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Biomedical subjects

S S Ellenberg

Publications and source records attributed to S S Ellenberg.

At least 55 records · Page 3Linked to original sources
PubMed1985

Pancreatic cancer. Adjuvant combined radiation and chemotherapy following curative resection.

The efficacy of combined radiation and fluorouracil as adjuvant therapy for pancreatic cancer is suggested by a prospective randomized study conducted by the Gastrointestinal Tumor Study Group (GITSG). Twenty-two patients randomized to no adjuvant treatment and 21 to combined therapy were analyzed. Neither life-threatening toxic reaction nor death due to toxic effect was encountered. The study was terminated prematurely because of an unacceptably low rate of accrual combined with the observation of increasingly large survival differences between the study arms. Median survival for the treatment group (20 months) was significantly longer than that observed for the control group (11 months). Four patients, three in the treated and one in the control group, have survived five years or longer following surgery. The extent of the tumor and initial performance status were significantly and independently related to survival.

Adenocarcinoma↗
PubMed1985

Randomized phase II clinical trials.

The sources of variability influencing the results of phase II trials are reviewed. Randomized designs for phase II testing are presented and evaluated. Phase II designs with "standard therapy" control groups are not found to be broadly useful. Designs which randomize among new agents or schedules appear to be of value both scientifically and logistically where patient accrual is adequate. The rationale and advantages of this design are described. The concept of ranking and selection of new agents and schedules is presented as an alternative to testing the null hypothesis of therapeutic equivalence. Sample size calculations demonstrate potential advantages of this approach in appropriate situations. The conduct of pilot or "phase II" studies of combinations is also discussed and randomized designs with early stopping rules are proposed.

Antineoplastic Agents↗
PubMed1984

Vertebral abnormalities associated with synthetic retinoid use.

Frequent symptoms of back and neck stiffness led to a radiographic investigation of the vertebral spine in patients receiving synthetic retinoids, isotretinoin and etretinate. X-ray examination of fifty patients with various skin disorders who received retinoids for at least 2 years were compared with seventy-two age- and sex-matched untreated patients. Differences in frequencies of defined abnormalities, which included anterior spinal ligament calcification and presence of osteophyte at two or more vertebral levels in the absence of joint space narrowing, were determined for treated and untreated patients. When the entire group of treated patients was compared with the entire group of those untreated, no statistically significant differences were observed. When only patients with basal cell nevus syndrome ( BCNS ) or basal cell carcinoma (BCC) who had never received retinoid were compared with those who received isotretinoin, the frequency of the defined abnormalities was significantly higher in the treated group (P less than 0.01). This study suggests that the ingestion of isotretinoin at mean total dose of 150,060 mg for an average of 2.9 years is associated with a statistically significant increase in developing an associated ossifying diathesis in patients with BCNS or BCC, when compared with matched, untreated controls.

Adult↗
PubMed1983

Leukemia and preleukemia after adjuvant treatment of gastrointestinal cancer with semustine (methyl-CCNU).

We evaluated the risk of acute nonlymphocytic leukemia, acute myelodysplastic syndrome, and preleukemia in 3633 patients with gastrointestinal cancer who were treated in nine randomized clinical trials. Among 2067 patients given semustine (methyl-CCNU) as adjuvant therapy, leukemic disorders developed in 14, whereas only one leukemic disorder (acute nonlymphocytic leukemia) occurred among 1566 patients given other therapies (relative risk = 12.4; 95 per cent confidence interval = 1.7 to 250). The six-year cumulative mean risk (+/- S.E.) of acquiring a leukemic disorder after treatment with semustine was 4.0 +/- 2.2 per cent; the incidence rate was 2.3 cases per 1000 persons per year. Risk increased significantly with time after treatment. The risk of leukemic disorders did not differ according to sex, race, age at treatment, or initial tumor type, nor was it enhanced by concomitant radiotherapy or immunotherapy. In addition, no excess of acute nonlymphocytic leukemia was seen in 44,370 patients treated for gastrointestinal cancer in Connecticut during the period 1935 to 1974, before the advent of nitrosourea chemotherapy. This study provides quantitative evidence that nitrosoureas are leukemogenic in human beings and confirms previous observations that adjuvant chemotherapy with alkylating agents may increase the risk of leukemia.

Acute Disease↗
PubMed1981

Risk factors for fatal heart attack in young women.

Deaths of 338 women at ages 15-44 years attributed to myocardial infarction (MI) on death certificates during an 18-month period in five metropolitan areas were investigated. Evidence of recent MI or evidence that death occurred suddenly was obtained for about half (163) from records of hospitals or medical examiners or from relatives. A case-control study (involving one deceased control, and one hospitalized living control) of risk factors for heart attack was then conducted using interviews with relatives and abstracts of records of hospitals and physicians identified by the relatives as sources of medical care. Information was obtained on history of prior MI, other heart disease, diabetes, thromboembolism, stroke, hypertension, high cholesterol, obesity, oophorectomy, oral contraception and cigarette smoking. Data are presented on the prevalence of these potential risk factors for the case group and each control group, and for subsets of cases consisting of those without prior heart disease, definite MI only, sudden death only, and white women only. Multivariate analyses identify somewhat different sets of risk factors and different levels of risk for the various subgroups. In general, the risk factors are those that have been reported for men, despite the major difference in level of mortality.

Adolescent↗
PubMed1980

Fatal myocardial infarction and the role of oral contraceptives.

