Ef fi cacy of Mind-body Therapy on Stress Reduction in Cancer Care
7.9 Yoga
Eastern culture has long considered yoga to be an effective treatment option for managing stress. Recent studies indicate that yoga is quickly becoming one of the most widely accepted mind-body therapies in the US as well (Tindel et al. 2005 ) . With the increasing popularity of yoga, it is perhaps unsurprising that many cancer patients, as well as their family members, are beginning to view yoga as a viable adjunct treatment option.
The results of several studies indicate that yoga is indeed effective at helping individuals with cancer manage stress. For example, Culos-Reed et al. ( 2004 ) ran- domly assigned cancer survivors (mean age = 51.8 years), the majority of whom were women (93%), to either a 7-week Hatha yoga intervention group ( n = 20) or a waitlist control group ( n = 18). Cancer diagnoses varied, with the majority of patients being diagnosed with breast cancer. Although no differences were seen between groups at baseline, post-intervention results revealed that total stress scores as measured by the Symptoms of Stress Inventory (SOSI) (Leckie and Thompson 1979 ) were signi fi cantly lower for the intervention group than for the control group ( p < 0.05). SOSI subscale scores for habitual patterns, (e.g. smoking, nail baiting, drinking), cardiopulmonary arousal, and emotional irritability were also signi fi cantly lower for participants in the yoga intervention group ( p < 0.05 for all subscales).
Additionally, post-intervention scores for anger, tension, depression, confusion, and total mood disturbance, as measured by the POMS, improved signi fi cantly for yoga intervention participants ( p < 0.05 for all subscales), suggesting that yoga is effective at improving the total symptom pro fi le of cancer patients.
In an additional study, Banerjee et al. ( 2007 ) randomly assigned stage II and III breast cancer survivors who were undergoing radiotherapy to either a yoga interven- tion group ( n = 35, mean age = 47 years) or a supportive counseling control group ( n = 23, mean age = 43 years). Participants in the yoga intervention received instruc- tions on meditation, breathing, and stretching that had been modi fi ed to match their limitations. Each yoga session lasted for 90 min, however, the total number of yoga
sessions held was not reported. Results indicated that participants in the intervention group experienced signi fi cant improvements in psychological stress ( p < 0.001) as measured by the PSS, depression ( p < 0.001) and anxiety levels ( p < 0.001) as mea- sured by the HADS. Meanwhile, depression, anxiety, and stress actually became worse for participants in the control group. Blood sampling revealed that DNA damage levels were 14.5% lower for participants receiving yoga therapy when com- pared to control group participants, thus indicating lower genotoxic stress.
In a similar study, Raghavendra et al. ( 2007 ) randomly assigned chemotherapy patients with stage II or III breast cancer, to either a yoga intervention group ( n = 28) or a supportive therapy and coping preparation control group ( n = 34). Participants in the treatment condition received one, 30-min session of bedside yoga instruction prior to their fi rst session of chemotherapy. They also received audio and videocas- settes that guided them through 60-min, in-home, yoga sessions that they were asked to practice daily. Additionally, every ten days a yoga trainer would make a house visit to supervise participants while they completed their yoga session.
Participants in the control condition received a 60-min session of supportive-expres- sive counseling and education prior to their fi rst chemotherapy treatment. Following this initial session, control participants would receive 30-min counseling sessions every ten days, during a hospital visit. Main outcome measures included the fre- quency and intensity of nausea and vomiting as measured by the Morrow Assessment of Nausea and Emesis (MANE) (Morrow and Carnrike 1988 ) . Results suggested that the yoga intervention was signi fi cantly more effective than supportive counseling at reducing nausea frequency and intensity following chemotherapy ( p < 0.01). Yoga also signi fi cantly reduced the rates of anticipatory nausea ( p < 0.01) and anticipatory vomiting ( p < 0.05). Furthermore, participant scores on the Beck Depression Inventory (BDI) (Beck et al. 1961 ) , the State Trait Anxiety Inventory, and a symp- tom distress checklist were signi fi cantly lower for participants receiving the yoga intervention then they were for controls for all measures ( p < 0.01) (Raghavendra et al. 2007 ) . This suggests that yoga may be a successful intervention for controlling symptoms thought to arise from high stress levels.
