Simultaneous detection of circulating immunological parameters and tumor biomarkers in early stage breast cancer patients during adjuvant chemotherapy

BACKGROUND

Chemotherapy-induced immune suppression has mainly been studied in patients with advanced cancer, but the influence of chemotherapy on the immune system in early stage cancer patients has so far not been studied systematically. The aim of the present study was to monitor the immune system during anthracycline- and taxane-based adjuvant chemotherapy in early stage breast cancer patients, to assess the impact of circulating tumor cells on selected immune parameters and to reveal putative angiogenic effects of circulating endothelial cells.

METHODS

Peripheral blood samples from 20 early stage breast cancer patients were analyzed using a flow cytometric multi-color of antibodies to enumerate lymphocyte and dendritic cell subsets, as well as endothelial and tumor cells. An enzyme-linked immunosorbent assay (ELISA) was used to measure the levels of various serological factors.

RESULTS

During chemotherapy, all immunological parameters and angiogenesis surrogate biomarkers showed significant decreases. The numbers of circulating tumor cells showed significant inverse correlations with the numbers of T helper cells, a lymphocyte subset directly related to effective anti-tumor responses. Reduced T helper cell numbers may contribute to systemic immunosuppression and, as such, the activation of dormant tumor cells.

CONCLUSIONS

From our results we conclude that adjuvant chemotherapy suppresses immune function in early stage breast cancer patients. In addition, we conclude that the presence of circulating tumor cells, defined as pan-cytokeratin(+), CD326(+), CD45(-) cells, may serve as an important indicator of a patient's immune status. Further investigations are needed to firmly define circulating tumor cells as a predictor for the success of breast cancer adjuvant chemotherapy.

Circulating endothelial cells and endothelial progenitors as predictive markers of clinical response to bevacizumab-based first-line treatment in advanced colorectal cancer patients

BACKGROUND

Despite the consistent clinical results demonstrated by studies on anti-angiogenic drugs targeted against the vascular endothelial growth factor in metastatic colorectal cancer (mCRC) patients, no specific direct/indirect biomarker of their efficacy has been validated. In this field, circulating endothelial cells (CECs) and endothelial progenitor cells (CEPs) have recently been proposed as noninvasive biomarkers.

PATIENTS AND METHODS

The absolute numbers of CEPs, total CECs (tCECs) and their resting (rCECs) and activated subsets were evaluated by multiparameter flow cytometry in 40 mCRC patients at baseline and before the administration of the third and sixth course of a bevacizumab-based first-line treatment. Fifty healthy subjects were utilized as control.

RESULTS

The overall response rate was 80%, overall clinical benefit was 90% and median progression-free survival (PFS) was 13.8 months. In our patients, tCECs and rCECs were significantly increased compared with healthy subjects. The patients who achieved a radiological response showed, at baseline, a significant decrease of rCECs and a trend in decrease of tCECs in comparison with patients not achieving response. Finally, a baseline absolute number of tCEC and rCEC <40 cells/ml was evidenced in patients with a longer PFS. No correlation was found regarding CEP.

CONCLUSIONS

Our study suggests significant correlations between both tCEC and rCEC baseline levels and the antitumor efficacy of a bevacizumab-based combination therapy in mCRC patients, thus confirming that these biomarkers could be used in the clinical setting as an early predictor of tumor response.

A six-colour flow cytometric method for simultaneous detection of cell phenotype and apoptosis of circulating endothelial cells

Blood circulating endothelial cells (CECs), with their resting and activated subsets, (rCECs and aCECs) and circulating progenitors cells (CEPs) are two extremely rare cell populations that are important in tissue vascularization. Their number and function are modulated in diseases involving vascular injury, such as human tumours. Although a consensus on the phenotypic definition of endothelial cells, as well as on the optimal enumeration technique, is still lacking, the number of clinical studies based on assessment of these cells is rapidly expanding, as well as the analytical methods employed. The present study aimed to develop a rapid and sensitive flow cytometric method of quantifying and characterizing CECs (with both their subsets and the apoptotic fraction) and CEPs. We analysed peripheral blood samples from 21 subjects with a six-colour flow cytometric approach allowing detection of the cell phenotype of CECs and CEPs using a monoclonal antibodies panel and a dedicated gating strategy. Apoptotic CECs were detected with Annexin V and dead cells with 7-amino-actinomycin D staining. The described technique proved to be a new, reliable, tool increasing our knowledge of the biology of CECs and CEPs and can readily be applied in the study of many pathological conditions characterized by endothelial damage.

