Computer assisted quantitative immunofluorescence of tumor tissue marker expression and clinical outcome to chemotherapy in advanced breast cancer patients.

Chemotherapy is frequently used in the treatment of advanced breast cancer. The identification of patient-specific tumor characteristics that can improve the ability to predict response to chemotherapy would help optimize advanced breast cancer treatment approaches. Quantitative immunofluorescence (QIF) may be applied to the standardization of protein analysis, resulting in increased sensitivity and reproducibility. In the current pilot study, QIF was used to correlate the expression of beta tubulin III and thymidylate synthase with clinical outcome associated with taxane and capecitabine treatment, respectively. QIF analysis is based on fluorescent dye-labeled monoclonal antibody staining followed by computer-assisted microscopy to measure the expression of molecular markers in tumor samples derived from a retrospective database. The interpretation of the tumor marker expression levels results in classification of breast tumors as sensitive or resistant to a mechanistically related drug. Overall diagnostic accuracy of QIF for taxane based therapy was 88% (CI 75.0 - 95.3) with a positive predictive value of 86% and a negative predictive value of 100%, while diagnostic accuracy QIF for capecitabine therapy was 86% (CI 88.0-96.0) with a positive predictive value of 80% and a negative predictive value of 100%. In this study, QIF showed retrospectively a potential for predictive value when analyzing chemotherapeutic treatments for individual advanced stage breast cancer patients. The predictive power of the QIF for chemotherapy confirms that further studies utilizing larger clinical cohorts are warranted.

Assessment of circulating tumor cells (CTCs) in prostate cancer patients with low-volume tumors.

The objective of this study was to assess the incidence of circulating tumor cells (CTCs) in prostate cancer patients with low-volume tumors (less than 0.5 cc) after radical prostatectomy (RP). Blood samples were collected from 64 RP patients to assess the incidence of CTCs following RP. The specimens were processed by whole-mount section. Clinicopathological data (e.g. patient age, race, specimen weight, tumor volume, grade, stage and surgical margin status) and follow-up PSA data were compared to CTC status. Of the 64 RP patients, nine had 'low-volume prostate cancer'. Seven of these patients had detectable levels of CTCs. In two of the seven patients with detectable CTCs, PSA elevation was also observed. Isolation and detection of circulating epithelial cells is possible in low-volume prostate cancer patients. In the setting of low-volume prostate cancer, CTCs may be associated with the presence of detectable PSA levels. However, the detection of CTCs did not predict PSA failure.

The significance of circulating epithelial cells in Breast Cancer patients by a novel negative selection method.

PURPOSE: A negative selection method for the enumeration and characterization of circulating epithelial/cancer cells (CCC) in Breast Cancer (BC) patients is described. This manual procedure yields reproducible results of high sensitivity and selectivity suitable for research laboratories. PATIENTS AND METHODS: We conducted a prospective blood sampling study in 105 women with stage 1-4 BC attending clinics at the University of Maryland Greenebaum Cancer Center to define the prevalence of CCC utilizing our sensitive double gradient centrifugation and magnetic cell sorting CCC detection and enumeration method. CCC were isolated and enumerated from 15 to 20 ml of venous blood drawn before the start of systemic therapy and periodically thereafter for up to 24 months. One or more CCC/sample was considered a positive result. RESULTS: We analyzed 487 samples for the presence of CCC; the median number of samples/patient was 4 (range 1-8). CCC were detected in 56% of patients, 19%-stage 1; 43%-stage 2; 46%-stage 3; 83%-stage 4. The probability of being positive for the presence of CCC is significantly associated with the stage of cancer (P < 0.0001). The frequency of CCC positive patients and samples increased with the advancing stage of disease. Presence of more than 10 CCC/sample was associated with the decreased survival and increased probability of having metastatic disease P = 0.001. CONCLUSIONS: Increasing number of CCC/sample correlates with the adverse outcome and poorer survival (P < 0.0001). Our CCC test based on the negative selection procedure may provide valuable prognostic information.