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PURPOSE: To determine whether adolescents with cancer, who in comparison to younger patients have a higher cancer incidence and lower mortality reduction, have equal access to national cancer clinical trials. METHODS: The ethnic/racial distribution of 29,859 subjects < 20 years of age entered onto National Cancer Institute-sponsored clinical trials between January 1, 1991, and June 30, 1994, was compared with the expected distribution of patients of the same age in the United States. RESULTS: The Children's Cancer Group and Pediatric Oncology Group had 29,134 (97.6%) of the total study entries among < 20-year-old subjects during the 3.5 years of surveillance. The adult cooperative groups accounted for < 3% of the clinical trials entries in the 15-19-year age range. When analyzed nationally by region, the under-representation of the older adolescent subjects was universal. From other analyses, the two pediatric cooperative groups were estimated to have registered > 94% of the children < 15 years of age who were expected to have been diagnosed to have cancer, but only 21% of the cancer patients in the 15-19-year age group. CONCLUSIONS: The national pediatric cancer cooperative groups allow the majority of American children < 15 years of age and their families equal opportunity to access clinical cancer trials, regardless of race or ethnicity. Among patients 15-19 years of age, however, > 75% are not being enrolled by any cooperative group sponsored by the National Cancer Institute. Thus, older adolescents are disadvantaged with respect to access to the national clinical trials, regardless of their race or ethnicity.

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PURPOSE: To determine the ethnic/racial distribution of patients entered in national pediatric cancer clinical trials relative to the patient population served. METHODS: The ethnic/racial distribution of 29,134 patients < 20 years of age entered in clinical trials conducted by the Children's Cancer Group (CCG) and Pediatric Oncology Group (POG) between January 1, 1991 and June 30, 1994 were compared with the expected distribution of patients of the same age in the United States. The latter was predicted from the 1989 to 1991 crude incidence data of the National Cancer Institute (NCI) Surveillance, Epidemiology, and End Results (SEER) program applied to the 1990 United States census. RESULTS: Of the patients on CCG and POG trials, 11.6% were reported to be Hispanic, 10.4% were African-American, and 4.7% were other racial groups. The expected values were 9.1%, 10.7% and 4.3%, respectively. Representation of minority patients was equal or greater than expected for 24 of 27 subgroups analyzed. CONCLUSIONS: In the United States, minority children with cancer are proportionately represented on clinical trials of the two national pediatric cancer cooperative groups. They and their families are provided with an equal opportunity to access clinical cancer trials and the potential benefits of cancer research.

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PURPOSE: To describe the rationale for independent data monitoring committees (DMCs) for National Cancer Institute (NCI)-sponsored phase III cooperative group clinical trials. DESIGN: We review the necessity for interim monitoring of outcome data during the course of randomized clinical trials and summarize the reasons for establishing DMCs with requisite expertise and with appropriate independence from study investigators. RESULTS: The important components of the policy for cooperative group DMCs are described with a focus on the makeup of these bodies and on the complementary roles of study committee leadership and DMCs in protecting patient safety during the conduct of randomized clinical trials. CONCLUSION: The cooperative group DMCs that are independent of the study committees and that have the requisite expertise to examine accumulating data and to base decisions on monitoring guidelines that are specified in advance by the study committee provide a body able to protect patient safety, to protect the integrity of the clinical experiments on which patients have consented to participate, and to assure the public that conflicts of interest do not compromise either patient safety or trial integrity.

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BACKGROUND: A confirmatory randomized clinical trial is a trial that is aimed at assessing whether a treatment effect observed in a previous randomized trial (or trials) is real and important. There is often considerable disagreement about the need for such confirmatory trials. PURPOSE: Our aim is to provide a general statistical framework for evaluating whether a confirmatory trial is warranted in a particular situation. METHODS AND RESULTS: The results of two clinical trials are considered: 1) a Cancer and Leukemia Group B trial comparing induction chemotherapy plus radiotherapy with radiotherapy alone in the treatment of patients with locally advanced non-small-cell lung cancer and 2) a North Central Cancer Treatment Group trial comparing surgery plus adjuvant chemotherapy with surgery alone in the treatment of patients with advanced colon cancer. In our analysis, we argue that differences in the interpretation of results from a randomized trial are based on differences in prior beliefs about the efficacy of the treatment(s) under study. We believe that a major factor in the decision to perform a confirmatory trial is prior skepticism about the clinical worth of the treatment in question. Both the level of prior skepticism and the minimum treatment effect deemed clinically worthwhile require subjective judgment. We develop a Bayesian framework to allow differences in interpretation to be examined systematically and the need for a confirmatory trial to be assessed. Our model allows the addition of prior belief (specified in the form of a prior distribution of treatment effect) to the results of a trial to yield a posterior distribution. The interpretation of trial results is based on the posterior distribution and will vary as the prior distribution (i.e., the prior belief) varies. To aid in the interpretation of trial results, we also advocate the specification of a minimum clinically worthwhile treatment effect at the start of a trial. CONCLUSIONS AND IMPLICATIONS: Our approach acknowledges that a number of different prior beliefs are possible, giving rise to a range of interpretations of results from a clinical trial. This approach provides a formal and systematic basis for considering both the range of likely opinions and the subsequent decision to be made with regard to the need for a confirmatory trial. We recommend that this approach be considered in the discussion of future confirmatory randomized clinical trials.

