Pharmacogenetic modulation of combined hormone replacement therapy by progesterone-metabolism genotypes in postmenopausal breast cancer risk

Combined hormone replacement therapy (CHRT) containing estrogens and progestins is associated with breast cancer risk. The authors evaluated interactions between CHRT use and progestin metabolism genotypes at CYP3A4 and the progesterone receptor (PGR) and their effects on breast cancer risk using the population-based Women's Insights and Shared Experiences (WISE) Study (1999-2002) of postmenopausal Caucasian women (522 breast cancer cases, 708 controls). The authors observed an elevated risk of ductal tumors in women with 3 or more years of CHRT use and PGR 331A alleles compared with those who had neither factor (odds ratio = 3.35, 95% confidence interval (CI): 1.13, 9.99; two-sided p(interaction) = 0.035). They also observed an elevated risk of progesterone receptor-positive tumors in women who had had 3 or more years of CHRT use and PGR 331A alleles compared with those who had neither factor (odds ratio = 3.82, 95% CI: 1.26, 11.55; p = 0.028). Finally, they observed an increased risk of estrogen receptor-negative tumors in women without CHRT exposure and CYP3A4*1B alleles compared with those who had neither factor (odds ratio = 6.46, 95% CI: 2.02, 20.66; p = 0.024), although the biologic interpretation of this result requires further study. When stratified by recency of use, PGR effects were observed only in current CHRT users, while CYP3A4 effects were observed only in former CHRT users. Breast cancer risk in women who have used CHRT may be influenced by genetic factors involved in progestin metabolism.

Exposure to soy-based formula in infancy and endocrinological and reproductive outcomes in young adulthood

CONTEXT

A large body of evidence documents the role of phytoestrogens in influencing hormone-dependent states. Infants fed soy formula receive high levels of phytoestrogens, in the form of soy isoflavones, during a stage of development at which permanent effects are theoretically possible. However, a paucity of data exists on the long-term effects of infant soy formulas.

OBJECTIVE

To examine the association between infant exposure to soy formula and health in young adulthood, with an emphasis on reproductive health.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective cohort study conducted from March to August 1999 among adults aged 20 to 34 years who, as infants, participated during 1965-1978 in controlled feeding studies conducted at the University of Iowa, Iowa City (248 were fed soy formula and 563 were fed cow milk formula during infancy).

MAIN OUTCOME MEASURES

Self-reported pubertal maturation, menstrual and reproductive history, height and usual weight, and current health, compared based on type of formula exposure during infancy.

RESULTS

No statistically significant differences were observed between groups in either women or men for more than 30 outcomes. However, women who had been fed soy formula reported slightly longer duration of menstrual bleeding (adjusted mean difference, 0.37 days; 95% confidence interval [CI], 0.06-0.68), with no difference in severity of menstrual flow. They also reported greater discomfort with menstruation (unadjusted relative risk for extreme discomfort vs no or mild pain, 1.77; 95% CI, 1.04-3.00).

CONCLUSIONS

Exposure to soy formula does not appear to lead to different general health or reproductive outcomes than exposure to cow milk formula. Although the few positive findings should be explored in future studies, our findings are reassuring about the safety of infant soy formula.

Risk of bleeding and hypoprothrombinaemia associated with NMTT side chain antibiotics: using cefoperazone as a test case

