Borislav Belev

Role of Ki-67 as a prognostic factor in gastrointestinal stromal tumors

AIMnTo investigate primarily the prognostic value of Ki-67, as well as other parameters, in gastrointestinal stromal tumors (GISTs).nnnMETHODSnKi-67, c-KIT, platelet-derived growth factor receptor-alpha (PDGFRα), smooth muscle actin (SMA), CD34, S100 were stained for immunohistochemistry which was performed on formalin-fixed, paraffin-embeded sections on representative block from each case. Proliferation index counted by Ki-67 antibody was calculated as a number of positive nuclear reaction over 100 cells. Immunoreactivity for c-KIT and PDGFRα was evaluated semiquantitatively (weak, intermediate, strong) and for c-KIT type of reactivity was analyzed (cytoplasmic, membrane and dot-like staining). Immunoreactivity for SMA, CD34 and S100 were was evaluated as positive or negative antigen expression. Pathologic parameters investigated in this study included tumor size, cell type (pure spindle, pured epitheloid mixed spindle and epitheloid), mitotic count, hemorrhage, necrosis, mucosal ulceration. Clinical data included age, gender, primary tumor location and spread of disease. χ² test and Students t-test were used for comparisons of baseline characteristics. The Coxs proportional hazard model was used for univariable and multivariable analyses. Survival rates were calculated by Kaplan-Meier method and statistical significance was determined by the log-rank test.nnnRESULTSnAccording to the stage of disease, there were 36 patients with localized disease, 29 patients with initially localized disease but with its recurrence in the period of follow up, and finally, 35 patients had metastatic disease from the very beginning of disease. Tumor originated most commonly in the stomach (41%), small intestine was the second most common location (36%). The mean size of primary tumors was 6.5 cm. The mean duration of follow-up was 60 mo. Multiple parameters were analyzed for their effect on overall survival, but no one reached statistical significance (P = 0.06). Analysis of time to progression/relapse in initially localized disease (univariate analysis), tumor size, mitotic count, Ki-67 and type of d-KIT distribution (cytoplasmic vs membrane/dot-like) showed statistically significant correlation. In multivariate analysis in the group of patients with localized disease, there were only 2 parameters that have impact on relapse, Ki-67 and SMA (P < 0.0001 and P < 0.034, respectively). Furthermore, Ki-67 was analyzed in localized disease vs localized with recurrence and metastatic disease. It was shown that there is a strict difference between these 2 groups of patients (median value was 2.5 for localized disease vs 10.0 for recurrent/metastatic disease, P < 0.0001). It was also shown that the cut-off value which is still statistically significant in terms of relapse on the level of 6%. The curves for survival on that cut-off level are significantly different (P < 0.04, Cox F).nnnCONCLUSIONnKi-67 presents a significant prognostic factor for GIST recurrence which could be of great importance in evaluating malignant potential of disease.

Nm23 gene product expression in invasive breast cancer: Immunohistochemical analysis and clinicopathological correlation

The nm23 gene/protein is a putative metastatic suppressor identified a decade ago in a melanoma cell line. A number of laboratory, clinical and pathological studies have been carried out to define its real biological and biochemical function as a step in a complex metastatic process. In our study we examined the significance of nm23 expression in 164 breast cancer patients, aged 35 to 74 years, in comparison to other parameters such as age, menopausal status, histological grade, tumor size, lymph node status, and hormone receptor status. Overall survival (OS) and disease-free survival (DFS) were analyzed. The median follow-up was 84 months. Significant changes in OS were found for tumor size, nodal involvement and histological grade but there was no convincing correlation with nm23 expression. When patients were stratified according to nm23 expression, it was shown that overall survival in nm23 -positive patients was no longer than that in nm23 negative patients. It was also shown that patients who were lymph node negative and older than 50 years had longer OS than nm23 -negative patients. A statistical analysis shows that there is a correlation between axillary node status and nm23 expression (p = 0.018) as well as between patients ages and nm23 expression (p = 0.043). There was no statistically significant correlation between nm23 expression, lymph node status and their combination on DFS.

Prognostic value of different factors in breast carcinoma.

Introduction The aggressive biological behavior of invasive and metastatic cancer is considered to be the most insidious and life-threatening aspect for breast cancer patients. It is mostly the result of changes in many molecular characteristics of tumor cells, including alterations in the mechanisms controlling cell growth and proliferation. Aim The aim of this retrospective study was to identify predictors of aggressive biological behavior and metastatic potential in breast carcinoma among a number of intrinsic bio-markers of tumor cells such as steroid receptors and oncogene and tumor suppressor gene products. Methods Routine formalin-fixed, paraffin-embedded tumor samples were used and sections were stained immunohistochemically with the DAKO Strept ABC method to determine the expression of estrogen receptors (ER), progesterone receptors (PgR), HER-2/neu, bcl-2, Ki-67, p53 and nm23 in 192 consecutive breast carcinoma patients. The results of the quantitative immunohistochemical assays were correlated with clinical and histological data such as patient age, overall survival, tumor size, axillary lymph node status, hystological type, tumor grade, Nottingham prognostic index (NPI) and therapeutic regimens. Results Univariate analysis revealed that survival was significantly longer for patients with small tumors (P = 0.007), lower tumor grade (P = 0.021), negative axillary lymph nodes (P = 0.002), presence of nm23 protein (P = 0.002), and for patients treated with adjuvant hormonal therapy (P = 0.010). In multivariate analysis the independent factors positively affecting survival were absence of axillary lymph node metastases (P = 0.002), nm23 expression (P = 0.009) and hormonal therapy (P = 0.050). Among patients with positive axillary nodes there was a significantly higher survival rate in patients with nm23 expression compared with nm23-negative patients (P <0.001). Conclusion Identification of a subset of node-positive breast cancer patients with a more favorable prognosis according to nm23 expression might be clinically useful.

