National Institutes of Health Consensus Development Conference Statement: adjuvant therapy for breast cancer, November 1-3, 2000.

OBJECTIVE: Our goal was to provide health-care providers, patients, and the general public with an assessment of currently available data regarding the use of adjuvant therapy for breast cancer. PARTICIPANTS: The participants included a non-Federal, non-advocate, 14-member panel representing the fields of oncology, radiology, surgery, pathology, statistics, public health, and health policy as well as patient representatives. In addition, 30 experts in medical oncology, radiation oncology, biostatistics, epidemiology, surgical oncology, and clinical trials presented data to the panel and to a conference audience of 1000. EVIDENCE: The literature was searched with the use of MEDLINE(TM) for January 1995 through July 2000, and an extensive bibliography of 2230 references was provided to the panel. Experts prepared abstracts for their conference presentations with relevant citations from the literature. Evidence from randomized clinical trials and evidence from prospective studies were given precedence over clinical anecdotal experience. CONSENSUS PROCESS: The panel, answering predefined questions, developed its conclusions based on the evidence presented in open forum and the scientific literature. The panel composed a draft statement, which was read in its entirety and circulated to the experts and the audience for comment. Thereafter, the panel resolved conflicting recommendations and released a revised statement at the end of the conference. The panel finalized the revisions within a few weeks after the conference. The draft statement was made available on the World Wide Web immediately after its release at the conference and was updated with the panel's final revisions. The statement is available at http://consensus.nih.gov. CONCLUSIONS: The panel concludes that decisions regarding adjuvant hormonal therapy should be based on the presence of hormone receptor protein in tumor tissues. Adjuvant hormonal therapy should be offered only to women whose tumors express hormone receptor protein. Because adjuvant polychemotherapy improves survival, it should be recommended to the majority of women with localized breast cancer regardless of lymph node, menopausal, or hormone receptor status. The inclusion of anthracyclines in adjuvant chemotherapy regimens produces a small but statistically significant improvement in survival over non-anthracycline-containing regimens. Available data are currently inconclusive regarding the use of taxanes in adjuvant treatment of lymph node-positive breast cancer. The use of adjuvant dose-intensive chemotherapy regimens in high-risk breast cancer and of taxanes in lymph node-negative breast cancer should be restricted to randomized trials. Ongoing studies evaluating these treatment strategies should be supported to determine if such strategies have a role in adjuvant treatment. Studies to date have included few patients older than 70 years. There is a critical need for trials to evaluate the role of adjuvant chemotherapy in these women. There is evidence that women with a high risk of locoregional tumor recurrence after mastectomy benefit from postoperative radiotherapy. This high-risk group includes women with four or more positive lymph nodes or an advanced primary cancer. Currently, the role of postmastectomy radiotherapy for patients with one to three positive lymph nodes remains uncertain and should be tested in a randomized controlled trial. Individual patients differ in the importance they place on the risks and benefits of adjuvant treatments. Quality of life needs to be evaluated in selected randomized clinical trials to examine the impact of the major acute and long-term side effects of adjuvant treatments, particularly premature menopause, weight gain, mild memory loss, and fatigue. Methods to support shared decision-making between patients and their physicians have been successful in trials; they need to be tailored for diverse populations and should be tested for broader dissemination.

Developing community partnerships to promote adolescent health.

The author discusses a very successful community partnership entitled the "South Carolina Health Connection Project (SCHCP) established in the state of South Carolina to curtail the high incidence of teenage pregnancies in that state. Over 18 community organizations supported the project funded by the American Association for the Advancement of Science (AAAS) in 1997 in which 2,000 youth participated.

Phase I and pharmacologic study of topotecan: a novel topoisomerase I inhibitor.

PURPOSE: A phase I and pharmacologic study was undertaken to determine the maximum-tolerated dose (MTD), describe the principal toxicities, and characterize the pharmacologic behavior of topotecan, which is a semisynthetic analog of camptothecin with broad preclinical antitumor activity and the first topoisomerase I-targeting agent to enter clinical development in the United States since studies of sodium camptothecin over 2 decades ago. PATIENTS AND METHODS: Thirty-minute infusions of topotecan were administered daily for 5 consecutive days every 3 weeks to patients with advanced solid malignancies at doses ranging from 0.5 to 2.5 mg/m2/d. RESULTS: At doses of 1.5 and 2.0 mg/m2, grade 3 and 4 neutropenia occurred in most courses; however, neutropenia was brief and rarely associated with fevers or treatment delays. Neutropenia was more severe in patients with extensive prior treatment than in minimally pretreated patients, but these differences were not substantial. At 2.5 mg/m2, topotecan induced profound and prolonged neutropenia that was frequently associated with fever and treatment delays in minimally pretreated patients. Topotecan also induced mild depressions in the hematocrit level in the majority of courses; however, precipitous drops requiring transfusional therapy occurred in 14% of courses and suggested a drug-induced hemolytic effect. Unlike sodium camptothecin, hemorrhagic cystitis was not observed. Thrombocytopenia, skin rash, diarrhea, and vomiting occurred infrequently and were modest in severity. Responses were observed in non-small-cell lung carcinoma and platinum-refractory ovarian carcinoma. Drug disposition in plasma was described by a biexponential model, with renal elimination accounting for 38.7% of drug disposition. Topotecan was rapidly hydrolyzed in vivo to a less active, open-ring form. CONCLUSIONS: Neutropenia is the dose-limiting toxicity, and 1.5 mg/m2 is the recommended starting dose of topotecan for both minimally and heavily pretreated patients in future phase II trials, with escalation to 2.0 mg/m2 if treatment is well tolerated. Non-small-cell lung and platinum-refractory ovarian carcinomas should be among those evaluated in phase II trials of topotecan.

