Radiation dose and leukemia risk in patients treated for cancer of the cervix.

To quantify the risk of radiation-induced leukemia and provide further information on the nature of the relationship between dose and response, a case-control study was undertaken in a cohort of over 150,000 women with invasive cancer of the uterine cervix. The cases either were reported to one of 17 population-based cancer registries or were treated in any of 16 oncologic clinics in Canada, Europe, and the United States. Four controls were individually matched to each of 195 cases of leukemia on the basis of age and calendar year when diagnosed with cervical cancer and survival time. Leukemia diagnoses were verified by one hematologist. Radiation dose to active bone marrow was estimated by medical physicists on the basis of the original radiotherapy records of study subjects. The risk of chronic lymphocytic leukemia, one of the few malignancies without evidence for an association with ionizing radiation, was not increased [relative risk (RR) = 1.03; n = 52]. However, for all other forms of leukemia taken together (n = 143), a twofold risk was evident (RR = 2.0; 90% confidence interval = 1.0-4.2). Risk increased with increasing radiation dose until average doses of about 400 rad (4 Gy) were reached and then decreased at higher doses. This pattern is consistent with experimental data for which the down-turn in risk at high doses has been interpreted as due to killing of potentially leukemic cells. The dose-response information was modeled with various RR functions, accounting for the nonhomogeneous distribution of radiation dose during radiotherapy. The local radiation doses to each of 14 bone marrow compartments for each patient were incorporated in the models, and the corresponding risks were summed. A good fit to the observed data was obtained with a linear-exponential function, which included a positive linear induction term and a negative exponential term. The estimate of the excess RR per rad was 0.9%, and the estimated RR at 100 rad (1 Gy) was 1.7. The model proposed in this study of risk proportional to mass exposed and of risk to an individual given by the sum of incremental risks to anatomic sites appears to be applicable to a wide range of dose distributions. Furthermore, the pattern of leukemia incidence associated with different levels of radiation dose is consistent with a model postulating increasing risk with increasing exposure, modified at high doses by increased frequency of cell death, which reduces risk.

In vitro and in vivo inhibition of mitogen-driven T-cell activation by recombinant interferon beta.

Recombinant interferon beta (rIFN beta) is being tested as experimental immunotherapy for exacerbating-remitting MS. To clarify the possible mechanisms of a therapeutic response to rIFN beta in MS patients, we conducted studies on the effects of rIFN beta on mitogen-driven T-cell activation by stimulating peripheral blood mononuclear cells (PBMC) with concanavalin A (ConA) or with anti-CD3 monoclonal antibodies in the presence or absence of rIFN beta. We monitored T-cell activation using proliferation assays or by expression of surface activation markers detected by flow cytometry. In vitro rIFN beta, in concentrations > or = 10 U/ml, inhibited PBMC proliferation or surface expression of interleukin-2 receptor (IL-2R), transferrin receptor, or CD2. In contrast, rIFN gamma augmented mitogen-driven IL-2R expression. PBMC isolated from normal volunteers or MS patients responded to ConA and rIFN beta in a similar manner. We conducted pilot in vivo studies in exacerbating-remitting MS patients participating in a double-blind placebo-controlled clinical trial of rIFN beta. PBMC were isolated from study participants immediately before and 24 hours after a weekly study injection. IL-2R expression by T cells was determined following a ConA stimulus. While there was no significant change following placebo injection, rIFN beta recipients showed significantly reduced ConA-driven IL-2R expression following study injection. The results document in vitro and in vivo inhibition of mitogen-driven T-cell activation by rIFN beta. This suggests a possible mechanism underlying a therapeutic response to rIFN beta in MS patients.

A longitudinal study of T1 hypointense lesions in relapsing MS: MSCRG trial of interferon beta-1a. Multiple Sclerosis Collaborative Research Group.

