Abstract

背景

SINOPSIS

INTRODUCTION

Women with a new diagnosis of breast cancer frequently experience stress, emotional distress, anxiety, and fatigue before, during, and after treatment. Quality of life (QoL) in the first year after breast cancer diagnosis is significantly affected1 and correlates positively with survival.² Alternative methods of exercise like yoga have shown promise in improving QoL in breast cancer survivors.³,⁴ Yoga is a complementary, mind-body exercise and relaxation strategy.⁵ The term yoga comes from a Sanskrit word that means yoke (harmony) or union, and yoga has been described as the union of mind, body, and spirit, consisting of skills, tools, or techniques such as pranayama (breath work); asana (physical postures, movement); and meditation (concentration, mental clarity, and awareness). According to Yoga Journal, 11 million people in the United States perform yoga occasionally, and approximately 6 million practice yoga on a regular basis. In small pilot studies, hatha yoga, the most commonly practiced form of yoga in the United States, has been found to decrease stress, anxiety, and fatigue.^6–9

Studies designed using yoga to assess physical and psychological benefits, QoL, emotional outcomes, and fatigue in breast cancer survivors have primarily shown positive and beneficial effects.⁸ Studies of individuals participating in stress reduction programs such as yoga or other mindfulness-based exercises also have shown a reduction in salivary cortisol levels,¹⁰,¹¹ which can be a surrogate marker for stress levels. Breast cancer malignancy has been associated with activation of the hypothalamic-pituitary-adrenal (HPA) axis, and the biopsychological aspects of a new cancer diagnosis can subsequently result in cortisol dysregulation.¹¹ Salivary cortisol and cortisone were therefore also examined in this study.

Even though the effects of yoga have been studied in breast cancer survivors at different stages of treatment, there is limited data on the effects of yoga in the immediate postdiagnosis period. The pilot study sought to examine the feasibility of a yoga practice (YP) in the period immediately following a breast cancer diagnosis. We hypothesized that compared with the control group (CG) participants, participants in a yoga group (YG) would experience improvement in QoL, mood, stress, and fatigue, and we predicted a greater decrease in cortisol levels from pre- to posttreatment in the YG.

METHODS AND DESIGN

Thirty women with a new diagnosis of biopsy-proven breast cancer were enrolled between November 1, 2010, and August 30, 2011. Participants were recruited from the Breast Cancer Clinic at Mayo Clinic in Rochester, Minnesota, where they received preoperative education and counseling regarding potential breast cancer surgical options.

RESULTS

For recruitment, 43 patients were approached over the course of 9 months (recruitment rate, 70%). Feasibility of the intervention was good, and adherence to protocol high, with 15 participants (100%) in the YG attending the first individual session and 13 (87%) attending all three individual yoga sessions (Figure 1). Six patients (40%) attended five or more of the recommended eight group sessions (median 3 classes), and 11 (73%) reported performing the home-based, DVD-guided exercises at least once weekly. One participant (7%) in each group dropped out of the study (Figure 2).

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Figure 1

Yoga adherence.

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Figure 2

Flow of patients through the study.

The groups were similar in baseline characteristics (Table 1) with the YG having a higher rate of lumpectomy vs mastectomy. Radiation was more common in the YG, but this is to be expected given the higher lumpectomy rate.

Table 1

Baseline Characteristics and the Subsequent Treatment Modalities

	Control (n = 15)	Yoga (n = 15)
Age (y), mean (range)	55 (40-73)	58 (48-75)
Type of surgery, n (%)
Mastectomy	8 (53)	5 (33)
Lumpectomy	7 (47)	10 (67)
Adjuvant therapy, n (%)
None	5 (33)	1 (7)
Hormonal therapy only (Arimidex, Tamoxifen)	2 (13)	3 (20)
Radiation (± hormonal therapy)	4 (27)	7 (47)
Chemotherapy (± radiation or hormonal therapy)	4 (27)	4 (27)

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Quality of Life and Mood

Certain aspects of QoL and mood improved significantly within both groups. The emotional well-being (FACT-B) QoL score increased by a median 2.5 points in the YG (P = .02) and by 4.5 points in the CG (P = .007). Tension-anxiety, depression-dejection, and confusion-bewilderment mood scores (POMS) also significantly improved within both groups (median improvements ranged from 0.4 to 0.9). There was no significant difference between the YG and CG with respect to preand postintervention, with the exception of social/family well-being (P = .045) where improvement was slightly higher for the CG (median improvement, 2.5) than the YG (median improvement, 0; Table 2).