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BACKGROUND: The National Cancer Institute (NCI)-sponsored clinical trials cooperative groups place more than 25 000 American patients in treatment trials every year. Equal access and proportional representation of all races/ethnicities is desired. PURPOSE: Our objectives were to evaluate the inclusion of African-Americans, Hispanics, and non-Hispanic whites in NCI-sponsored treatment trials and to determine if there is proportional racial/ethnic representation. METHODS: During the period of January 1, 1991, through June 30, 1994, 99 495 cancer patients were enrolled in clinical trials and declared themselves as non-Hispanic black, non-Hispanic white, or Hispanic (of any race). In the analysis, participants in NCI treatment trials were subdivided into three age groups: birth to 19 years, 20-49 years, and 50 or more years. The racial/ethnic composition of each of these age groups was compared with the racial/ethnic makeup of the American population with cancer. Estimates of the number of incident cancer cases per year were made for each racial/ethnic group within each age group using data from the Surveillance, Epidemiology, and End Results (SEER) Program and the 1990 Census. The percentage of all cancer patients who were in each racial/ethnic group were compared with the population that entered clinical trials. Comparisons are also made separately for patients with leukemia and breast, colorectal, lung, and prostate cancers. RESULTS: Among patients 0-19 years old, 20-49 years old, and 50 years old or older there is relatively proportional representation of non-Hispanic blacks, Hispanics, and non-Hispanic whites in trials. It is noted that more than 70% of cancer patients aged 0-19 years are estimated to enter cooperative group clinical trials compared with 4.0% of cancer patients aged 20-49 years and 1.5% of patients aged 50 years or older. CONCLUSIONS: Accrual of American cancer patients to NCI-sponsored treatment trials generally parallels the incident burden of disease among non-Hispanic African-Americans, Hispanics, and non-Hispanic whites. IMPLICATIONS: This study shows that the NCI clinical trials are, as a whole, racially/ethnically representative of the American population and suggests that there is equal access to NCI clinical trials.

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In 1990, the five leading causes of cancer death in men aged 65 and older were carcinomas of the lung, prostate, colon and rectum, and pancreas, and leukemia. For women in this age group, the five leading causes of cancer death were carcinomas of the lung, breast, colon and rectum, pancreas, and ovary. To determine the representation of the elderly in clinical trials, the 1992 accrual of the National Cancer Institute (NCI)-sponsored Clinical Cooperative Group treatment trials (which included more than 8000 elderly patients) for the aforementioned sites was compared with the 1990 incidence data from the NCI's Surveillance, Epidemiology, and End Results program. Of the male patients enrolled in the trials, an average of 39% were older than 65 (47.3% lung, 79.5% prostate, 47.5% colorectal, 45.6% pancreas, and 9.6% leukemia); whereas 25.9% of all women enrolled in trials were 65 or older (43.6% lung, 17.3% breast, 46.2% colorectal, 59.6% pancreas, and 35.4% ovary). With respect to incidence, older patients generally are underrepresented in cancer treatment trials. With the exception of the data on prostate cancer, each of the comparisons using the Z statistic gave probability values of less than 0.01. The most significant discrepancies between incidence and participation in cancer treatment protocols were noted for leukemia in males and breast cancer in females. Possible explanations for these findings include (1) a research focus on aggressive therapy, which may be unacceptably toxic to the elderly; (2) presence of comorbidity in the elderly; (3) fewer trials available specifically aimed at older patients; (4) limited expectations for long term benefits on the part of physicians, relatives, and the patients themselves; and (5) a lack of financial, logistic, and social support for the participation of elderly patients in clinical trials. Recognizing this situation, NCI recently sponsored a number of trials that specifically target the elderly. This paper describes the status of all major Phase II and III clinical trials that recently were closed, still are active, or now are in review that address the clinical care of this important segment of the U.S. population.

