Search PubMed⌕ Search

Biomedical subjects

O W Brawley

Publications and source records attributed to O W Brawley.

At least 37 records · Page 2Linked to original sources
PubMed1997

National cancer clinical trials: children have equal access; adolescents do not.

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.

Adolescent↗
PubMed1997

Prostate cancer incidence and mortality rates among white and black men.

This paper presents prostate cancer incidence and mortality rates in the United States by factors associated with the disease at diagnosis and explores racial differences in these rates. The analysis is based on population-based cancer data from the Surveillance, Epidemiology, and End Results (SEER) Program of the National Cancer Institute. Incidence rates increased sharply from 1973 to 1992 (more so among whites), with the increase attributed to screening and preferential finding of low-risk, slow-growing tumors (that is, length bias). Mortality rates increased slightly (more so among blacks). The 1988-1992 white and black prostate cancer mortality rates comprise cases diagnosed as early as 1973. These rates remained fairly constant for each stage category at diagnosis, except for black men diagnosed with localized or unstaged disease, in whom the rates increased. Of the white prostate cancer cases, 33% are diagnosed with localized disease, 16% are diagnosed with regional disease, and 38% are diagnosed with distant disease. The corresponding percentage for black patients are 31, 12, and 45%. Prostate cancer mortality rates for blacks diagnosed with localized, regional, distant, and unstaged disease are 1.9, 1.5, 2.4, and 2.0 times those of whites. The time from diagnosis to death depends on the stage and age at diagnosis, with the time somewhat longer for whites than blacks. This longer time period is due, in part, to better staging and length bias. The effect of therapy on prostate cancer mortality rates is unclear.

Adult↗
PubMed1996

Representation of African-Americans, Hispanics, and whites in National Cancer Institute cancer treatment trials.

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.

Black or African American↗
PubMed1996

Cancer chemoprevention trials.

Clinical Trials Referral Resource is designed to serve as a ready reference for oncologists to help identify clinical trials that might be suitable for their patients. We hope it also will enhance accrual to clinical trials by informing practicing oncologists of ongoing protocols. Currently in the United States less than 10% of eligible adult patients are entered on clinical trials. The result is a delay in answering important therapeutic and scientific questions and disseminating therapeutic advances to the general oncology community. It should be emphasized that including a specific trial does not imply that it is more important than another trial. Among the criteria for selection are that the trial is addressing an important question and is not expected to close in the immediate future (less than 1 year), and that initial staging or laboratory tests required for patient eligibility are widely practiced and available. Information on other protocols can be accessed via Physician's Data Query (PDQ). We emphasize that this is an attempt to encourage referral of patients to these trials. We are specifically not soliciting additional members for the cooperative groups, nor are we suggesting how practicing oncologists should be treating patients not in a study. This month's installment of Clinical Trials Referral Resource is devoted to cancer chemoprevention trials. For patient entry information contact the person listed in each individual trial.

Adult↗
PubMed1995

Design of the Prostate Cancer Prevention Trial (PCPT).

The PCPT is a chemoprevention trial of finasteride with a primary endpoint of biopsy-proven presence or absence of prostate cancer. A total of 18,000 healthy men, aged 55 years and older, will be randomized. Half will receive finasteride (5 mg/day) and half will receive placebo (one matching tablet per day) for 7 years. The trial is designed to have 92% power to detect a 25% reduction in period prevalence of biopsy-proven disease using a two-sided test with alpha = 0.05. The trial is complicated by the known impact of finasteride on the major screening test for prostate cancer, prostate specific antigen (PSA). This paper describes the PCPT design with reference to alternatives that were considered. The chosen design depends on five critical assumptions that must be monitored closely throughout the 9-year trial.

Aged↗
PubMed1994

The potential for hormonal prevention trials.

Breast and prostate cancer are significant causes of morbidity and mortality and are very similar in etiology, epidemiology, and modalities of treatment. Investigational strategies in the prevention of these malignancies also have strong parallels. The National Cancer Institute is sponsoring several large scale clinical trials involving hormonal manipulation and cancer prevention. In the Breast Cancer Prevention Trial, 16,000 women at high risk for breast cancer are being randomized to receive the antiestrogen agent tamoxifen or placebo for 5 years in an effort to determine if breast cancer development can be inhibited. In a similar trial, the Prostate Cancer Prevention Trial, 18,000 men older than 55 years of age will be randomized to receive finasteride, a 5-alpha-reductase inhibitor, or placebo to determine if inhibition of dihydrotestosterone synthesis in the prostate over a prolonged period will lead to a decreased incidence of prostate cancer. Both clinical trials offer the possibility of demonstrating that a hormonal intervention can decrease an individual's risk of developing breast or prostate cancer. They also have the potential of providing critical information about cancer risk, etiology, screening, and genetics, as well as quantifying the risks and benefits of specific preventive interventions.

