[Smooth muscle tumors of uncertain malignant potential]. / Gladkomyshechnye opukholi s neopredelennym zlokachestvennym potentsialom.

OBJECTIVE: To investigate microsatellite instability in smooth muscle tumors of uncertain malignant potential and to compare the results with clinical and morphological data. SUBJECT AND METHODS: Histological and immunohistochemical studies were conducted in 26 patients aged 30-63 years (mean age, 37 years) with leiomyomatosis; which revealed intravenous leiomyomatosis in 20 cases, metastasizing leiomyoma in 2, disseminated peritoneal leiomyomatosis in 3, and smooth muscle tumor of uncertain malignant potential in 1 case. Microsatellite instability was studied by fragment analysis on a genetic analyzer using a test system of six markers: D10S1146, D10S218, D10S24, D10S1213, D3S1295, and D9S942. RESULTS: Microsatellite repeat changes characteristic of leiomyosarcomas (heterozygosity loss and/or microsatellite instability in at least one locus studied) were found in 6 patients; all were clinically and morphologically diagnosed as having intravenous leiomyomatosis. In 3 of these 6 cases, leiomyomatosis was accompanied by metastases to the lungs and spread to the peritoneum; heart damage was noted in 2 cases. The data analysis did not allow identification of any significant clinical and morphological criteria for this group. CONCLUSION: Leiomyomatosis is not a transitional form from benign leiomyoma to leiomyosarcoma, as evidenced by the difference in the status of molecular markers. Analysis of molecular genetic changes in DNA from tumor tissue samples cannot categorically clarify the nature of the disease by identifying the signs of genetic instability; however, there is a need for further accumulation of experience in studying tumors of this group and in identifying the possible association with disease prognosis.

[Procedure for intraoperative material examination in breast cancer after neoadjuvant therapy to estimate residual cancer burden using the RCB system].

Currently, neoadjuvant therapy has been shown to be effective in treating HER2-positive breast cancer; the development and assessment of novel medications and therapy regimens are being continued. A tumor response to the treatment is the most important factor in planning adjuvant therapy. The use of different systems to evaluate a therapeutic effect gives rise to significant differences in estimating the rate of complete morphological regression according to the results of performed therapy. The paper describes a procedure to estimate cancer burden using the RCB system. This procedure is highly reproducible and recommended by the 2015 European Society for Medical Oncology Clinical Practice Guidelines for the management of primary breast cancer.