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In the past decade, therapy-related acute myeloid leukemia (t-AML) following treatment with regimens that include inhibitors of topoisomerase-II (TOPO-II) has been reported with increasing frequency. These cases of t-AML generally have a shorter latency period than t-AML following alkylator therapy, are associated with chromosomal translocations (especially involving chromosome band 11q23), and usually present as M4 or M5 FAB subtype. Although the epipodophyllotoxins (etoposide and teniposide) have been most often implicated, similar cases of t-AML occur following therapy with other classes of Topo-II inhibitors (e.g., anthracyclines). There is wide variation in published studies in the estimates of risk of t-AML following epipodophyllotoxin therapy. These varying estimates may reflect a number of factors, including: small sample size leading to large confidence intervals around risk estimates; varying susceptibility of different patient populations; varying schedules of epipodophyllotoxin administration; different cumulative doses of epipodophyllotoxins; and administration of epopodophyllotoxins with additional agents that may alter the leukemogenic effect of the epipodophyllotoxins. Available data suggest that children with acute lymphocytic leukemia (ALL) treated with high cumulative doses of epipodophyllotoxins using either weekly or twice-weekly schedules of administration have a relatively high risk of developing t-AML (5-12% cumulative risk). On the other hand, germ cell patients treated with relatively low cumulative doses of etoposide (usually 1,500-2,500 mg/m2) appear to have a low risk for developing t-AML. There is inadequate experience at this time with higher cumulative doses of etoposide (e.g., 4,000-5,000 mg/m2 as used for pediatric solid tumors) given on a daily x 5 schedule to allow estimates of risk to be developed for this schedule and cumulative dose. The Cancer Therapy Evaluation Program (CTEP) of the National Cancer Institute (NCI) has developed a monitoring plan designed to obtain reliable estimates of the risk of t-AML following epipodophyllotoxin treatment. Twelve Cooperative Group clinical trials that use epipodophyllotoxins at either low (< 1,500 mg/m2), moderate (1,500-3,999 mg/m2), or higher cumulative doses (> 4,000 mg/m2) are being prospectively monitored for cases of t-AML occurring among patients entered onto the trials.

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Neoadjuvant therapy has come to play an increasingly prominent role in the treatment of cancer. Originally defined as systemic therapy given before local treatment, the concept has been extended to include radiation therapy given before surgery. Potential advantages include improved local and distant control, direct evaluation, and organ-sparing treatment. Potential disadvantages include increased toxicity and cost, potential delay in effective treatment, and obscuring of pathologic staging. Neoadjuvant therapy in cancer treatment may be viewed in three categories: tumors in which neoadjuvant treatment has been shown effective, thus becoming standard therapy; tumors in which it has been shown to facilitate organ-sparing, and tumors in which its utility has not been shown. For patients with osteogenic sarcoma, for example, preoperative chemotherapy and limb salvage therapy have become the standard of care. Response to chemotherapy, ascertained by histologic review of the surgical specimen, can be used to tailor postoperative chemotherapy. In patients with advanced laryngeal squamous cell carcinoma, neoadjuvant chemotherapy followed by radiation has permitted laryngeal preservation in a majority of patients without compromising overall survival. Phase II and III studies conducted in women with breast cancer have demonstrated promising results for neoadjuvant chemotherapy given before radiation therapy and/or surgery. Phase III studies to compare neoadjuvant therapy to standard therapy in patients with breast cancer are underway. For neoadjuvant therapy, as with other innovations in cancer treatment, it is crucial that a new strategy must be compared closely to standard therapy in terms of recurrence, survival, and impact on organ sparing, as well as quality of life and treatment costs.

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The Cancer Therapy Evaluation Program, National Cancer Institute (CTEP, NCI) strongly supports the role of controlled clinical trials in improving the care of children with cancer, and particularly the central role that the pediatric Cooperative Groups play in this process. Trends that threaten the ability to perform these trials include the increasingly limited financial resources available for clinical investigations and the sentiment within some circles that controlled clinical trials may be inappropriate for ethical reasons. The inherent risks of accepting a new therapy without rigorous comparison to existing therapy strongly support the need for randomized trials with adequate accrual to answer important therapeutic questions in a timely and reliable fashion. Retrospective analysis of multiple clinical trials is one method for identifying compelling hypotheses to be tested prospectively. Using this method, we have demonstrated the association between doxorubicin dose intensity and positive response and outcome for patients with Ewing sarcoma and osteosarcoma, thereby providing direction for the selection of important therapeutic questions to be addressed in future clinical trials for these malignancies.

