Cardiorespiratory fitness in breast cancer patients undergoing adjuvant therapy

Figures & data

Figure 1. Stratification of study population with respect to breast cancer treatment at time point of cardiopulmonary exercise testing (CPET).

Table I. Characteristics of the study population.

TOTAL n, %	TOTAL		No CT		Started CT		Post neo. CT		Post adj. CT		p*
	222	100%	87	100%	87	100%	23	100%	25	100%
Age [years], mean (SD)	54.8	(9.3)	57.3	(8.7)	53.5	(9.6)	51.8	(10.0)	53.5	(7.7)	0.011
Weight [kg], mean (SD)	71.7	(14.1)	73.1	(14.2)	69.6	(12.7)	70.9	(11.4)	74.6	(19.5)	0.28
Height [cm], mean (SD)	165.5	(6.6)	164.7	(7.1)	165.8	(6.5)	165.7	(4.9)	167.4	(6.4)	0.29
BMI at baseline, mean (SD)	26.2	(4.9)	27.0	(5.2)	25.3	(4.4)	25.9	(4.5)	26.5	(5.9)	0.16
Hemoglobin [g/dl], mean (SD)	12.8	(1.2)	13.5	(0.9)	12.3	(1.1)	12.8	(0.9)	11.4	(1.0)	<.0001
Resting HR, mean (SD)	82.6	(14.5)	77.9	(12.8)	85.3	(14.2)	80.8	(10.3)	91.6	(18.3)	<.0001
Days since surgery, mean (SD)	66.6	(51.2)	44.2	(13.0)	58.9	(29.1)	59.2	(55.5)	177.8	(51.8)	<.0001
Days since CT end, mean (SD)	54.8	(49.1)	n.a.		n.a.		80.2	(55.5)	27.1	(15.9)	0.0001
Stage, n (%)
0	15	6.8%	12	13.8%	1	1.1%	2	8.7%	0	0.0%	<.0001
1	101	45.5%	57	65.5%	29	33.3%	8	34.8%	7	28.0%
2	80	36.0%	18	20.7%	43	49.4%	9	39.1%	10	40.0%
3	26	11.7%			14	16.1%	4	17.4%	8	32.0%
ECOG, n (%)
0	190	85.6%	77	88.5%	74	85.1%	19	82.6%	20	80.0%	0.21
1	24	10.8%	8	9.2%	7	8.0%	4	17.4%	5	20.0%
2	1	0.5%	1	1.1%	0	0.0%	0	0.0%	0	0.0%
missing	7	3.2%	1	1.1%	6	6.9%	0	0.0%	0	0.0%
Taxane therapy, n (%)	82	36.9%	n.a.		34	39.1%	23	100.0%	25	100.0%	<.0001
Anthracycline therapy, n (%)	119	53.6%	n.a.		74	85.1%	22	95.7%	23	92.0%	0.43
Herceptin therapy, n (%)	28	12.6%	n.a.		19	21.8%	4	17.4%	5	20.0%	0.89
Hormone therapy, n (%)	65	29.3%	47	54.0%	0	0.0%	8	34.8%	10	40.0%	<.0001
Beta-blocker use, n (%)	35	15.8%	15	17.2%	10	11.5%	4	17.4%	6	24.0%	0.45
Smoking before diagnosis, n (%)	38	17.1%	16	18.4%	16	18.4%	5	21.7%	1	4.0%	0.31
Walking before diagnosis, n(%)
0–1 h/wk	46	20.7%	14	16.1%	24	27.6%	5	21.7%	3	12.0%	0.052
> 1–3 h/wk	70	31.5%	26	29.9%	25	28.7%	10	43.5%	9	36.0%
> 3–5 h/wk	46	20.7%	14	16.1%	25	28.7%	3	13.0%	4	16.0%
> 5 h/wk	47	21.2%	27	31.0%	10	11.5%	4	17.4%	6	24.0%
missing	13	5.9%	6	6.9%	3	3.4%	1	4.3%	3	12.0%
Cycling before diagnosis, n(%)
none	77	34.7%	33	37.9%	25	28.7%	10	43.5%	9	36.0%	0.26
> 0–1 h/wk	76	34.2%	26	29.9%	32	36.8%	7	30.4%	11	44.0%
> 1–3 h/wk	42	18.9%	17	19.5%	18	20.7%	6	26.1%	1	4.0%
> 3 h/wk	19	8.6%	8	9.2%	10	11.5%	0	0.0%	1	4.0%
missing	8	3.6%	3	3.4%	2	2.3%	0	0.0%	3	12.0%
Sports before diagnosis, n (%)											0.048
none	75	33.8%	38	43.7%	19	21.8%	11	47.8%	7	28.0%
> 0–9 MET*h/wk	53	23.9%	23	26.4%	19	21.8%	5	21.7%	6	24.0%
> 9–21 MET*h/wk	45	20.3%	13	14.9%	25	28.7%	4	17.4%	3	12.0%
> 21 MET*h/wk	43	19.4%	12	13.8%	21	24.1%	3	13.0%	7	28.0%
missing	6	2.7%	1	1.1%	3	3.4%	0	0.0%	2	8.0%
Sports in adolescence, n (%)											0.078
no sports	83	37.4%	35	40.2%	29	33.3%	8	34.8%	11	44.0%
non-competitive	87	39.2%	41	47.1%	30	34.5%	10	43.5%	6	24.0%
competitive	47	21.2%	10	11.5%	26	29.9%	5	21.7%	6	24.0%
missing	5	2.3%	1	1.1%	2	2.3%			2	8.0%