Table 2

Changes in the Quality of Life (QoL), Mood, Fatigue, Stress, and Cortisol Levels

	Yoga		Control		Yoga vs Control
	Post-Pre median (IQR)	Pa	Post-Pre median (IQR)	Pa	Pb
QoL (FACT-B)c
Physical well-being	−1.5 (−7.0, 0.0)	.03d	−0.8 (−9.0, 1.0)	.14	.69
Social/family well-being	0.0 (−2.0, 1.0)	.40	2.5 (0.0, 3.7)	.03d	.045d
Emotional well-being	2.5 (0.0, 5.0)	.02d	4.5 (1.0, 6.0)	.007d	.45
Functional well-being	1.0 (−3.0, 3.0)	.98	−0.5 (−1.0, 4.0)	.79	.85
FACT-G: Total	2.4 (−11.0, 7.0)	.92	3.5 (−2.0, 11.0)	.35	.43
FACT-B: Additional concerns	2.0 (0.0, 4.0)	.13	1.5 (−1.0, 5.0)	.08	.91
FACT-B: Total	3.9 (−11.0, 10.0)	.70	6.5 (−2.5, 12.0)	.12	.49
FACT-B: Trial outcome index	2.5 (−8.0, 6.0)	.80	−0.3 (−6.0, 4.0)	.74	.85
Mood (POMS)
Tension-anxiety	−0.9 (−1.2, −0.3)	<.001d	−0.6 (−1.0, −0.3)	.007d	.43
Vigor-activity	−0.3 (−1.0, 0.3)	.30	−0.1 (−1.0, 0.3)	.53	.65
Fatigue-inertia	−0.4 (−1.0, 0.4)	.39	−0.3 (−0.6, 0.0)	.38	.87
Depression-dejection	−0.4 (−0.6, 0.0)	.008d	−0.4 (−1.3, 0.0)	.03d	.98
Confusion-bewilderment	−0.8 (−1.6, −0.2)	<.001d	−0.8 (−1.2, −0.4)	.001d	.84
Anger-hostility	−0.2 (−0.6, 0.0)	.04d	0.1 (−0.7, 0.4)	.58	.46
Overall	−0.5 (−0.7, −0.1)	.002d	−0.4 (−0.8, 0.0)	.048d	.73
Fatigue (BFI)e	−0.1 (−0.8, 0.8)	.99	−0.3 (−2.7, 0.7)	.45	.49
Perceived Stress (PSS)e	−1.5 (−6.0, 0.0)	.03d	−1.5 (−7.0, 0.0)	.06	.94
Cortisol, ng/dL	−10.0 (−39.0, 2.1)	.32	−12.1 (−40.9, −4.2)	.02d	.55
Cortisone, ng/dL	−86.0 (−191.0, 63.0)	.32	−74.5 (−323.0, 19.0)	.09	.92

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^aP value comparing paired differences (post vs pre) with the Wilcoxon signed rank test.

^bP value comparing the post/pre differences between yoga vs control with the Wilcoxon rank sum test.

^cPositive difference = improvement.

^dP ≤ .05.

^eNegative difference = improvement.

Abbreviations: POMS, Profile of Mood States; Post, postintervention; Pre, preintervention.

DISCUSSION

This study sought to examine the feasibility of YP started at the time of breast cancer diagnosis and potential impact on QoL, mood, stress, fatigue, and cortisol levels. Recruitment for the study was fairly quick with patients' interest in yoga relatively high (70%). Adherence with the study protocol was good, with a majority of participants attending all three individual yoga sessions (87%) as well as performing the home-based exercises (73%). Attendance at studio group-sessions was somewhat lower (40%), supporting previous research indicating that studio attendance may be much lower than home practice frequency.¹⁶ Overall recruitment and attendance records do, however, suggest feasibility of YP immediately after diagnosis.

Contrary to prediction, overall QoL did not significantly change from pre- to postintervention for either of the groups in this study. The emotional well-being sub-scale significantly improved within both groups but with no significant difference between groups. Other significant findings suggest that the CG improved in social well-being, and the YG worsened in physical well-being.

These results contradict findings from other studies of yoga vs waitlist groups in breast cancer survivors where improved QoL16 or a protective effect for social well-being8,¹⁷,¹⁸ have been found in the YG. Patients not receiving chemotherapy have also demonstrated significant improvement in emotional, social, spiritual, and overall QoL, and adherence has been positively associated with physical well-being and negatively associated with fatigue and distressed mood.⁸ One small, randomized controlled study with a yoga intervention in 18 patients with more advanced breast cancer (stages II-IV) nevertheless found no improvement in QoL.¹⁹

Our study differs significantly from the above studies in that recruitment was started at the time of breast cancer diagnosis. This is a particularly challenging time for patients, with significant emotional turmoil and impaired QoL.²⁰ The improved emotional well-being seen across groups could potentially be a reflection of returning to baseline following the initial turmoil of diagnosis. The decrease in the physical well-being observed in our study might be secondary to treatments received including breast irradiation, but it remains unclear why this negative change was seen only in the YG, especially given the minimal side effects reported by the participants and high satisfaction reported with the intervention.

