Stem Cells Inhibition by Bevacizumab in Combination with Neoadjuvant Chemotherapy for Breast Cancer.

Preclinical works have suggested cytotoxic chemotherapies may increase the number of cancer stem cells (CSC) whereas angiogenesis inhibition may decrease CSC proliferation. We developed a proof of concept clinical trial to explore bevacizumab activity on breast CSC. Breast cancer patients requiring preoperative chemotherapy were included in this open-label, randomized, prospective, multicenter phase II trial. All received FEC-docetaxel combination, and patients randomized in the experimental arm received concomitant bevacizumab. The primary endpoint was to describe ALDH1 (Aldehyde dehydrogenase 1) positive tumor cells rate before treatment and after the fourth cycle. Secondary objectives included safety, pathological complete response (pCR) rate, disease-free survival (DFS), relapse-free survival (RFS), and overall survival (OS). Seventy-five patients were included. ALDH1+ cells rate increase was below the predefined 5% threshold in both arms for the 32 patients with two time points available. Grade 3 or 4 adverse events rates were similar in both arms. A non-significant increase in pCR was observed in the bevacizumab arm (42.6% vs. 18.2%, p = 0.06), but survival was not improved (OS: p = 0.89; DFS: p = 0.45; and RFS: p = 0.68). The increase of ALDH1+ tumor cells rate after bevacizumab-based chemotherapy was less than 5%. However, as similar results were observed with chemotherapy alone, bevacizumab impact on breast CSC cells cannot be confirmed.

A multicentre randomised controlled trial to evaluate the efficacy, morbidity and functional outcome of endoscopic transanal proctectomy versus laparoscopic proctectomy for low-lying rectal cancer (ETAP-GRECCAR 11 TRIAL): rationale and design.

BACKGROUND: Total mesorectal excision is the standard surgical treatment for mid- and low-rectal cancer. Laparoscopy represents a clear leap forward in the management of rectal cancer patients, offering significant improvements in post-operative measures such as pain, first bowel movement, and hospital length of stay. However, there are still some limits to its applications, especially in difficult cases. Such cases may entail either conversion to an open procedure or positive resection margins. Transanal endoscopic proctectomy (ETAP) was recently described and could address the difficulties of approaching the lower third of the rectum. Early series and case-control studies have shown favourable short-term results, such as a low conversion rate, reduced hospital length of stay and oncological outcomes comparable to laparoscopic surgery. The aim of the proposed study is to compare the rate of positive resection margins (R1 resection) with ETAP versus laparoscopic proctectomy (LAP), with patients randomly assigned to each arm. METHODS/DESIGN: The proposed study is a multicentre randomised trial using two parallel groups to compare ETAP and LAP. Patients with T3 lower-third rectal adenocarcinomas for whom conservative surgery with manual coloanal anastomosis is planned will be recruited. Randomisation will be performed immediately prior to surgery after ensuring that the patient meets the inclusion criteria and completing the baseline functional and quality of life tests. The study is designed as a non-inferiority trial with a main criterion of R0/R1 resection. Secondary endpoints will include the conversion rate, the minimal invasiveness of the abdominal approach, postoperative morbidity, the length of hospital stay, mesorectal macroscopic assessment, functional urologic and sexual results, faecal continence, global quality of life, stoma-free survival, and disease-free survival at 3 years. The inclusion period will be 3 years, and every patient will be followed for 3 years. The number of patients needed is 226. DISCUSSION: There is a strong need for optimal evaluation of the ETAP because of substancial changes in the operative technique. Assessment of oncological safety and septic risk, as well as digestive and urological functional results, is particularily mandatory. Moreover, benefits of the ETAP technique could be demonstrated  in post-operative outcome. TRIAL REGISTRATION: ClinicalTrial.gov: NCT02584985 . Date and version identifier: Version n°2 - 2015 July 6.

Marketing Authorization Procedures for Advanced Cancer Drugs: Exploring the Views of Patients, Oncologists, Healthcare Decision Makers, and Citizens in France.