BACKGROUND: T1 hypointense lesions (T1 black holes) are focal areas of relatively severe CNS tissue damage detected by MRI in patients with MS. OBJECTIVE: To determine the natural history of T1 hypointense lesions in relapsing MS and the utility of T1 hypointense lesions as outcome measures in MS clinical trials. METHODS: MR studies were from the Multiple Sclerosis Collaborative Research Group trial. Longitudinal results are reported in 80 placebo- and 80 interferon beta-1a (IFNbeta-1a)-treated patients with mild to moderate disability relapsing-remitting MS. RESULTS: There was a small but significant correlation between T1 hypointense lesion volume and disability at baseline and on trial (r = 0.22, r = 0.28). In placebo patients there was a 29.2% increase in the mean volume of T1 hypointense lesions (median 124.5 mm3) over 2 years (p < 0.001 for change from baseline), as compared to an 11.8% increase (median 40 mm3) in the IFNbeta-1a-treated patients (change from baseline not significant). These treatment group comparisons did not quite reach significance. The most significant contributor to change in T1 hypointense lesions was the baseline number of enhancing lesions (model r2 = 0.554). Placebo patients with more active disease, defined by enhancing lesions at baseline, were the only group to show a significant increase in T1 hypointense lesion volume from baseline. CONCLUSION: The development of T1 hypointense lesions is strongly influenced by prior inflammatory disease activity, as indicated by enhancing lesions. These results suggest that treatment with once weekly IM IFNbeta-1a (30 mcg) slows the 2-year accumulation of these lesions in the brain.

A longitudinal study of brain atrophy in relapsing multiple sclerosis. The Multiple Sclerosis Collaborative Research Group (MSCRG).

OBJECTIVE: To determine if progressive brain atrophy could be detected over 1- and 2-year intervals in relapsing MS, based on annual MR studies from the Multiple Sclerosis Collaborative Research Group (MSCRG) trial of interferon beta-1a (Avonex). METHODS: All subjects had mild to moderate disability, with baseline expanded disability status scores ranging from 1.0 to 3.5, and at least two relapses in the 3 years before study entry. Atrophy measures included third and lateral ventricle width, brain width, and corpus callosum area. RESULTS: Significant increases were detected in third ventricle width at year 2 and lateral ventricle width at 1 and 2 years. Significant decreases in corpus callosum area and brain width were also observed at 1 and 2 years. Multiple regression analyses suggested that the number of gadolinium-enhancing lesions at baseline was the single significant contributor to change in third ventricle width. Atrophy over 1 and 2 years as indicated by enlargement of the third and lateral ventricle and shrinkage of the corpus callosum was greater for patients entering the trial with enhancing lesions. Greater disability increments over 1 and 2 years were associated with more severe third ventricle enlargement. CONCLUSION: In patients with relapsing MS and only mild to moderate disability, significant cerebral atrophy is already developing that can be measured over periods of only 1 to 2 years. The course of cerebral atrophy in MS appears to be influenced by prior inflammatory disease activity as indicated by the presence of enhancing lesions. Brain atrophy measures are important markers of MS disease progression because they likely reflect destructive and irreversible pathologic processes.

Incidence and significance of neutralizing antibodies to interferon beta-1a in multiple sclerosis. Multiple Sclerosis Collaborative Research Group (MSCRG)

BACKGROUND: Interferon beta is an effective treatment for relapsing multiple sclerosis (MS). As with other protein drugs, neutralizing antibodies (NAB) can develop that reduce the effectiveness of treatment. OBJECTIVES: To determine the incidence and biological significance of NAB to interferon beta-la (IFN-beta-1a; Avonex; Biogen, Cambridge, MA) in MS patients. METHODS: A two-step assay for NAB to IFN-beta-1a was developed and used to assay serum samples from participants in the phase III clinical trial of IFN-beta-1a, and from patients in an ongoing open-label study of IFN-beta-1a. The biological significance of NAB to IFN-beta-1a was determined by relating the NAB assay result to in vivo induction of the IFN-inducible molecules neopterin and beta-2 microglobulin, and the clinical significance was determined by comparing clinical and MRI measures of disease activity after 2 years of IFN-beta-1a therapy in patients who were NAB+ and NAB-. The incidence of NAB was compared in MS patients who had used only IFN-beta-1a with the incidence in MS patients who had used only IFN-beta-1b. RESULTS: In patients in the open-label study, development of NAB to IFN-beta-1a resulted in a titer-dependent reduction in neopterin induction after interferon injections. In patients in the phase III study, development of NAB was associated with a reduction in beta-2 microglobulin induction. In the phase III study, a trend toward reduced benefit of IFN-beta-1a on MRI activity in NAB+ versus NAB- patients was observed. The incidence of NAB to IFN-beta-1a in the open-label study was approximately 5% over 24 months of treatment of IFN-beta-1a therapy, but was four- to sixfold higher using the same assay for patients exposed only to IFN-beta-1b for a similar duration. There were no clinical, MRI, or CSF characteristics that were predictive of which patients would develop NAB. CONCLUSIONS: NAB directed against IFN-beta have in vivo biological consequences in patients with MS. The frequency with which MS patients develop NAB against IFN-beta is significantly greater with IFN-beta-1b therapy compared with IFN-beta-1a therapy. Treatment decisions in MS patients treated with IFN-beta should take into account development of NAB.