BMI, body mass index; CT, chemotherapy; ECOG, Eastern Cooperative Oncology Group (performance status); HR, heart rate; MET, metabolic equivalent; SD, standard deviation.

*One-way ANOVA for continuous variables, χ² or Fisher's exact test for categorical variables.

Table II. Maximal (peak) and submaximal fitness parameters, mean (SD).

		TOTAL		No CT		Started CT		Post neo. CT		Post adj. CT
	n	mean	(SD)	mean	(SD)	mean	(SD)	mean	(SD)	mean	(SD)
Peak fitness measures
VO2peak relative [ml/min/kg]	176	20.6	(6.7)	19.8	(5.4)	23.0	(7.1)	19.2	(6.8)	15.5	(4.8)
VO2peak absolute [ml/min]	176	1416	(415)	1405	(374)	1544	(424)	1312	(353)	1076	(340)
Peak work rate [W]	176	111	(28)	112	(27)	118	(27)	107	(24)	87	(24)
Peak RER	176	1.18	(0.09)	1.15	(0.08)	1.17	(0.07)	1.22	(0.09)	1.23	(0.11)
Peak HR [beats/min]	176	157	(18)	154	(16)	161	(17)	157	(22)	151	(20)
Submaximal fitness measures
VT relative [ml/min/kg]	200	10.7	(2.9)	10.3	(2.4)	11.4	(3.4)	10.3	(2.8)	10.0	(2.1)
VT absolute [ml/min]	200	748	(163)	742	(145)	769	(196)	721	(137)	721	(115)
HR at 50 watts [beats/min]	220	112	(16)	107	(13)	115	(15)	114	(16)	119	(19)

CT, chemotherapy; HR, heart rate; RER, respiratory exchange ratio; SD, standard deviation; VO_2peak, peak oxygen consumption; VT, ventilatory threshold.

Figure 2. Distribution of VO_2peak, presented as percentage of expected values for healthy women with the same age and BMI. The boxes present the 1st and 3rd quartiles, the middle line the medians, and the Whisker-ends the 5th and 95th percentiles.

Figure 3. Adjusted mean values of each treatment category regarding VO_2peak, VT, and HR50. Least square means were calculated using analyses of covariance models adjusted for age, BMI, smoking before diagnosis, walking, cycling, and sports before diagnosis, sports during adolescence, use of beta-blocker, and pre-existing heart diseases. Differences between categories were tested using Tukey-Kramer tests and all statistically significant differences (p < 0.05) are indicated in the figures.