Correlation of immunological effects of anti-VEGF therapy with progression-free survival of advanced colorectal cancer patients

e14559

Background: The clinical efficacy of Bevacizumab (BEV) in advanced colorectal cancer (mCRC) could be related not only to its well-established effect on tumor neoangiogenesis but also to a counteraction of VEGF-mediated dendritic cell (DC) abnormalities. The addition of BEV to chemotherapy (CT) may improve the number and function of blood DCs in cancer pts. We have focused on the correlation between this effect and the clinical efficacy of a BEV-based, 1st-line treatment for mCRC. Methods: Starting from January 2007 we performed a flow cytometric analysis of PB lymphocytes and DC subsets in 53 mCRC pts who had not received prior CT for metastatic disease or for whom 6 months had elapsed since adjuvant CT (M/F: 31/22, median age: 59yrs; range 32–75; ECOG PS <2), before and every 3 courses of a BEV+CT (5-FU± CPT11± Oxaliplatin) program. Biological data of the 42 evaluable pts that received all the planned treatment were correlated to both tumor response (OR) and progression free survival (PFS). Results: During treatment, DCs and their subsets showed a progressive, significant increase in absolute number, with respect to baseline, both in responder (CR,PR,SD) (67%) and in non responder pts. This effect on the DC profile was evidenced in responder pts up to 4 weeks since the last treatment course. After therapy completion, pts with PFS > 15 months (58%) showed DC and DC1 absolute number significantly higher with respect to pts with shorter PFS (p< .02). Conclusions: The recovery of blood DCs induced by 1st- line, BEV-based therapy in mCRC pts indicates a potential additional anticancer mechanism of this drug. The improvement of DC number does not influence OR but correlates with longer PFS. This suggests that BEV can influence tumor regrowth by contributing to overcome the impairement of the host immune surveillance induced by VEGF.

No significant financial relationships to disclose.

Lack of effect of pegfilgrastim on anemia in breast cancer patients treated with dose-dense chemotherapy

11071

Background: A greater risk of anemia has been evidenced among breast cancer (BC) pts receiving dose-dense CT. A recent report showed that filgrastim may play a role in worsening anemia in BC pts receiving intensified Epirubicin (E) + Cyclophosphamide (CTX), by inducing stem cells to differentiate into more committed hematopoietic progenitors (Papaldo P. JCO, 2006). No data are available about the impact of pegfilgrastim-induced leucocytosis on Hb levels without prophylactic erythropoietic support. Methods: We have focused on this point in 36 BC pts. 14 N+ pts received 4 cycles of E 90 mg/sqm + CTX 600 mg/sqm every 14 days in adjuvant setting. 22 pts with locally advanced disease received 4 cycles of E 75 mg/sqm + Docetaxel 80 mg/sqm every 14 days as primary CT. All pts received prophylactic pegfilgrastim 6 mg s.c, after CT. Three groups were defined on the basis of WBC: A = <10 x 103/mL; B = between 10 and 20 x 103/mL and C = > 20 x 103/mL. WBC and Hb levels at the beginning of treatment were normal in all pts and were subsequently determined on day 1 of each treatment cycle. Results: All pts received the planned CT dose intensity. Only 3 pts developed G2 anemia and were excluded from the analysis, because of receiving darbepoietin alpha support. Among the 14 pts treated in adjuvant setting, 5 dropped in group A, 6 in group B and 3 in group C. The mean Hb decrease from the baseline to the last CT course was - 1.5 g/dL; -1.4, -1.8 and -1.4 in group A, B and C, respectively. In the primary setting, 4 pts dropped in group A, 12 in group B and 4 in group C. The mean Hb decrease was -1.5 g/dL; -1.3, -1.4 and -1.8 in group A, B and C respectively. No statistically significant correlation was found between the Hb levels and the degree of leukocytosis. Conclusions: Pegfilgrastim does not worsen anemia in BC pts treated with dose- dense CT, even when its use is related to some degree of leucocytosis.