BACKGROUND: The past decades have seen advances in cancer treatments in terms of toxicity and side effects but progress in the treatment of advanced cancer has been modest. New drugs have emerged improving progression free survival but with little impact on overall survival, raising questions about the criteria on which to base decisions to grant marketing authorizations and about the authorization procedure itself. For decisions to be fair, transparent and accountable, it is necessary to consider the views of those with relevant expertise and experience. METHODS: We conducted a Q-study to explore the views of a range of stakeholders in France, involving: 54 patients (18 months after diagnosis); 50 members of the general population; 27 oncologists; 19 healthcare decision makers; and 2 individuals from the pharmaceutical industry. RESULTS: Three viewpoints emerged, focussing on different dimensions entitled: 1) 'Quality of life (QoL), opportunity cost and participative democracy'; 2)'QoL and patient-centeredness'; and 3) 'Length of life'. Respondents from all groups were associated with each viewpoint, except for healthcare decision makers, who were only associated with the first one. CONCLUSION: Our results highlight plurality in the views of stakeholders, emphasize the need for transparency in decision making processes, and illustrate the importance of a re-evaluation of treatments for all 3 viewpoints. In the context of advanced cancer, our results suggest that QoL should be more prominent amongst authorization criteria, as it is a concern for 2 of the 3 viewpoints.

"They should take time": disclosure of clinical trial results as part of a social relationship.

Disclosing overall scientific results to clinical trial participants has become an ethical obligation. Here we studied how participants understand these results in view of their experience of clinical trials and illness in general and what modes of disclosure they preferred. Interviews were conducted with 29 breast cancer patients in France during 2009, using an in-depth qualitative approach. The findings obtained show that the "results" of research are understood quite differently by various patients depending on their expectations about clinical trials. Most of the women interviewed expected to receive personally tailored results at an individual encounter with their own clinical oncologist. Their preferred mode of disclosure was a consultation with their doctors because personal encounters promote mutual recognition and set up a symbolic process of exchange. The results of this study show that medical interventions should not be regarded solely from the technical point of view, but also in terms of the social relationships involved.

[How to share results of clinical trials with study participants?]. / Que signifie pour les participants la notion de « résultats ¼ d'un essai thérapeutique ?

Informing research participants of the results of clinical trials in which they were enrolled is in agreement with patients' rights and human dignity; such feedback is considered an ethical standard applied to clinical research. Cancer patients who participate in a clinical trial usually want to know the results. Here we analysed the literature about the different ways of disclosure of clinical trial results to participants, questioning their expectations and the meanings they give to the results. We describe some of the dilemma and intertwining between clinical care and clinical research. We highlight how the standardisation of sharing such results to participants could raise difficulties particularly for the relationship between doctor and patients.

Patients' regrets after participating in a randomized controlled trials depended on their involvement in the decision making.

OBJECTIVE: To identify the factors associated with long-term regrets expressed a posteriori by randomized controlled trial (RCT) participants questioned about their decision to participate in an RCT. STUDY DESIGN AND SETTING: Participants were questioned 6 years on average after their inclusion in a breast cancer adjuvant therapy RCT. Among 115 women from 21 centers, 93 (81%) answered a self-administered questionnaire based on the Decision Regret Scale (DRS). RESULTS: Mean DRS score was 16.8 (standard deviation=15.9); 43.0% of participants expressed mild regret, and 25.8% expressed moderate to strong regret. A quarter of the women (25.6%) said that the decision was taken by the doctor alone, and 13.5% said it was not consistent with their own wishes. In the multivariate ordinal regression analysis, an involuntarily passive role in decision making was found to be associated with greater regret (cumulative proportional odds ratio=7.3, 95% confidence interval=2.0-27.6), regardless of age and being allotted or not to the standard treatment in the RCT. CONCLUSION: Whether patients' regret depended on their level of participation in the decision making or vice versa could not be determined in this cross-sectional survey, but efforts should be made to ensure that patients' participation in trials is always based on an active personal decision.

Transparency in the presentation of trial results may not increase patients' trust in medical researchers.

BACKGROUND: One of the expected benefits of sharing trial results with participants is that it may enhance trust in medical researchers (TMRs). PURPOSE: In a prospective study on a sample of clinical trial participants, we investigated the effect on the participants' TMRs of providing final trial results to participants via the Internet. METHODS: Participants in the FNCLCC-PACS04 trial (ClinicalTrials.gov Identifier: NCT00054587) were surveyed on average 6 years after enrollment, when the trial results were available. In the current study, they were randomized to receive (experimental group) or not to receive (control group) a letter informing them that the results of the trial could be consulted on a specific website. TMRs was measured before randomization and 6 months later using mailed self-administered questionnaires. RESULTS: The response rate was 93% (N = 107). TMRs remained unchanged in the control group (mean effect size = -0.06, 95% confidence interval (CI): -0.28 to 0.17, p = 0.617) but decreased in the experimental group (-0.30, 95% CI: -0.53 to -0.06, p = 0.015). However, the difference between the two effect sizes was not statistically significant (p = 0.144). LIMITATIONS: The results obtained here on the disclosure of final trial results to breast cancer patients via the Internet cannot be generalized to all situations involving the disclosure of phase III randomized controlled trial results. CONCLUSIONS: Transparency is an ethical research requirement, but it may not enhance participants' TMRs.