Impact of interferon beta-1a on neurologic disability in relapsing multiple sclerosis. The Multiple Sclerosis Collaborative Research Group (MSCRG).

BACKGROUND AND OBJECTIVE: A phase III double-blind, placebo-controlled clinical trial demonstrated that interferon beta-1a (IFN beta-1a) (Avonex, Biogen) significantly delayed progression of disability in relapsing MS patients. The primary clinical outcome was time from study entry until disability progression, defined as > or = 1.0 point worsening from baseline Kurtzke Expanded Disability Status Scale (EDSS) score persisting for at least two consecutive scheduled visits separated by 6 months. The objective of this study was to examine the magnitude of benefit on EDSS and its clinical significance. METHODS: Post hoc analyses related to disability outcomes using data collected during the double-blind, placebo-controlled phase III clinical trial. RESULTS: (1) Clinical efficacy related to disability did not depend on the definition of disability progression. A significant benefit in favor of IFN beta-1a was observed when > or = 2.0 point worsening from baseline EDSS was required or when worsening was required to persist for > or = 1.0 year. (2) Placebo recipients who reached the primary clinical outcome worsened by a larger amount from baseline EDSS than did IFN beta-1a recipients who reached the primary study outcome. (3) Significantly fewer IFN beta-1a recipients progressed to EDSS milestones of 4.0 (relatively severe impairment) or 6.0 (unilateral assistance needed to walk). (4) Cox proportional hazards models demonstrated that the only baseline characteristic strongly correlated with longer time to disability progression was IFN beta-1a treatment. CONCLUSIONS: The primary clinical outcome for the IFN beta-1a clinical trial underestimated clinical benefits of treatment. Results in this report demonstrate that IFN beta-1a treatment is associated with robust, clinically important beneficial effects on disability progression in relapsing MS patients.

Cerebrospinal fluid abnormalities in a phase III trial of Avonex (IFNbeta-1a) for relapsing multiple sclerosis. The Multiple Sclerosis Collaborative Research Group.

BACKGROUND AND OBJECTIVE: This report provides results of CSF analyses done in a subset of relapsing remitting MS patients participating in a placebo-controlled, double-blind, phase III clinical trial of IFNbeta-Studies supported by the National Multiple Sclerosis Society (grants RG2019, RG2827),a (Avonex , Biogen). The clinical trial demonstrated that IFNbeta-1a treatment resulted in significantly reduced disability progression, annual relapse rate, and new brain lesions visualized by cranial magnetic resonance imaging. The objectives of the current study were to determine: (a) whether CSF abnormalities in MS patients correlated with disease or MRI characteristics, and (b) effects of IFNbeta-1a therapy on these CSF abnormalities. METHODS: CSF was analyzed from 262 (87%) of the 301 study subjects at entry into the clinical trial, and a second CSF sample was analyzed from 137 of these 262 subjects after 2 years of therapy. CSF cell counts, oligoclonal bands (OCB), IgG index, and free kappa light chains were measured using standard assays. Baseline CSF results were compared with demographic, disease, and MRI parameters. Differences in on-study relapse rate, gadolinium enhancement, and EDSS change according to baseline CSF status was used to determine the predictive value of CSF for subsequent clinical and MRI disease activity. Change in CSF parameters after 104 weeks were used to determine the effects of treatment. RESULTS: (1) At study baseline, 37% of the subjects had abnormal CSF WBC counts, 61% had abnormal levels of CSF free kappa light chains, 84% had abnormal IgG index values, and 90% were positive for OCB. (2) Baseline IgG index, kappa light chains, and OCB showed weakly positive, statistically significant correlations with Gd-enhanced lesion volume and T2 lesion volume. WBC showed a statistically significant correlation with Gd-enhancing lesion volume but was uncorrelated with T2 lesion volume. (3) There was an associated between baseline CSF WBC counts and on-study clinical and MRI disease activity in placebo recipients. (4) IFNbeta-1a treatment resulted in significantly reduced CSF WBC counts, but there was no treatment-related change in CSF IgG index, kappa light chains, or OCB, which remained relatively stable over time in both patient groups. CONCLUSIONS: The current study documents significant reductions in CSF WBC counts in patients treated with IFNbeta-1a for 104 weeks. This finding is considered relevant to the therapeutic response, since CSF WBC counts were found to be positively correlated with subsequent clinical and MRI disease activity in placebo-treated relapsing MS patients.