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BACKGROUND: Recent reports have documented the occurrence of treatment-related acute myeloid leukemia (AML) following therapy with epipodophyllotoxins. These reports have led to growing concern among oncologists, which could lead to premature abandonment of these agents at a time when the relationship between cumulative dose of epipodophyllotoxin and risk of treatment-related AML has not been determined. PURPOSE: Because of the increasingly important role of epipodophyllotoxins in the treatment of several types of adult and pediatric tumors, the Cancer Therapy Evaluation Program (CTEP) of the National Cancer Institute (NCI) has developed a monitoring plan to obtain reliable estimates of the risk of treatment-related AML following epipodophyllotoxin treatment. METHODS: We identified 12 NCI-supported Cooperative Group clinical trials in which patients with solid tumors are being treated with epipodophyllotoxins at different cumulative doses. One trial is using a moderate dose of teniposide (900 mg/m2), and 11 trials are using etoposide at a low dose (< 1500 mg/m2), a moderate dose (1500-3999 mg/m2), or a high dose (> or = 4000 mg/m2). Cases of treatment-related AML and treatment-related myelodysplastic syndrome (MDS) (hereafter referred to as treatment-related AML/MDS) occurring in these trials are reported to CTEP, with initial analysis for each cumulative dose group triggered by the reporting of four cases of treatment-related AML/MDS in that group. For each analysis, total patient follow-up for the group is determined and cumulative 6-year incidence rate is calculated. RESULTS: Three cases of treatment-related AML and one case of treatment-related MDS (with documented monosomy 7) were reported in a group of 207 patients who received etoposide at a low cumulative dose. The calculated 6-year rate of development of treatment-related AML/MDS was 3.2% (95% upper confidence interval bounded by 7.2%). CONCLUSIONS: The 6-year cumulative rate of treatment-related AML/MDS (3.2%) is within the range previously reported for alkylator-based regimens that did not include epipodophyllotoxins. IMPLICATIONS: Previous reports have suggested that higher cumulative doses of alkylators are associated with increased risk of treatment-related AML, and a critical goal of the monitoring plan is to determine whether a similar relationship exists for the epipodophyllotoxins. Estimates will be developed for leukemogenic risk for the moderate- and high-cumulative-dose groups when four cases of treatment-related AML/MDS have been identified within each group.

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The goal of this study was to use dose-intensity analyses of published Ewing's sarcoma and osteogenic sarcoma trials to determine which agents were most closely associated with a favorable response. The percentage of patients with more than 90% tumor necrosis following neoadjuvant chemotherapy was the end point for analysis of osteogenic sarcoma trials, and disease-free survival and percentage of patients with distant-only relapse were the end points for analysis of Ewing's sarcoma trials. The data were analyzed using logistic regression analysis to circumvent the distortion of univariate analysis resulting from the correlation between doxorubicin dose intensity and the dose intensity of other agents. Our analysis suggests that doxorubicin dose intensity is an important determinant of favorable outcome for both Ewing's sarcoma and osteogenic sarcoma and that the dose intensities of other agents do not contribute as significantly to outcome as does doxorubicin dose intensity. Increasing dactinomycin dose intensity was associated with a poorer outcome in treatment of osteogenic sarcoma and Ewing's sarcoma, most likely resulting from regimens with a higher dactinomycin dose intensity having a lower doxorubicin dose intensity. While our analysis of osteogenic sarcoma trials is consistent with significant activity for cisplatin and high-dose methotrexate (and likely ifosfamide), a rank ordering of the efficacy of these agents when given with doxorubicin in multiagent regimens is not possible. Our analysis illustrates the importance of analyzing the contributions of individual agents to combination chemotherapy regimens. In the design of future clinical trials for osteogenic sarcoma and Ewing's sarcoma, careful attention should be given to optimizing doxorubicin dose intensity in regimens to be tested.

