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Hematopoietic stem cells mobilization and immune response in tumor-bearing mice.

INTRODUCTION: Malignant diseases are known to modulate the number and function of myeloid, erythroid, and lymphoid cells. Since these cells are derived from hematopoietic stem cells (HSC), it is not clear if the observed effects of cancer on such cells are direct or indirect via stem cells. The purpose of this study was to evaluate the effect of breast cancer upon the levels and activity of peripheral blood hematopoietic stem cells. MATERIALS AND METHODS: Four weeks following the establishment of 4T1 breast cancers in BALB/c mice, the animals were killed, blood and spleen harvested, and processed for light density mononuclear cells. Colony forming unit in culture assay was used to determine the activity of HSCs. Flow cytometry was used to determine the levels of lineage negative HSCs expressing c-kit and Sca-1 antigen (Lin c-kitSca-1). Mitogenic, cytotoxic and ELISPOT assays were used to evaluate functional properties of cells. Plasma cytokine levels were determined with ELISA assay. RESULTS: In tumor-bearing mice, there was a 2- and 4-fold increase in the levels and proliferative capacity of HSCs, respectively, compared with controls. Contemporaneously, there was a 13-fold increase in plasma G-CSF in tumor-bearing animals compared with controls (0.225 ng/ml versus 3.0 ng/ml). Furthermore, the number of interferon gamma-secreting cells was significantly increased in tumor-bearing animals. Concurrently, cytotoxic activity of NK cells was significantly increased in tumor-bearing animals as compared with controls (22.4 +/- 10.6 versus 10.3 +/- 2.95; P < 0.05). SUMMARY: These results suggest that (1) breast cancer mobilizes hematopoietic stem cells in mice presumably through G-CSF production, and (2) that such cancer-mobilized stem cells give rise to immune cell lineages which are functionally hyperactive in their cytotoxic activities. Such cells could be expected to have appreciable therapeutic benefit in terms of cancer cell cytotoxic activity when used as part of stem cell transplantation therapy in cancer patients.

Animals↗

Recombinant human stem cell factor mediates chemotaxis of small-cell lung cancer cell lines aberrantly expressing the c-kit protooncogene.

Accumulating evidence suggests that c-kit and its ligand, stem cell factor (SCF), play an important role in the regulation of at least three lineages of stem cell growth and possibly in leukemogenesis, while only limited data are available that suggest possible involvement of c-kit/SCF in the development of human solid tumors such as lung cancer. We have recently reported that c-kit is aberrantly expressed almost exclusively in small-cell lung cancer (SCLC) among various types of solid tumors. The present study revealed that c-kit protein ectopically expressed in SCLC is indistinguishable from that in leukemia cell lines with megakaryocytic characteristics with respect to amount, molecular size, and autophosphorylation status in response to recombinant human SCF. Furthermore, significant chemotactic response as well as moderate in vitro cell growth was induced in SCLC cell lines by the addition of recombinant human SCF, suggesting that c-kit/SCF may play an important biological role in the development of SCLC. Our extensive search for activating mutations naturally occurring in the c-kit gene revealed an amino acid substitution in the transmembrane domain of an SCLC cell line, although the functional consequences of this variant allele are yet to be determined.

Carcinoma, Small Cell↗

High dose chemotherapy and autologous stem cell transplantation as adjuvant therapy for primary breast cancer patients with four or more lymph nodes involved: long-term results of an international randomised trial.

