No abstract

The expression of glutathione S-transferase mu was measured by a qualitative immunoenzymatic assay in the blood samples of 108 women (63 breast cancer patients and 45 healthy controls) in order to analyze the relationships of GST-mu phenotype and smoking habits with tumor characteristics of breast cancer patients, such as tumor extension, nodal status, hormone receptor status and DNA content by flow cytometry. GST-mu was expressed in 53/108 (49%) of cases without any significant difference between healthy or neoplastic subjects, smokers or non-smokers, pre or post-menopausal, younger or older subjects. Moreover, the percentages of the GST-mu phenotype did not differ significantly in patients with different ER and PgR tumor status, tumor extension or nodal status. By contrast, aneuploid DNA tumor content was shown to be significantly associated with GST-mu expression (24% and 76% GST-mu positive, respectively, in diploid and aneuploid cases; p < 0.003). The biological meaning of this association remains to be interpreted.

No abstract

In order to verify whether the HER-2/neu gene is involved in the initial phases of neoplastic disease or in its progression, we evaluated the amplification and overexpression of this gene in the primary tumor and in synchronous metastatic axillary lymph nodes of 26 women with operable breast cancer. HER-2/neu was amplified in 35% and overexpressed in 33% of the primary sites; similar percentages were found in lymph nodes. The clear correlation between the two disease sites regarding gene, mRNA and protein levels, supports the hypothesis that this gene is involved in the initial and invasive phases of neoplasia. Its actual role with respect to other biological tumor characteristics during the metastatic process should be investigated further.

To evaluate different methodologic approaches for HER-2/neu analysis, we performed Southern, Northern, Western blot and histochemical assay on 112 samples from 86 primary tumors and 26 synchronous axillary metastatic lymph nodes of patients affected by operable breast cancer. Simultaneous statistical analysis of data obtained with the four methods (31 samples) showed that Western blot detected a higher percentage of alterations than the other assays (Cochran and Victor tests, 0.01 less than p less than 0.05). The same result was emphasized by pair analysis (McNemar, p less than 0.05), which evaluated the assay data two by two. Immunohistochemical evaluations were more in accord with immunoprecipitation data when performed on frozen or Bouin-fixed, paraffin-embedded tissues than on formalin-fixed, paraffin-embedded tissues.