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Four major staging systems have been used to estimate the prognosis for children with local and regional neuroblastoma (NBL). Data obtained at diagnosis for 251 neuroblastoma patients from two Childrens Cancer Study Group (CCSG) studies were analyzed according to staging systems of the CCSG, St Jude Children's Research Hospital, the Pediatric Oncology Group (POG), and the Union Internationale Contre le Cancer (UICC) tumor-nodes-metastasis (TNM) system. The most significant variables were found to be age, tumor stage, extent of tumor removal, transgression of the midline by tumor infiltration, and site of primary tumor. Involvement of lymph nodes per se was not a bad prognostic sign unless associated with extension beyond the midline, the latter being the single most important prognostic variable. All four staging systems had value for prognostication and all identified with accuracy the low stage patient (stage I, stage A) who fares well (greater than or equal to 87% survival). The CCSG definition of stages II and III disease discriminated prognostic groups best among the remaining patients, and was able to identify the child with local-regional NBL with poor survival. The estimated 5-year survival rates for children with regional tumor (stage III, IIIA[N]), according to the four systems were 44%, 74%, 74%, and 74% for the CCSG, St Jude, POG, and UICC methods, respectively. We conclude that all four staging systems effectively define good-prognosis patients with localized disease but that the CCSG staging system most accurately identifies patients with regional tumor who have a poor outcome.

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The use of histocompatability antigen (HLA)-matched platelets has been advocated for the support of thrombocytopenic cancer patients. We randomized 78 newly diagnosed cancer patients prospectively (before thrombocytopenia) to receive either HLA-matched or mismatched single-donor platelet transfusions. Three hundred forty-one platelet transfusions were given for 80 separate episodes of therapy-induced thrombocytopenia in 33 patients. Forty-five patients receiving intensive chemotherapy did not develop significant (less than 20,000 platelets/mm3) thrombocytopenia and did not receive a platelet transfusion. No marked difference was observed between the matched and mismatched groups in regard to number of total platelet transfusions per patient (median, 3 vs. 5, respectively; P = 0.076), number of platelet transfusions per episode (median, 3.0 vs. 3.5, respectively; P = 0.28), or days between transfusions (median, 2 vs. 2, respectively, P greater than 0.4). Bleeding episodes, although rare, tended to be of increased severity in the mismatched group. Febrile patients receiving mismatched platelets tended to have a lower posttransfusion increment increase than their nonfebrile counterparts (P = 0.068), although a similar trend could not be demonstrated between febrile and nonfebrile patients who received matched platelets (P = 0.22). Patients treated as outpatients had significantly higher posttransfusion increments than when transfused as inpatients when they were given mismatched platelets (P less than 0.0005). Development of antiplatelet antibody did not appear to affect response to platelet transfusions. Only one patient developed sustained high-level antibody titers. In patients where thrombocytopenia was significant, the transfusion of HLA-matched platelets did not appear to offer a significant advantage. However, HLA-matched platelet transfusions tended to be associated with higher posttransfusion increments in febrile patients and a trend toward fewer severe bleeding episodes. A multi-institution trial containing a large number of patients is needed to evaluate trends observed in this study.

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Teniposide, a semisynthetic epipodophyllotoxin, was found to be highly active against murine leukemias, and the combination of teniposide with cytosine arabinoside (ara-C) was curative in murine leukemia models. The antitumor activity in preclinical models prompted introduction of teniposide into the clinic in 1971. Although teniposide as a single agent rarely produced a complete remission in heavily pretreated leukemia patients, teniposide plus ara-C produced complete remissions in some patients with refractory and relapsed acute lymphoblastic leukemia (ALL). Innovative front-line and salvage regimens using teniposide have been developed that incorporate a multi-drug strategy with early intensification, rotation of drug combinations in maintenance, and regional therapy in an effort to improve the cure rate in leukemia. However, as the complexity of these regimens increases, the contribution of an individual component such as teniposide becomes less clear. Although some of these regimens for newly diagnosed and relapsed ALL are now thought to represent the best available therapy, teniposide remains an investigational agent. In this review, we outline and discuss the conflicts arising from the need to answer drug-specific issues, and, at the same time, facilitate the implementation of innovative, curative regimens.

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A phase I study of ICRF-187 as a 2-hour iv infusion daily for 3 days was conducted in 46 evaluable pediatric patients. The maximum tolerated dose was 3500 mg/m2/day X 3 based on changes in hepatic function and coagulation abnormalities encountered when larger dosages were administered. One patient with acute lymphocytic leukemia achieved a complete remission and four cleared the blood of lymphoblasts. No other objective responses were seen. Pharmacokinetic analysis showed that the children had a larger volume of distribution per kilogram of body weight in the central compartment and total body and a more rapid total-body clearance than adults. These parameters can explain only part of the increased tolerance of children to ICRF-187.

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