A retrospective cohort study was performed to determine the incidence of hypoprothrombinaemia and bleeding in patients receiving cefoperazone, a third-generation cephalosporin that contains an NMTT side chain. 374 patients receiving cefoperazone from February 1983 to March 1986 at a teaching hospital in Philadelphia were compared with 497 patients receiving either ceftizoxime or cefotaxime during the same period, and with 476 patients receiving ceftazidime from April 1985 to December 1987. Adverse events (any bleeding episodes, decrease in haemoglobin, prolongation of prothrombin time (PT), and prolongation of partial thromboplastin times (PTT)) were evaluated, if occurring during the period from the start of cephalosporin therapy, or the start of therapy with one of the two control drugs, for 14 days after the last date of the first course of therapy were recorded. An increased risk of hypoprothrombinaemia was associated with the use of cefoperazone: the prothrombin time was prolonged by 5 s or more in 12.3% of patients receiving cefoperazone vs. 5.8% of patients receiving ceftizoxime or cefotaxime, and vs. 5.8% receiving ceftazidime; the adjusted odds ratios (95% CIs) were 3.6 (1.7-7.4) and 3.8 (1.8-7.8), respectively, and these increased at higher doses of cephalosporin. No protection was apparent from the administration of vitamin K prior to or during the course of cephalosporin. No overall increased risks were observed for bleeding (adjusted odds ratios (95% CIs) were 1.1 (0.8-1.4) vs. ceftizoxime or cefotaxime, and 0.9 (0.6-1.2) vs. ceftazidime), decrease in haemoglobin, or increased partial thromboplastin time. In subgroup analyses, increased risks of bleeding were observed with high dose cefoperazone use [2.8 (1.5-5.5) vs. ceftizoxime or cefotaxime, and 2.3 (1.1-4.6) vs. ceftazidime]. Patients receiving NMTT side chain antibiotics should be monitored for hypoprothrombinaemia, but any increase in bleeding is likely to be small, and prophylactic vitamin K is probably not warranted.

Gastrointestinal tract bleeding associated with naproxen sodium vs ibuprofen

BACKGROUND

The risk of gastrointestinal tract bleeding requiring hospitalization associated with naproxen sodium was compared with that with ibuprofen, using a prescription database to approximate over-the-counter dosing.

OBJECTIVE

To evaluate the safety of naproxen sodium.

METHODS

A claims database containing Ohio Medicaid data from January 1986 through February 1993 and Michigan Medicaid data from April 1983 through July 1993 was used to compare 101,318 patients dispensed naproxen sodium with 277,601 patients dispensed ibuprofen. Using a case-cohort design, all 59 patients from the full cohort who had been hospitalized with upper gastrointestinal tract bleeding (UGIB) that developed within 14 days after the first prescription for the study drugs were compared with a subcohort made up of a 10% random sample of subjects selected from the combined drug cohorts.

RESULTS

The incidence of UGIB occurring within 14 days after the first prescription in the naproxen sodium cohort was 26 (0.026%) of 101,318 (95% confidence interval [CI], 0.017%-0.038%), compared with 33 (0.012%) of 277,601 patients (95% CI, 0.008%-0.017%) in the ibuprofen cohort. Overall, the use of naproxen sodium vs ibuprofen was associated with an adjusted relative risk of 2.0 (95% CI, 1.1-3.8). Among people with multiple prescriptions, the crude relative risk for those receiving therapy in a dose typical of over-the-counter use was 4.1 (95% CI, 1.2-13.8).

CONCLUSIONS

The overall incidence of UGIB is low with both drugs. There is little additional absolute risk posed by the use of low-dose naproxen sodium, compared with low-dose ibuprofen, despite an increased relative risk. However, given the widespread use of these drugs, a substantial number of additional cases of UGIB could result from use of naproxen sodium. This increased risk should be considered, especially for patients whose baseline risk of UGIB is elevated.

Is cimetidine associated with neutropenia?

BACKGROUND

Cimetidine is perceived as sufficiently safe that it is being considered for over-the-counter use. However, because of residual concerns about cimetidine-induced neutropenia, a study was conducted to evaluate this association.

METHODS

A population-based, case-control study was undertaken using a large database with Medicaid data from six states. Cases were defined as patients hospitalized with a discharge diagnosis of neutropenia. Medical records were sought to validate the diagnoses of neutropenia and to characterize the severity of disease. Four controls were randomly selected for each case, matched for age, sex, state, and year of diagnosis. The frequency of exposures to cimetidine in the 30 days prior to hospital admission in the cases was compared to that in the identical time periods in the controls.

