Biomedical subjects

Piotr Potemski

Publications and source records attributed to Piotr Potemski.

6 recordsLinked to original sources

PubMed2006

A comparative assessment of HER2 status in operable breast cancer by real-time RT-PCR and by immunohistochemistry.

BACKGROUND: The most commonly used methods for detecting HER2 gene amplification in breast cancer are immunohistochemistry and fluorescence in-situ hybridization. The aim of this retrospective study was to assess HER2 expression by real-time RT-PCR. MATERIAL/METHODS: Expression of HER2 was analyzed by real-time RT-PCR and immunohistochemistry in specimens of invasive ductal breast cancer tissue obtained from 131 women during radical mastectomy. RESULTS: There was a highly significant difference in mean relative gene expression between HER2-positive and HER2-negative patients as assessed by immunostaining (22.10+/-41.89 vs. 3.17+/-8.76; p<0.001). With a median follow-up of 56 months, the cancer-specific survival of HER2-positive patients assessed by RT-PCR was worse in all cases and in the node-positive group. In multivariate analysis, HER2 status was an independent prognostic factor in all patients. CONCLUSIONS: Real-time RT-PCR is a valuable method for determining HER2 status, but the selection of the cut-off point of the relative gene expression differentiating between HER2-negative and -positive tumors is essential.

Adult↗

PubMed2006

Ki-67 expression in operable breast cancer: a comparative study of immunostaining and a real-time RT-PCR assay.

The main purpose of this retrospective study was to compare Ki-67 expression in operable breast cancer examined by immunostaining and real-time reverse transcriptase polymerase chain reaction (RT-PCR). Relations between Ki-67 and classic prognostic factors were also investigated, and the prognostic relevance of Ki-67 expression was examined. Expression of Ki-67 was analyzed in specimens of invasive ductal breast cancer tissue obtained from 131 women during radical mastectomy. There was a significant, but weakly positive, correlation between Ki-67 expression assessed by immunostaining and real-time RT-PCR (tau=0.154, p=0.005). Higher Ki-67 expression in immunostaining and RT-PCR was more often seen in grade 3 tumors (p<0.001 and p=0.026, respectively). No significant relationship with age, disease stage, nodal involvement, estrogen receptor or HER2 status was found. In a univariate and multivariate analysis of cancer-specific survival with a median follow-up of 56 months, Ki-67 expression determined by immunostaining or real-time RT-PCR was no prognostic factor. We demonstrated that Ki-67 expression levels measured by immunostaining and real-time RT-PCR were weakly concordant, and both were related to higher tumor grade. Ki-67 expression did not influence survival.

Adenocarcinoma↗

PubMed2006

Cyclin E expression in operable breast cancer quantified using real-time RT-PCR: a comparative study with immunostaining.

OBJECTIVE: The main purpose of this retrospective study was to compare cyclin E expression levels in operable breast cancer patients determined using real-time RT-PCR and immunostaining. The prognostic relevance of cyclin E was also investigated. METHODS: Specimens of invasive ductal breast cancer tissues obtained from 124 women during radical mastectomy were analyzed. RESULTS: Of the tumor samples, 40.3 and 59.7% showed high expression of cyclin E in RT-PCR and immunostaining, respectively. The overall agreement probability was 0.032 according to Scott's pi statistic. With a median follow-up of 55.5 months, cyclin E expression assessed using immunostaining was an independent negative prognostic factor in the node positive group (hazard ratio 3.1; 95% CI 1.0-9.2; P = 0.045). Cyclin E expression correlated with absence of steroid receptors and younger age. RT-PCR results did not predict survival in any group of patients. CONCLUSIONS: Disagreement between real-time RT-PCR and immunostaining was demonstrated. Immunostaining seems to be the more reliable method for assessing cyclin E in breast cancer cells.

Adult↗

PubMed2006

Prognostic relevance of basal cytokeratin expression in operable breast cancer.

