The long-term effects of posttreatment exercise on pain in young women with breast cancer
Background Persistent pain after treatment has been identified in breast cancer populations, with prevalence rates ranging from 25%-60%. Age, surgical procedure, axillary node dissection, and radiation therapy have shown correlation with chronic pain development.
Objective To conduct a pilot randomized controlled trial targeting young breast cancer patients to determine the effectiveness of a 12-week exercise program on long-term levels of upper-limb pain, as measured by the Brief Pain Inventory-Short Form (BPI-SF), and pain measured by physical examination of specific shoulder movements.
Methods Young adults (18-45 years of age) recently diagnosed with breast cancer consenting to participate in this study were randomly allocated to intervention or control groups. The exercise intervention group participated in a 12-week exercise program starting 3-4 weeks after the cessation of radiation therapy, and the control group received standard care consisting of encouragement for an active lifestyle and pamphlets on the benefits of exercise. The location and severity of pain and its interference with daily life were recorded at the following 6 time points: postsurgery and preradiation (T1, baseline), postradiation and preintervention (T2), and 4 points during an 18-month period postradiation (T3-T6 at 3, 6, 12, and 18 months). In addition, clinical physical assessment of range of motion and pain on active shoulder movements were recorded at each time point.
Results 59 young breast cancer patients participated in the study (exercise group: n = 29; control group: n = 30). Over the course of the trial, there were no significant differences between study groups in the BPI-SF measures of pain interference and severity scores. Improvements in pain on shoulder movements were noted in the intervention group at 3 and 6 months postintervention (T3 and T4) but were not sustained over time (by T6, 18 months postradiation). Shoulder girdle-chest wall pain improved at 12 and 18 months postradiation in both groups but persisted despite exercise intervention. Recordings of shoulder pain on physical examination of range showed a distinct pattern of temporal improvement (T3-T5), followed by low levels of pain recurrence at 18 months postradiation (T6) in both groups.
Limitations Stringent exclusion criteria, including the absence of any shoulder pathology or pre-existent medical comorbidities impacting upper limb function, long-term follow-up, and the relatively small population of breast cancer patients in this age demographic, limited and prolonged recruitment for this study. In addition, the general activity levels of the young breast cancer survivors who agreed to participate in this exercise intervention study may have had an impact on the significance of results.
Conclusion Transient improvements in shoulder pain can be attributed to a 12-week exercise program, but they did not translate to long-term benefits. Moreover, the BPI-SF did not capture shoulder pain and limitations related to upper-limb disability in this study, in contrast with the findings on physical examination.
Funding This study was funded by Hope & Cope, a grant from the CURE Foundation, and grants from the Jewish General Hospital's Weekend to End Breast Cancer.
Accepted for publication May 15, 2018
Correspondence Mary-Ann Dalzell, MScxPT; madalzell5@gmail.com
Disclosures Thierry Muanza holds an intellectual property patent (United States Provisional Patent Application No. 62/359,918; Title: Adipose Mesenchymal Stromal Cells for Treating Radiation-Induced Oral Mucositis). Mary-Ann Dalzell, Richard Dalfen, Beatrice Fournier, Marize Ibrahim, Petr Kavan, Michael Palumbo, Warren Sateren, and Nadia Smirnow report no disclosures or conflicts of interest.
Citation JCSO 2018;16(3):e145-e151
©2018 Frontline Medical Communications
doi https://doi.org/10.12788/jcso.0395
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Breast cancer is one of the most prevalent cancers in women worldwide, with more than 1 million new cases diagnosed annually.1 Prognosis for the disease has improved significantly, but 25% to 60% of women living with breast cancer experience some level of pain ranging from mild to severe, the nature of which can evolve from acute to chronic.2 Pre-, intra-, and post-treatment risk factors have been found to correlate with the development of acute and chronic pain and include young age, type of breast surgery (lumpectomy or total mastectomy), axillary node dissection, radiation therapy, and hormonal therapy.3-5 Chemotherapy, particularly anthracycline- and taxane-based regimens, has also been shown to induce pain, arthralgia, myalgia, and peripheral neuropathy during treatment.6 In particular, postradiation pain may result from subcutaneous fibrosis with fixation to underlying musculature and the development of fibrous flaps in the internal axilla.7 These tissue changes are commonly subclinical, occurring 4 to 12 months postradiation,8 and can progress undetected until pain and upper-limb disability develop.
The presence of persistent pain has a considerable impact on the quality of life in survivors of breast cancer: psychological distress is prevalent (anxiety, depression, worry, fear), the performance of daily activities is diminished (eg, bathing, dressing, preparing meals, shopping), and economic independence is compromised by the inability to work or reduced employment and income. These factors directly and indirectly contribute to an increase in the use of health care services.9,10
The management of pain is often characterized by pharmacologic-related treatment, such as the use of opioids and nonsteroidal anti-inflammatory medications, and nonpharmacologic-related treatment, such as exercise. Empirical evidence has shown that rehabilitative exercise programs, which commonly include a combination of resistance training and aerobic exercises, can effectively reduce pain in breast cancer survivors.10-12 Women living with breast cancer who are directed to rehabilitative exercise programs experience an improvement not only in pain levels but also in their ability to engage in activities of daily living, in their psychological health, and in their overall quality of life.13-15 However, despite evidence to support exercise programs to reduce pain related to breast cancer treatment, residual pain and upper-limb discomfort are common complaints in breast cancer survivors, and there is little focus on the duration of effectiveness of such programs for reducing pain after treatment for breast cancer. The objective of this study was to determine if an exercise program initiated postradiation would improve long-term pain levels in a carefully selected population of young women who were living with breast cancer and had no history of shoulder pathology or significant treatment complications.
Methods
Design
We used a pilot randomized control trial to compare the long-term effectiveness of a 12-week postradiation exercise program versus standard care on residual pain levels in young women (aged 18-45 years) living with breast cancer. The program was initiated 3 to 4 weeks postradiation to allow for acute inflammatory reactions to subside. Pain severity and interference were assessed using the Brief Pain Inventory-Short Form (BPI-SF), a tool for assessing cancer pain.16,17 Pain levels for isolated shoulder movements were also recorded on examination by a physical therapist. All measures were collected at 6 time points (T1-T6): postsurgery and preradiation (T1, baseline), postradiation and preintervention (T2), and 4 points during an 18-month period postradiation (T3-T6 at 3, 6, 12, and 18 months postradiation).
Sample
Young women living with breast cancer who met our eligibility criteria were identified from 2 clinics at the Jewish General Hospital – the Segal Cancer Center and the Department of Radiation Oncology in Montréal, Québec, Canada. Inclusion criteria included women with a diagnosis of stage I to stage III breast cancer, who were 18 to 45 years old, were scheduled for postoperative adjuvant radiation therapy, had an Eastern Cooperative Oncology Group Performance Status of 0 or 1 (normal ambulatory function, minimal symptoms), and who consented to participate in the study. Exclusion criteria included women with a metastatic (stage IV) diagnosis; significant musculoskeletal, cardiac, pulmonary, or metabolic comorbidities that would not allow for participation in physical activity; a previous breast cancer diagnosis with treatment to the ipsilateral or contralateral sides; postsurgical lymphedema; postsurgical capsulitis, tendonitis, or other shoulder inflammatory complications; and any contraindication to exercise. The recruitment goal was outlined as 50 patients per group; however, a protracted accrual time because of the stringent study criteria yielded a sample of 29 and 30 patients for the intervention and control groups, respectively, which was sufficient for significant testing of differences between the 2 study groups.18
