G. Robustelli Della Cuna

Mitomycin C as an alternative to irradiation to inhibit the feeder layer growth in long-term culture assays

BACKGROUND Mitomycin C (MMC), an antitumoral antibiotic, has been described inhibiting the proliferation of different cell types in vitro. Since irradiation is commonly used to stop the cell growth of adherent cells in several experimental models, we aimed to define the optimal dose and incubation time of MMC capable of inhibiting the growth of murine fibroblasts, used as an adherent feeder layer in long-term hematopoietic culture assay. METHODS M2 10B4 (both parental and engineered to produce human IL-3 and G-CSF) and Sl/Sl (engineered to produce human IL-3 and steel factor) murine fibroblast cell-lines, frequently used in LTC-IC assay, were incubated with increasing doses of MMC for either a short (3 h) or a long (16 h) period. The efficiency of MMC in stopping the cell growth was evaluated for 5 days following MMC removal. The effects of MMC treatment on human hematopoietic cells were studied using both LTC-IC and limiting dilution (CAFC) assays. RESULTS The growth of M2 10B4 cells was stopped at 3 and 16 h in the presence of 20 microg/mL and 2 microg/mL of MMC, respectively while Sl/Sl fibroblasts required a lower dose of drug (2 and 0.2 microg/mL, respectively). No significant difference was found between the number of LTC-IC or CAFC obtained from cultures containing irradiated or MMC-treated feeder cells. DISCUSSION MMC inhibits the growth of murine fibroblasts used as adherent feeder cells in long-term culture assays, without interfering with the subsequent growth of co-cultured hemopoietic cells. Different cell types might present a different sensitivity to MMC and therefore a dose-response curve to MMC has to be obtained for each cell type of interest.

Epithelial tumour cell detection and the unsolved problems of nested RT-PCR: a new sensitive one step method without false positive results

Sensitive detection of circulating epithelial cancer cells might have important therapeutic and prognostic implications in patients with breast cancer (BC) receiving high-dose chemotherapy and PBSC support. We have compared the specificity and sensitivity of the recently developed ‘one tube’ reverse transcriptase PCR (RT-PCR) assay with the more widely used nested RT-PCR method for detection of cytokeratin 19 (CK19)-positive cells. The analysis of 30 control samples provides evidence that one tube RT-PCR is highly specific in contrast to the nested method which showed 23% false positive results. The sensitivity of both techniques to detect tumour contamination was 10−6. PBSC harvests from 45 BC patients were tested with both RT-PCR methods and the results were compared with immunocytochemistry (ICC). The five samples found positive by ICC were also positive by one tube RT-PCR; in addition, 11 more samples were positive by one tube RT-PCR analysis. The greater number of PBSC found positive by one tube RT-PCR might be due to the larger number of cells analysed. We conclude that one tube RT-PCR is sensitive and reveals no false positive results. This method is less time consuming than the nested one, technically simpler and should be considered for tumour cell detection.

A new 'two step' procedure for 4.5 log depletion of T and B cells in allogeneic transplantation and of neoplastic cells in autologous transplantation

To evaluate a new ‘two step’ method for purging T, B and neoplastic cells from hematopoietic progenitor cells (PC), PCs were collected by apheresis and some suspensions were deliberately contaminated with 2–5% breast cancer cells. PCs were first processed through CellPro columns for positive selection of cells that express CD34. After this first step, the mean CD34+ cell recovery was 68 ± 12%, and CD34+ cell purity was 61 ± 11%; CD3+ and neoplastic cell depletion were 2.1 ± 0.4 and 1.9 ± 0.4 logs, respectively. Cells were further processed through the StemSep device for direct depletion of T and B cells or of breast cancer cells. After the first and the second step, overall CD34+ cell recovery was 50 ± 7%, T and B cell removal was 4.7 ± 0.4 log and neoplastic cell purging was 4.4 ± 0.3 log, ie significantly superior to methods described in the past.

Role of tumor cells contaminating the graft in breast cancer recurrence after high-dose chemotherapy

One of the possible drawbacks to autologous stem cell transplantation in breast cancer (BC) patients is the potential for tumor contamination in the transplanted product. We present a patient with advanced disease who received high-dose chemotherapy (HDC) and PBPC support as consolidation therapy after achieving complete remission with standard-dose first-line treatment, and suffered recurrence of the disease 6 months after transplantation. Retrospective analysis revealed the presence of contaminating cells in the leukapheretic product, and clinical evidence suggested a role for these cells in the tumor relapse.

