[Current Trends in the Implantation of the Touch Prosthesis at the Thumb Carpometacarpal Joint: Results of the 1st German-Speaking User Meeting]. / Aktuelle Trends bei der Implantation der Touch-Prothese am Daumensattelgelenk: Ergebnisse des 1. deutschsprachigen Anwendertreffens.

The introduction of the new generation of thumb carpometacarpal (CMC I) joint implants for the treatment of CMC I osteoarthritis has significantly broadened the scope of hand surgery in recent years. However, the technical demands of the procedure and the many details that need to be considered require appropriate training and a learning curve. To share experiences with the Touch CMC I prosthesis, we held the first German-speaking CMC I joint prosthetics user meeting in Zurich. After some basic introductory lectures on biomechanics and the principles of prosthetic fitting of the CMC I joint, the various challenges associated with CMC I joint prosthetics were discussed in interactive expert panels. Subsequently, cases were discussed in small groups under expert guidance and the respective conclusions were discussed in plenary. The main results of this symposium are summarised in this manuscript.

Differential expression pattern of estrogen receptors, aromatase, and sulfotransferase in breast cancer tissue and corresponding lymph node metastases.

Patients with hormone receptor positive breast cancer who are treated with endocrine therapy generally have a good prognosis. However, resistance to hormonal therapy and progression occurs, and the reasons for this are manifold. It has been proposed that the local estrogenic environment has a role in the process of local invasion and progression. We have determined the expression pattern of estrogen receptor α, estrogen receptor ß, and the epithelial and stromal expression of the estrogen-metabolizing enzymes aromatase and sulfotransferase by immunohistochemistry in tissue arrays, containing 50 paraffin-embedded sets of tissues obtained from breast cancer and from corresponding metastatic axillary lymph nodes of the same patients. We have found statistically significant higher estrogen receptors α and ß expression in primary tumors than in corresponding lymph node metastases (p = 0.0004 and p = 0.003, respectively). Aromatase was also expressed more frequently in epithelial as well as in stromal cells of the malignant tumor when compared to according lymph node metastases (p = 0.08 and p = 0.12, respectively). While in lymph node metastases only estrogen receptor α and stromal aromatase expression were correlated (p = 0.01), significant associations were seen between the estrogen receptor ß and sromal aromatase, and epithelial sulfotransferase (p = 0.0006 and p = 0.03, respectively) in the primary tumor. We hypothesize that the decreased expression of local estrogens by aromatase, in combination with a decreased expression of estrogen receptors α and ß in lymphatic metastases, renders these metastases hormone insensitive and could contribute to the poor response to endocrine therapy that is often seen in nodal-positive tumors.