Hematopoietic progenitor cell transplantation in breast cancer: current status and future directions

Long-term survival in patients with metastatic breast cancer receiving intensified chemotherapy and stem cell rescue: data from the Italian registry

The median survival of women with metastatic breast cancer (MBC) is 18-24 months, and fewer than 5% are alive and disease free at 5 years. We report toxicity and survival in a cohort of MBC patients receiving high-dose chemotherapy (HDC) with autologous hematopoietic SCT (AHSCT) in Italy between 1990 and 2005. Data set for survival analysis has been obtained for 415 patients. Clinical parameters including probability of transplant-related mortality (TRM), PFS and OS. With a median follow-up of 27 months (range 0-172), OS and PFS at 5 and 10 years in the whole population were 47/23 and 32/14%, respectively. A total 239 patients are alive with a median follow-up of 33 months (range 2-174). Survival was significantly more pronounced in patients harboring hormone receptor positive tumors (P=0.028), without visceral metastases (P=0.009) and in women with chemosensitive disease (P<0.0001). Sixty eight patients (20.4%) who received HDC in partial response, stable or progressive disease underwent conversion to CR. TRM was 2.5% overall and 1.3% since 2000. Our findings suggest that could be a role for HDC and AHSCT in delaying disease progression and possibly cure a subset of MBC patient harboring chemosensitive tumors.

Autologous hematopoietic stem cell transplantation for breast cancer in Europe: critical evaluation of data from the European Group for Blood and Marrow Transplantation (EBMT) Registry 1990-1999

The aim of this study was to identify trends in high-dose chemotherapy (HDC) with autologous hematopoietic stem cell transplantation (ASCT) and to assess survival in a large cohort of breast cancer (BC) patients receiving this therapy in Europe from 1990 to 1999. A total of 7471 patients who received HDC with ASCT between January 1, 1990 and December 31, 1999 were reported to the European Group for Blood and Marrow Transplantation Registry. Data required for demographics and survival analysis were available for 2679 patients with high-risk primary BC; 921 patients with inflammatory BC (IBC), and 2295 patients with metastatic disease. The main evaluation parameters were progression-free survival (PFS) and overall survival (OS). Between 1990 and 1998, autotransplants for BC increased 30-fold. Significant trends included use of blood-derived rather than marrow-derived stem cells, increment of reporting centers and decrease of mortality within 100 days from transplantation. The 5-year PFS and OS probabilities were 53 and 68% for high-risk disease and 42 and 53% for IBC, respectively. For metastatic disease 5-year PFS and OS probabilities in the whole cohort were 18 and 27%, respectively, while for women transplanted in complete remission the 5-year PFS was 29%. In conclusion, HDC with ASCT has been increasingly used until 1998 and the 100-day mortality rate has been constantly less than 2% from 1995 to date. The 5-year survival of high-risk BC is related to the number of axillary nodes involved at surgery. Outcome of patients with IBC is encouraging, suggesting the need for randomized trials. Patients with metastatic disease responding to pretransplant chemotherapy and harboring ER+ tumors have a better outcome.

Immunotherapy of cancer by active vaccination: does allogeneic bone marrow transplantation after non-myeloablative conditioning provide a new option?

The critical role of antigen-specific T cells in cancer immunotherapy has been amply demonstrated in many model systems. Though success of clinical trials still remains far behind expectation, the continuous improvement in our understanding of the biology of the immune response will provide the basis of optimized cancer vaccines and allow for new modalities of cancer treatment. This review focuses on the current status of active therapeutic vaccination and future prospects. The latter will mainly be concerned with allogeneic bone marrow cell transplantation after non-myeloablative conditioning, because it is my belief that this approach could provide a major breakthrough in cancer immunotherapy. Concerning active vaccination protocols the following aspects will be addressed: i) the targets of immunotherapeutic approaches; ii) the response elements needed for raising a therapeutically successful immune reaction; iii) ways to achieve an optimal confrontation of the immune system with the tumor and iv) supportive regimen of immunomodulation. Hazards which one is most frequently confronted with in trials to attack tumors with the inherent weapon of immune defense will only be briefly mentioned. Many question remain to be answered in the field of allogeneic bone marrow transplantation after non-myeloablative conditioning to optimize the therapeutic setting for this likely very powerful tool of cancer therapy. Current considerations to improve engraftment and to reduce graft versus host disease while strengthening graft versus tumor reactivity will be briefly reviewed. Finally, I will discuss whether tumor-reactive T cells can be "naturally" maintained during the process of T cell maturation in the allogeneic host. Provided this hypothesis can be substantiated, a T cell vaccine will meet a pool of virgin T cells in the allogeneically reconstituted host, which are tolerant towards the host, but not anergised towards tumor antigens presented by MHC molecules of the host.

