Background and objectives Estrogen receptor signaling and cyclin D1 have a major role in tumor cell proliferation in breast cancer. Desmoid tumors are rare neoplasms that may respond to endocrine treatment. The present study aimed to investigate the expression levels and the clinical relevance of estrogen receptor beta (ERβ) and cyclin D1 in desmoid tumors. Methods This study consists of 83 patients with a surgically treated desmoid tumor. ERβ and cyclin D1 expression was examined by immunohistochemistry in tissue microarrays. Cyclin A and Ki67 were studied in our previous work. Results Median ERβ expression was 10.8%. ERβ expression correlated with expression of the proliferation antigens Ki67 (rp = 0.35, P = 0.003), cyclin D1 (rp = 0.34, P = 0.004), and cyclin A (rp = 0.34, P = 0.004). ERβ immunoexpression showed a trend towards predictive impact for recurrence as a continuous variable. Further explorative analysis indicated that very high ERβ expression was related to high risk of relapse (hazard ratio [HR] 2.6; P = 0.02).Median cyclin D1 expression was 15.6%. High cyclin D1 expression was associated with high Ki67 and cyclin A expression. Cyclin D1 was not associated with time to recurrence. Conclusions ERβ and cyclin D1 immunopositivity correlated with high proliferation in desmoid tumors. High ERβ expression might be predictive for postoperative recurrence.

Radiotherapy is a valuable option for treating desmoid tumors. Radiotherapy dose appears to be significantly associated to local control.

Our study indicates that cyclin A may be a new prognostic biomarker in surgically treated desmoid tumors.