Timing of prenatal care and risk of sudden infant death syndrome.

Sudden infant death syndrome (SIDS) is the leading cause of death during post-neonatal life. Mothers whose infants succumb to SIDS are reported to initiate prenatal care later than control mothers. Previous studies have not always controlled for socioeconomic status (SES) of mothers or other potential confounders such as gestational age or birthweight of infants. The purpose of this study was to assess whether timing of prenatal care adjusted for these potential confounders was an independent risk factor for SIDS. SIDS cases (N = 148) were identified from the Upstate New York livebirth cohort for 1974 (N = 132,948) and compared to randomly selected controls (N = 355) who were frequency-matched on maternal age, race, parity and residence and infant's birth date. Data were abstracted from matched vital certificates (97% response), hospital delivery records (89% response) and selected sample of autopsy reports (100% response). Odds ratios (OR) and 95% confidence intervals (CI) were obtained using unconditional logistic regression. A significant inverse relationship was observed for number of prenatal visits and risk of SIDS; a significant direct relationship was observed between trimester prenatal care initiated and risk of SIDS. The results suggest that timing of prenatal care is important in assessing SIDS risk even after adjusting for potential confounders of early prenatal care utilization.

Chromosome aberrations in lymphocytes from women irradiated for benign and malignant gynecological disease.

Excess leukemias have occurred after partial-body radiotherapy for cervical cancer and benign gynecological disease (BGD). However, the level of risk is nearly the same in both groups, about twofold, despite a tenfold difference in average dose to active bone marrow (8 Gy vs 0.7 Gy, respectively). High-dose cell killing has been postulated as one explanation for this apparent inconsistency. To examine whether chromosome aberration rates observed in lymphocytes many years after exposure might serve as population markers of cancer risk, blood samples were taken from 60 women treated for BGD (34 with radiation) and cytogenetic data compared with previous results from 96 women irradiated for cervical cancer. Remarkably, the rate of stable aberrations, which reflects nonlethal damage in surviving stem cells, was only slightly higher among the cancer patients. Thus the lower-dose regimens to treat benign disorders resulted in much higher aberration yields per unit dose than those for cervical cancer. Assuming that the fraction of cytogenetically aberrant stem cells that survive radiotherapy contributes to the leukemogenic process, these data are then consistent with the epidemiological observations of comparable overall leukemia risks seen in these two irradiated populations. Accordingly, for patient populations given partial-body radiotherapy, stable aberrations at a long time after exposure appear to serve as biomarkers of effective risk rather than as biomarkers of radiation dose received.

Leukemia, lymphoma, and multiple myeloma after pelvic radiotherapy for benign disease.

The relationship between exposure to sparsely ionizing radiation and mortality due to cancers of hematopoietic and lymphopoietic tissues was studied among 12,955 women treated for benign gynecological disorders at any of 17 hospitals in New England or New York State and followed for an average of 25 years; 9770 women were treated by radiation (intracavitary 226Ra, external-beam X rays), while 3185 were treated by other methods, including curettage, surgery, and hormones. The average age at treatment was 46.5 years, and the mean dose to active bone marrow among irradiated women was 119 cGy. Forty deaths due to acute, myelocytic, or monocytic leukemia were observed among irradiated women. This number was 70% higher than expected based on U.S. mortality rates [standardized mortality ratio (SMR) = 1.7; 90% confidence interval (CI) 1.3-2.3]. A deficit was recorded among nonirradiated women, based on three observed deaths (SMR = 0.5; 90% CI 0.1-1.2). A well-defined gradient in the SMR with dose among exposed women was not detected. The SMR was highest within 5 years after irradiation but remained elevated even after 30 years. The temporal pattern differed by subtype of leukemia: excess mortality due to chronic myelocytic leukemia occurred almost exclusively within the first 15 years, whereas the SMR for acute leukemia, though also elevated, varied little over time. Cancers of lymphoreticular tissue occurred more often than expected based on U.S. mortality rates, but not appreciably differently for irradiated and nonirradiated women. There was little or no evidence of effects attributable to radiotherapy for chronic lymphocytic leukemia [relative risk (RR) = 1.1; 90% CI 0.5-3.0], Hodgkin's disease (RR = 0.9; 90% CI 0.3-3.2), non-Hodgkin's lymphoma (RR = 0.9; 90% CI 0.6-1.6), or multiple myeloma (RR = 0.6; 90% CI 0.3-1.4). These results corroborate previous findings indicating that acute and myelocytic leukemias are the most prominent malignancies after exposure to sparsely ionizing radiation, occurring in excess shortly after irradiation, and that lymphomas are either not caused by radiation or are induced only rarely.