Infectious complications in breast cancer patients undergoing peripheral blood stem cell transplantation: a single center retrospective analysis towards outpatient strategy

Infectious complications were retrospectively analyzed in 129 transplants, performed in 90 patients, to identify characteristics that qualify breast cancer patients for outpatient-based PBSCT. Thirty-one cases (24%) did not develop fever. Of the remaining 98 cases, 84.7% developed fever during severe neutropenia. On univariate analysis, disease stages II-III, first PBSCT, mucositis grades II-IV and the use of two alkylators were associated with a higher risk of fever development. The latter two factors also affected fever occurrence on multivariate analysis. A longer median time to fever onset was observed in patients conditioned with single as compared to double alkylating agent-containing regimens (respectively 8th vs 6th day, P < 0.00001). As compared with metastatic breast cancer (MBC), high risk breast cancer showed a 2.3-fold increased risk of developing early fever during neutropenia (CI 2.3-3.8), remaining the only variable still significant on multivariate analysis (P = 0.0039). Combination antibiotic therapy was equivalent to single agent therapy. Patients suffering from microbiologically documented fever were at higher risk of undergoing second-line antibiotic therapy. In conclusion, MBC patients treated with a conditioning regimen containing only one alkylating agent and adequate prophylaxis for mucositis may qualify for outpatient-based PBSCT on the basis of a lower risk of infection.

Comparison of double and triple high-dose chemotherapy with autologous blood stem cell transplantation in patients with metastatic breast cancer

In patients with metastatic breast cancer (MBC), early dose intensification with multiple cycles of peripheral blood stem cell-supported high-dose chemotherapy (HDCT) seems superior to a late dose-intensification strategy. We compared the progression-free survival (PFS) and overall survival (OS) of 20 patients treated with a double (D)-HDCT regimen to 20 patients who received a triple (T)-HDCT, matched by age, estrogen receptor (ER) status, adjuvant chemotherapy, initial disease-free interval, predominant metastatic site, and number of metastatic sites. At a median follow-up of 41.5 months (range, 14-88 months) an intent-to-treat analysis showed no difference in PFS (p = 0.72) and OS (p = 0.93) between the matched patients. For all 76 patients treated within the D- or T-HDCT trial, median PFS and OS was 13 months (range, 2-78 months) and 24.5 months (range, 7-78 months), respectively. In multivariate analysis independent predictors of shorter OS included negative ER (relative risk [RR] = 3.0 [95% confidence interval (CI) 1.5-5.9]; p = 0.002), more than two metastatic sites (RR = 2.4 [95% CI 1.0-5.7]; p = 0.049) and failure to achieve complete remission/no evidence of disease (CR/NED) after HDCT (RR = 4.5 [95% CI 2.0-10.1]; p < 0.0001). These data show that early dose intensification with T-HDCT is not superior to a D-HDCT regimen in patients with MBC. ER-negative tumors, more than two metastatic sites and no CR/NED after HDCT, are associated with inferior outcome.

Eradication of multiple myeloma and breast cancer cells by TH9402-mediated photodynamic therapy: implication for clinical ex vivo purging of autologous stem cell transplants

High-dose chemotherapy combined with autologous transplantation using bone marrow or peripheral blood-derived stem cells (PBSC) is now widely used in the treatment of hematologic malignancies as well as some solid tumors like breast cancer (BC). However, some controversial results were recently obtained in the latter case. The presence of malignant cells in the autograft has been associated with the recurrence of the disease, and purging procedures are needed to eliminate this risk. The aim of this study was to evaluate the potential of the photosensitizer 4,5-dibromorhodamine methyl ester (TH9402), a dibrominated rhodamine derivative, to eradicate multiple myeloma (MM) and BC cell lines, while sparing more than 50% of normal pluripotential blood stem cells from healthy volunteers. The human BC MCF-7 and T-47D and MM RPMI 8226 and NCI-H929 cell lines were used to optimize the photodynamic purging process. Cell concentration and the cell suspension thickness as well as the dye and light doses were varied in order to eventually treat 1-2 L of apheresis. The light source consisted of two fluorescent scanning tubes emitting green light centered about 515 nm. The cellular uptake of TH9402 was measured during the incubation and washout periods and after photodynamic treatment (PDT) using spectrofluorometric analysis. The limiting dilution assay showed that an eradication rate of more than 5 logs is obtained when using a 40 min incubation with 5-10 microM dye followed by a 90 min washout period and a light dose of 5-10 J/cm2 (2.8 mW/cm2) in all cell lines. Agitating the 2 cm thick cell suspension containing 20 x 10(6) cells/mL during PDT was essential for maximal photoinactivation. Experiments on mobilized PBSC obtained from healthy volunteers showed that even more drastic purging conditions than those found optimal for maximal eradication of the malignant cell lines were compatible with a good recovery of hematopoietic progenitors cells. The absence of significant toxicity towards normal hematopoietic stem cells, combined with the 5 logs eradication of cancer cell lines induced by this procedure suggests that TH9402 offers an excellent potential as an ex vivo photodynamic purging agent for autologous transplantation in MM and BC treatment.