OBJECTIVE: We investigated whether basal cytokeratin (CK5/6 or CK17) expression had an impact on survival in patients with operable breast cancer. METHODS: Expression of CK5/6 or CK17 was analyzed by immunohistochemistry in 195 women with breast cancer. RESULTS: In total, 72 (37%) tumor samples were regarded as being positive for CK5/6 or CK17. The basal-like phenotype as defined by basal cytokeratin expression, lack of estrogen receptor (ER) and absence of HER2 overexpression was found in 48 (25%) cases. Positive staining for CK5/6 or CK17 was associated with worse prognosis when compared with patients negative for basal cytokeratins in all cases (5-year cancer-specific survival rate 59.4 vs. 77.5%, p = 0.0273) and in the node-negative group (70.5 vs. 90.8%, p = 0.0208) but not in the node-positive group (43.9 vs. 65.4%, p = 0.1182). To determine the real prognostic value of basal cytokeratins, survival in a group of ER-negative patients was analyzed depending on CK5/6 or CK 17 expression. No influence on survival was observed. The outcome of patients whose cancers were positive for cyclin E regardless of ER status was not changed by CK5/6 or CK17 expression. In multivariate analysis, independent prognostic factors affecting survival in the whole group included: nodal involvement, HER2 status and cyclin E expression. Neither ER status nor basal cytokeratin expression retained statistical significance. CONCLUSION: We demonstrated that the poor prognosis associated with the basal-like phenotype of breast cancer was determined by ER absence and cyclin E expression and not by CK5/6 or CK17 expression.

Adult↗

PubMed2005

Immunohistochemical identification of basal-type cytokeratins in invasive ductal breast carcinoma--relation with grade, stage, estrogen receptor and HER2.

Gene expression analyses with cDNA microarray technology identified distinct groups of breast cancers. Tumors with no ER expression could be divided into three subgroups: "basal-like" subtype, HER2-positive subtype, and "normal breast-like". "Basal-like" subtype was characterized by high expression of keratins 5 and 17, laminin and fatty acid binding protein 7. In the present study, we analyzed the usefulness of immunohistochemistry for separation of the distinct subtypes of the breast ductal carcinomas and provided further characterization of "basal-like subtype". A consecutive series of 195 primary operable invasive breast carcinomas was immunostained for HER2, ER, PGR, CK5/6 and CK17. CK5/6 or CK17 were expressed in 72 cases (36.9%), and 41 cases (21%) presented expression of CK5/6 or CK17 without ER/PGR or HER2. ER/PGR was present in 109 cases (55.9%), but in this group there were 8 cases with HER2 overexpression and 17 cases with basal-cytokeratin positivity. Similarly, in 17 out of 72 "basal-like" tumors there was ER/PGR positivity, and also in 17 of them there was HER2 overexpression. Three of these cases belonged to all three groups, representing expression of all markers. Tumor grade differed significantly (p < 0.001) between luminal and basal cytokeratin- or HER2-positive tumors. Differences for tumor size and lymph node status were not statistically significant. Our study showed that immunohistochemistry is useful for dividing breast cancers into separate subgroups, but further analyses for better characterization of cases presenting two or three markers should be performed.

Biomarkers, Tumor↗

PubMedDate not supplied

Amifostine improves hemodynamic parameters in doxorubicin-pretreated rabbits.

Amifostine reduces nephrotoxicity and myelotoxicity of alkylating agents. Little is known about its role in preventing cardiotoxicity. We studied if amifostine could affect the hemodynamic parameters in doxorubicin-pretreated rabbits. The animals were divided into six groups consisting of 6 rabbits each. Group 1--doxorubicin iv 2 mg/kg of body weight 4 times every 14 days (cumulative dose 8 mg/kg); group 2--a dose of doxorubicin was 3 mg/kg (cumulative dose 12 mg/kg); groups 3 and 4--amifostine iv 30 mg/kg 15 min prior to doxorubicin 2 and 3 mg/kg, respectively, groups 5 and 6--amifostine- and physiological saline-treated controls. Two-three weeks after the last dose the animals were anesthetized and cardiac index (CI) i.e. cardiac output/body weight, and total peripheral resistance (TPR) were calculated using the method of human I(125) albumin dilution. Mean CI was 71.4 +/- 40.5 ml/min/kg in group 2, 135.8 +/- 41.2 in group 5 (p < 0.001), and 116.4 +/- 47.8 in group 6 (p < 0.001), TPR was 4.7 +/- 3.3 kPa x s/l, 1.1 +/- 1.2 (p < 0.001), and 1.9 +/- 1.1 (p < 0.001), respectively. In group 4, CI was 135.4 +/- 33.2, and TPR was 1.1 +/- 0.6. The differences in CI and TPR between groups 2 and 4 were statistically significant (p < 0.001). In conclusion, pretreatment with doxorubicin at the total dose of 12 mg/kg significantly reduced CI and increased TPR. Amifostine improved CI and TPR in doxorubicin-pretreated rabbits.

Amifostine↗