Fresh frozen neoplastic tissues from 70 infiltrating ductal breast carcinomas were analysed for cytosolic oestrogen receptor (ER) protein content using a solid phase enzyme immunoassay (EIA) method based on a "sandwich" principle (Abbott ER-EIA monoclonal). Formalin-fixed, paraffin-embedded sections from the same carcinomas were examined for nuclear immunoreactivity against a monoclonal antibody for ER protein (Dako) using the standard avidin-biotin complex immunoperoxidase (IP) method after microwave antigen retrieval. The degree of ER positivity by IP was also scored according to a visual estimation of the percentage of cells expressing immunopositivity and the intensity of staining. Twenty-eight (40%) of the carcinomas were ER-positive by EIA and 34 (48.6%) were positive by IP. Twenty-five (35.7%) were ER-positive and 33 (47.1%) were ER-negative by both methods. Nine (12.9%) were ER-negative by EIA but were positive by IP, this discrepancy being ascribed to sampling inadequacy for EIA. However, 3 (4.3%) tumours were ER-positive by EIA and negative by IP. This discrepancy may be variously due to inadequate antigen retrieval, faulty technique and the possibility that the two methods do not measure identical ER proteins. IP appears to have an advantage over EIA in that it has a higher pick-up rate, does not require fresh tissue and can be applied to archival material. However, to reduce false negative estimations, it may be necessary to run IP staining using more than one ER antibody. Standardisation of the IP method for ER is desirable before this method is to be widely adopted in Malaysian laboratories. Quantitation of ER positivity by IP scoring correlated poorly with actual cytosolic levels. Caution should be exercised in attaching patient management value to visual IP scoring.
Discriminant analysis of six trace element concentrations measured by instrumental neutron activation analysis (INAA) in 26 paired-samples of malignant and histologically normal human breast tissues shows the technique to be a potentially valuable clinical tool for making malignant-normal classification. Nonparametric discriminant analysis is performed for the data obtained. Linear and quadratic discriminant analyses are also carried out for comparison. For this data set a formal analysis shows that the elements which may be useful in distinguishing between malignant and normal tissues are Ca, Rb and Br, providing correct classification for 24 out of 26 normal samples and 22 out of 26 malignant samples.
The traditional classification of infiltrating breast carcinomas into ductal and lobular can be diagnostically challenging in a small proportion of cases with equivocal histological features and in in-situ lesions with overlapping features. Distinguishing between the infiltrating ductal (IDC) and lobular (ILC) carcinomas is clinically important because of the different pattern of systemic metastases and prognostic evaluation. E-cadherin is a potentially useful immunohistochemical marker which may serve to differentiate between the two tumour types. We therefore studied E-cadherin expression in 32 cases of breast carcinomas comprising 16 IDCs and 16 ILCs. The correlation between E-cadherin expression and the histological grade of IDCs was also analysed. Our results showed complete loss of E-cadherin expression in all ILCs, while the IDCs consistently showed variable E-cadherin positivity. No significant correlation was found between E- cadherin expression and the histological grade of IDCs. We conclude from this study that E-cadherin is a useful marker to differentiate between IDC and ILC of the breast. A larger study of IDCs is now needed to further evaluate the correlation between E-cadherin and tumour grade to estimate its prognostic potential.
This investigation was carried out to gain insight into the prevalence of pS2 expression in invasive ductal breast carcinoma in the Malaysian population and its correlation with oestrogen receptor (ER) protein expression and tumour aggressiveness. Seventy consecutive infiltrating ductal breast carcinomas treated with mastectomy and axillary lymph node clearance were investigated, using the standard avidin-biotin complex immunoperoxidase method with microwave antigen retrieval and commercial monoclonal antibodies (Dako), for expression of pS2 and human ER. This was correlated against histological grade (modified Bloom and Richardson) and the presence of axillary lymph node metastasis of these carcinomas. Four (5.7%) were grade 1, 40 (57.1%) grade 2 and 26 (37.1%) grade 3 tumours. A total of 45 (64%) showed histological evidence of axillary lymph node metastasis. Forty (57%) were ER-positive, while 31 (44%) were pS2-positive. There was a statistically significant correlation between pS2 and ER expressions (chi2-test with Yates correction: P<0.005). There was no correlation between pS2 expression and histological grade (P>0.1) and the presence of lymph node metastasis (P>0.1). Our findings support the views that pS2 may be a co-marker of endocrine responsiveness in invasive breast cancer and that it does not influence breast cancer biology in terms of potential for metastatic spread.
The p27 V109G polymorphism was investigated using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method in a hospital-based Malaysian population. Peripheral blood samples were collected from 230 breast cancer patients and 200 normal and healthy women who had no history of breast disease or breast cancer. We evaluated the association between the p27 polymorphism and breast cancer risk, and clinico-pathological parameters in the population. The distribution of genotype and allele frequencies of p27 V109G polymorphism were not significantly different between the breast cancer cases and normal subjects (P=0.376). Women who were homozygous (OR=1.73; 95% CI, 0.62-4.92) or heterozygous (OR=1.26; 95% CI, 0.75-2.12) for G allele, or carriers of G allele genotype (OR=1.34; 95%, 0.83-2.16) or G allele (OR=1.36; 95% CI, 0.90-2.05) were not associated with breast cancer risk. No significant correlation was noted between G allele genotype and breast cancer risk among patients under 50 (OR=1.28; 95% CI, 0.62-2.66) or 50 years and older (OR=1.38; 95% CI, 0.71-2.66) at diagnosis. The G allele genotype was significantly associated with lymph node metastases but independent of ER status and histological grade. In conclusion, the polymorphic variant at codon 109 of p27 gene may not be a marker for determining patients' risk of developing breast cancer but it may be a potential genetic marker for poor prognosis, thereby a marker for tumor prognosis.