Radiation dose and second cancer risk in patients treated for cancer of the cervix.

The risk of cancer associated with a broad range of organ doses was estimated in an international study of women with cervical cancer. Among 150,000 patients reported to one of 19 population-based cancer registries or treated in any of 20 oncology clinics, 4188 women with second cancers and 6880 matched controls were selected for detailed study. Radiation doses for selected organs were reconstructed for each patient on the basis of her original radiotherapy records. Very high doses, on the order of several hundred gray, were found to increase the risk of cancers of the bladder [relative risk (RR) = 4.0], rectum (RR = 1.8), vagina (RR = 2.7), and possibly bone (RR = 1.3), uterine corpus (RR = 1.3), cecum (RR = 1.5), and non-Hodgkin's lymphoma (RR = 2.5). For all female genital cancers taken together, a sharp dose-response gradient was observed, reaching fivefold for doses more than 150 Gy. Several gray increased the risk of stomach cancer (RR = 2.1) and leukemia (RR = 2.0). Although cancer of the pancreas was elevated, there was no evidence of a dose-dependent risk. Cancer of the kidney was significantly increased among 15-year survivors. A nonsignificant twofold risk of radiogenic thyroid cancer was observed following an average dose of only 0.11 Gy. Breast cancer was not increased overall, despite an average dose of 0.31 Gy and 953 cases available for evaluation (RR = 0.9); there was, however, a weak suggestion of a dose response among women whose ovaries had been surgically removed. Doses greater than 6 Gy to the ovaries reduced breast cancer risk by 44%. A significant deficit of ovarian cancer was observed within 5 years of radiotherapy; in contrast, a dose response was suggested among 10-year survivors. Radiation was not found to increase the overall risk of cancers of the small intestine, colon, ovary, vulva, connective tissue, breast, Hodgkin's disease, multiple myeloma, or chronic lymphocytic leukemia. For most cancers associated with radiation, risks were highest among long-term survivors and appeared concentrated among women irradiated at relatively younger ages.

Semi-automatic brain region extraction (SABRE) reveals superior cortical and deep gray matter atrophy in MS.

In multiple sclerosis (MS), atrophy occurs in various cortical and subcortical regions. However, it is unclear whether this is mostly due to gray (GM) or white matter (WM) loss. Recently, a new semi-automatic brain region extraction (SABRE) technique was developed to quantify parenchyma volume in 13 hemispheric regions. This study utilized SABRE and tissue segmentation to examine whether regional brain atrophy in MS is mostly due to GM or WM loss, correlated with disease duration, and moderated by disease course. We studied 68 MS patients and 39 normal controls with 1.5 T brain MRI. As expected, MS diagnosis was associated with significantly lower (P < 0.001) regional brain parenchymal fractions (RBPFs). While significant findings emerged in 11 GM comparisons, only four WM comparisons were significant. The largest mean RBPF percent differences between groups (MS < NC) were in the posterior basal ganglia/thalamus region (-19.3%), superior frontal (-15.7%), and superior parietal (-14.3%) regions. Logistic regression analyses showed GM regions were more predictive of MS diagnosis than WM regions. Eight GM RBPFs were significantly correlated (P < 0.001) with disease duration compared to only one WM region. Significant trends emerged for differences in GM, but not WM between secondary progressive (SP) and relapsing-remitting MS patients. Percent differences in GM between the two groups were largest in superior frontal (-9.9%), medial superior frontal (-6.5%), and superior parietal (-6.1%) regions, with SP patients having lower volumes. Overall, atrophy in MS is diffuse and mostly related to GM loss particularly in deep GM and superior frontal-parietal regions.

The use of goal attainment scaling to evaluate a cancer research training program for high school and college students.

