The influence of an IL-4 variable number tandem repeat (VNTR) polymorphism on breast cancer susceptibility

Figures & data

Figure 1 VNTR polymorphism locus within the IL-4 gene.

Abbreviation: VNTR, variable number tandem repeat.

Figure 2 Agarose gel electrophoresis showing different VNTR genotypes in the IL-4 gene. The size of the bands was determined through comparison to a 50 bp ladder. Lane 1 represents the 1R\1R genotype, with one band at 183 bp; lane 2 contains the 2R\2R genotype, as indicated by one band at 253 bp. On the other hand, the heterozygous genotype 1R\2R is represented by lane 3 (two bands with sizes of 183 bp and 253 bp, respectively).

Table 1 Genotypic and allelic frequency distribution of the VNTR in the IL-4 gene for cases and controls

Genotypes and alleles	Case group	Control group	p-value*
1R	39 (10.8%)	48 (13.3%)	0.107
2R	321 (89.2%)	312 (86.7%)
1R\1R	2 (1.1%)	0 (0%)	0.303
2R\2R	143 (79.4%)	132 (73.3%)
1R\2R	35 (19.5%)	48 (26.7%)

Note: *P<0.05 is considered significant using Pearson Chi–squared test.

Table 2 Association of IL-4 polymorphism with clinical characteristics of breast cancer patients

Clinical characteristics		Genotype frequency (1R\2R) (%)	Genotype frequency (2R\2R) (%)	p-value
BMI**	≤25	39.10	21	0.035
	>25	60.90	79
First pregnancy (age)*	<20	24.30	33.60	0.684
	≥20	75.70	66.4
Age at breast cancer diagnosis*	<45	32.60	33.80	0.847
	≥45	67.40	66.20
Age at first menstruation**	<13	28.90	30.90	0.190
	≥13	71.10	69.10
Breastfeeding status*	Yes	65.20	66.20	0.702
	No	34.80	33.80
Age at menopause**	<50	45.80	45.80	0.679
	≥50	54.20	54.2
Family history*	Yes	26.1	34	0.863
	No	73.9	66
Allergy*	Yes	21.70	29.80	0.973
	No	78.30	70.20
Smoking*	Yes	29.50	29	0.582
	No	70.50	71
Comorbidity*	Yes	45.70	34.30	0.820
	No	54.30	65.70

Notes: *Genotype–phenotype association p-value using Pearson Chi-squared test. **Genotype–phenotype association p-value using ANOVA test. p<0.05 is considered significant.

Table 3 Association of IL-4 polymorphism with pathological characteristics of breast cancer patients

Pathological characteristics		Genotype frequency (1R\2R) (%)	Genotype frequency (2R\2R) (%)	p-value
Progesterone receptor*	Positive	44.40	54.70	0.247
	Negative	55.60	45.30
Estrogen receptor*	Positive	75.60	79.50	0.189
	Negative	24.40	20.50
Tumor differentiation*	Low differentiation	29.50	33.60	0.028
	Mid & high differentiation	70.50	66.40
Axillary lymph nodes*	Free of tumor	47.90	50	0.771
	Show metastatic Carcinoma	52.10	50
Tumor stage*	Stage 1&2	95.10	89.50	0.246
	Stage 3&4	4.90	10.50
Histology classification*	In situ carcinoma	13.30	20.50	0.093
	Invasive carcinoma	86.70	79.50
Tumor size**	≤2CM	23.40	23.70	0.592
	2<x≤5	29.80	37.40
	>5	46.80	38.90
Lymph node involvement*	Yes	84.80	82.40	0.340

Notes: *Genotype–phenotype association p-value using Pearson Chi-squared test. **Genotype–phenotype association p-value using ANOVA test. p<0.05 is considered significant.

Data availability

The datasets generated and/or analyzed over the course of the study are not publicly available but are available from the corresponding author on reasonable request.