In a more recent study, Danhauer et al. ( 2008 ) asked women who were diagnosed with either ovarian cancer ( n = 37) or breast cancer ( n = 14) to complete ten weekly sessions of restorative yoga. The mean age of participants was 58.9 years, and 61% of the participants were undergoing treatment during the study. Each of the ten yoga sessions was led by a certi fi ed yoga instructor. Participants completed an average of 5.9 sessions.
Outcome measures were recorded at baseline, post-intervention, and two months follow-up. Results revealed that decreases in state anxiety, as measured by the STAI, were not signi fi cant from baseline to post-intervention ( p = 0.10). However, when base- line scores were compared to scores at two months follow-up, the decrease in state anxiety reached signi fi cance ( p £ 0.01), suggesting that the full-bene fi ts of yoga may not manifest until weeks after participation. However, a control group was not included in the experimental design of the study, eliminating the possibility for comparison.
In an additional study conducted by Vadiraja et al. ( 2009 ) , women diagnosed with stage II or III breast cancer and undergoing radiotherapy were randomized to either a yoga intervention group ( n = 42) or a brief supportive therapy control group ( n = 33).
Participants in the yoga intervention were required to attend a minimum of three 60-min yoga sessions per week for a period of six weeks while undergoing radio- therapy. Each session was taught by a trained yoga instructor at the hospital.
Intervention group participants were also asked to complete a self-guided yoga ses- sion at home on days when they did not go to the hospital. Participants in the control condition met with a trained social worker for at least 15-min every ten days. They were accompanied by a caretaker, and both were provided instruction on coping and social support. Outcomes included anxiety and depression as measured by the Hospital Anxiety and Depression Scale (HADS), perceived stress as measured by the Perceived Stress Scale (PSS), and biological stress as measured by cortisol sam- pling. Results revealed that participants in the yoga condition showed a signi fi cant decrease in early morning cortisol levels ( p < 0.001) and also in pooled mean corti- sol levels ( p < 0.01). Additionally, post-intervention cortisol levels were signi fi cantly lower for the intervention group when compared to the control group ( p = 0.03).
However, when baseline distress levels were utilized as a control variable, only participants categorized as being under low-distress showed signi fi cant drops in cortisol ( p = 0.03). Anxiety and depression scores were signi fi cantly improved at post-intervention for both groups when compared to baseline. However, depression scores for participants in the yoga intervention group were signi fi cantly lower than those of the control group ( p = 0.002), indicating that yoga provided additional bene fi ts not received by patients receiving standard care. Finally, perceived stress scores dropped signi fi cantly for participants in the yoga intervention group ( p < 0.001), but not for participants in the control group ( p = 0.17).
In a study examining the bene fi ts of yoga in a pediatric population of cancer patients, Thygeson et al. ( 2010 ) accrued 11 children and 5 adolescents at an inpatient hematology/oncology unit, as well as 33 parents of inpatient children diagnosed with either cancer or a blood disorder, to participate in one 45-min yoga session. The State Trait Anxiety Inventory for Children (STAIC) (Spielberger et al. 1983 ) and the STAI were used to measure distress both immediately before and soon after the yoga ses- sion. Results revealed that pre- and post-intervention scores did not signi fi cantly differ for the child cohort ( p = 0.21). However, baseline scores for children were already within the normal range. Conversely, anxiety scores were signi fi cantly improved in the adolescent cohort ( p = 0.04) and in the parent cohort ( p < 0.001).
Furthermore, 7 of the 33 parents involved in the study mentioned yoga’s ability to reduce stress as the main bene fi t they received from participating in the study.
These studies lend support to the argument that yoga is effective at helping both cancer patients and their family members manage stress. However, there are some holes in the research literature that should be examined. For example, many of the studies listed here lacked a control group or designated patients receiving standard care as controls. Future studies should attempt to compare the bene fi ts of yoga to other well-known treatment options. Additionally, several of these studies incorpo- rated small sample sizes. While this might provide support for the power of these interventions, large scale studies are needed to con fi rm these preliminary results.
Finally, future studies should incorporate follow-up testing to determine whether or not the bene fi ts of yoga persist over time.