Overview of autologous stem cell transplantation

There has been a dramatic increase in the number of autologous peripheral blood stem cell transplants over the last decade. Faster recovery of cell counts, lesser transplant morbidity, shorter hospital stay and reduced cost compared with marrow autografts have been the main advantages of autologous peripheral blood cell over marrow transplants. In this paper we attempt to review the advances in the biology and mobilization of stem cells, and focus on clinical results of autologous peripheral stem cell and marrow transplants for disease specific sites such as breast cancer, myeloma, autoimmune diseases, germ cell tumors, the acute and chronic leukemias, the non-Hodgkin's lymphomas and Hodgkin's disease. We also discuss transplant related complications, gene therapy and the different methods of purging. This review was intended for autologous peripheral stem cell transplants, however, unavoidably, it also discusses autologous marrow transplantation and aspects common to both procedures.

Utility of obtaining blood cultures in febrile neutropenic patients undergoing bone marrow transplantation

Infection remains an important cause of morbidity and mortality after bone marrow or stem cell transplantation. To evaluate the role of obtaining blood cultures for intermittent or persistent fever in neutropenic patients on antibiotic therapy, we performed a retrospective chart review of 196 consecutive patients admitted to the Bone Marrow Transplant Unit at the University of North Carolina Hospitals from 1995 to 1998. From the cohort of 196 patients, 154 patients developed neutropenic fever. The initial blood culture was positive in 16 of 145 patients during the first fever episode giving a prevalence of 11%. From the total of 109 patients that had blood cultures drawn after day 1 of fever, five patients had blood cultures positive for a pathogen, a prevalence of 4.6%. In only one patient, did blood cultures drawn after day 1 identify an organism not present on day 1 (prevalence 0.9%). After reviewing the results in the first 105 patients, we changed our timing of collection of blood cultures. Forty-nine patients were treated in this manner and we found that the mean number of blood cultures decreased from 9.2 to 4.7 per patient without a change in the frequency of infectious complications or length of hospitalization.

Immune reconstitution following high-dose chemotherapy with stem cell rescue in patients with advanced breast cancer

The present study examines the nature of humoral and cellular immune reconstitution in 28 patients with advanced breast cancer following high-dose chemotherapy with stem cell rescue. Patients underwent testing of T, B, NK and dendritic cell function at serial time points until 1 year post transplant or until the time of disease progression. Abnormalities in T cell phenotype and function were observed following high-dose chemotherapy that persisted for at least 6-12 months. The vast majority of patients experienced an inversion of the CD4/CD8 ratio and demonstrated an anergic response to candida antigen. Mean T cell proliferation in response to PHA and to co-culture with allogeneic monocytes was significantly compromised. In contrast, mean IgG and IgA levels were normal 6 months post transplant and NK cell yields and function were transiently elevated following high-dose chemotherapy. Dendritic cells generated from peripheral blood progenitors displayed a characteristic phenotype and were potent inducers of allogeneic T cell proliferation in the post-transplant period. The study demonstrates that patients undergoing autologous transplantation for breast cancer experience a prolonged period of T cell dysfunction. In contrast, B, NK, and DC recover more rapidly. These findings carry significant implications for the design of post-transplant immunotherapy.

