Background: Breast cancer is the most common cancer in women worldwide and although mortality (129 000/year) stagnates, incidence (370 000/year) is increasing. In addition to histological type, grade, stage, hormonal and c-erbB2 status there is therefore a strong need for new and reliable prognostic and predictive factors. Methods and results: This minireview focuses on two potential prognostic and predictive candidates Tpl2/Cot and COX-2 and summarise information about them.

Conclusion: Tumor progression locus 2 (Tpl2/Cot) is a serine/threonine protein kinase belonging to the family of MAP3 kinases. Activated Tpl2/Cot leads to induction of ERK1/2, JNK, NF-κB and p38MAPK pathways. The first study on Tpl2/Cot mRNA in breast cancer showed its increase in 40% of cases of breast cancer but no available data exist on protein expression. Cyclo-oxygenase 2 (COX-2) is inducible by growth and inflammatory factors and contributes to the development of various tumours. Expression of COX-2 in breast cancer varied from 5-100% in reviewed papers with significantly higher values in poorly differentiated tumours. Tpl2/Cot and COX-2 have their importance in different intracellular pathways and some of these are involved in cancer development. Briefly, the results from recent studies suggest that Tpl2/Cot and COX-2 could be prognostic factors in breast cancer.