Significant improvements were seen in overall mood and multiple mood domains (tension-anxiety, depression-dejection, confusion-bewilderment, and anger hostility) across both groups with no significant between-group difference. Again, these findings are in contrast with other studies assessing similar outcomes and showing significant improvements in mood following yoga intervention.¹⁸,²¹ A possible explanation for these contradicting findings could be the fact that our participants were recruited immediately following diagnosis when patients are still attempting to adjust to the emotional turmoil of a new cancer diagnosis. It is possible that the passage of time and reassurance that the cancer is being treated could have led to significant improvement in QoL and mood well beyond a potential positive effect from a yoga intervention in this study.

Cancer diagnoses and subsequent treatments generally involve significant stressor exposure and persistent levels of fatigue. As with QoL and mood, our findings showed significant improvements in perceived stress levels for both groups, and again, these findings are contrary to existing research showing yoga interventions to be associated with improved stress levels compared with control groups. One of the most common symptoms reported by breast cancer survivors is fatigue, and it has been estimated that as many as 33% of these patients experience persistent fatigue.⁶ Even though a few well-conducted randomized studies have shown yoga to be associated with decreased levels of fatigue following breast cancer treatments,⁷ fatigue levels did not change for either group in the current study.

Cortisol level decreased from the initial measure to postintervention in both groups, although more significantly in the CG. Previous studies show contradicting findings in this area following yoga intervention, either not finding any change in cortisol slope,¹⁹ or finding significant improvement in cortisol levels for the postintervention YG.¹⁸

Studies examining the impact of yoga interventions in breast cancer survivors have examined a number of psychosocial factors, mainly through random recruitment. Studies targeting patients with specific symptoms, or at a very early stage in the course of illness, are rare, however. This could potentially explain how conflicting results may occur.

Results from this pilot study did not indicate clear benefits for patients undergoing YP immediately postdiagnosis. It is possible that during this period patients may be feeling overwhelmed, and the shock of the new breast cancer diagnosis may prevent them from truly benefiting from interventions. Improvements were found in emotional well-being, anxiety, depression, and levels of confusion in both groups, however, and breast cancer patients could potentially experience improvement in QoL, mood, and levels of perceived stress following treatment completion regardless of the interventions implemented. Study results show that the feasibility of YP immediately after breast cancer diagnosis was good, and adherence to individual sessions was very high. Participants pointed to relaxation as the most effective aspect of the intervention as well, indicating that YP immediately postdiagnosis may be most beneficial if individualized and if it included relaxation (eg, breathing) components. Given the novelty of this study, as well as the sample size and pilot study factors, further research is clearly warranted.

When developing future studies, in addition to increasing the sample size, we would consider offering more flexibility for participation in yoga programs immediately postdiagnosis, potentially through home-based interventions such as DVD or interactive ehealth-type practice rather than mandatory classes. Targeting patients with higher levels of symptoms such as stress, distress, or fatigue prior to the intervention may also increase the likelihood of detecting more substantial intervention benefit.

Acknowledgment

Notes

Disclosure The authors declare no competing interests.

Contributor Information

Sandhya Pruthi, Sandhya Pruthi, MD, and Daniela L. Stan, MD, are consultants, Division of General Internal Medicine, United States.

Daniela L Stan, Sandhya Pruthi, MD, and Daniela L. Stan, MD, are consultants, Division of General Internal Medicine, United States.

Sarah M Jenkins, Sarah M. Jenkins is a statistician and Marianne Huebner, PhD, is a research consultant, Division of Biomedical Statistics and Informatics, United States.

Marianne Huebner, Sarah M. Jenkins is a statistician and Marianne Huebner, PhD, is a research consultant, Division of Biomedical Statistics and Informatics, United States.

Beth A Borg, Beth A. Borg, RN, MHA, is an administrator and Barbara S. Thomley is a complementary and integrative medicine coordinator, Division of General Internal Medicine, United States.

Barbara S Thomley, Beth A. Borg, RN, MHA, is an administrator and Barbara S. Thomley is a complementary and integrative medicine coordinator, Division of General Internal Medicine, United States.

Susanne M Cutshall, Susanne M. Cutshall, MS, RN, CNS, is an integrative health specialist, Department of Surgery, United States.

Ravinder Singh, Ravinder Singh, PhD, is a consultant, Department of Laboratory Medicine and Pathology, United States.

Sadhna Kohli, Sadhna Kohli, PhD, is an associate consultant, Oncology Research, United States.

Judy C Boughey, Judy C. Boughey, MD, is a consultant, Division of General Surgery, and Valerie Lemaine, MD, MPH, is a senior associate consultant, Division of Plastic Surgery, Department of Surgery, all at Mayo Clinic, Rochester, Minnesota, United States.

Valerie Lemaine, Judy C. Boughey, MD, is a consultant, Division of General Surgery, and Valerie Lemaine, MD, MPH, is a senior associate consultant, Division of Plastic Surgery, Department of Surgery, all at Mayo Clinic, Rochester, Minnesota, United States.

Lise Solberg Nes, Lise Solberg Nes, PhD, is a psychologist in the Department of Medicine, University of Minnesota, Minneapolis, United States.

REFERENCES