Breast cancer cells frequently metastasize to the skeleton, where they lead to tumor-induced osteolysis and subsequent morbidity. Marc Lacroix has investigated the interrelationships between BCC and bone cells. With colleagues, he discovered that BCC produce soluble factors increasing osteoclast activity, notably interleukin-11, the production of which is reduced by the cyclooxygenase inhibitoraspirin. BCC also reduce the proliferation of osteoblasts and their production of collagen, the main protein component of bone. Marc Lacroix also examined the response BCC to the anti-osteolytic agent calcitonin In close collaboration with Prof. Guy Leclercq, Marc Lacroix has studied various aspects of estrogen receptor biology, ligand-binding and transcriptional activity, and life-cycle.
Recent work
The amount of data on breast cancer available for the scientific and medical community is growing rapidly. According to PubMed, a search engine offering access to the MEDLINEdatabase of citations and abstracts of biomedical research articles, 7918 papers containing the expression «breast cancer» were published in 2006. Their number was 3592 in 1996, 1455 in 1986 and only 626 in 1976. In general, the older information is overlaid by more recent data and forgotten to some extent. In 2004, Lacroix and colleagues collected and assembled data from hundreds of articles related to the biology, pathology and genetics of in situ, invasive and metastaticbreast cancers. These papers were covering a time period of about 25 years. Lacroix et al. concluded that despite undergoing increasing genetic alteration, most individual breast cancers rather surprisingly maintain their phenotype when they evolve from in situ to the metastatic state. This conclusion was in opposition to a progression model widely accepted at that time, which was suggesting that carcinomain situ could evolve into invasive carcinoma and subsequently produce metastases through an accumulation of molecular abnormalities possibly allowing extensive phenotype changes and subsequent gain of aggressiveness.