Application of whole blood and peripheral blood progenitor cells (PBPC) and new strategies for rescue after intensive cyclic chemotherapy in high-risk breast cancer

The efficacy of autologous peripheral stem cells given as mobilized whole blood or leukapheresis product for hematopoietic rescue after intensive chemotherapy was studied in 34 consecutive female patients with high-risk breast cancer. All patients received six cycles of chemotherapy regimen EC (epirubicin 150 mg/m2 and cyclophosphamide 1250 mg/m2) at 14-day intervals. In the first cycle, chemotherapy was given on day 1, and 24 h later mobilization of PBPC was started with G-CSF at a dose of 5 microg/kg/day for 13 days. In all other cycles, G-CSF was given at the same dose from day 7. On days 11, 12, and 13, leukaphereses were performed, and whole blood was collected on day 14 (the peak incidence of colony-forming units-granulocyte-macrophage [CFU-GM] burst-forming units-erythrocyte [BFU-E], and colony-forming unit-granulocyte-erythrocyte-macrophage-megakaryocyte [CFU-GEMM]). The second cycle of chemotherapy was started on day 15, and 24 h later, whole blood (collected in the first cycle) was reinfused, and the same was done in the third cycle. In the fourth to sixth chemotherapy cycles, leukapheresis product was used for hematopoietic rescue. The median increment of absolute values in both whole blood and leukapheresis product was as follows: CD34+ cells over baseline was approximately 17.4-fold, CFU-GM was 85.3-fold, BFU-E was 95.9-fold, and CFU-GEMM was 44.2-fold. In the cycles with whole blood support, the mean values of applied progenitors per cycle were CD34+ cells 1.52 x 10(6)/kg, CFU-GM, 1.18 x 10(5)/kg, BFU-E 2.54 x 10(5)/kg, CFU-GEMM 0.31 x 10(5)/kg. In the courses with PBPC support, the mean values of progenitors were CD34+ 2.04 x 10(6)/kg, CFU-GM 1.59 x 10(5)/kg, BFU-E 2.87 x 10(5)/kg, and CFU-GEMM 0.34 x 10(5)/kg. Leukopenia in patients supported with whole blood versus leukapheresed PBPC was as follows: grade 4, 13/6 (38.2%/17.6%), grade 3, 19/23 (55.9%/70.6%), and grade 2, 1/4 (2.9%/11.8%), respectively. Thrombocytopenia was grade 4, 11/6 (32.4%/17.6%), grade 3, 10/7 (29.4%/20.6%), grade 2, 7/13 (20.6%/38.2%), and grade 1, 6/6 (17.6%/17.6%), respectively. The median follow-up analysis was at 24.6 (7-36) months. High-risk patients previously treated with surgery and adjuvant chemotherapy (n = 5) were not evaluated for response. In 21 patients with locally advanced or inflammatory breast carcinoma the response rate (RR) was 94%, CR was 90%, and PR was 15%. No response to therapy was observed in 1 patient. In 8 patients with metastatic disease, RR was 75%, there was no CR, and PR was 75%. Two patients died during therapy. Relapse-free survival (RFS) in the adjuvant group was 23.7 (range 12-36) months and in the group with locally advanced disease was 18.2 (range 7-27) months. In the group with metastatic disease, time to tumor progression (TTP) was 12.1 (range 1-16) months. Mean duration of hospital stay for whole blood reinfusion in the second and third chemotherapy cycles was 6.7 (range 5-8) days and for PBPC in the fourth to sixth cycles was 6.2 (range 4-8) days, which at p < 0.001 was not statistically significant.

Increased expression of preprotachykinin-I and neurokinin receptors in human breast cancer cells: implications for bone marrow metastasis

Neuropeptides are implicated in many tumors, breast cancer (BC) included. Preprotachykinin-I (PPT-I) encodes multiple neuropeptides with pleiotropic functions such as neurotransmission, immune/hematopoietic modulation, angiogenesis, and mitogenesis. PPT-I is constitutively expressed in some tumors. In this study, we investigated a role for PPT-I and its receptors, neurokinin-1 (NK-1) and NK-2, in BC by using quantitative reverse transcription-PCR, ELISA, and in situ hybridization. Compared with normal mammary epithelial cells (n = 2) and benign breast biopsies (n = 21), BC cell lines (n = 7) and malignant breast biopsies (n = 25) showed increased expression of PPT-I and NK-1. NK-2 levels were high in normal and malignant cells. Specific NK-1 and NK-2 antagonists inhibited BC cell proliferation, suggesting autocrine and/or intercrine stimulation of BC cells by PPT-I peptides. NK-2 showed no effect on the proliferation of normal cells but mediated the proliferation of BC cells. Cytosolic extracts from malignant BC cells enhanced PPT-I translation whereas extracts from normal mammary epithelial cells caused no change. These enhancing effects may be protein-specific because a similar increase was observed for IL-6 translation and no effect was observed for IL-1alpha and stem cell factor. The data suggest that PPT-I peptides and their receptors may be important in BC development. Considering that PPT-I peptides are hematopoietic modulators, these results could be extended to understand early integration of BC cells in the bone marrow, a preferred site of metastasis. Molecular signaling transduced by PPT-I peptides and the mechanism that enhances translation of PPT-I mRNA could lead to innovative strategies for BC treatments and metastasis.