Goal attainment scaling has been used frequently in the evaluation of mental health services. The purpose of this study was to assess the usefulness of the goal attainment scaling methodology in the evaluation of a cancer research training program. Subjects were 62 high school and college students participating in a summer research program. Prior to the program, all students were asked to predict the specific outcomes they expected to attain in relation to eight independent dimensions of the research training program. At the close of the program students were asked to indicate the outcome they attained for each dimension. Students also ranked the importance of each dimension. The analyses indicated that participants entered the program with accurate expectations of their ultimate achievement and satisfaction with the program. Significant differences were found for expected outcomes on a number of program dimensions for the high school and college students at the preprogram assessment. Significant differences were also found for the high school and college students' importance rankings at both the pre-program and post-program period. Goal attainment scaling proved to be a valuable and flexible technique for the evaluation of a cancer research training program.

Mortality of a municipal worker cohort: II. Females.

Women have become an increasingly important segment of the total work force, yet there are very few published occupational mortality studies of female workers. This paper reports the findings of a retrospective cohort mortality study of 1,371 full-time female municipal employees of the City of Buffalo, New York, who were employed at least 1 day between January 1, 1950, and October 1, 1979, and who worked a minimum of 5 years. Vital status was ascertained for 88% of the female cohort, resulting in the identification of 214 observed deaths. This predominantly white-collar, service-oriented female cohort demonstrated significantly lower mortality than that expected based on U.S. mortality rates for white females. This strong "healthy-worker effect" was consistent across the time period of the study, across cause-specific mortality especially for all malignant neoplasms and all diseases of the circulatory system, and across different workers groups. Findings are discussed in light of the methodological issues involved in occupational studies of female workers.

Assessment of in utero hypoxia and risk of sudden infant death syndrome.

Few data are available on the role of hypoxia in sudden infant death syndrome (SIDS). The purpose of this study was to assess whether 10 antenatal factors consistent with in utero hypoxia were associated with an increased risk of SIDS. Cases and two sets of controls were chosen from the Upstate New York Live Birth Cohort for 1974 (n = 132,948). One hundred and forty-eight SIDS cases were identified, along with 114 dead controls made up of all other sudden deaths. Randomly selected live controls were frequency-matched to cases on mother's age, race, residence, parity, and infant's birthdate (n = 355). Data were collected from vital certificates (97% response), hospital delivery records (89%), and autopsy reports (100%). Odds ratios and 95% confidence intervals were calculated using Mantel-Haenszel techniques and logistic regression. Abnormal uterine bleeding was the only statistically significant (P less than 0.05) risk factor observed when dead controls were used (OR = 5.4). When live controls were used, statistically significant increases in risk were found for: placenta praevia (OR = 21.8), abruptio placentae (OR = 3.7), multiple birth (OR = 29.6), pregnancy interval less than or equal to 12 months (OR = 3.8), sexually transmitted disease (OR = 6.4), and eclampsia (OR = 17.7). These results lend support to a possible hypoxic aetiology of SIDS; however, differences by control group suggest that some factors are not specific to SIDS alone but may be risk factors for infant mortality in general.

Intrauterine growth retardation and risk of sudden infant death syndrome (SIDS)

The purpose of this study was to assess whether intrauterine growth retardation was associated with an increased risk of sudden infant death syndrome (SIDS). A total of 148 SIDS cases were identified from the Upstate New York (exclusive of New York City) live birth cohort for 1974 (n = 132,948). Dead controls represented all other sudden deaths (n = 114). Live controls were randomly selected and matched to cases on mother's age, race, parity, and residence and infant's birth date (n = 355). Data were collected from vital certificates (response, 97%), medical records (89%), and autopsy reports (100%). Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated with the use of logistic regression techniques to control for confounding. With live controls, significant risks were observed for gestations less than 37 weeks (OR = 2.2, CI 1.2-4.1), birth weights less than 2,500 g (OR = 2.5, CI 1.3-5.0) and birth lengths less than or equal to 47.0 cm (OR = 3.4, CI 1.8-6.4). Birth length less than or equal to 47.0 cm was the only significant risk factor observed when dead controls were used (OR = 2.9, CI 1.3-6.8). Risk decreased with increasing gestation and birth size. Postterm infants (greater than or equal to 42 weeks) were at lowest risk (live controls OR = 0.9, CI 0.5-1.6; dead controls OR = 0.6, CI 0.3-1.1). When gestational age was controlled for, SIDS infants were found to have reductions in both weight and length; this suggests that responsible mechanisms begin early in pregnancy.