Full access to medical records does not modify anxiety in cancer patients: results of a randomized study.

BACKGROUND: Information is crucial for increasing the patients' empowerment and autonomy in relevant decision-making processes, especially in malignant diseases. However, the extent to which information should be delivered is debated. The objective of this study was to assess the impact of providing systematic full access (SFA) to the medical record on anxiety, quality of life, and satisfaction. METHODS: Patients with newly diagnosed breast cancer, colon cancer, or lymphoma who had received adjuvant chemotherapy in an outpatient setting were included in a randomized controlled trial comparing those who requested access (RA) and those who provided SFA to the medical record. Anxiety was assessed using the Spielberger State-Trait Anxiety Inventory before, during, and at the end of treatment. Quality of life was evaluated using the European Organization for Research and Cancer quality-of-life questionnaire (EORTC QLQ-C30) before and at the end of treatment. Patients' satisfaction and perception of the organized medical record (OMR) were evaluated using a specifically designed questionnaire at the end of treatment. RESULTS: Most patients (98%) who had the opportunity to obtain the OMR chose to do so. Anxiety levels did not increase in the SFA arm, although they did not differ significantly compared with anxiety levels in the RA arm. The patients who had full access to their medical record were more satisfied with information (odds ratio, 1.68; 95% confidence interval, 0.98-2.9) and felt sufficiently informed more often (odds ratio, 1.86; 95% confidence interval, 1.08-3.19), but the differences were not statistically significant at the 5% level. CONCLUSIONS: Allowing full access to personal medical records increased satisfaction without increasing anxiety in patients with newly diagnosed cancer.

Assessment of care by breast cancer patients participating or not participating in a randomized controlled trial: a report with the Patients' Committee for Clinical Trials of the Ligue Nationale Contre le Cancer.

PURPOSE: Cancer patients participating in randomized controlled trials (RCTs) have not been found to have better clinical outcomes than other patients. Our objective was to assess the impact of RCTs on patients' satisfaction with care. PATIENTS AND METHODS: A prospective study was carried out in a cohort of women with breast cancer (N = 455) divided into those invited to participate in an RCT (201 acceptances, 66 refusals) and a comparable control group not invited to participate (n = 188). All the patients underwent the same treatment (fluorouracil, epirubicin, and cyclophosphamide 100 mg/m2 for six cycles). One and 7 months after the beginning of chemotherapy, self-administered satisfaction scores were used to compare the women's assessment of their care (Comprehensive Assessment of Satisfaction with Care validated scale). RESULTS: At the beginning of chemotherapy, women to whom RCT had been proposed rated the doctors' availability (average +/- standard deviation [SD]: RCT acceptance group, 3.60 +/- 0.78; RCT refusal group, 3.68 +/- 0.87; control group, 3.41 +/- 0.82; P < or = .02) and the doctors' communication (average +/- SD: RCT acceptance group, 3.56 +/- 0.88; RCT refusal group, 3.67 +/- 0.88; control group, 3.39 +/- 0.84; P .05) higher than those to whom the trial was not proposed. After the treatment, participants in the RCT felt that their doctor was more supportive (average +/- SD: RCT acceptance group, 3.04 +/- 0.92; control group, 2.77 +/- 0.85; P = .005) and more informative about their illness and treatment (average +/- SD: RCT acceptance group, 3.34 +/- 0.88; control group, 3.08 +/- 0.92; P = .006) than those in the control group. The general level of satisfaction was also higher in the RCT acceptance group. CONCLUSION: Women participating in an RCT have a more positive picture of their doctors' care than others, probably because of the structural effects of the informed consent and data collection processes.

Decision-making and breast cancer clinical trials: how experience challenges attitudes.

