The long-term effects of posttreatment exercise on pain in young women with breast cancer B reast 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 taxanebased regimens, has also been shown to induce pain, arthralgia, myalgia, and peripheral neuropathy during treatment. 6 In particular, postradiation pain may result 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...