Four-day infusion of fluorouracil plus vinorelbine as salvage treatment of heavily pretreated metastatic breast cancer.

AbstractAims.Anthracyclines-taxanes containing regimens are widely used for breast cancer treatment both in neoadjuvant–adjuvant setting and in metastatic disease. Recently high-dose chemotherapy (HDC) with autologous stem cell support has been introduced as adjuvant treatment for high-risk primary breast cancer and for selected subsets of women with metastatic disease. Therefore, salvage treatment for previously treated patients with progressive disease becomes even more problematic. A regimen of continuous infusion of fluorouracil (FU) and vinorelbine (VNR) has been evaluated in heavily pretreated metastatic breast cancer patients. Patients and methods.Forty-eight women, median age 52 years, with previously treated breast cancer entered the study. All but one received more than one line of prior systemic chemotherapy for metastatic disease. Furthermore 14 women had undergone HDC with peripheral blood progenitor cells transplantation in adjuvant setting (6 pts), or metastatic disease (8 pts). Treatment consisted of four-day infusion of FU (1000 mg/m2/day) plus VNR (20 mg/m2/iv. day 1 and 5), recycled every 3 weeks for a total of six courses. Drugs administration was discontinued for G4 toxicity, tumor progression or patients refusal. Results.Twenty PR and four CR for an overall response rate of 50% (95%C.I. 36–64%) were recorded. The therapeutic efficacy of the tested regimen was documented both in patients unresponsive to previous anthracyclines-taxanes combinations and in those relapsing after HDC. The median duration of response was 9 months and median survival 16 months. One third of patients experienced Grade-3 stomatitis–mucositis, hematological toxicity was mild and no cardiac toxicity was observed. Twentyfive women (52%) suffered from infusion-related phlebitis (in half of patients a central venous device was necessary at some point of the treatment program). Conclusions.The combination of FU infusion and VNR iv is an effective salvage treatment for heavily pretreated metastatic breast cancer patients, and may represent a valid alternative when other cytotoxic regimens are not feasible.

Collection of circulating progenitor cells after epirubicin, paclitaxel and filgrastim in patients with metastatic breast cancer.

The efficacy of high-dose chemotherapy (HDC) and circulating progenitor cell (CPC) transplantation in metastatic breast cancer (MBC) relies mainly on giving this treatment after a response to conventional induction chemotherapy has been achieved. For this reason an optimal mobilization regimen should be therapeutically effective while minimizing the number of leucaphereses required to support the myeloablative therapy. The combination of an anthracycline and paclitaxel in chemotherapy-untreated MBC has produced impressive response rates. We evaluated the CPC-mobilizing capacity of the combination epirubicin (90 mg m(-2)) and paclitaxel (135 mg m(-2)) followed by filgrastim (5 microg kg(-1) day(-1)) starting 48 h after chemotherapy administration in ten patients with MBC who were eligible for an HDC and CPC transplantation programme. Leucaphereses were performed by processing at least two blood volumes per procedure at recovery from neutrophil nadir when CD34+ cells in the peripheral blood exceeded 20 microl(-1). In most patients (six out of 10) more than 2.5 x 10(6) CD34+ cells kg(-1), a threshold considered to be sufficient for haematopoietic reconstitution, were collected with a single apheresis. In the remaining four patients an additional procedure, performed the following day, was enough to reach the required number of progenitors. These data suggest that the epirubicin-paclitaxel combination, besides being a very active regimen in MBC, is effective in releasing large amounts of progenitor cells into circulation.

Hormonal modulation of brain tumour growth: a cell culture study

SummaryTissue samples derived from two neuroepithelial tumours and five meningiomas were obtained at surgery from seven patients and cultured in order to study the effect of dexamethasone (DEX) and testosterone acetate (TA) on cell proliferation.Glucocorticoid and androgen receptors (GR, AR) were determined both on tissue samples (7 cases) and on five out of the seven cell cultures obtained by tumours.GR and AR were present respectively in 5 and in 4 out of the tumour specimens assayed and in 4/5 and 2/3 of the tested cell cultures.DEX activity on cell growth was tested on six cell cultures. Four of them showed a significant growth inhibition at the highest drug concentration. On the contrary, a significant growth stimulation was observed in four out of the five cultures, where GR were present, using low hormone concentrations. Treatment with pharmacological doses of TA caused a significant cytotoxicity in all the tested cultures. Low TA concentrations inhibited cell growth in one out of the two cell cultures which contained AR, but were ineffective in cultures lacking AR.Our preliminary results suggest a possible role in growth regulation by DEX and TA in intracranial tumours, on the basis of the presence of specific hormone receptors.