No significant financial relationships to disclose.

Reduced number and function of peripheral dendritic cells in coeliac disease

Dendritic cells (DC) play a pivotal role in shaping the immune response in both physiological and pathological conditions. In peripheral blood at least two subsets, the myeloid and plasmacytoid, have been described as having different T stimulatory functions and a variable degree of maturation. Certainly, antigen presentation plays a crucial role in the pathogenesis of coeliac disease and circulating immune cells are thought to reflect the state of immune response within the gut. Therefore, we aimed to investigate the quantitative and phenotypical modifications of peripheral blood DC, together with their functional properties, in this pathological condition. Blood samples from 11 untreated patients before and after a course of gluten-free diet, 27 treated patients and 14 controls underwent flow-cytometric analysis, while immunomagnetically sorted DC from the CD patients and eight human leucocyte antigen (HLA)-DQ2/8(+) bone marrow donors were used to evaluate maturation status through the CD83 expression, cytokine profile for interleukin (IL)-6, IL-10, IL-12 and interferon (IFN)-alpha by enzyme-linked immunosorbent assay (ELISA), and functional properties by mixed leucocyte reaction before and after pulsing with digested gliadin. We found that in both untreated and treated patients, a significant reduction of the entire DC population, mainly the plasmacytoid subset, in comparison to healthy controls was observed. In active disease, an impaired allogenic lymphocyte reaction and a significant reduction of IFN-alpha production, paralleled by the presence of a more immature status, were also demonstrated. All the latter modifications have been reverted by pulsing DC with digested gliadin.

Biological effects of pegfilgrastim after myelosuppressive chemotherapy in breast cancer

10521

Background: The dose and schedule of chemotherapy (CT), that play a crucial role in the outcome of pts with chemosensitive tumors, were made feasible with the primary use of colony stimulating factors. Few data are available on the in vivo biological effects of the “long-lasting” cytokine pegfilgrastim. We have focused on the cytokinetic effects on the CD34+/38+ peripheral blood (PB) progenitor cell subset and on its influence on neutrophils functional parameters. Methods: We studied PB samples from 14 breast cancer pts (median age 47 yrs; 35–61 yrs), treated with Docetaxel (80 mg/sqm, d 1) + Epirubicin (75 mg/sqm, d 1) + pegfilgrastim (6 mg s.c. on d +1). The % of CD34+/38+ circulating progenitor cells (CPCs) (sorted with immunomagnetic procedure) undergoing G0/G1, S and G2/M phases of the cell cycle or showing apoptotic features were evaluated using flow cytometry. Annexin V was quantitated at a single cell level and correlated with cell cycle phases. On PB buffy coat smears, alkaline phosphatase activity by cytochemistry, actin polymerization using FITC-labelled phalloidin and apoptosis by TUNEL technique, were evaluated on neutrophils. Results: Seven days following CT + pegfilgrastim the CD34+/38+ absolute numbers were: 46 (27–74) and 41 (25–66) on day 14+ from CT.On day 7+ the % of CD34+/38+ CPCs in S-phase was 13.0 ± 9 while 3.7% ± 6 of this cell subset showed apoptotic features. One week later, these values were 8.4% ± 7 and 7.7% ± 5, respectively. We also observed: stability of the absolute neutrophil count for all the duration of treatment; a significant increase of the leucocyte alkaline phosphatase; abnormalities of actin assembly in neutrophils, indicative of changes in cytoskeleton organization, and a significant reduction of neutrophil apoptosis. Conclusions: 1) pegfilgrastim exerts stimulatory effects on cell cycle status of PB CD34+/38+ CPCs, protecting them from apoptosis; this is evident 7 days after its administration and tends to decrease one week later 2) pegfilgrastim improves the neutrophil function by inhibiting their accelerated apoptosis and prolonging survival. These data could be useful when dose-dense CT is planned with pegfilgrastim support.

