Molecular pathogenesis of bilateral breast cancer.

Bilateral breast cancer (biBC) offers intriguing possibilities for molecular genetic investigations, however it is disproportionally less studied than its unilateral counterpart. By now, genetic research has succeeded to resolve at least two important aspects of biBC pathogenesis. First, it has been confirmed, that the vast majority if not all biBC arise due to clonally independent events but not due to contralateral metastatic spread.

Expression of caspase-3 and -7 does not correlate with the extent of apoptosis in primary breast carcinomas.

Association between the rate of apoptosis and expression of the several relevant molecules (Bcl-2, pro- and active caspase-3, and caspase-7) was studied in 61 primary breast carcinomas. The rate of apoptosis detected both morphologically and by the TUNEL assay appeared to be high in 18 (30%), moderate in 14 (23%), and low in 29 (48%) carcinomas. High apoptotic index was strongly associated with advanced tumor grade and estrogen receptor positive (ER+) status but not with other investigated clinical or morphological parameters.

Concordance of allelic imbalance profiles in synchronous and metachronous bilateral breast carcinomas.

Bilateral breast cancer (biBC) is a common form of breast cancer; however, it has not been subjected to systematic comparative genetic studies. We allelotyped 28 biBCs on 14 chromosomal arms, addressing 2 lines of questions: (i) does comparison of genetic profiles disclose contralateral metastases misdiagnosed as second primaries? and (ii) do shared environmental and host factors drive the development of true biBC along similar genetic routes? Allelotyping provided unambiguous proof for distinct clonality in 23 of 28 cases. In another 4 biBCs, the genotyping data did not exclude the hypothesis of metastatic spread, whereas clinical and histologic data were in favor of bilaterality.

CYP17 genetic polymorphism in endometrial cancer: are only steroids involved?

Initiation and/or promotion of endometrial cancer is known to be associated with estrogen and androgen (androstenedione) excess as well as with hyperinsulinemia/insulin resistance. It is possible that some allelic polymorphisms of the genes involved in steroidogenesis or steroid metabolism contribute to endometrial cancer susceptibility. We evaluated here the role of CYP17 biallelic (MspAI) polymorphism in 114 endometrial cancer patients compared with 182 healthy women.

Cancer progression and tumor cell motility are associated with the FGFR4 Arg(388) allele.

Expression analysis of genes encoding components of the phosphotyrosine signaling system by cDNA array hybridization revealed elevated levels of FGFR4 transcripts in several mammary carcinoma cell lines. In the FGFR4 gene transcript from MDA-MB-453 mammary carcinoma cells, a G to A conversion was discovered that results in the substitution of glycine by arginine at position 388 in the transmembrane domain of the receptor. The Arg(388) allele was also found in cell lines derived from a variety of other tumor types as well as in the germ-line of cancer patients and healthy individuals.