Randomized, Controlled, Multicenter Phase III Trial of Standard-Dose Fluorouracil-Epirubicin- Cyclophosphamide (FEC), Compared with Time-Intensive FEC (FEC-G) and Mitoxantrone-Methotrexate-Mitomycin C (MMM-G) in Metastatic Breast Carcinoma

Abstract The purpose of this multicenter phase III trial was to assess the impact of a time-intensification of FEC (fluorouracil, epirubicin, cyclophosphamide) and MMM (mitoxantrone, methotrexate, mitomycin C) regimens, supported by lenograstim (G-CSF) on the objective response rate, time to progression and survival of patients with chemotherapy-naive metastatic breast cancer (mbc). Women with mbc were randomized to receive as first-line chemotherapy either standard-dose FEC (all doses in μg/m2): arm A (500, 75, 500 every 21 days), or time-intensified FEC-G: arm B (500, 75, 500 every 14 days), or time-intensified MMM-G: arm C (mitoxantrone 10, methotrexate 35 every 14 days and mitomycin C 10 every 28 days), both with support of lenograstim (G-CSF 150 μg/m2/day sc for 10 days). All study treatments were administered for six cycles. Eligible female patients were in the 31-70 year range with histologically proven mbc, and measurable or evaluable disease. An intent-to-treat analysis was performed. The overall response rate (CR + PR, intent-to-treat analysis) was significantly improved in the time-intensified FEC-G regimen (69%) in comparison with standard-dose FEC (41%), p=0.002. Time-intensified MMM-G (51%) did not lead to a significant improvement in the response rate. The percentage of complete responses was significantly higher in the FEC-G arm as compared to standard-dose FEC (17% vs. 4.7%; p=0.002). The median duration was longer in the intensified-dose arms without, however, achieving a statistically significant improvement. The median time to progression (TTP), and the median survival time did not differ between the three treatment arms. Grade 3-4 leukope-nia was significantly higher (p<0.001) in the standard FEC regimen-treated patients. Thrombocytopenia was significantly higher (p<0.001) in both intensified regimens. Alopecia and mucositis were significantly more frequent in both anthracy-cline-containing regimens (p=0.003). Other hematological and non hematological toxicities were similar in the 3 treatment arms. The increase of dose-intensity of both FEC and MMM regimens improved activity, but not efficacy as compared to standard FEC regimen in our group of chemotherapy-naive, metastatic breast cancer patients.

Cytotoxic chemotherapy preceding apheresis of peripheral blood progenitor cells can affect the early reconstitution phase of naive T cells after autologous transplantation

Summary:Transient T cell immunodeficiency is a common complication following hematopoietic stem cell transplantation. In breast cancer patients transplanted with autologous peripheral blood progenitor cells (PBPC) harvested after cytotoxic treatment with either cyclophosphamide or epirubicin plus paclitaxel, we evaluated T cells infused in grafts and in peripheral blood during the early reconstitution phase. We found that PBPC grafts harvested after treatment with epirubicin plus paclitaxel contained substantially larger numbers of T cells with less altered composition than after cyclophosphamide. Three months after high-dose cytotoxic chemotherapy, the numbers and the kinetics of circulating naive T cells, but not of memory and CD28− T cells, correlated positively with the number of naive T cells infused PBPC grafts. Finally, retrospective analysis of two cohorts of patients transplanted in different clinical settings with PBPC grafts harvested following cyclophosphamide or epirubicin plus paclitaxel showed apparently different susceptibilities to develop endogenous varicella zoster virus reactivation in the first year after high-dose cytotoxic chemotherapy. On the whole, these data indicate that number and composition of T cells in PBPC grafts vary according to the former cytotoxic therapy, and suggest that autologous transfer of T cells may accelerate the early T cell reconstitution phase and possibly ameliorate immune competence in patients rendered lymphopenic by high-dose chemotherapy.

Multidisciplinary treatment for central nervous system tumours with nitrosourea compounds

SummaryThe authors report the results of a controlled clinical trial in patients with primitive and metastatic CNS tumours treated with combined therapy: surgery, radiotherapy, and chemotherapy (BCNU or CCNU). A total of 102 patients were treated, 50 with BCNU, and 52 with CCNU. The overall response (R. + P.R.) was 68% for the BCNU group, and 65% for the CCNU group. No significant differences were found between the two types of treatment, either in terms of response or in terms of quality and length of survival.