BACKGROUND: The purpose of this study was to assess whether a short course of anthracycline containing chemotherapy followed by high dose therapy with autologous stem-cell support improves disease-free and overall survival as compared with conventional, anthracycline containing chemotherapy, in patients with primary breast cancer and four or more histologically involved lymph nodes. PATIENTS AND METHODS: Two hundred and eighty one patients entered into a randomised clinical trial were allocated to receive standard, conventional treatment (5-fluorouracil, epirubicin and cyclophosphamide-FEC for six cycles) or FEC for three cycles followed by high dose therapy consisting of cyclophosphamide, thiotepa and carboplatin and stem cell rescue (HDT). To be eligible, patients had to be free of overt metastatic disease and be < or =60 years of age. Analyses were according to intention to treat. RESULTS: At a median follow up of 68 months, 118 patients have experienced a relapse or death from breast cancer (62 in the FEC followed by HDT arm and 56 in the conventional FEC arm) and a total of 100 patients have died (54 in the FEC followed by HDT arm and 46 in the conventional FEC arm). No significant difference was observed in relapse-free survival [hazard ratio 1.06, 95% CI 0.74-1.52, p = 0.76] or overall survival [hazard ratio 1.18, 95% CI 0.80-1.75, p = 0.40]. Five patients died from treatment related causes, three as a consequence of HDT and two in the conventional FEC arm. CONCLUSIONS: At the present time, no benefit has been observed from replacing three cycles of conventional chemotherapy with the HDT regimen described here. Patients should continue to receive conventional chemotherapy as adjuvant therapy for breast cancer.

Adult↗

Prognostic model for relapse after high-dose chemotherapy with autologous stem-cell transplantation for stage IV oligometastatic breast cancer.

PURPOSE: To study prognostic factors after high-dose chemotherapy (HDC) for patients with stage IV oligometastatic breast cancer. PATIENTS AND METHODS: Sixty patients with minimal metastatic disease amenable to local therapy enrolled onto a prospective HDC trial were analyzed for potential prognostic factors. Tumor blocks were retrospectively collected from referring institutions. RESULTS: Median follow-up was 62 months (range, 4 to 120 months). Median relapse-free survival (RFS) and overall survival (OS) times were 52 and 80 months, respectively. Five-year RFS and OS rates were 52% (95% confidence interval [CI], 39% to 64%) and 62% (95% CI, 49% to 74%), respectively. HER-2 expression, number of tumor sites, primary axillary nodal ratio (number of positive nodes divided by number of sampled nodes), number of positive axillary nodes, and delivery or omission of radiotherapy to metastases correlated with RFS. HER-2 overexpression and more than one site were independent adverse risk factors for RFS. HER-2 and the axillary nodal ratio were independent predictors of OS. The following prognostic categories for RFS were established (RFS rate, median RFS): good risk, no factors (77%, 80 months); intermediate risk, one factor (41%, 28 months); and poor risk, both factors (10%, 10 months). CONCLUSION: Long-term results in patients with oligometastatic breast cancer are encouraging but need validation in prospective randomized studies. HER-2 expression, number of sites, and primary nodal ratio are independent outcome predictors. Confirmation of these observations in this selected population would imply the need for reevaluation of the current tenet that early detection of metastatic breast cancer recurrence is of no benefit.

Adult↗

Post-operative sequential high-dose chemotherapy with haematopoietic stem cell support as front-line treatment in advanced ovarian cancer: a phase II multicentre study.

In spite of multimodal management including aggressive surgery and chemotherapy, the prognosis of advanced ovarian cancer (AOC) remains poor. Multicycle high-dose chemotherapy (HDC) with haematopoietic stem cell (HSC) support has been shown to be a promising procedure in various cancers including AOC. We conducted a phase II multicentre study to evaluate feasibility, toxicity and efficacy of post-operative front-line sequential HDC with HSC support in AOC. Thirty four patients with stage IIIC/IV received a post-operative sequential combination of high-dose cyclophosphamide/epirubicin (D1, D21) with HSC harvesting, high-dose carboplatin (D42, D98) followed by HSC infusion, and dose-dense paclitaxel (D63, D77, D119, D133). Rh-G-CSF (filgrastim) was administered following all cycles. Primary endpoint was pathological complete response rate (pCR). Thirty patients received at least 7 of the scheduled 8 cycles. Haematological toxicity was significant but manageable. Grade 3/4 extra-haematopoietic toxicities were relatively uncommon and reversible. No toxicity-related death was observed. The observed pCR was 37% and did not reach the initial endpoint. Post-operative front-line sequential HDC in AOC is feasible and safe in a multicentre setting. The observed pCR does not support a clear advantage over conventional treatment. This approach remains an experimental strategy to further optimise and validate.

Adult↗

Randomized trial of single compared with tandem high-dose chemotherapy followed by autologous stem-cell transplantation in patients with chemotherapy-sensitive metastatic breast cancer.

