[Increasingly sophisticated detection of lymph node metastases: the problem of stage migration]

The standard technique for the detection of lymph node metastases (LNM) underdiagnosis a large proportion of the cases. The more intensive the search for LNM, the larger the number of LNM detected. Most of these newly detected LNM are of microscopic size ('micrometastases'). As a result of a more accurate lymph node staging, more patients have a higher stage of disease (stage migration). In addition to direct methods for revealing LNM microscopically, indirect molecular methods such as the polymerase chain reaction have become available. These methods are extremely sensitive but possibly have an unacceptable low specificity. Caution is needed when introducing techniques for molecular ultrastaging. The clinical significance of newly detected LNM is yet ill understood. Owing to the recent introduction of the sentinel node procedure lymph nodes are much more intensively examined. This may lead to stage migration for a substantial number of women and it is yet unclear whether this is to their benefit. The results of observational research to determine the clinical significance of (micro) metastases should not lag behind the ever increasing sensitivity of detection techniques.