5-alpha Reductase Inhibitors↗
PubMed1994

Chemoprevention of prostate cancer.

Primary prevention of prostate cancer is a relatively new concept. Through large-scale studies it is possible that we may be able to define better the risk for prostate cancer and identify those who would benefit from an intervention to lower their risk of disease. As risk for prostate cancer is better defined, a number of interventions may eventually be tested. Several interventions are sufficiently mature that they can be implemented in large-scale trials. Diet modification is an intervention that is ready for evaluation. It may also have additional benefits by decreasing mortality from other malignancies and cardiac disease. 5 alpha-reductase inhibitors are also ready for testing. The National Cancer Institute and its clinical cooperative groups have begun a large trial to assess finasteride in the prevention of prostate cancer.

5-alpha Reductase Inhibitors↗
PubMed1994

A randomized pilot study of alternating or simultaneous zidovudine and didanosine therapy in patients with symptomatic human immunodeficiency virus infection.

A randomized pilot study comparing alternating and simultaneous regimens of zidovudine and didanosine (ddl) was conducted in 41 patients with AIDS or symptomatic human immunodeficiency virus (HIV) infection. Patients on each regimen received the same overall amounts of zidovudine and didanosine over time. CD4 cell counts in patients on the simultaneous regimen reached a maximum (mean +/- SE) of 108 +/- 16/mm3 above baseline (two-tailed P < or = .0001) and were significantly higher than in patients on the alternating regimen at all time points during weeks 6-45. At 54 weeks, the CD4 cell counts in the patients on the simultaneous regimen were still 40 +/- 19/mm3 above baseline. Patients on the simultaneous regimen also had significantly greater weight gain. While toxicities were generally mild and comparable between the regimens, 1 patient on the simultaneous regimen died of pancreatitis and lactic acidosis. Thus, simultaneous therapy provided more sustained elevations in CD4 cells than alternating therapy over 1 year and may be worth exploring in larger controlled trials.

AIDS-Related Opportunistic Infections↗
PubMed1994

After a treatment breakthrough: a comparison of trial and population-based data for advanced testicular cancer.

PURPOSE: To determine to what extent the benefits of cisplatin-based combination chemotherapy have been disseminated to all American men diagnosed with advanced testicular cancer. PATIENTS AND METHODS: One hundred seventy-two advanced testicular cancer cases from five population-based registries of the Surveillance, Epidemiology, and End Results (SEER) Program diagnosed from 1978 to 1984 were compared with 133 diagnostically comparable cases from the Memorial Sloan-Kettering Cancer Center (MSKCC) vinblastine, dactinomycin, and bleomycin (VAB) regimens 7 through 9. Exclusions were made in both series for cases with elevated markers only, abdominal disease only, or extragonadal tumors. Ratings of extent of disease using the Indiana University system (minimal/moderate or advanced) were available for the MSKCC cases, and were determined retrospectively on the SEER cases based on information abstracted from medical records. RESULTS: Among the SEER cases, 89% reported receiving chemotherapy, and 95% of these received cisplatin-containing regimens. Survival among the MSKCC patients was significantly better than for the SEER cases in the minimal/moderate extent of disease category (95% and 73% 3-year survival rate, respectively); however, the difference for advanced cases was only marginally significant (52% and 40% 3-year survival rates, respectively). Survival did not vary significantly by year of diagnosis in either series. CONCLUSION: Although most of the patients in the SEER series received cisplatin-based chemotherapy, this alone did not produce results equivalent to that in the MSKCC series. Since the patients were selected to be as diagnostically comparable as possible at baseline, remaining differences in survival may be due to adherence to a fixed regimen and level of dose-intensity, adequacy of diagnostic work-up, implementation of salvage therapies and debulking surgery, and unknown factors related to who is willing and able to travel to a tertiary care center for treatment. Whatever the reason for not achieving optimal results in the SEER series, the very modest survival improvements over the time period 1978 to 1984 indicates that the differences in outcome between the two series were basically stable over the study period.

Adolescent↗
PubMed1994

5-Alpha-reductase inhibition and prostate cancer prevention.

Studies of prostate biology support the concept that dihydrotestosterone is the principal androgen responsible for normal and hyperplastic growth of the prostate gland. Cancer is a process of malignant transformation evolving over time, involving cellular growth and division. Therefore, an altered endocrine state, such as suppression of dihydrotestosterone activity, may have an impact on prostate cells inhibiting carcinogenic transformation. In vitro and in vivo preclinical observations support this hypothesis. A placebo-controlled randomized trial using finasteride, an inhibitor of the enzyme that converts testosterone to dihydrotestosterone, is planned. The endpoint of this trial will be reduction of prostate cancer incidence.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