PURPOSE: To compare progression-free survival between single and tandem high-dose chemotherapy (HDT) followed by autologous stem-cell transplantation in chemotherapy-sensitive metastatic breast cancer patients. PATIENTS AND METHODS: Between February 1997 and June 2001, 187 patients with complete and partial remission were randomly assigned to receive either one or two cycles of HDT, consisting of thiotepa (125 mg/m2/d for 4 days), cyclophosphamide (1,500 mg/m2/d for 4 days), and carboplatin (200 mg/m2/d for 4 days), followed by autologous stem-cell transplantation. RESULTS: One hundred seventy one of 187 randomly assigned patients completed first HDT, but only 52 of 85 completed the second HDT cycle in the tandem HDT arm. The rate of complete remission on an intent-to-treat-basis was 33% in the single-dose HDT arm and 37% in the tandem HDT arm (P = .48). The median progression-free survival times in single and tandem HDT arms were 9.4 and 11.2 months, respectively (one-sided P = .06; two one-sided P = .12), whereas median overall survival time tended to be greater after single versus tandem HDT (29 v 23.5 months, respectively; P = .4). In a multivariate analysis for progression-free survival, tandem HDT (hazard ratio [HR] = 0.71; 95% CI, 0.52 to 0.98; P = .03) and achievement of complete remission after induction chemotherapy (HR = 0.59; 95% CI, 0.37 to 0.96; P = .03) were factors for a better progression-free survival, whereas the factor of three or more sites of metastases (HR = 1.66; 95% CI, 1.12 to 2.47; P = .01) was associated with a worse progression-free survival. CONCLUSION: Despite a trend of improved progression-free survival, tandem HDT cannot be recommended for patients with chemotherapy-sensitive metastatic breast cancer because of a trend for shorter overall survival and higher toxicity compared with single HDT.

Adult↗

[Immunotherapy with allogeneic haematopoietic stem cell transplantation: current status and perspectives].

OBJECTIVES: Cancer represents a major problem of public health. New therapeutic approaches are needed to complete the present strategies. The use of immunotherapy for cancer treatment is a promising strategy. Allogeneic stem cell transplantation (allo-SCT) is the most widely used form of immunotherapy. The allogeneic immune effectors infused with the graft can recognize and eradicate the patients' tumoral cells. CURRENT KNOWLEDGE AND KEY POINTS: The curative potential of allo-SCT is classically based on the cytoreduction of tumoral cells induced during the high dose chemo- and/or radiotherapy-based conditioning regimen and the immune control mediated by allogeneic immune effectors (graft versus tumor effect, GVT). Allo-SCT is currently under important mutations because of better understanding of the GVT mechanisms and the development of new treatment techniques: (a) allo-SCT of peripheral blood stem cells after mobilization with G-CSF; (b) donor lymphocyte infusion (DLI); and (c) development of reduced intensity conditioning regimens aiming to reduce the toxicity while favoring the immune component of the anti-tumoral effect. FUTURE PROSPECTS AND PROJECTS: In addition to its established efficacy in hematological malignancies, several arguments are in favor of the use of allo-SCT in neoplastic solid tumors. Promising results from advanced cancer patients were already obtained. The present experience shows clearly that the allo-SCT strategy should be developed and refined because of the potential benefit that can be expected in some patients' sub-groups.

Hematopoietic Stem Cell Transplantation↗

Phase I/II trial of multicycle high-dose chemotherapy with peripheral blood stem cell support for treatment of advanced ovarian cancer.

