Single circulating tumor cell profiling: a new perspective for targeted therapy?

Evaluation of: Powell AA, Talasaz AH, Zhang H et al. Single cell profiling of circulating tumor cells: transcriptional heterogeneity and diversity from breast cancer cell lines. PLoS ONE 7(5), e33788 (2012). Circulating tumor cells (CTCs) may represent a possible useful tool to better define the prognosis of patients. The presence of CTCs can help to predict an increased risk for disease relapse, and they might be an early marker for treatment efficacy that could help in deciding treatment continuation. Cancer metastasis occurs when cells, shed from the primary tumor, enter the circulation and begin to grow in distant locations around the body. In metastatic stages, shed cells may differ from those of the primary tumor, as the tumor phenotype can change during the course of the disease. It is important to identify relevant targets expressed on these cells to provide clinical information on therapy choice, efficacy and drug resistance. Many efforts are now devoted to the characterization of the single cell. This article focuses on the possibility of profiling single CTCs in patients with breast cancer.

Prognostic role of CA15.3 in 7942 patients with operable breast cancer.

To assess the prognostic value of presurgical CA15.3 in a large cohort of patients with early breast cancer. A total of 7.942 consecutive patients with breast cancer operated at the European Institute of Oncology between 1998 and 2005 and with presurgical values of CA 15.3 available were included. We explored patterns of recurrence by baseline CA 15.3 values. Mean CA15.3 was 17.0 U/ml. CA15.3 was associated with age, tumor size, nodal involvement, Ki-67 labeling index, grade, HER2 expression, molecular subtype, and perivascular invasion. CA15.3 was independently associated with distant metastases [HR > 20 U/ml vs. ≤ 20 U/ml: 1.34 (95% CI 1.15-1.56)] and death [HR > 20 U/ml vs. ≤ 20 U/ml: 1.30 (95% CI 1.11-1.53)]. When considering CA15.3 as continuous variable, we observed a constant risk of metastasis and death from the lowest values to about 15-20 U/ml, and then a significantly increasing risk with increasing values of CA15.3. Finally, CA15.3 provided significant additional information to the common prognostic factors to predict the occurrence of metastases (C-index P value 0.04). In patients with operable breast cancer, presurgical CA15.3 value is an independent prognostic factor for metastases and deaths. CA15.3 provides additional information to the common prognostic factors and should be considered in the adjuvant therapeutic algorithm.

Interference of antibiotic therapy on blood cultures time-to-positivity: analysis of a 5-year experience in an oncological hospital.

This study performed a retrospective analysis on the relationship between blood culture time-to-positivity (TP) and type of isolated microorganism, antibiotic administration, and immunological status of the patients. We analyzed the data related to 1,218 positive blood cultures. When compared to Gram positive bacteraemia, the percentage of Gram negative growth was higher and the mean TP significantly shorter (p < 0.0001). In patients receiving antibiotics, median and mean TPs of blood culture were different for Gram positive bacteraemia (log-rank p = 0.0022, Wilcoxon p < 0.0001) but not for Gram negative (log-rank p = 0.4011, Wilcoxon p = 0.1585). No statistically significant effect on TP was found for sampling site, interaction between sampling site and antibiotic administration, and immunological status of the patient. In conclusion, TP is independent of antibiotic therapy in cases of Gram negative bacteraemia, while for Gram positive bacteraemia a prolongation of TP occurs.

Epidermal growth factor receptor serum (sEGFR) level may predict response in patients with EGFR-positive advanced colorectal cancer treated with gefitinib?

PURPOSE: Epidermal growth factor receptor-overexpression reported in colorectal cancer, justifies therapeutic use of EGFR-inhibitors. We have recently conducted a phase II study in 57 patients with EGFR-positive advanced colorectal cancer (ACC) who received gefitinib-FOLFOX6 followed by gefitinib-single agent as maintenance. Main biological objective was to assess sEGFR as surrogate marker of tyrosine kinase inhibition and as predictor of response. METHODS: sEGFR, evaluated by quantitative ELISA, was investigated as predictive factor both taking into account the basal value only, and its whole pattern over time. sEGFR was collected at baseline and at every 2-months assessment in 42 cases. Thirty-three patients reported CR/PR as best objective response (BOR), while nine showed SD/PD. RESULTS: Retrospectively, on average, the sEGFR values reported by both responders (CR/PR) and not responders (SD/PD) were already different at baseline (49.4 +/- 6.2 and 42.4 +/- 8.4 ng/ml respectively). This difference was statistically significant (p = 0.042). Although sEGFR trend over time confirmed the basal difference (p = 0.032), this result should be taken with caution, due to the small number of patients reporting EGFR values besides the basal one. CONCLUSIONS: Higher sEGFR at baseline was associated to BOR and may be considered a significant predictor of outcome in patients with ACC.