OBJECTIVE: The aim of this study was to measure women's preferences about decision-making and their impact to participate or not to a hypothetical randomised controlled trial (RCT). METHODS: We surveyed prospectively breast cancer patients invited to participate in a clinical RCT (group 1a=201 acceptances, group 1b=66 refusals) or not invited (group 2=188). All women had the same treatment. RESULTS: Decision-making preferences of patients who had refused clinical RCT entry were more patient's centred (72.3%) compared to those of patients who accepted (35.0%, P<0.001). Altruism was not a significant determinant of patients' participation. Randomisation was considered acceptable in 52.0% (group 1a) compared to 16.9% and 21.1% for group 1b or group 2, respectively (P<0.001). It was the main predictor of willingness to participate in a hypothetical RCT (adjusted odds ratio (OR(adj)) 4.6; 95% confidence interval [2.7-7.7]; P<0.001) with the patient group allocation (OR(adj) group 1a=5.0 [2.9-8.7]; group 1b=0.2 [0.0-0.8]; group 2=1 [referent]; P<0.001). After multivariate adjustment, willingness to participate was also significantly related with medical decision-making preferences (OR(adj) 2.2 [1.0-4.9]; P=0.045), with the feeling of being unable to refuse a doctor's proposal (OR(adj) 1.8 [1.1-3.2]; P=0.031), and with satisfaction with doctors' communication (OR(adj) 3.1 [1.5-7.8]; P<0.001). CONCLUSIONS: Patients' acceptance to participate in a RCT is preferred to be doctor's decision, whereas refusal is a personal one. When proposing a RCT, doctors must deal with patients' a priori negative feelings about randomisation. They should thoroughly discuss the reasons for and importance of randomisation as well as the other aspects of participating in the trial in order to give patients all of the information they need to make an informed decision.

Weekly administration of docetaxel for symptomatic metastatic hormone-refractory prostate carcinoma.

BACKGROUND: The current Phase II study investigated the clinical benefit, impact on quality of life (QOL), and tolerability of weekly docetaxel in symptomatic patients with metastatic hormone-refractory prostate carcinoma (HRPC). METHODS: Patients received weekly docetaxel 35 mg/m(2) intravenously for 6 consecutive weeks followed by a 2-week rest repeatedly for a maximum of 24 weeks of treatment. Clinical benefit evaluations, based on Karnofsky performance status (KPS) and pain, were assessed weekly during therapy. A clinical benefit response was defined as a sustained (> or = 4-week) improvement in at least one of these parameters without worsening in the other. Patient-assessed QOL (using the European Organization for Research and Treatment of Cancer QLQ-C30), changes in prostate-specific antigen (PSA) levels, tumoral response, and toxicity also were evaluated. RESULTS: Thirty men (median age, 67 years), 15 of whom had received previous chemotherapy, were treated. Overall, 46% of patients achieved a positive pain response and 48% achieved a 50%-or-greater reduction in PSA. KPS was high at baseline (80%), and no significant changes in this parameter were observed. Compared with baseline, all scores improved after the first cycle of therapy, particularly emotional (P = 0.015), pain (P = 0.001), constipation (P = 0.001), and global QOL (P = 0.011) scores. After the second cycle, dyspnea scores decreased (P = 0.010). At the last QOL assessment, there also was deterioration in terms of fatigue (P = 0.013), dyspnea (P = 0.010), and physical functioning (P = 0.017). Toxicity was mild and included neutropenia (Grade 3-4, n = 2). CONCLUSIONS: Of these elderly symptomatic patients with HRPC, half had received previous chemotherapy. Weekly docetaxel was found to be associated with improvements in clinical benefit response and in QOL and was well tolerated.

[Perception of information in through an survey educational booklet on biomedical research oncology: among 129 patients eligible for a clinical trial]. / Perception de l'information à travers une brochure sur la recherche biomédicale en cancérologie : Enquête auprès de 129 patients éligibles pour un essai clinique.

The purpose of this study was to evaluate patients' opinion on the content of an educational booklet (EB) on the objectives of the biomedical research in oncology, and, on the respect of their rights in case of participation to a clinical trial (CT). One hundred and twenty-nine patients treated for cancer at the Institut Paoli-Calmettes (Marseilles, France) and eligible for a CT were included in the study. They received the EB with the information letter and the informed consent sheet related to the CT. After reading, patients completed a survey questionnaire (10 items). About 84% of them stated that the EB content was comprehensible by the majority of patients. However, 18.2% required more information on the different phases of CTs and 39.4% more information on their own treatments. Furthermore, 41.4% were not/not entirely assured that they would receive all the information in case of participation to a CT and about 23% that their rights would be respected. Only 9.6% of patients knew the existence of the local ethical committees (CCPPRB); its intervention (information provided by the EB) was not considered as reassuring by 28.6% of patients. This study has important implications for patients eligible for CTs.