No significant financial relationships to disclose.

Impaired bone marrow hematopoietic progenitor cell function in rheumatoid arthritis patients candidated to autologous hematopoietic stem cell transplantation

We have evaluated bone marrow morphology, percentage of bone marrow CD34(+) cells, proliferative activity of bone marrow precursors, clonogenic assay (BFU-E and CFU-GM) in short-term bone marrow cultures, and bone marrow cell apoptosis, together with serum TNF-alpha and IL-6, in 16 chronic, refractory RA patients, as well as in five healthy controls. Of 16 RA patients (68.7%), 11 showed a reduced bone marrow cellularity, while it was normal in all the controls. In RA patients, the median percentage of CD34(+) bone marrow cells, the median percentage of proliferating bone marrow myeloid precursors, and the median number of both BFU-E and CFU-GM colonies were significantly lower than observed in the controls. As far as TNF-alpha and IL-6 titers is concerned, the latter did not significantly differ from controls' values, while TNF-alpha titers were significantly lower in healthy controls. Finally, the median apoptotic index of early bone marrow myeloid cells of RA patients was significantly higher compared with controls. These observations may identify the biological risk factors for impaired mobilization and/or engraftment when RA patients are candidates for autologous hematopoietic stem cell grafting.

AL amyloidosis. Characterization of amyloidogenic cells by anti-idiotypic monoclonal antibodies

BACKGROUND

AL amyloidosis is characterized by systemic tissue deposition of monoclonal Ig light chains synthesized by a bone marrow plasma cell (PC) clone whose biologic characteristics remain undetermined.

EXPERIMENTAL DESIGN

Anti-idiotypic (anti-Id) monoclonal antibodies (MoAbs) were used as specific probes to identify and study amyloidogenic cells in two patients by means of immunofluorescence methods. These MoAbs recognized populations of bone marrow pre-PC, PC, and peripheral blood lymphocytes. To test whether the circulating Id+ lymphocytes were capable of PC differentiation, peripheral blood lymphocytes were incubated with the differentiation-inducing agents, interleukin-3 and interleukin-6 in liquid culture. Preincubation with the anti-Id MoAb and complement was used to inhibit formation of Id+PC in vitro.

RESULTS

The anti-Id MoAb identified three types of cells in the bone marrow with cytoplasmic Ig having the same isotype as the monoclonal component: a) lymphoid cells, that were slightly larger than common peripheral blood lymphocytes (47% CD45RA+, 28% CD45R0+, 97% CD38-, 100% CD10-, 100% mu-chain-); b) lymphoplasmacytoid cells with more abundant cytoplasm and Id+ Ig (CD45RA-, CD45RO-, CD10-, 53% CD38+); 3) mature PC that were very similar to normal PC in morphology and antigenic profile (CD38+, PCA1+, CD56-). A different picture was seen when anti-Id MoAb were used to detect peripheral blood Id+ elements: analysis revealed a population of mature resting surface Ig+ B lymphocytes. Circulating Id+ lymphocytes differentiated in vitro to PC and lymphoplasmacytoid cells that were very similar to those present in the bone marrow. A significant reduction in the number of Id+ PC was obtained after incubation with the anti-Id MoAb and complement.

CONCLUSIONS

This study shows that the amyloidogenic cell clone is constituted by at least the following cell populations: a fraction of bone marrow cells (lymphoid, lymphoplasmacytoid cells and PC) and a subset of peripheral blood post-switched B lymphocytes. The results suggest a relationship among these cells, indicating that circulating Id+ lymphocytes may be the possible precursors of the more differentiated bone marrow population.