Immunohistochemical profile of invasive lobular carcinoma of the breast: predominantly vimentin and p53 protein negative, cathepsin D and oestrogen receptor positive

Vimentin, p53 protein and cathepsin D positivity were assessed by immunohistochemistry, and oestrogen receptor (ER) by an enzyme immunoassay, in invasive lobular carcinomas (LC) of the breast. While vimentin was positive in only 5% (3/57) and p53 protein was positive only in 3% (2/63), cathepsin D was expressed in 86% (48/56) and ER in 78% (25/32). Classical LC were negative for p53 protein and all except one were cathepsin D positive. These results are in contrast to invasive ductal breast carcinomas (DC), where the reported average incidence of vimentin and p53 protein is much higher (19% and 33% respectively) and that of cathepsin D and ER lower (63% and 67% respectively). Thus lack of expression of vimentin and lack of p53 positivity together with high incidence of expression of cathepsin D and ER are more often associated with lobular than with ductal differentiation of invasive breast cancer. The results show that LC, distinguished morphologically, can further be defined by its immunohistochemical profile. This in turn may point to underlying biological differences between LC and DC.

The effect on lymphocyte chromosomes of additional radiation burden due to fallout in Salzburg (Austria) from the Chernobyl accident

An investigation has been carried out to determine whether chromosome aberrations in peripheral blood lymphocytes reflect the elevated environmental dose of low-LET ionising radiation, mainly due to radiocesium from Chernobyl fallout, to the population living in Salzburg city. Sixteen volunteers were sampled 1 year after the Chernobyl accident. Two of these persons were also sampled before the accident, and then in 1988 and 1990. The radioactive environment of Salzburg city and the radiation burden of its inhabitants have been frequently determined before and after the accident. The Cs-137 content of the volunteers was measured by whole-body counting. The additional external plus internal radiation doses in the year 1987 to the tested individuals ranged between 15 and 68% of the former normal environmental burden. The aberration frequencies showed a sharp increase of about a factor 6 from the pre-Chernobyl dose rate (0.9. mGy/year) to the post-Chernobyl dose rate (about 2 mGy/year total) but then decreased again with higher additional dose. In the two persons analysed before and up to 4 years after the accident the aberration yield showed a significant increase from 1984/85 to 1987, a decrease in 1988 and a further decrease in 1990. If these last 2 values are plotted against additional dose they fit the curve of the pooled 1987 values. The dose-effect curves revealed the same tendency as we found in various previous investigations and support the assumption that repair enzymes could be triggered by a certain amount of damage to the DNA.