L. Kronberger et al., Selective decrease of serum immunoglobulin G1 as marker for early stages of invasive breast cancer, BREAST CANC, 64(2), 2000, pp. 193-199
The diagnostic value of the decrease in percentage of immunoglobulin G1 (%I
gG1) in breast cancer was analyzed with special emphasis on early tumor sta
ges. IgG1 and total IgG were preoperatively measured in the sera of a total
of 801 individuals using a modified quantitative affinity chromatography.
Group A consisted of 174 healthy individuals of both sexes, group B of 324
female patients with benign breast disease, and group C of 303 patients wit
h invasive and non-invasive breast cancer. Within group C, 13 patients pres
ented with intraductal carcinoma, and 22 patients with a pT1a-tumour (diame
ter less than 0.5 cm). The %IgG1 values were compared among groups A, B and
C. In addition, correlations were sought between %IgG1 values of group C a
nd tumor size, stage (UICC), histopathological grade and oestrogen (ER) and
progesteron receptor (PR) expression. The mean value of %IgG1 in group A w
as 63.3 +/- 0.5 s.e.m., in group B 57.75 +/- 0.4 s.e.m. and in group C 52.3
7 +/- 0.5 s.e.m. The differences of mean values were highly significant bet
ween all three groups. Sensitivity and specificity of %IgG1 to discriminate
between group A and C were 75% and 87%, and between group B and C 62% and
63%, respectively. The significant decrease of %IgG1 in total serum IgG is
able to distinguish patients with breast cancer of more than 5 mm in diamet
er from healthy controls and patients with benign breast diseases. Finally,
calculated posterior probabilities revealed that within certain concentrat
ion limits %IgG1 may provide predictive information with high probabilities
.