Changes in serum lipid and lipoprotein levels in postmenopausal patients with node-positive breast cancer treated with tamoxifen.

Tamoxifen has been used for a long time as an adjuvant hormonal treatment in breast cancer patients. We studied 62 newly diagnosed postmenopausal women, aged 50-79 years, with node-positive breast cancer and receiving adjuvant tamoxifen (20 mg per day). Total serum cholesterol, triglycerides, HDL-cholesterol, LDL-cholesterol, VLDL-cholesterol, apo AI, apo AII, apo B and Lp(a) were determined before the surgery and 3, 6, 9, 12 and 24 months after starting tamoxifen treatment. Tamoxifen significantly reduced total serum cholesterol (6.13 ± 1.20 mmol/L vs 5.21 ± 1.05 mmol/L) (P <0.01), LDL-cholesterol (3.72 ± 0.70 mmol/L vs 2.93 ± 0.51) (P <0.01) and Lp(a) (0.11 ± 0.07 g/L vs 0.02 ± 0.01 g/L) (P <0.01). There were no changes in triglycerides or HDL-cholesterol serum levels during tamoxifen treatment. The results indicate that an additional beneficial effect of adjuvant tamoxifen therapy may be that it decreases cardiovascular risk in such patients.

Lack of prognostic significance of connexin-43 labeling in a series of 46 gastrointestinal stromal tumors

Background Gastrointestinal stromal tumors (GISTs) are mesenchymal tumors with variable malignant potential. Connexin-43 (C×43) is the commonest gap-junction protein and has been frequently investigated in oncology. Our aim was to establish the immunohistochemical expression of C×43 in relation to GIST location, size, Ki67 index, tumor grade and follow-up. Materials and methods The study included postoperative samples of 46 patients treated for GIST in the 1999–2010 time frame. Complete clinical workup was available for 38 patients (82.6%); total surgical resection was carried out in 32 (84.2%) patients, while 13 (34.2%) patients underwent chemotherapy. Median follow-up was 40.7 months (range, 1-134). Results The calculated incidence of GIST in our setting was 11.5 per million. C×43 was expressed in 43/46 (93.5%) GIST cases, with a significant difference between stomach- and small intestine-derived tumors (p=0.006). Ki67 was 10% on average (range, 1–22) and was not correlated with tumor location (p=0.194). C×43 did not show significance with regard to tumor size (p=0.264) or higher tumor grade (p=0.658), as opposed to Ki67, which significantly correlated with both (p=0.0048 and p<0.001, respectively). C×43 and Ki67 were not significantly correlated (p=0.708). Ki67 correlated with time to recurrence (p=0.022). Ki67 >11% was taken as the indication to start imatinib chemotherapy (sensitivity 61.5%, specificity 92.0%, p=0.022). Ten (66.7%) of 15 patients with long-term (>5 years) follow-up were in remission. Conclusion C×43 was frequently expressed in GISTs regardless of tumor site. However, no significant relationships to histopathological parameters suggestive for prognosis were found. Further investigations might clarify the roles of C×43 in GIST oncogenesis.

Significance of surgery for prognosis of gist in cohort from transitional healthcare settings

OBJECTIVEnDespite significant improvement in survival of gastrointestinal stromal tumors (GIST) due to use of tyrosine kinase inhibitors, surgery still represents the important part of clinical management. The aim of our study was to retrospectively analyze prognosis of GIST depending on the success of surgical treatments and utilization of chemotherapy in transitional country with relatively limited resources.nnnMETHODSncohort of consecutive patients operated for GIST in tertiary medical center, within time frame 1999-2012.nnnRESULTSn54 patients, in age range 20-85 years (63.3 ± 14.7), male to female ratio 28 (51.9%):26 (48.1%), respectively. Complete excision with clean resection margins (R0) was obtained in 44 (81.5%)of total patients i.e. 44/47 (93.6%) of localized GISTs. Mean follow up was 3.9 ± 3.3 years and 19 patients (35.2%) received imatinib. Rate of overall survival was 40 (74.1%), disease-free survival 31 (57.4%) and 20 (37.0%) experienced recidivism. Follow-up parameters showed significant difference in connection with utilization of imatinib, completeness of resection and existence of metastatic disease (all p < 0.05). ROC analyzes revealed critical value of Ki-67 > 9% as significant predictor of long-term mortality; sensitivity 64.3% [95%CI = 35.1-87.2]; specificity 75.0% [58.8-87.3]; (AUC = 0.693; p = 0.049).nnnCONCLUSIONnRate of complete resections in studied sample of patients from transitional background was overall peer comparable with reports from the developed countries. On the other hand, relatively dominant prognostic position of surgical treatments might be consequence of limited utilization of adjuvant treatment with tyrosine kinase inhibitors.