Ovarian cancer is chemosensitive, but most patients with advanced disease die from tumor progression. As 25% of the patients can be cured by chemotherapy, it is reasonable to evaluate high-dose chemotherapy (HDCT). Forty-eight patients with untreated ovarian cancer were entered in a multicenter phase I/II trial of multicycle HDCT. Median age was 46 (19-59 years); International Federation of Gynecology and Obstetrics-stage was III in 79% and IV in 21%; 31% had residual disease >1 cm after surgery. Two courses of induction/mobilization therapy with cyclophosphamide (250 mg/m2) and paclitaxel (250 mg/m2) were used to collect peripheral blood stem cells. HDCT consisted of two courses of carboplatin (area under curve (AUC) 18-22) and paclitaxel followed by one course of carboplatin and melphalan (140 mg/m2) with or without etoposide (1600 mg/m2). Main toxicity was gastrointestinal. Limiting carboplatin to AUC 20 and eliminating etoposide resulted in manageable toxicity (69% without grade 3/4 toxicity). One patient died from treatment-related pneumonitis. At 8 years median follow-up, median progression-free-survival (PFS) and overall survival (OS) is 13.3 and 37.0 months. Five-years PFS and OS is 18 and 33%. Multicycle HDCT is feasible in a multicenter setting. A European phase III trial based on this regimen is evaluating the efficacy of HDCT.

Adult↗

High dose chemotherapy and autologous bone marrow or stem cell transplantation versus conventional chemotherapy for women with early poor prognosis breast cancer.

BACKGROUND: Overall survival rates are disappointing for women with early poor prognosis breast cancer. Autologous transplantation of bone marrow or peripheral stem cells (in which the patient is both donor and recipient) has been considered a promising technique because it allows much higher doses of chemotherapy to be used. OBJECTIVES: To compare the effectiveness of high dose chemotherapy and autograft versus conventional chemotherapy for women with early poor prognosis breast cancer. Outcomes were survival rates, toxicity and quality of life. SEARCH STRATEGY: We searched the Cochrane Breast Cancer Group specialised register, The Cochrane Controlled Trials Register (Cochrane Library Issue 3, 2004), MEDLINE (1966 to November 2004), EMBASE (1980 to November 2004), PsycINFO (1984 to November 2004), Cinahl (1982 to November 2004), web sites of co-operative research groups and ASCO (American Society of Clinical Oncologists) and reference lists of articles found. SELECTION CRITERIA: Randomised controlled trials comparing high dose chemotherapy and autograft versus conventional chemotherapy for women with early poor prognosis breast cancer. DATA COLLECTION AND ANALYSIS: Fifteen trials were considered. Thirteen were included and two were excluded. Three independent reviewers extracted data. MAIN RESULTS: Analysis included 2535 women randomised to receive high dose chemotherapy with autograft and 2529 randomised to receive conventional chemotherapy. There were 65 treatment-related deaths on the high dose arm and four on the conventional dose arm (RR 8.58 (95% CI 4.13, 17.80). Many studies have not completed follow-up and have reported only preliminary results. There was a statistically significant benefit in event-free survival for women in the high dose group at three years (RR 1.12 (95% CI 1.06, 1.19)) and at four years (RR 1.30 (95% CI 1.16, 1.45)). At five and six years there was no statistically significant difference between the groups in event-free survival. With respect to overall survival, there was no statistically significant difference between the groups at any stage of follow up. Morbidity was more common and more severe in the high dose group. However there was no statistically significant difference between the groups with respect to the incidence of second cancers at five to seven years' follow up. Women in the high dose group reported significantly worse quality of life scores immediately after treatment, but few statistically significant differences were found between the groups by one year. AUTHORS' CONCLUSIONS: There is insufficient evidence to support the routine use of high dose chemotherapy with autograft for women with early poor prognosis breast cancer.

Antineoplastic Combined Chemotherapy Protocols↗

Benefits of granulocyte-colony-stimulating factor after stem cell transfusion in intensive sequential chemotherapy for breast cancer.

The aim of this study was to evaluate the clinical and economic benefit of filgrastim given with intensive sequential chemotherapy. Women with poor-prognosis breast cancer received four cycles of high-dose cyclophosphamide (3 g/m2) and doxorubicin (75 mg/m2), followed by filgrastim 5 microg/kg/dy, stem cell collection after the cycle 1, and stem cell infusion after cycle 3 and cycle 4. The first cohort received filgrastim after the fourth cycle but the second cohort did not.Thirty three patients were included in the first cohort and 13 in the second. The results indicate that the duration of grade IV neutropenia was shorter in the group given filgrastim as was the median time to recover an absolute neutrophil count (ANC) > 1.0 x 10(9)/L. The rate and duration of the rehospitalizations were higher in the group not receiving filgrastim. We found that costs such as drugs and hospitalizations were significantly higher (p = 0.032 and p = 0.049) in the non-filgrastim-treated group. Using ANC > 1.0 x 10(9)/L as an intermediary efficiency criterion it was more cost effective to give filgrastim. It can be concluded from this study that filgrastim can decrease the duration of grade IV neutropenia in patients receiving intensive sequential chemotherapy. This, in turn, reduces the cost of hospitalization. However, in our study, this reduction of neutropenia did not have any impact on further therapy.