Variation of circulating tumor cell levels during treatment of metastatic breast cancer: prognostic and therapeutic implications.

BACKGROUND: This study aimed to evaluate the prognostic significance of circulating tumor cells (CTCs) detection in advanced breast cancer patients. PATIENTS AND METHODS: We tested 80 patients for CTC levels before starting a new treatment and after 4, 8 weeks, at the first clinical evaluation and every 2 months thereafter. CTCs were detected using the CellSearch System. RESULTS: Forty-nine patients had >or=5 CTCs at baseline. At the multivariate analysis, baseline number of CTCs was significantly associated with progression-free survival [hazard ratio (HR) 2.5; 95% confidence interval (CI) 1.2-5.4]. The risk of progression for patients with CTCs >or=5 at last available blood draw was five times the risk of patients with 0-4 CTCs at the same time point (HR 5.3; 95% CI 2.8-10.4). Patients with rising or persistent >or=5 CTCs at last available blood draw showed a statistically significant higher risk of progression with respect to patients with <5 CTCs at both blood draws (HR 6.4; 95% CI 2.8-14.6). CONCLUSION: CTCs basal value is a predictive indicator of prognosis and changes in CTC levels during therapy may indicate a clinical response. Testing CTC levels during targeted treatments might substitute other measurement parameters for response evaluation.

Oxaliplatin combined with 5-fluorouracil and methotrexate in advanced colorectal cancer.

BACKGROUND: A promising regimen including 5-Fluorouracil, methotrexate and oxaliplatin is reported. PATIENTS AND METHODS: Patients with untreated measurable metastatic disease received bolus 5-Fluorouracil (600 mg/m2) on days 2 and 16, modulated by methotrexate (200 mg/m2) 24 h earlier, alternated with 4 weeks of continuous infusion of 5-Fluorouracil (200 mg/m2/daily) plus oxaliplatin (130 mg/m2) on days 29 and 56, followed by 2 weeks of rest. Serum vascular endothelial growth factor (VEGF) was analyzed at baseline and before every cycle. RESULTS: Fifty-eight patients were enrolled. Objective remissions were reported in 45.6% (95% CI=34.3%, 57.3%). The median progression-free survival was 7.8 months and the median overall survival was 19.4 months. No grade 4 toxicity was reported, except for one case of diarrhea. The serum VEGF evaluated in 23 patients showed a decreasing trend during therapy. CONCLUSION: The regimen was active, well tolerated and may be a possible option in patients not suitable for radical surgery.

Metronomic low-dose oral cyclophosphamide and methotrexate plus or minus thalidomide in metastatic breast cancer: antitumor activity and biological effects.

BACKGROUND: We previously demonstrated efficacy and impact on serum vascular endothelial growth factor (VEGF) for metronomic cyclophosphamide (C) and methotrexate (M) in patients with breast cancer. New metronomic schedules were investigated. PATIENTS AND METHODS: Patients with advanced breast cancer were randomized to receive oral C (50 mg daily) and M (2.5 mg twice daily on days 1 and 4) (arm A) or the same regimen plus thalidomide (200 mg daily) (arm B). RESULTS: The mean VEGF level decreased from 378.9 (+/-274.4) pg/ml at baseline to 305.9 (+/-203.6) pg/ml at 2 months (P<0.001), with similar change with respect to baseline in both arms. In 171 evaluable patients we observed three complete remissions (CR) in both arms A and B, 15 partial remission (PR) in arm A and seven in arm B, for an overall response of 20.9% [95% confidence interval (CI) 12.9% to 31%] in arm A and 11.8% (95% CI 5.8% to 20.6%) in arm B. The clinical benefit (CR+PR+SD>or=24 weeks) was 41.5% for both arms. Toxicity was generally mild. Higher neurological toxicity (2% versus 60%; P<0.0001) and constipation (8% versus 51%; P<0.0001) was observed in arm B. CONCLUSIONS: Metronomic low-dose CM induced a drop in VEGF, and was effective and minimally toxic. The addition of thalidomide did not improve results.

Low-dose oral methotrexate and cyclophosphamide in metastatic breast cancer: antitumor activity and correlation with vascular endothelial growth factor levels.

