Table 1.
Baseline characteristics of the analysis cohort
| Variable | Overall* (n = 87) | Breast cancer (n = 60) | Lung cancer/lymphoma (n = 27) |
|---|---|---|---|
| Age, y | 52.5 [40.2–60.0] | 53.0 [42.0–60.5] | 49.0 [27.5–60.0] |
| Sex | |||
| Female | 74 (85.1) | 60 (100) | 14 (51.9) |
| Male | 13 (14.9) | 0(0) | 13 (48.1) |
| Race | |||
| White | 66 (75.9) | 43 (71.7) | 23 (85.2) |
| Black or African American | 18 (20.7) | 14 (23.3) | 4 (14.8) |
| Asian/Pacific Islander | 3 (3.4) | 3 (5.0) | 0(0) |
| Anthracycline and/or trastuzumab as part of current treatment | 45 (51.7) | 34 (56.7) | 11 (40.7) |
| Past anthracycline exposure | 6 (6.9) | 2 (3.3) | 4 (14.8) |
| BMI (kg/m2) | 28.4 ± 6.7 | 28.5 ± 6.9 | 28.1 ± 6.3 |
| Current or past smoking | 34 (39.1) | 23 (38.3) | 11 (40.7) |
| Hypertension | 24 (27.6) | 20 (33.3) | 4 (14.8) |
| Diabetes mellitus | 9 (10.3) | 6 (10.0) | 3 (11.1) |
| Hypercholesterolemia or statin use | 26 (29.9) | 18 (30.0) | 8 (29.6) |
| ACEI/ARB or beta-blocker use | 24 (27.6) | 21 (35.0) | 3 (11.1) |
| Primary radiation technique | |||
| Protons (passive scattering) | 6 (7.0) | 4 (6.7) | 2 (7.4) |
| Protons (scanning) | 17 (19.5) | 4 (6.7) | 13 (48.2) |
| 3D Conformal | 45 (51.7) | 44 (73.3) | 1 (3.7) |
| IMRT | 19 (21.8) | 8 (13.3) | 11 (40.7) |
| Total radiation dose, Gy | 52.6 [50.4–60.0] | 52.6 [50.4–60.0] | 50.4 [30.6–63.3] |
| MHD, Gy | 2.1 [1.1–5.2] | 1.3 [0.9–2.4] | 7.3 [5.7–13.4] |
| V5, % | 6.8 [1.5–22.1] | 2.3 [1.1–7.9] | 34.5 [19.9–47.8] |
| V30, % | 0.3 [0–3.5] | 0.1 [0–0.9] | 7.9 [2.7–21.2] |
| hs-cTnT (ng/L) | 11 [6–21] | 11 [6–23] | 11 [8–18] |
| NT-proBNP (ng/L) | 72 [35–118] | 72 [42–118] | 70 [25–114] |
| PIGF (ng/L) | 18 [15–23] | 18 [15–23] | 20 [16–26] |
| GDF-15 (ng/L) | 1026 [727–1663] | 1012 [676–1512] | 1171 [756–2493] |
| LVEF, % | 52 [48–56] | 52 [48–56] | 52 [46–54] |
| Longitudinal strain, % | −14 [−16 to −12] | −13 [−16 to −12] | −14 [−16 to −12] |
| Circumferential strain, % | −23 [−25 to −19] | −22 [−25 to −18] | −24 [−25 to −22] |
Abbreviations: 3D = 3-dimensional; ACEI = angiotensin-converting enzyme inhibitor; ARB = angiotensin receptor blocker; BMI = body mass index; DBP = diastolic blood pressure; GDF-15 = growth differentiation factor 15; hs-cTnT = high-sensitivity cardiac troponin T; IMRT = intensity modulated radiation therapy; MHD = mean heart dose; NT-proBNP = N-terminal pro-B-type natriuretic peptide; PIGF = placental growth factor; RT = radiation therapy; SBP = systolic blood pressure.
Categorical variables were summarized with count (%); normally distributed continuous variables were summarized with the mean ± standard deviation, non-normally distributed continuous variables were summarized with the median [interquartile range]; V5 and V30 indicate the percent volume of heart receiving 5 Gy and 30 Gy, respectively.
Patients with available biomarker measurements at pre-RT and after completion of RT were included.