Dose-intensive chemotherapy for breast cancer with brain metastases: a case series

Most clinical trials using dose-intensive chemotherapy exclude patients with brain metastases. This exclusion was based on anecdotal experience reflecting high treatment-related mortality. We analyzed the outcome of 11 patients with metastatic breast cancer who had brain metastases, diagnosed either before or during high-dose chemotherapy. In three patients, the death was attributed to non-central nervous system (CNS) regimen-related toxicity. Five patients died as a results of non-CNS disease progression. One patient died as a result of both CNS and non-CNS disease progression. Two patients are alive without disease progression with follow-up of 13.4 and 7.3 months, respectively. Of the five patients who have survived 1 year, four have hormone receptor expression and continued on antihormone therapy after high-dose therapy. These results are the first to show that breast cancer patients having brain metastases who receive high-dose chemotherapy do not experience more treatment-related complications or treatment failure as a result of the metastatic CNS disease. To this end, exclusion of these patients from high-dose therapy trials, especially those with expression of hormone receptors, needs to be reevaluated.

Adjuvant dose-intense chemotherapy with peripheral blood stem cell support in stage II-III breast cancer with five to nine involved axillary lymph nodes

The purpose of this study is to determine outcomes for patients with high-risk nonmetastatic breast cancer undergoing high-dose chemotherapy with peripheral blood stem cell support. Forty-three patients with stage II-III disease, five to nine positive axillary lymph nodes, and a median age of 44 years (range, 27-60 years) were enrolled in a study that included: 1) standard dose doxorubicin, 5-fluorouracil, and methotrexate adjuvant therapy; 2) cyclophosphamide, etoposide, filgrastim, and peripheral blood stem cell harvest; and 3) high-dose cyclophosphamide, thiotepa, and carboplatin (CTCb) followed by peripheral blood stem cell infusion. All 43 patients received doxorubicin, 5-fluorouracil, and methotrexate, 42 (98%) received etoposide, and 41 (95%) received CTCb. Thirty-two patients (74%) are alive, 28 (65%) without relapse at a median of 55 months (range, 41-87 months). Two died (5%) of treatment-related causes, (subclavian catheter complication after etoposide and late radiation pneumonitis), and nine other deaths (21%) were associated with recurrent breast cancer. The probabilities of overall and event-free survival at 4 years were 0.77 and 0.67, respectively, compared with 0.82 and 0.69, respectively, for 72 similar patients with 10 or more positive axillary nodes receiving the same sequence of therapy. Thus, patients with five to nine positive axillary lymph nodes have a similar risk of failure after high-dose chemotherapy and peripheral blood stem cell support as patients with 10 or more positive axillary lymph nodes.

High-Dose Chemotherapy in the Adjuvant Treatment of Breast Cancer: Benefit/Risk Analysis

BACKGROUND: High-dose chemotherapy (HDRx) may improve the prognosis of patients with high-risk breast cancer but at the expense of increased toxicity. However, no randomized, controlled trials have been published that clearly demonstrate the superiority of HDRx over conventional adjuvant chemotherapy. METHODS: We developed a simple model to compare benefits and risks of HDRx with conventional adjuvant chemotherapy (SDRx). The model integrates data on efficacy and risks of two competing treatment strategies into a single decision rule. RESULTS AND CONCLUSIONS: Using data from phase II studies, we show that if a disease-free survival is considered to be the most important outcome, HDRx should be administered when the probability of breast cancer relapse at five years exceeds 54% to 71% for patients with 4 to 9 positive nodes and exceeds 29% to 40% for patients with >9 positive nodes. If the endpoint of interest is five-year overall survival, then the treatment should be administered when the probability of relapse exceeds 77% to 83% for patients with 4 to 9 nodes involved and 22% to 31% for those with >9 lymph nodes involved. While awaiting results of randomized, controlled trials to definitively establish the efficacy rate of HDRx, we also found that HDRx could be considered in the management of high-risk breast cancer if its efficacy rate is at least 54% to 60% superior to SDRx in reducing relapse risk in breast cancer patients with 4 to 9 nodes and at least 31% to 38% for >9 positive nodes. If survival data are used instead of disease-free survival outcomes, HDRx efficacy should be at least 47% to 48% superior to SDRx in reducing death risk in breast cancer patients with 4 to 9 nodes and at least 27% to 30% superior for >9 positive nodes to consider its use in the adjuvant setting.