Abstract P6-08-37: Cardiorespiratory fitness (VO2max) before, during and after adjuvant treatment in breast cancer patients
Authors: Frydenberg Hanne , Bettum Tora J , Lofterød Trygve , Edvardsen Elisabeth , Flote Vidar G , Finstad Sissi E , Bertheussen Gro F , Schlichting Ellen , McTiernan Anne , Thune Inger 
Published: May 2015

Background: Breast cancer treatment may result in reduced exercise capacity that may in turn lead to reduced maximum oxygen consumption (VO2max). However, whether physical exercise can counteract any observed decline in VO2max in breast cancer patients undergoing adjuvant breast cancer treatment, is less known.

Material & methods: The women participating in the Norwegian Energy Balance and Breast Cancer Aspect (EBBA)-II pilot study, were aged 35-75 years and diagnosed with stage I-II breast cancer. Performing a maximum exercise test on a treadmill (modified Balke protocol), VO2max was assessed at four times; preoperative, 6, 12 and 24 months postoperative. The patients were randomized postoperative to a control group (n=31) or an intervention group (n=29) stratified by menopausal status. The 12 months exercise intervention program consisted of group-based exercise, 60 minutes twice a week and a minimum of 60 minutes of individual exercise. Regression models were used to study the associations between treatment regime and VO2max.

Results: Breast cancer patients (n=60) with a mean age at diagnosis of 55.3 years (38.0-69.0 years), had a mean body mass index of 25.1 kg/m2, and a mean preoperative VO2max of 32.4 ml/min/kg. Comparing the intervention group to the control group, the intervention group maintained VO2max throughout the treatment period, and improved their VO2max with 7.8 % from 12 to 24 months postoperative (p=0.117), while the control group had a 15% reduction in VO2max 6 months after surgery (p&lt;0.001), which improved 14 % at 12 months and additionally 6 % at 24 months postoperative (p=0.025). Among those patients receiving chemotherapy (60%), and being in the control group, a decline in VO2max of 22.9 % (p&lt;0.001) at 6 months postoperative was observed. In comparison, patients in the intervention group who received chemotherapy had a 4.5 % reduction in VO2max at 6 months postoperative (p = 0.159). Thereafter, in the control group, VO2max improved with 21.6 % at 12 months postoperative (p=0.006), while in the intervention group VO2max improved with 13.4 % 24 months postoperative (p=0.038). Patients in the intervention group who did not receive any chemotherapy increased their VO2max by 6% 6 months postoperative (p=0.174), while patients in the control group who did not receive any chemotherapy had a reduction in VO2max of 2.1 % at 6 month postoperative (p=0.630).

Conclusion: Our findings suggest that systematic physical training may counteract a decline in VO2max in breast cancer patients receiving adjuvant treatment, including chemotherapy, and is of clinical interest, but needs to be replicated in larger studies.

Citation Format: Hanne Frydenberg, Tora J Bettum, Trygve Lofterød, Elisabeth Edvardsen, Vidar G Flote, Sissi E Finstad, Gro F Bertheussen, Ellen Schlichting, Anne McTiernan, Inger Thune. Cardiorespiratory fitness (VO2max) before, during and after adjuvant treatment in breast cancer patients [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P6-08-37.