RESULTS

When investigators simultaneously controlled for multiple, potentially confounding variables by using conditional logistic regression, the odds ratio associated with the use of cimetidine was 1.2 (P = 0.33), with a one-sided upper 95% confidence limit of 2.6 for all patients over 20 years of age, and 0.6 (P = 0.30) with a one-sided upper 95% confidence limit of 3.1 for validated cases over 12 years of age. Neither a dose-response relationship was evident (P = 0.899 and P = 0.716, respectively, when excluding the nonusers, or P = 0.245 and P = 0.215, respectively, when including the nonusers). From these data, one can exclude the occurrence of hospitalization with neutropenia or agranulocytosis due to cimetidine occurring more often than once in every 116,000 patients and once in every 573,000 patients receiving a 6-week course of the drug, respectively.

CONCLUSION

If there is an association between cimetidine and neutropenia, it appears to be very small.

Breast silicone implants and risk of systemic lupus erythematosus

The uncertain safety of breast implants has been a major controversy of late, both in the lay press and in the scientific literature. A case-control study had been performed in the Philadelphia metropolitan area during 1985-1987 to investigate potential risk factors for systemic lupus erythematosus (SLE). A total of 219 eligible cases who met the American Rheumatism Association criteria for SLE were identified from the medical practices of cooperating rheumatologists in the area; 195 (89%) of these were enrolled in the study. Friends of the cases, matched to the cases on sex and age (+/- 5 years) served as controls. For the current investigation, conducted during June 1992 through September 1992, we attempted to re-contact each of these individuals. Using a short telephone interview, we asked each subject to provide information on any surgery that they may have had prior to the index date, i.e. the year of diagnosis of SLE in the cases and the same year for the age-matched friend controls. Specific questions were asked about plastic surgery in general and breast implants in particular. 148 (75.9%) of the 195 SLE cases being sought and 111 (77.6%) of the 143 controls being sought agreed to be re-interviewed for this study. Only 1 (0.8%) out of 133 female SLE cases reported having had a breast implant, 8 years prior to the diagnosis of SLE. This compared to 0 out of the 100 female friend controls (Fisher exact one-tailed p-value = 0.57).(ABSTRACT TRUNCATED AT 250 WORDS)

Aberrant integrin expression in the endometrium of women with endometriosis

Integrins are ubiquitous cell adhesion molecules that undergo dynamic alterations during the normal menstrual cycle in the human endometrium. The alpha v beta 3 vitronectin receptor integrin is expressed in endometrium at the time of implantation, but its presence is delayed in endometrium that is assessed to be out of phase using classical histological features. To investigate the expression of this integrin in women with endometriosis, we assessed the presence of the beta 3-subunit throughout the menstrual cycle in 268 "in-phase" endometrial biopsies, using immunohistochemistry. The beta 3-subunit was expressed on endometrial epithelium after days 19-20 of the menstrual cycle. In 241 women whose biopsies were obtained after day 19, a lack of beta 3 expression was found to be closely related to the diagnosis of endometriosis (by Wilcoxon test, P = 0.02). This defect in integrin expression was associated with nulliparity, inversely related to the stage of disease, and occurred despite the presence of in-phase histological features. In a prospective double blind assessment of this integrin, we found endometrial beta 3 analysis to have a high specificity and positive predictive value as a nonsurgical diagnostic test for minimal and mild endometriosis. In conclusion, aberrant integrin expression in the native endometrium is associated with the finding of endometriosis and may identify some women with decreased cycle fecundity due to defects in uterine receptivity.

Nonsteroidal anti-inflammatory drugs and neutropenia

BACKGROUND

The association between nonsteroidal anti-inflammatory drugs (NSAIDs) and neutropenia is based primarily on case reports only.