Effect of P-glycoprotein expression on the accumulation and cytotoxicity of topotecan (SK&F 104864), a new camptothecin analogue.

Topotecan (TPT, 9-dimethylaminomethyl-10-hydroxycamptothecin) is the first topoisomerase I-directed cytotoxic agent to enter clinical trials in the United States in two decades. The effect of P-glycoprotein (Pgp) overexpression on TPT cytotoxicity was examined in CHRC5 (colchicine-resistant) and AuxB1 (parental) Chinese hamster ovary cells. Examination of the IC50 values observed in colony-forming assays revealed that the CHRC5 cells were 15-fold (SD, +/- 3; n = 3) resistant to TPT after a 1-h exposure and 3.2-fold (SD, +/- 1.4; n = 4) resistant in continuous exposure experiments. Band depletion immunoblotting revealed that 4-fold higher concentrations of extracellular TPT were required to induce the formation of topo I-DNA complexes in CHRC5 cells as compared to AuxB1 cells. To assess the role of Pgp in this resistance, drug accumulation and cytotoxicity assays were repeated in the absence and presence of quinidine. Addition of quinidine enhanced TPT accumulation (measured by high-performance liquid chromatography) and diminished the IC50 for TPT to a greater extent in CHRC5 cells than in AuxB1 cells. To examine whether similar effects could be detected in Pgp-expressing human cells, MCF-7/Adriar breast cancer cells and KG1a human acute myelogenous leukemia cells were examined. Quinidine or verapamil enhanced TPT accumulation in both of these cell lines but had no effect in parental MCF-7 cells or a variety of human leukemia cell lines that do not overexpress Pgp. Cytotoxicity measurements performed by counting the number of surviving cells (MCF-7/Adriar) or employing a modified, highly stable tetrazolium dye reduction assay (leukemia cell lines) revealed that quinidine diminished the IC50 for TPT in the Pgp-overexpressing cell lines but not in the control lines. These results suggest that Pgp overexpression diminishes TPT accumulation and TPT cytotoxicity in hamster and human cells. It should be stressed, however, that these effects were substantially smaller than the effects of Pgp overexpression on the accumulation and cytotoxicity of the anthracycline daunorubicin and the epipodophyllotoxin etoposide in the same cell lines.

Phase I and pharmacokinetic study of hepsulfam (NSC 329680).

Hepsulfam (NSC 329680), a bifunctional alkylating agent structurally related to busulfan, has entered clinical trial based on its broader preclinical antitumor activity compared with that of busulfan and its i.v. formulation which may circumvent the many problems arising from the p.o. administration of busulfan, such as significant individual differences in bioavailability. In this Phase I study, 53 patients received 95 courses of hepsulfam at doses ranging from 30 to 480 mg/m2 administered i.v. over 30 min every 28 days. Hematological toxicity was dose limiting. Leukopenia and thrombocytopenia were dose related, delayed in onset, and sustained for long durations. Toxicity was cumulative in most patients receiving more than one course. This pattern of myelosuppression suggests that hepsulfam is cytotoxic to hematopoietic stem cells. Although hematological toxicity was not particularly severe during most courses, its lengthly duration precluded the prompt administration of subsequent courses. Minimal nonhematological effects were observed. Pharmacokinetic studies revealed that the clearance rate of hepsulfam is linear over the dose range studied and that its plasma disposition is biphasic with mean alpha and beta half-lives of 19 +/- 18 (SE) min and 337 +/- 248 (SE) min, respectively. The area under the plasma clearance curve correlated with the percentage of change in WBC using a sigmoidal Emax model and with the duration of thrombocytopenia in patients with hematological toxicity. Based on the protracted duration of the toxicity of multiple doses that were greater than 210 mg/m2, the recommended starting dose for Phase II trials is 210 mg/m2. However, these trials should be pursued with caution because of the protracted nature of hepsulfam's myelosuppression. Because hepsulfam produced minimal nonhematological toxicity, substantial dose escalation above 480 mg/m2 may be possible with hematopoietic stem cell support.