Adult↗

Cytosine deaminase adenoviral vector and 5-fluorocytosine selectively reduce breast cancer cells 1 million-fold when they contaminate hematopoietic cells: a potential purging method for autologous transplantation.

Ad.CMV-CD is a replication incompetent adenoviral vector carrying a cytomegalovirus (CMV)-driven transcription unit of the cytosine deaminase (CD) gene. The CD transcription unit in this vector catalyzes the deamination of the nontoxic pro-drug, 5-fluorocytosine (5-FC), thus converting it to the cytotoxic drug 5-fluorouracil (5-FU). This adenoviral vector prodrug activation system has been proposed for use in selectively sensitizing breast cancer cells, which may contaminate collections of autologous stem cells products from breast cancer patients, to the toxic effects of 5-FC, without damaging the reconstitutive capability of the normal hematopoietic cells. This system could conceivably kill even the nondividing breast cancer cells, because the levels of 5-FU generated by this system are 10 to 30 times that associated with systemic administration of 5-FU. The incorporation of 5-FU into mRNA at these high levels is sufficient to disrupt mRNA processing and protein synthesis so that even nondividing cells die of protein starvation. To test if the CD adenoviral vector sensitizes breast cancer cells to 5-FC, we exposed primary explants of normal human mammary epithelial cells (HMECs) and the established breast cancer cell (BCC) lines MCF-7 and MDA-MB-453 to the Ad.CMV-CD for 90 minutes. This produced a 100-fold sensitization of these epithelial cells to the effects of 48 hours of exposure to 5-FC. We next tested the selectivity of this system for BCC. When peripheral blood mononuclear cells (PBMCs), collected from cancer patients during the recovery phase from conventional dose chemotherapy-induced myelosuppression, were exposed to the Ad.CMV-CD for 90 minutes in serum-free conditions, little or no detectable conversion of 5-FC into 5-FU was seen even after 48 hours of exposure to high doses of 5-FC. In contrast, 70% of 5-FC was converted into the cytotoxic agent 5-FU when MCF-7 breast cancer cells (BCCs) were exposed to the same Ad.CMV-CD vector followed by 5-FC for 48 hours. All of the BCC lines tested were shown to be sensitive to infection by adenoviral vectors when exposed to a recombinant adenoviral vector containing the reporter gene betagalactosidase (Ad.CMV-betagal). In contrast, less than 1% of the CD34-selected cells and their more immature subsets, such as the CD34+CD38- or CD34(+)CD33- subpopulations, were positive for infection by the Ad.CMV-betagal vector, as judged by fluorescence-activated cell sorting (FACS) analysis, when exposed to the adenoviral vector under conditions that did not commit the early hematopoietic precursor cells to maturation. When artificial mixtures of hematopoietic cells and BCCs were exposed for 90 minutes to the Ad.CMV-CD vector and to 5-FC for 10 days or more, a greater than 1 million fold reduction in the number of BCCs, as measured by colony-limiting dilution assays, was observed. To test if the conditions were damaging for the hematopoietic reconstituting cells, marrow cells collected from 5-FU-treated male donor mice were incubated with the cytosine deaminase adenoviral vector and then exposed to 5-FC either for 4 days in vitro before transplantation or for 14 days immediately after transplantation in vivo. There was no significant decrease in the reconstituting capability of the male marrow cells, as measured by their persistence in female irradiated recipients for up to 6 months after transplantation. These observations suggest that adenovirus-mediated gene transfer of the Escherichia coli cytosine deaminase gene followed by exposure to the nontoxic pro-drug 5-FC may be a potential strategy to selectively reduce the level of contaminating BCCs in collections of hematopoietic cells used for autografts in breast cancer patients.