BACKGROUND: Anticancer chemotherapy is thought to be effective by means of direct cytotoxicity on tumor cells. Alternative mechanisms of efficacy have been ascribed to several common anticancer agents, including cyclophosphamide (CTX), methotrexate (MTX), anthracyclines and taxanes, postulating an antiangiogenic activity. PATIENTS AND METHODS: We evaluated the clinical efficacy and impact on serum vascular endothelial growth factor (VEGF) levels of low-dose oral MTX and CTX in patients with metastatic breast cancer. MTX was administered 2.5 mg bd on days 1 and 2 each week and CTX 50 mg/day administered continuously. RESULTS: Sixty-four patients were enrolled, 63 were evaluable: Eastern Cooperative Oncology Group (ECOG) performance status 0-1, > or =2 sites of metastatic disease (n = 50 patients), progressive disease at study entry (n = 51), 1 regimen for metastatic disease (n = 32) and > or =2 regimens (n = 20). Among the 63 evaluable patients, there were two complete remissions (CR), 10 partial remissions (PR) for an overall response rate of 19.0% (95% CI 10.2% to 30.9%) and an overall clinical benefit (CR+ PR+ stable disease >24 weeks) of 31.7% (95% CI 20.6% to 44.7%). Grade > or =2 leucopenia was registered in only 13 patients. The median serum VEGF level for the subgroup of patients on treatment for at least 2 months decreased with treatment from 315 pg/ml (95% CI 245 to 435) at baseline to 248 pg/ml (95% CI 205 to 311) at 2 months (P <0.001). Both responders and non-responders showed similar reductions in serum VEGF (P = 0.78). After 6 months patients still on treatment had a median VEGF level of 195 pg/ml (95% CI 96 to 355), which was significantly lower than the median baseline values (P = 0.001). CONCLUSIONS: Continuously low-dose CTX and MTX is minimally toxic and effective in heavily pretreated breast cancer patients. A drop in VEGF was associated with the treatment and so alternative hypotheses, other than that of direct toxicity on tumor cells, must be favored when trying to explain the anticancer effect.

Clinical application of growth factors for collection of circulating hematopoietic progenitors in breast cancer patients treated with high-dose cyclophosphamide.

Seventy-seven (68 operable breast cancer with > 9 metastatic axillary nodes and 9 inflammatory breast cancer) entered this study. During hematopoietic recovery after cancer therapy with high-dose cyclophosphamide (7 g/m2; HD-CTX) circulating hematopoietic progenitors were collected by leukapheresis (LK) in all patients and then cryopreserved for autologous transplantation. Following HD-CTX, 70 patients were treated with hematopoietic growth factor(s) for 14 days: 38 with rhGM-CSF (group a), 16 with rhIL-3 (group b), 11 with sequential rhIL-3 and rhGM-CSF (group c), 5 with sequential rhIL-3 and rhG-CSF (group d). Seven control patients (group e) did not receive any growth factor. Leukaphereses, carried out over 2-4 consecutive days per patient, were started earlier in group c and in group d patients (mean day: +12 after HD-CTX). The sequential administration of rhIL-3 and rhG-CSF (group d) resulted in clearly higher yield of CFU-GM and CD34+ cells per leukapheresis (65.9 x 10(4)/Kg versus 20.9 x 10(6)/Kg, respectively) if compared with other groups of treatment.

Quantization of CD34+ peripheral blood hematopoietic progenitors for autografting in cancer patients.

After myeloablative regimens, combined reinfusion of peripheral blood hematopoietic circulating progenitor cells (CPC) and bone marrow, yields a very rapid hematopoietic recovery. Therefore, based on the knowledge that CPC express the CD34 and CD33 differentiation antigen, we have developed a direct immunofluorescence flow cytometry assay to detect the peak of CPC in the peripheral blood of patients treated with high dose chemotherapy and growth factors. This assay, compared to CFU-GM assay, has the following advantages: 1) easy to do 2) standardized method 3) real time information on CPC number. This work illustrates the practical aspects of this assay and substantiate the widespread use of the CD34/33 flow cytometry assay to guide harvesting of circulating hematopoietic progenitors for autologous transplantation.

Subcellular metabolism of exogenous GM1 ganglioside in normal human fibroblasts.

The metabolization of exogenous GM1 in normal human fibroblasts at a subcellular level is investigated in the present paper. For this a GM1 ganglioside, radiolabelled on the sphingosine moiety, was given to the cells and all the formed metabolites analyzed, in a time-course study, in enriched fractions of lysosomes, plasma membrane and microsomes. After feeding the cells, the radioactivity incorporation was relevant in the enriched lysosomal and plasma membrane subfractions whereas it was modest in the enriched microsomal fraction. The kinetic curves obtained for each enriched fraction, following a 3-day chase period, suggested a translocation of exogenous GM1 from the plasma membrane to the lysosomal apparatus and, of GM1 itself together with its metabolites, to the Golgi or endoplasmic reticulum and finally again to the plasma membrane.