A phase III trial of intramuscular recombinant interferon beta as treatment for exacerbating-remitting multiple sclerosis: design and conduct of study and baseline characteristics of patients. Multiple Sclerosis Collaborative Research Group (MSCRG).

The design and conduct of a randomized, double-blinded, placebo-controlled, multicenter, phase III study of recombinant interferon beta-1a (IFN-beta-1a) as treatment for exacerbating-remitting MS are described, as are baseline characteristics of the study population. The purpose of the study was to determine if 6.0 x 10(6) IU (30 micrograms) of IFN-beta-1a, administered by weekly intramuscular (i.m.) injections, was effective in delaying the onset of sustained disability. The primary outcome measure was time to onset of treatment failure, defined as a worsening on the Kurtzke Expanded Disability Status Scale (EDSS) of greater than or equal to 1.0 point compared with baseline, persisting for at least 6 months. An intent-to-treat design was used. The primary outcome measure was analyzed using the Mantel-Cox log-rank statistic and Kaplan-Meier survival curves. Secondary outcomes included quantitative measures of upper and lower extremity function, neuropsychological test performance, functional and quality of life assessments and several measures derived from annual brain MRI studies. Entry criteria included prestudy exacerbation rates of at least 0.67 per year and EDSS scores of 1.0-3.5. A total of 301 MS patients were randomly assigned to receive weekly i.m. injections of IFN-beta-1a or placebo. The average age of the study population at entry was 37 years; 92% were Caucasian and 73% were women. The mean prestudy disease duration was 6.5 years, mean prestudy exacerbation rate was 1.2 per year and the mean EDSS score was 2.3. The randomization yielded well-balanced treatment arms. Various aspects of the study are discussed, including: (1) the decision to focus study design on sustained disability; (2) the rationale for the treatment regimen; (3) measures taken to assure the reliability of the primary outcome measure; and (4) a description of the secondary outcome measures.

Development of a multiple sclerosis functional composite as a clinical trial outcome measure.

The primary clinical outcome measure for evaluating multiple sclerosis in clinical trials has been Kurtzke's expanded disability status scale (EDSS). New therapies appear to favourably impact the course of multiple sclerosis and render continued use of placebo control groups more difficult. Consequently, future trials are likely to compare active treatment groups which will most probably require increased sample sizes in order to detect therapeutic efficacy. Because more responsive outcome measures will be needed for active arm comparison studies, the National Multiple Sclerosis Society's Advisory Committee on Clinical Trials of New Agents in Multiple Sclerosis appointed a Task Force that was charged with developing improved clinical outcome measures. This Task Force acquired contemporary clinical trial and historical multiple sclerosis data for meta-analyses of primary and secondary outcome assessments to provide a basis for recommending a new outcome measure. A composite measure encompassing the major clinical dimensions of arm, leg and cognitive function was identified and termed the multiple sclerosis functional composite (MSFC). The MSFC consists of three objective quantitative tests of neurological function which are easy to administer. Change in this MSFC over the first year of observation predicted subsequent change in the EDSS, suggesting that the MSFC is more sensitive to change than the EDSS. This paper provides details concerning the development and testing of the MSFC.

Neuropsychological effects of interferon beta-1a in relapsing multiple sclerosis. Multiple Sclerosis Collaborative Research Group.

Cognitive dysfunction is common in multiple sclerosis (MS), yet few studies have examined effects of treatment on neuropsychological (NP) performance. To evaluate the effects of interferon beta-1a (IFNbeta-1a, 30 microg administered intramuscularly once weekly [Avonex]) on cognitive function, a Comprehensive NP Battery was administered at baseline and week 104 to relapsing MS patients in the phase III study, 166 of whom completed both assessments. A Brief NP Battery was also administered at 6-month intervals. The primary NP outcome measure was 2-year change on the Comprehensive NP Battery, grouped into domains of information processing and learning/memory (set A), visuospatial abilities and problem solving (set B), and verbal abilities and attention span (set C). NP effects were most pronounced in cognitive domains vulnerable to MS: IFNbeta-1a had a significant beneficial effect on the set A composite, with a favorable trend evident on set B. Secondary outcome analyses revealed significant between-group differences in slopes for Brief NP Battery performance and time to sustained deterioration in a Paced Auditory Serial Addition Test processing rate, favoring the IFNbeta-1a group. These results support and extend previous observations of significant beneficial effects of IFNbeta-1a for relapsing MS.