Phase I and pharmacokinetic study of escalating dose of docetaxel administered with granulocyte colony-stimulating factor support in adult advanced solid tumors.

PURPOSE: The purpose of our study was to assess the feasibility, toxicity, and pharmacokinetics of an escalating dose of docetaxel when administered with granulocyte colony-stimulating factor (G-CSF) support every 3 weeks. EXPERIMENTAL DESIGN: Patients with advanced solid malignancies were treated with escalating doses of docetaxel as a 1-h infusion every 3 weeks, supported by s.c. administration of human recombinant glycosilated G-CSF Granocyte (lenograstim), 5 microg/kg/day (from day 4 until neutrophil count >0.5-10(g)/liter for two consecutive days). Plasma sampling was performed to characterize the pharmacokinetics of docetaxel at the new recommended high-dose level. RESULTS: Forty-seven patients were treated with 116 courses of docetaxel at eight dose levels ranging from 100-185 mg/m(2). Dose-limiting toxicities were nonhematologic and included mucositis and dermatitis. Severe skin toxicity observed at 185 mg/m(2) led to discontinuing the study, and 175 mg/m(2) was selected as the recommended dose of docetaxel + G-CSF for future Phase II studies. Analysis of multiple courses revealed dermatitis, mucositis, arthralgia/myalgia, and neuropathy as the main dose-related toxic events. At 175 mg/m(2) mean +/- SD values for docetaxel plasmatic peak, area under the curve, clearance, volume of distribution, and terminal half-life were 6.7 +/- 1.7 microg/ml, 9.7 +/- 4 microg.h/ml, 34.2 +/- 12 liters/h, and 122.7 +/- 124 liters, respectively. Of the 16 patients treated at 175 mg/m(2), 8 patients responded (7 breast cancer and 1 lung cancer patients) including one complete response (1 breast cancer patient). CONCLUSIONS: Using G-CSF support allows substantial dose escalation of docetaxel. Whether such a dose increase improves the response rate warrants further investigation. At the highest dose level studied, pharmacokinetic parameters seem to maintain a linear profile.

Nurses' repeat measurement of chemotherapy symptoms: feasibility, resulting information, patient satisfaction.

The aim of this study was to investigate the feasibility and acceptability of a repeated measurement of 5 major side effects (pain, nausea, vomiting, anxiety, and fatigue) experienced by patients during an entire course of chemotherapy. Forty-nine inpatients receiving intravenous chemotherapy in the Medical Oncology Department of the Institut Paoli-Calmettes (Marseilles, France) were included in the study. At the study entry and every 12 hours from beginning of chemotherapy course, nurses assessed symptoms using Visual Analogic Scales (except for vomiting measured in number of episodes). Patients' pretreatment characteristics and their degree of satisfaction with nursing assessment were also recorded. The mean number of symptom measures was 2.9 in courses of less than 3 days, 5.4 in courses of 3 days, and 7.5 in courses of more than 3 days. Symptom patterns varied according to length of course. Furthermore, patients' pretreatment characteristics (age, sex, marital status, education level, type of cancer) had an impact on symptom scores at baseline and during treatment. About 80% of patients judged the nursing assessment as not constraining and 55% considered that its impact on their care was positive. This study demonstrates that repeated measurement of chemotherapy side effects was feasible and provide useful information for symptom management that might increase patient treatment satisfaction.

Efficacy and tolerance of a scalp-cooling system for prevention of hair loss and the experience of breast cancer patients treated by adjuvant chemotherapy.