Adenoviridae↗

Capecitabine in patients with breast cancer relapsing after high-dose chemotherapy plus autologous peripheral stem cell transplantation--a phase II study.

Capecitabine, a tumor-selective, oral fluoropyrimidine, has demonstrated significant antitumor activity in patients with metastatic breast cancer. In this open-label monocenter phase II study the efficacy and safety of capecitabine in patients with metastatic breast cancer who relapsed after high-dose chemotherapy was examined. Female patients 18-65 years of age, with a histologically confirmed diagnosis of metastatic breast cancer, who relapsed after high-dose chemotherapy (adjuvant and/or metastatic) followed by autologous peripheral blood stem cell transplantation (PBSCT) and who had been treated in their course of the disease with an anthracycline and/or an anthracycline/taxane containing regimen were included into this clinical study. Capecitabine was applied as the first salvage chemotherapy at relapse after high-dose chemotherapy (1250 mg/m(2) b.i.d. p.o. for 14 days followed by 7 days rest period). Responding patients or those with stable disease after two treatment cycles were offered to continue treatment until tumor progression. Response rate, time to disease progression, survival, toxicity and quality of life were assessed. Fourteen patients between 35 and 60 years (median 45.5 years) entered this study and received a median number of 5 cycles (range 1-19) of capecitabine. All patients were evaluable for response. All patients had been pretreated with 1-2 cycles of high-dose chemotherapy plus PBSCT. Furthermore, 13 patients had additionally received local radiotherapy. On average, the patients showed metastatic disease in two organ sites (range 1-4 sites). One patient obtained a complete response and five patients a partial response, accounting for a response rate of 42.9% [95% confidence interval (17.7%; 71.1%)]. All responses were already achieved at the first observation time point 6 weeks after treatment initiation. Two further patients obtained stable disease for at least 12 weeks. At the time of final analysis all patients have progressed. Median time to progression was 2.8 months (range 0.4-13.3 months). No median survival time was reached (range 3.9-36.5 months, at the time of reporting eight patients were alive and six patients had died). Two patients developed grade III granulocytopenia. Five patients developed grade III hand-foot syndrome. One patient had the combination of nausea, fever and diarrhea grade III. All adverse events were considered manageable. We conclude that capecitabine as single-agent oral chemotherapy is active and well tolerated in heavily pretreated patients with breast cancer. It can be safely used in patients who have been intensively pretreated by myelotoxic chemotherapy or who have even relapsed after high-dose chemotherapy with PBSCT.

Adult↗

High-dose therapy in breast cancer: out of favor but not out of promise.

The evidence for use of high-dose chemotherapy and autologous stem cell transplantation for breast cancer still remains inconclusive at best. A number of prospective randomized phase III studies have been either published or presented recently or are underway in North America and Europe. It will be crucial to complete the available prospective randomized phase III study and obtain the data when all studies reach a mature status. Only then will level I evidence become available to determine the efficacy and effectiveness of high-dose chemotherapy and autologous stem cell transplantation in breast cancer. Bone Marrow Transplantation (2000).

Antineoplastic Agents, Alkylating↗

Phase I/II study of tandem cycles of high-dose chemotherapy followed by autologous hematopoietic stem cell support in women with advanced ovarian cancer.

The objectives of this study were to investigate the tolerability of a novel high-dose chemotherapy (HDC) regimen with peripheral blood progenitor cell (PBPC) support in patients with pretreated advanced ovarian cancer and to determine the maximum-tolerated dose (MTD) of topotecan in this setting. Advanced ovarian cancer patients previously treated with platinum-based first-line therapy were enrolled. After PBPC mobilization and harvesting, patients received three consecutive cycles of HDC with PBPC support. Cycle 1 was carboplatin area under the concentration curve 20 and paclitaxel 250 mg/m(2). Cycle 2 was topotecan starting at 5 mg/m(2), dose escalated in 2 mg/m(2) increments, and etoposide 600 mg/m(2). Cycle 3 was thiotepa 500 mg/m(2). After each cycle, PBPCs were infused. Granulocyte colony stimulating factor (5 microg/kg/day) was administered until neutrophil recovery occurred. Seventeen patients were enrolled; all were safety evaluable. The most common nonhematologic toxicity was grade 3 mucositis (44%). Engraftment of PBPCs was successful in all patients after each cycle, and no treatment-related deaths occurred. Of 14 patients with measurable disease, 5 (36%) had complete responses, 2 (14%) had partial responses, and 4 (29%) had stable disease. The median progression-free and overall survivals were 7 and 18 months, respectively. The MTD of topotecan was not reached. The tolerability and activity of this regimen in patients with advanced ovarian cancer warrant further investigation.

