Impact of community-based exercise program participation on aerobic capacity in women with and without breast cancer.

BACKGROUND: Evidence for exercise as an efficacious strategy to improve aerobic capacity of breast cancer survivors (BCS) has come largely from intervention studies conducted in laboratory settings. There is an increasing need to translate to community-type settings, but the efficacy of those interventions using gold standard evaluation is not well-established. AIM: To investigate whether similar improvement in aerobic capacity (maximal oxygen consumption [VO2]) measured with gold standard testing can be achieved through a community-based setting in BCS. METHODS: A peak cardiopulmonary exercise test (VO2peak), 6-min walk test (6MWT), and timed up and go test (TUG) were assessed pre- and post-16 wk of progressive intensity aerobic and strength training exercise at a community center. RESULTS: The sample consisted of 31 early BCS (< 1 year since treatment completion) and 15 controls (CTLs). Both groups significantly improved VO2peak (+1.2 mL/kg/min; P = 0.030), 6MWT (+35 meters; P < 0.001), and TUG (-0.44 s; P < 0.01) following training. Both groups improved peak cycling power during the cardiopulmonary exercise test with BCS improving by +10 watts more than the CTLs (P = 0.020). Average exercise attendance was 71% (34 of 48 possible days), but compliant days averaged only 60% of total days for aerobic, and < 40% for strength in both groups. CONCLUSION: Community-based exercise programs can be an effective strategy to improve aerobic capacity and physical function for early-stage BCS but potentially not to the same extent observed in laboratory-based randomized controlled trials. Further research is needed to explore barriers and facilitators of exercise engagement in community-based centers to maximize training benefits for adults with cancer.

Exercise training partially rescues impaired mucosal associated invariant t-cell mobilization in breast cancer survivors compared to healthy older women.

Exercise may attenuate immunosenescence with aging that appears to be accelerated following breast cancer treatment, although limited data on specific cell types exists and acute and chronic exercise have been investigated independently in older adults. PURPOSE: To determine the mucosal associated invariant T (MAIT) cell response to acute exercise before (PRE) and after (POST) 16 weeks of exercise training in breast cancer survivors (BCS) and healthy older women (CON). METHODS: Age-matched BCS and CON performed 45 min of intermittent cycling at 60% peak power output wattage. Blood samples were obtained at rest, immediately (0 h) and 1 h after exercise to determine MAIT cell counts, frequency, and intracellular cytokine expression. RESULTS: At PRE, MAIT cell counts were greater in CON (137%) than BCS at 0 h (46%, p < 0.001), with increased MAIT cell frequency in CON but not BCS. TNFα+ and IFNγ+ MAIT cell counts increased at 0 h by ~120% in CON (p < 0.001), while BCS counts and frequencies were unchanged. Similar deficits were observed in CD3+ and CD3+ CD8+ cells. At POST, exercise-induced mobilization and egress of MAIT cell counts and frequency showed trends towards improvement in BCS that approached levels in CON. Independent of group, TNFα frequency trended to improve (p = 0.053). CONCLUSIONS: MAIT mobilization in older BCS following acute exercise was attenuated; however, exercise training may partially rescue these initial deficits, including greater sensitivity to mitogenic stimulation. Using acute exercise before and after interventions provides a unique approach to identify age- and cancer-related immuno-dysfunction that is less apparent at rest.

The Effects of 16 Weeks of Exercise Training on Neutrophil Functions in Breast Cancer Survivors.

Following therapy, breast cancer survivors (BCS) have an increased risk of infections because of age and cancer dysregulation of inflammation and neutrophil functions. Neutrophil functions may be improved by exercise training, although limited data exist on exercise and neutrophil functions in BCS.Sixteen BCS [mean age: 56 (SD 11) years old] completed 16 weeks of community-based exercise training and a 45-minute acute bout of cycling before (Base) and after (Final) the exercise training program. Exercise training consisted of 3 x 40 - 60 minute mixed mode aerobic exercises, comprising 10 - 30 minutes aerobic and 30 minutes resistance training. At Base and Final, we took BCS blood samples before (PRE), immediately after (POST), and 1 hour after (1Hr) acute exercise to determine neutrophil counts, phenotype, bacterial killing, IL-6, and IL-8 levels. Eleven healthy, age- and physical activity levels-matched women (Control) completed the acute bout of exercise once as a healthy response reference. Resting Responses. BCS and Controls had similar Base PRE absolute neutrophil counts [mean (SD): 3.3 (1.9) v 3.1 (1.2) x 109/L, p=0.801], but BCS had lower bacterial phagocytosis [3991 (1233) v 4881 (417) MFI, p=0.035] and higher oxidative killing [6254 (1434) v 4709 (1220) MFI, p=0.005], lower CD16 [4159 (1785) v 7018 (1240) MFI, p<0.001], lower CXCR2 [4878 (1796) v 6330 (1299) MFI, p=0.032] and higher TLR2 [98 (32) v 72 (17) MFI, p=0.022] expression, while IL-6 [7.4 (5.4) v 4.0 (2.7) pg/mL, p=0.079] levels were marginally higher and IL-8 [6.0 (4.7) v 7.9 (5.0) pg/mL, p=0.316] levels similar. After 16 weeks of training, compared to Controls, BCS Final PRE phagocytosis [4510 (738) v 4881 (417) MFI, p=0.146] and TLR2 expression [114 (92) v 72 (17) MFI, p=0.148] were no longer different. Acute Exercise Responses. As compared to Controls, at Base, BCS phagocytic Pre-Post response was lower [mean difference, % (SD): 12% (26%), p=0.042], CD16 Pre-Post response was lower [12% (21%), p=0.016] while CD16 Pre-1Hr response was higher [13% (25%), p=0.022], TLR2 Pre-Post response was higher [15% (4%) p=0.002], while IL-8 Pre-Post response was higher [99% (48%), p=0.049]. As compared to Controls, following 16 weeks of training BCS phagocytic Pre-Post response [5% (5%), p=0.418], CD16 Pre-1Hr response [7% (7%), p=0.294], TLR2 Pre-Post response [6% (4%), p=0.092], and IL-8 Pre-Post response [1% (9%), p=0.087] were no longer different. Following cancer therapy, BCS may have impaired neutrophil functions in response to an acute bout of exercise that are partially restored by 16 weeks of exercise training. The improved phagocytosis of bacteria in BCS may represent an exercise-induced intrinsic improvement in neutrophil functions consistent with a reduced risk of infectious disease. Clinical Trial Registration: ClinicalTrials.gov, identifier NCT03760536.