Immunohistochemical staining of breast tumour specimens showing the presence of IgA1 in the invasive part of the tumour.

<p>A) In Sample 2, 40% of the tumour cells in the invasive part were stained with anti-IgA1 with a relative intensity of 3. Strong cytoplasmic and plasma membrane staining of IgA1 is observed in the invasive part of the section (INV) but only very weak staining in the <i>in situ</i> part (INSU). B) In Sample 7, 80% of the cells were IgA1-positive with a relative intensity of 3.</p

Results of sandwich IgA ELISA of human serum and cultivation supernatant from dense cultures of MCF-7 and T47D breast carcinoma cell lines.

<p>Serum or conditioned culture supernatant from two different breast carcinoma cell lines (MCF-7 sup. and T47D sup.) were incubated in test plates coated with HPA, GOD3-2C4 (Tn) or polyclonal anti-IgA antibody (IGA). A polyclonal anti-IgA HRP conjugated antibody was used for detection, and the results are presented as the quotient between a coated non-binding control and the relevant catcher reagent. Mouse serum (CTRL) and fresh RPMI 1640 cultivation medium (Medium) were used as negative controls.</p

Staining with anti-Tn and anti-pIgR in Sample 33.

<p><b>Scale bar = 50 µm.</b> A) Anti-Tn, B) Anti-pIgR.</p

Intermediate staining percentage of IgA1-positive tumour cells in Sample 1 compared to staining for HPA.

<p><b>Scale bar = 50 µm</b> A) Anti-IgA1, B) HPA.</p

High percentage of IgA1-positive tumour cells compared with staining with HPA in tumour Sample 30.

<p><b>Scale bar = 50 µm.</b> A) Anti-IgA1, B) HPA.</p

Very low percentage of IgA1-positive tumour cells in tumour Sample 33.

<p><b>Scale bar = 50 µm.</b> A) Anti.IgA1, B) HPA.</p

Immunohistochemical staining of specimens from individual breast cancer tumours showing the presence of IgA1 in both lymphocytes and tumour cells.

<p>A) A section showing weak positive staining of cancer cells (Can) and intensively stained lymphocytes (lym). B) Intense anti- IgA1 staining of cancer cells in Sample 28, an ER/PGR-negative tumour in which 100% of the invasive part of the section was regarded as being maximally stained for IgA1 with an intensity of 3.</p

The 44 different IgA hinge glycopeptides tested with Helix Pomatia Lectin and anti-Tn antibody.

<p>Bold and <u>S</u> and <u>T</u> indicate O-glycosylation with Ga1NAc.</p

Staining with anti-Tn and anti-pIgR in Sample 1.

<p><b>Scale bar = 50 µm.</b> A) Anti-Tn, B) Anti-pIgR.</p

Highly reproducible results of breast cancer biomarkers when analysed in accordance with national guidelines – a Swedish survey with central re-assessment

<p><i><b>Background.</b></i> Biomarkers are crucial for decisions regarding adjuvant therapy in primary breast cancer, and their correct assessment is therefore of the utmost importance.</p> <p><i><b>Aims.</b></i> To investigate the concordance between Swedish pathology departments and a reference laboratory, for routine analysis of oestrogen receptor (ER), progesterone receptor (PR), Ki67, and human epidermal growth factor receptor 2 (HER2), alone, and in combination (St Gallen subtypes).</p> <p><i><b>Methods.</b></i> This survey included 27 of the 28 pathology laboratories in Sweden, covering 98% of cases of primary breast cancer surgery in Sweden. Paraffin-embedded tumour blocks (n = 270) were collected and sent to the central reference laboratory, together with the originally stained slides, for re-analysis. The primary evaluations were previously performed according to national Swedish guidelines, without any knowledge of the subsequent central assessment.</p> <p><i><b>Results.</b></i> The agreement for ER, PR, and Ki67 was 99% [kappa value (κ) = 0.95], 95% (κ = 0.85), and 85% (κ = 0.70), respectively. The agreement for HER2 (0/1 + vs. 2+/3+) was 85% (κ = 0.64), but when equivocal tumours were further analysed with in situ hybridisation, only one discrepancy was observed. Discrepancies between results for ER and PR seem to be explained by analytical differences, whereas the interpretation of staining seems to be more critical for Ki67 and HER2 immunohistochemistry. The agreement between the results from the Swedish laboratories and the reference laboratory, based on the St Gallen subtypes, was 88% (κ = 0.81).</p> <p><i><b>Conclusions.</b></i> When applying national guidelines, highly reproducible results were obtained in routine assessment of breast cancer biomarkers, and the results of this study confirm the clinical utility of these markers for decisions regarding the treatment of primary breast cancer.</p