The applicability and efficacy of a scalp cooling system were studied in 105 breast cancer patients receiving four cycles of adjuvant chemotherapy with mitoxantrone + cyclophosphamide (NC chemotherapy). Women accepting the scalp-cooling system were compared for alopecia both against those who refused and against a "reference" group of 109 patients similarly treated but without being offered a scalp-cooling system. Hair loss in the 105 study patients was evaluated by nurses using World Health Organization (WHO) criteria at each cycle of chemotherapy. Concomitantly, tolerance and side-effects of the helmet were also recorded in 48 accepting patients. Similarly to reference group patients, a subsample of 27 accepting patients self-assessed hair loss using a specific questionnaire measuring its frequency and severity and the distress associated with this symptom. Nurses' ratings ( n = 105) indicated that hair loss frequency was constantly lower, at each cycle of chemotherapy, in study patients with scalp-cooling system ( n = 77) than in those without ( n = 28). Differences between the two groups were statistically significant at cycles 1 and 3 ( P < 0.05). When compared with those reported by reference group patients ( n = 109), study patients' self-measures of alopecia frequency ( n = 27) provided even more marked results than those achieved by nurses (cycles 1-3: P < 0.01; cycle 4: P < 0.05). Tolerance was generally good and no scalp metastasis was observed among the 77 accepting patients followed up. This study demonstrates that scalp cooling was an effective method of protection against hair loss caused by NC chemotherapy. Its routine use as part of adjuvant chemotherapy, especially in cancers with low prevalences of scalp metastasis, should be seriously considered.

Retinoids, cisplatin and interferon-alpha in recurrent or metastatic cervical squamous cell carcinoma: clinical results of 2 phase II trials.

BACKGROUND: There is no standard treatment for inoperable recurrent or metastatic cancer of the uterine cervix. Retinoids and interferon, in combination with cytotoxic compounds, have been shown to be active in squamous cell carcinoma (SCC). This phase II trial sought to estimate the response rate and the tolerance to a 3-month treatment combining cisplatin, interferon-alpha (IFN-alpha) and all-trans-retinoic (tRA) or 13 cis retinoic acid (13Cis), in women with recurrent or metastatic cervical SCC. PATIENTS AND METHODS: Between November 1994 and October 1996, 33 patients, who had previously received aggressive treatment, and with metastatic and/or bulky disease were enrolled: 22 received tRA(40 mg/m(2)/day), 11 received 13Cis (1 mg/kg/day) in combination with IFN-alpha (6.106 UI/day SC) for 84 days plus cisplatin (40 mg/m(2)IV, days 1, 28 and 56). RESULTS: All patients were evaluable for response and/or toxicity. Toxicities were easily manageable and were never life-threatening, with major grade 3/4 vomiting (54%) and asthenia (54%). Seventeen patients (52%) stopped or reduced treatment because of toxicity or progression. Six objective responses (18%) were observed. No complete response was recorded. Median response duration was 4 months. Time to progression was 9 months [range 3.3 to 20.9] for responders and 7 months [range 1.7 to 32] for all patients. CONCLUSIONS: Regarding toxicity, this regimen should no longer be recommended in previously treated, advanced uterine SCC. However, the consistent response rate reported here may warrant further investigations in an early setting. Retinoid-based treatment with cytokines remains a promising field of research.

Transient detection of beta-galactosidase activity in hematopoietic cells, following reinjection of retrovirally marked autologous blood progenitors in patients with breast or ovarian cancer receiving high-dose chemotherapy.

OBJECTIVE: The aim of this report is to demonstrate the feasibility and safety of genetically modifying autologous human blood CD34(+) cells in vitro, with a retroviral vector that encodes a marker gene. The fate of genetically modified cells and their progeny was followed in vivo, after reinfusion in patients treated with high-dose chemotherapy for poor-prognosis breast or ovarian carcinomas. PATIENTS AND METHODS: Six patients received genetically modified autologous peripheral blood progenitors, together with unmanipulated aphereses, following high-dose chemotherapy. CD34(+) cells were immunoselected from aphereses, and retrovirally transduced by coculture with the retroviral vector producing cell line, to express a nuclear localized version of E. coli beta-galactosidase, encoded by a defective Moloney-murine leukemia virus-derived retroviral vector. Cells were reinfused to the patients after myeloablation, without prior ex vivo selection. RESULTS: Five out of six patients showed the transient presence of low numbers of beta-galactosidase(+) cells, as detected with an immunocytochemical assay, in the peripheral blood, during the first month following infusion. One patient had beta-galactosidase(+) clonogenic progenitors in her marrow at two months after transplantation, including HPP-CFC; intriguingly, this patient had the lowest percentage of X-gal(+) cells in her graft. Patients experienced side effects that are often observed after high-dose chemotherapy. CONCLUSIONS: Feasibility and safety of genetic modification of human hematopoietic stem and progenitor cells are demonstrated by this study. Ex vivo or in vivo selection is not mandatory, even in clinical situations where transduced cells have no survival advantage over wild-type cells; however, significant improvements in gene transfer technology are needed to achieve potentially useful levels of expression in such clinical situations.