Adult↗

[Phase I study of super high-dose chemotherapy for liver cancer with percutaneous isolated hepatic perfusion (PIHP) and peripheral blood stem cell transplantation (PBSCT)].

The aim of this study was to evaluate the phase I aspects of super high-dose chemotherapy for advanced liver cancer with combined use of PIHP and PBSCT. In 4 patients with HCC and 1 patient with colonic liver metastases, peripheral blood stem cells (PBSC) were mobilized by either i.v. infusion of ETP (180 mg/m2/day for 3 days) or i.a. infusion of doxorubicin (100-120 mg/m2). In 3 (60%) of 5 patients, PBSC for PBSCT were harvested in effective quantities (CFU-GM > or = 2 x 10(5)/kg or CD 34 positive cells > or = 2 x 10(6)/kg). In these 3 patients, a repeated PIHP with either doxorubicin, 5-fluorouracil, or CDDP was carried out 4 weeks after the 1st PIHP. Thereafter, auto-PBSCT was intravenously administered 2 days after PIHP. In the repeated PIHP treatments, although anti-cancer drugs were administered at doses equivalent to or even higher than those administered at the 1st PIHP, bone marrow suppressions were transient and well tolerated. Fatal complications were not observed in any patients. These results indicate that with the combined use of PIHP and PBSCT, high-dose regional chemotherapy of the liver can be safely repeated without systemic toxicities.

Adolescent↗

Stem cell stages and the origins of colon cancer: a multidisciplinary perspective.

Analysis of historical age-specific colorectal cancer rates, present day age-specific colonic adenoma prevalence and the few reports of direct measurements of genetic change in human tissues as a function of age in adults have led to a new set of hypotheses about carcinogenesis. A key observation, that the calculated rate of growth of preneoplasia is equal to the calculated growth rate of the juvenile colon, suggested that tumor initiation blocks the developmental step by which growing juvenile stem cells are transformed into or replaced by adult maintenance stem cells. In this hypothesis the slowly growing adenomatous polyps would simply be patches of highly organized juvenile tissue modified by the mechanical constraints of surrounding nongrowing adult tissue. As juvenile tissue presumably grows by net increase in stem cells creating crypts, tumor promotion could be achieved by transformation of an initiated stem cell into a fetal stem cell that would express the program of rapid net growth and differentiation into the heterogeneous cell types of fetal colonic organogenesis. (One additional interpretation of data from observations of point mutations in adult lung epithelium is that rates of genetic change in juvenile stem cells are markedly higher than in adult maintenance stem cells.) Unfortunately, the concept of a "stem cell" undergoing staged transitions in organ development and blocked or reverse transitions in carcinogenesis has lacked the physical embodiment of a cell that could be recognized, isolated, and analyzed. In an attempt to overcome this impediment we set reexamined fetal and adult colonic tissue, adenomas, and adenocarcinomas using a novel histological preparation method. Gostjeva then discovered that fetal and neoplastic tissues share a set of cells distinguished by specific nuclear morphotypes that appear to cooperate in creating the elements of the fetal organ, preneoplastic, and neoplastic lesions. In particular, microscopic examination of fetal gut at 5-7 wk gestation reveals tubular syncytia containing opened-mouthed, bell-shaped nuclei that account for some 30% of the nuclei in the protoorgan. These peculiar nuclei undergo both symmetric and asymmetric nuclear fissions, the latter creating all of the other nuclear morphotypes. These nuclear fissions are "amitotic" insofar as no general chromosome condensation is observed. Bell-shaped nuclei are rarely found in adult colonic crypt bases but are found in preneoplasia and neoplasia.

Adenomatous Polyps↗