The association between use of oral contraceptives (OC) and death from myocardial infarction (MI) in young women was investigated in a collaborative case-control study conducted in the five largest metropolitan areas in the US. Potential cases were identified from computer tapes of the National Center for Health Statistics. Controls were selected from among women who died from, or were hospitalized for, acute conditions other than heart disease or from accidents, and were matched to cases on age, geographic area, and year of death. Information on cause of death, personal characteristics, OC use, and the presence of conditions predisposing to MI was obtained from interviews with relatives and abstracts of hospital, clinic and physician records. Odds ratios as approximations to relative risks for fatal MI in relation to OC use, and the associated 95% confidence limits, were calculated overall and for subgroups determined by demographic and health history characteristics. Odds ratios in the total study population were not significantly different from one. However, odds ratios significantly different from one were found when attention was restricted to white subjects without contraindications to OC use, andincluding only those cases whose deaths were attributed to MI with the greatest degree of certainty. Smoking was found to be a significant risk factor for fatal MI.

Adolescent↗
PubMed1978

Low-dose heparin for prevention of venous thromboembolism in total hip arthroplasty and surgical repair of hip fractures.

Sixty-seven hip-arthroplasty and fifty-two hip-fracture patients participated in a placebo-controlled randomized double-blind study on the effects of low-dose heparin prophylaxis in the prevention of venous thromboembolism. In this study, a positive thromboembolic event meant a positive test by: (1) daily 125I-fibrinogen scanning, (2) contrast venography on the tenth postoperative day, or (3) radionuclide perfusion lung scan in confirmation of suspected clinical pulmonary emboli. Nineteen (59.4 per cent) of thirty-two placebo-treated arthroplasty patients showed evidence of a thromboembolic event in contrast with eight (22.9 per cent) of thirty-five heparin-treated patients (p less than 0.003). Heparin-treated arthroplasty patients required mean blood transfusions of 4.7 units, contrasted with a mean 3.2-unit transfusion requirement for placebo-treated patients (p less than 0.05). The incidence of observed bleeding complications was higher among the heparin-treated patients. Of the twenty-three placebo-treated patients with fracturs, 39.1 per cent had a thromboembolic event, while 41.4 per cent of the twenty-nine who received heparin showed evidence of thromboembolism, demonstrating that low-dose heparin afforded no protection, nor did it affect the incidence of bleeding complications or transfusion requirements in fracture patients.

Aged↗
PubMedDate not supplied

Safety considerations for new vaccine development.

Vaccines are highly effective and extremely safe. Although most known vaccine reactions are minor (e.g. fever, injection site pain or swelling), rare but serious reactions such as vaccine-associated paralytic polio do occur. When large populations are vaccinated, some adverse health events may occur by chance shortly after vaccination. It is difficult to determine whether these are truly coincidental or attributable to the vaccine. The most reliable way to assess causality is in a controlled study, but clinical trials of new vaccines are typically too small to detect rare but serious effects. If the size of these trials were increased, much more could be learned about the safety of a vaccine prior to its exposure to entire populations. This information would increase confidence in the safety of vaccines, would be a valuable resource for assessing spontaneous reports of adverse events after licensure, and would reduce the risk of licensing a new vaccine that had the potential to cause severe injury to a small proportion of vaccinees.

Adverse Drug Reaction Reporting Systems↗
PubMedDate not supplied

The epidemiology of fatalities reported to the vaccine adverse event reporting system 1990-1997.

PURPOSE: To examine the fatalities reported to the federally administered Vaccine Adverse Event Reporting System (VAERS), a passive surveillance system, in its first 7 years. METHODS: The working data set included variables such as demographic information, dates of vaccination, adverse event onset and death, vaccines administered, and vaccination facility data. Frequencies for these data and state reporting rates were calculated. RESULTS: A total of 1266 fatalities were reported to VAERS during July 1990 through June 1997. The number of death reports peaked in 1992-1993 and then declined. The overall median age of cases was 0.4 years, with a range of 1 day to 104 years. Nearly half of the deaths were attributed to sudden infant death syndrome (SIDS). CONCLUSIONS: The trend of decreasing numbers of deaths reported to VAERS since 1992-1993 follows that observed for SIDS overall for the US general population following implementation of the 'Back to Sleep' program. These data may support findings of past controlled studies showing that the association between infant vaccination and SIDS is coincidental and not causal. VAERS reports of death after vaccination may be stimulated by the temporal association, rather than by any causal relationship.

Adolescent↗
PubMedDate not supplied

New designs for the selection of treatments to be tested in randomized clinical trials.

The most important aspect of phase III randomized clinical trials is the selection of the experimental treatments to be tested. Often this decision is based on uncontrolled phase II trials. Substantial statistical attention has been focused on the design of phase III trials and for simple phase II trials, which determine whether a new drug has any anti-disease activity. Much less statistical effort has been devoted to the design and analysis of phase II trials for screening active experimental treatments to determine whether they are sufficiently active, relative to standard treatments, to warrant the conduct of a large randomized phase III trial. This problem is particularly acute in the development of drug combinations where many regimens are possible. We review several designs for such screening trials which we have developed.

Bayes Theorem↗
PubMedDate not supplied

Independent data monitoring committees: rationale, operations and controversies.

Data monitoring committees (DMCs) have become an increasingly common component of randomized clinical trials in recent years. As experience has accumulated, and more individuals and organizations have become involved in such activities, a variety of approaches to the operation of such committees has inevitably arisen. Because these committees play such a critical role in the process of new drug development, it is important to consider the implications of the different approaches that are being used. It is also timely to consider the present and possible future regulatory status of data monitoring committees. Published in 2001 by John Wiley & Sons, Ltd.

Clinical Trials as Topic↗