inadequately specified. Clinicians face the challenge of directing motivated and inquisitive survivors in their efforts to negotiate a dynamic landscape of staggering diversity. This article outlines the needs of cancer survivors that may be addressed through AETs, the pros and cons of common AETs, the current supportive evidence, and how clinicians may help survivors to identify beneficial and safe AETs.

Introduction

Alternative exercise traditions (AETs), such as Pilates, yoga, Tai Chi Chuan, Qigong, and various forms of dance, have been extensively promoted as methods of rehabilitation after cancer treatment. There are compelling reasons for this trend, as the putative and empirical benefits of these traditions are extensive. However, many remain underresearched, and the attributes assumed to mediate their beneficial effects inadequately specified. Clinicians face the challenge of directing motivated and inquisitive survivors in their efforts to negotiate a dynamic landscape of staggering diversity. This article outlines the needs of cancer survivors that may be addressed through AETs, the pros and cons of common AETs, the current supportive evidence, and how clinicians may help survivors to identify beneficial and safe AETs.

How alternative exercise traditions can benefit cancer populations

Cancer survivors are physically and mentally vulnerable because of the emotional strain caused by a cancer diagnosis and the physical and mental side effects of oncologic therapies. Arduous treatments, such as surgery, chemotherapy, and radiation, often cause a variety of symptoms that can interfere with functioning and cause distress. Strong associations have been reported between functional degradation and specific symptoms, including fatigue, sleep disturbance, hormonally induced symptoms, and mood disorders. In fact, reports suggest that symptoms, in concert with accumulated mild impairments, are the primary drivers of cancer-associated disablement. Although some survivors recover quickly from treatment toxicities, others suffer treatment-related symptoms for years, and some never fully recover.

Physical toxicities that can be long-lasting and have substantial impact on quality of life (QOL) include (but are not limited to) (1) lymphedema, often caused by surgery and/or radiation; (2) neuropathy, caused by certain types of chemotherapy (eg, the taxanes and platinums that are used to treat many solid tumors, most medications used for multiple myeloma, and the plant alkaloids that are active against many hematologic cancers as well as solid tumors); (3) fatigue, common after nearly all types of cancer treatments; (4) hot flashes and arthralgias, which can be caused by antiestrogen therapies and by chemotherapy-related ovarian damage; and (5) biomechanical dysfunction.

Lymphedema is a chronic condition that affects more than 10% of breast cancer survivors, and also can be problematic after treatment for skin, gynecologic, urologic, colorectal, and head and neck cancers. Neuropathy frequently causes longstanding numbness and tingling in survivors. In one study, severe neuropathy was present in 19% of recipients of standard doses of oxaliplatin 18 months after treatment for colorectal cancer. In another study, severe neuropathy of the hands was reported by 27% of breast cancer survivors 6 to 24 months after paclitaxel-based chemotherapy, and severe neuropathy of the feet was reported by 25%. Fatigue also is a major issue after cancer treatment. A study of 1294 breast, prostate, and colorectal cancer survivors found that 29% reported significant fatigue (defined as having FACT-F [Functional Assessment of Cancer Therapy: Fatigue] scores ≤34), and fatigue was associated with more physical symptom burden, depression, comorbidity, and disability. Furthermore, hot flashes and arthralgias are both bothersome in more than a quarter of the hundreds of thousands of breast cancer survivors who are taking endocrine therapy in the United States currently.

Sleep disturbances, anxiety, and depression are common in cancer survivors as well. One recent study showed that 39% of breast cancer survivors and 25% of prostate cancer survivors suffered insomnia 18 months after a curative surgery. In another study, 21% of adult cancer survivors were anxious and 13% were depressed 1 year after a cancer diagnosis. Depression was more likely in those with insufficient physical activity, possibly reflecting bidirectional causality. In addition, depression and anxiety can both cause sleep disturbances, and many other symptoms (including pain due to local cancer therapies or chemotherapy-induced peripheral neuropathy) can contribute to both insomnia and depression.

