[Tumor marker: practical usage of tumor marker for recurrent breast cancer--our experience]

The point of practical usage of monitoring tumor marker, CEA and CA15-3, for breast cancer patients was indicated and discussed. We presented several cases with recurrent breast cancer patients and verified the practical usefulness of monitoring tumor marker, CEA and CA15-3. Fundamental changing pattern of these markers in serum on semi-logarithmic graph was exhibited to show linear pattern and the two curves of CEA and CA15-3 kept basically parallel except several conditions, when both markers were positive. From the graphical changes of markers we could made early and correct judgement of the effect of the treatment. However, there existed several cases who showed strange and paradoxical changing pattern of these markers apart from clinical courses. That is the situation that heterogenetic changes of the tumor or tumor lysis syndrome are taken place. It was emphasized that the value of serum tumor markers should be taken notice of the changes of markers in these situations.