No abstract

The purpose of this study was to assess mammographic and sonographic findings in a long-term follow-up (>or=3 years) after breast-conserving surgery (BCS) and IORT, either applied as boost or exclusively. Follow-up-findings of 54 patients were retrospectively evaluated and compared to a control group of 48 patients, treated with BCS and whole-breast radiotherapy. After IORT patients had a higher incidence of fat necroses manifesting as oil cysts in the late follow-up mammograms (n = 31 vs n = 8); furthermore, oil cysts were larger in the IORT group (median 4.5 vs 1.4 cm(2)). In 25 IORT patients the oil cysts arose from partially organized hematomas/seromas, which in this group were generally more frequent (n = 38 vs n = 9) and larger (median 3.6 vs 1.8 cm(2)). After IORT a decreasing incidence of hematomas/seromas was reciprocal to an increasing incidence of oil cysts, and the size of both entities correlated with each other. Liquid lesions with polypoid inner wall thickening on ultrasound, attributed to organized hematomas/seromas or fat necroses, appear more frequently after IORT (n = 15 vs n = 1). In conclusion, IORT is associated with a high incidence of large oil cysts, which arise from likewise large partially organized wound cavities. On ultrasound pronounced partial organization with polypoid inner wall thickening is a frequent finding in those cavities.

Aggressive cancer cells show histological similarities to embryonic stem cells. As differentiated cells can re-acquire pluripotency and self-renewal by transfection with the transcription factors OCT4, SOX2, KLF4 and MYC, with Nanog as readout for success, we comprehensively investigated their occurrence and frequency in human astrocytomas of different malignancy grades, primary and matched recurrent glioblastomas, short- and long-term glioblastoma cultures and glioma cell lines. Among astrocytomas, mRNA expression of OCT4, MYC and (less robust) KLF4 increased with malignancy, while in recurrent glioblastomas MYC expression slightly decreased. Correlation analysis revealed distinct positive correlation between distinct stem cell markers, and this effect was most prominent in the recurrent glioblastoma cohort. In situ, embryonic stem cell factors were found also in more differentiated tumor regions. Respective cells were rarely actively proliferating and showed single or combined expression signatures, which, at least in parts, corresponded to observed positive correlations of mRNA expression. However, a 'master-marker' defining the complete glioma stem cell subset could not be confirmed. In glioma cell lines, long- and short-term cultures, embryonic markers were detected at comparable levels. Upon exposure to temozolomide, increased expression of KLF4 (and lesser Nanog and OCT4) was observed. Experimental intrinsic overexpression of SOX2, KLF4 or OCT4 did not affect the other stem cell factors. The embryonic stem cell factors comprehensively investigated in this project can control self-renewal and pluripotency, and therefore tumorigenicity. They should be considered for the development of future diagnostic and therapeutic strategies.