In addition to engendering symptoms, cancer therapies also can focally disrupt the biomechanics of discrete body parts or whole segments leading to compromised strength, flexibility, and coordination. Surgery, in addition to removing or reorganizing anatomy, may result in lasting soft tissue contractures and may blunt or distort afferent sensory information. Patients’ recovery from cancer surgeries is frequently interrupted by the initiation of chemotherapy and/or radiation therapy within weeks after their operations. The sequence and timing of anticancer therapies has been dictated by their impact on progression-free and overall survival rather than their potential to disable. Radiation alone or after surgery may incite progressive fibrosis; that is, scarification of connective tissues, and may contribute to the denervation of functionally vital muscle groups.

Unfortunately, biomechanical dysfunction, lymphedema, neuropathy, fatigue, hot flashes, insomnia, anxiety, and depression are difficult to treat, and all may substantially impair daily functioning and QOL. Better management strategies are needed for long-term physical toxicities and emotional distress in cancer survivors. Improvements in dynamic posture, isometric strengthening, flexibility, kinesthetic awareness, and balance may help improve physical and mental health in cancer survivors. These health benefits may be particularly important for those suffering QOL impairments due to long-term treatment toxicities. In addition, for certain cancers (eg, breast cancer and colorectal cancer), some data suggest that physical activity reduces risk of recurrence.

Alternative exercise traditions may be an accessible means of addressing function-degrading symptoms and impairments

Current health care delivery models, with their disproportionate emphasis on disease management, either neglect function-degrading symptoms or promote referrals to multiple specialists. The former is clearly unsatisfactory, and the latter approach is costly, not patient-centric, disjointed, and often ineffective in realizing the lasting behavioral changes that are required for functional restoration and symptom control. The consequences of our current system’s shortcomings are not trivial, as they contribute to the well-characterized persistence of symptoms and impairments among cancer survivors that degrade their ability to resume gainful employment and reengage in defining life roles.

AETs have emerged as a potential means to address the deficits in current delivery models. These traditions have a number of characteristics that positively distinguish them from allopathic delivery mechanisms. Perhaps most notable are accessibility and affordability. Allopathic delivery has been shaped by fee-for-service reimbursement, which generally requires 1:1 visits with certified, licensed practitioners. Such visits are expensive, exceeding out-of-pocket affordability for many survivors. Both commercial and federal payers have endeavored to contain costs by capping the number of clinic visits, as is now common with physical therapy (PT). Most AETs, in contrast, are delivered via group classes or 1:1 lessons priced to attract even patients with middle to low socioeconomic status. Additionally, many health clubs, including local YMCAs and employer-sponsored work site gyms, now offer AET classes. Free-standing dance and yoga studios are common in even small to mid-sized towns.

An additional distinguishing feature of AETs is their potential to simultaneously address needs spanning multiple domains, including social, physical, and psycho-emotional. The social support and community that develops naturally in many group classes counters the feelings of isolation that are experienced by many cancer survivors. The mindfulness dimension of yoga, Tai Chi, and chi gong has been shown to relieve stress, dysphoria, and anxiety in some cancer populations. From a physical impairment perspective, AETs offer the salient benefits of promoting integrated whole body movement and concurrently enhancing strength, coordination, balance, posture, and flexibility. Last, many survivors grapple with the somewhat paradoxic drives to do everything possible to prevent recurrence or progression of their cancer and to concurrently demedicalize their lives. Many AETs normalize rather than pathologize the sequelae of cancer and its treatment by focusing on balance, wellness, and vitality.

From a more concrete and biomechanical viewpoint, AETs also offer unique benefits relative to conventional therapeutic exercise. The aforementioned benefit of concurrently addressing strength, coordination, posture, and flexibility that characterizes most AETs also promotes the subtler and arguably more essential attribute of kinesthetic awareness. Almost without exception, cancer survivors’ bodies have been altered by treatment, generally in ways that undermine their ability to maintain adaptive biomechanics for static and dynamic body positioning. The underlying mechanisms are complex and beyond the scope of this article. In brief, afferent input to the central nervous system (CNS) may become attenuated or distorted, thereby undermining proprioception and the more rostral CNS mechanisms that maintain posture and healthy biomechanics. As a consequence, survivors may lose the ability to recognize when muscle groups fatigue, and begin to use compensatory, potentially maladaptive, motor patterns to complete an activity.

