Peripartum Blood Transfusions are Associated with Increased Risk of Cancer: A National Retrospective Cohort Study

Figures & data

Figure 1 Flowchart of participant enrollment.

Abbreviation: NHSE, National Health Screening Examination; NHSP-IC, National Health Screening Program for Infants and Children.

Table 1 Clinical Characteristics of Participants Stratified by Transfusion Status

	No Transfusion (n = 265,960)	Transfusion (n = 4569)	P-value
Age (years)	29.15 ± 3.04	30.01 ± 3.54	<0.01
BMI (kg/m^2)	20.59 ± 4.21	20.58 ± 2.62	0.89
Obesity (%)	5.83 (15,493)	6.26 (286)	0.21
Systolic BP (mmHg)	111.0 ± 11.11	111.4 ± 11.35	<0.01
Diastolic BP (mmHg)	69.99 ± 8.33	70.45 ± 8.61	<0.01
HTN (%)	4.14 (11,021)	5.41 (247)	<0.01
Fasting glucose (mg/dL)	86.15 ± 13.58	86.62 ± 20.26	0.12
DM (%)	3.21 (8,544)	4.73 (216)	<0.01
TC (mg/dL)	173.5 ± 31.83	173.3 ± 30.87	0.58
High TC (%)	17.03 (45,293)	17.33 (792)	0.59
AST (mg/dL)	19.47 ± 10.78	19.79 ± 10.21	0.03
ALT (mg/dL)	15.21 ± 16.67	15.63 ± 14.99	0.06
Abnormal LFT (%)	5.76 (15,316)	6.94 (317)	<0.01
Smoking (%)			0.23
Never	93.56 (248,831)	93.13 (4255)
Ever	2.89 (7685)	2.85 (130)
Current	3.55 (9444)	4.03 (184)
Multiple pregnancy (%)	1.60 (4246)	9,81 (448)	<0.01
Cesarean section (%)	32.87 (87,417)	52.40 (2394)	<0.01
Preterm birth (%)	2.96 (7862)	12.41 (567)	<0.01
Preeclampsia (%)	2.19 (5821)	9.46 (432)	<0.01
Postpartum hemorrhage (%)	5.51 (14,655)	41.48 (1895)	<0.01

Notes: Values are expressed as mean (SD) or %. Obesity was defined by BMI ≥25 kg/m². Abnormal liver function test (LFT) was defined as AST ≥31 mg/dL or ALT ≥31 mg/dL.

Abbreviations: BP, blood pressure; HTN, hypertension; DM, diabetes mellitus; TC, total cholesterol; AST, aspartate aminotransferase; ALT, alanine aminotransferase; LFT, liver function tests.

Table 2 Risk of the Development of Cancer According to Transfusion Status

	Unadjusted HR (95% CI)	Adjusted HR* (95% CI)
Any transfusion	1.25 (1.08, 1.44)	1.16 (1.01, 1.34)
1 unit (N = 1072)	1.23 (0.91,1.65)	1.13 (0.84,1.52)
2 units (N = 2196)	1.11 (0.89,1.38)	1.04 (0.84,1.30)
≥3 units (N = 1301)	1.51(1.18,1.93)	1.40 (1.10,1.79)

Note: *Adjusted for age, DM, HTN, obesity, abnormal LFT, high total cholesterol, smoking status, multiple pregnancy, cesarean section, preterm birth, and preeclampsia.

Table 3 Risk of the Development of Specific Cancer Types Based on Transfusion Status

	No Transfusion	Transfusion	Adjusted HR* (95% CI)
Liver	0.33 (882)	0.24 (11)	0.71 (0.39, 1.28)
Breast	0.33 (873)	0.22 (10)	0.57 (0.30, 1.06)
Thyroid	1.12 (2974)	1.44 (66)	1.22 (0.95, 1.56)
Gallbladder	0.05 (143)	0.13 (6)	2.30 (1.01, 5.26)
Brain	0.02 (62)	0.11 (5)	4.90 (1.93, 12.43)
Uterus	0.10 (271)	0.18 (8)	1.55 (0.76, 3.16)
Colon	0.80 (2133)	0.88 (40)	1.06 (0.77, 1.45)
Lung	0.02 (52)	0.11 (5)	4.57 (1.76, 11.86)
Stomach	0.10 (272)	0.15 (7)	1.45 (0.68, 3.10)
Ovary	0.06 (171)	0.20 (9)	2.79 (1.41, 5.54)
Others	0.25 (669)	0.35 (16)	1.22 (0.74, 2.01)

Note: *Adjusted for age, DM, HTN, obesity, abnormal LFT, high total cholesterol, smoking status, multiple pregnancy, cesarean section, preterm birth, and preeclampsia.

Figure 2 Cumulative incidence of cancer diagnoses. The incidence of cumulative cancer incidence is illustrated for transfusion recipients and non-recipients over a 9-year span. The greater incidence in cancer diagnoses among transfusion recipients remained persistent during this time, suggesting that this difference was not due to occult malignancies that predisposed those patients to requiring transfusions.