AETs often incorporate several strategies that enhance kinesthetic awareness. First, many begin with simple, supported movements that become progressively more complex. This is true of ballet, which progresses from barre to floor work, and from isolated, rudimentary to full-body, integrated movements. The progression allows practitioners to work on sustaining postural alignment before having to negotiate balance and 3-dimensional movement. Second, the mindfulness or conscious awareness of body emphasized by many AETs helps practitioners to increase their sensibility of adaptive versus aberrant body positioning. With practice, as their sensibility grows, participants consciously and, eventually, subconsciously correct themselves. Third, many AETs have developed well-delineated strategies that allow new practitioners to become sensitized to when their body is properly versus improperly aligned. Iyengar yoga is an exemplar in this regard, as it makes extensive use of “props,” for example, ropes, blocks, and bolsters, to enable practitioners to experience optimal positioning even when they may lack the strength and flexibility to maintain it independently. Last, many AETs are performed with mirrors, and even videotaping, to provide visual feedback that supplements an instructor’s corrections and a practitioner’s inherent sense of proper body positioning. Dance studios invariably have mirrors on more than 1 full wall to promote visually guided self-correction. Once students learn what proper alignment and biomechanics look like, they can begin the process of internalizing what they feel like. The intent is that practitioners will eventually become independent of the visual “crutch” of the mirror so that they can consciously, based on sensation alone, self-correct their posture and movement pattern.

Current limitations to the clinical integration of alternative exercise traditions

Why are all cancer survivors not systematically directed to AETs? One obstacle is the extensive heterogeneity across and even within AETs. Yoga, for example, may involve the passive and supported maintenance of static reclining postures, as in restorative Iyengar yoga, or the profoundly strenuous and dynamic movements of Ashtanga yoga. The potential benefits and harms of these 2 extremes of the yogic spectrum differ radically. The variance of other AETs may not be as marked as yoga; however, physical intensity is but one source of heterogeneity.

An additional concern is that the one-size-fits-many nature of AET classes undermines an instructor’s capacity to individualize dose, type, frequency, and intensity, which are cornerstones of effective therapeutic exercise. Reports increasingly indicate that specific parameters critically determine whether and to what extent an AET will affect a particular outcome, for example, function, QOL. This evidence suggest that, to reliably benefit cancer survivors, AETs may require a degree of rigor comparable to the quantification that has become standard for medically directed aerobic training. Inconsistencies that have emerged in the relative capacity of different AETs to affect different outcomes argue strongly that their nonspecific prescription in the hope of general benefit or other similarly vague goals is inappropriate. As with any other therapeutic modality, discreet therapeutic targets should be defined and administration of the appropriate AET individualized to realize these goals.

Inconsistencies in AET practitioner expertise and certification, as well as the extent of practitioner familiarity with vulnerabilities unique to cancer populations, are also problematic. Some AETs are distinguished by highly structured, incremental training programs linked to rigorous certifications; however, these tend to be the exception. Iyengar yoga is an exemplar of such an approach. Instructors pursue a systemized training pathway divided into formal levels of expertise.

Evidence in cancer

Most of the concerns regarding the pragmatic delivery of AETs are likely remediable through relatively inexpensive training and standardization approaches. However, such remediation would not be a trivial undertaking, and the allocated resources should be commensurate with the probability that standardized, high-quality AETs will improve key outcomes among cancer survivors. At this juncture, an extensive literature of inconsistent quality that spans diverse cancer populations frustrates efforts to precisely determine the effect size of any specific AET in improving a specific outcome. Details of delivery make a difference, and too often these are limitedly described. Perhaps most frustrating is the dearth of effort to accurately and consistently distinguish how AETs systematically differ from the exercise and movement approaches that are reimbursed by payers and well integrated into allopathic care pathways (eg, PT). The paragraphs that follow briefly describe and outline the current level of evidence of common AETs.