METHODS

A population-based, case-control study was performed with Medicaid claims data from six states. Cases were defined as patients hospitalized with neutropenia. Four controls per case were randomly chosen, matched for age, sex, state, and year. The frequency of exposure to NSAIDs in the 30 days before hospital admission in the cases was compared with the frequency in the identical period in the controls. The diagnosis of neutropenia was validated by review of medical records.

RESULTS

The crude odds ratio for NSAIDs as a class was 3.3 (90% confidence interval, 1.6 to 6.6). The multivariate adjusted odds ratio was 4.2 (90% confidence interval, 2.0 to 8.7). No single class of NSAID, nor any individual NSAID, was associated with a unique risk, although the data on individual NSAIDs were sparse. Even excluding phenylbutazone and indomethacin, an increased risk was observed (3.5 [1.6 to 7.6]).

CONCLUSIONS

Neutropenia is associated with the use of NSAIDs. However, given the low incidence of this disease, the additional number of cases of neutropenia caused by the use of NSAIDs is small. These data do not support the existence of a risk restricted to selected NSAIDs only.

Descriptive epidemiology of agranulocytosis

BACKGROUND

To determine the incidence of agranulocytosis, a descriptive epidemiologic study was performed.

METHODS

With the use of computerized Medicaid billing data from 1980 through 1985 from Minnesota, Michigan, and Florida, the ratio of persons hospitalized with a discharge diagnosis of neutropenia to persons with any claim for medical service was first used as an estimate of the incidence rate of the condition. Patients with cancer and patients receiving cytotoxic and immunosuppressive drugs were excluded. The information provided by a review of medical records for a subset of neutropenia cases was used to determine the proportion with neutropenia after excluding cases with recurrent or chronic neutropenia, and to determine the proportion with agranulocytosis.

RESULTS

The incidence rates (95% confidence intervals) of agranulocytosis, excluding recurrent or chronic disease, were 2.3 (1.4 to 3.7), 7.7 (6.6 to 8.9), and 15.4 (11.3 to 20.4) per million per year in each state, respectively. The overall incidence was 7.2 (6.3 to 8.1) per million per year.

CONCLUSIONS

Agranulocytosis is an extremely uncommon condition. The excess risk of agranulocytosis due to any drug other than cytotoxic drugs must, therefore, be very low.

The low risk of upper gastrointestinal bleeding in patients dispensed corticosteroids

PURPOSE

To determine the incidence of upper gastrointestinal bleeding in patients treated with corticosteroids.

PATIENTS AND METHODS

The incidence of upper gastrointestinal tract bleeding was assessed in a cohort of 19,880 patients from the Michigan Medicaid billing database with dermatitis and/or asthma treated with corticosteroids during 1980 to 1984. The frequency of upper gastrointestinal bleeding was assessed within 60 days after each corticosteroid prescription.

RESULTS

The incidence of upper gastrointestinal bleeding in patients without a past history of upper gastrointestinal bleeding who were exposed to corticosteroids was only 2.8 cases per 10,000 person-months. The rate of upper gastrointestinal bleeding was notably higher in patients receiving anticoagulants and those with a prior history of upper gastrointestinal bleeding (23.0 and 15.9 cases per 10,000 person-months, respectively).

CONCLUSION

Because the incidence of upper gastrointestinal bleeding in ambulatory patients treated with corticosteroids is so low, prophylactic therapy should be restricted to high-risk patients, if it is to be used at all.

No causal relationship between transdermal scopolamine and seizures: methodologic lessons for pharmacoepidemiology

Because of case reports suggesting that use of transdermal scopolamine might be associated with the subsequent development of seizures, a retrospective cohort study was performed with computerized Medicaid claims data. Patients receiving transdermal scopolamine were compared with patients receiving diphenhydramine, meclizine, prochlorperazine, and promethazine. A four-fold increased risk of seizures after transdermal scopolamine use was observed in the claims data. However, this was not supported by the primary medical records. All patients who had seizures after using transdermal scopolamine either had seizures before receiving the drug as well or did not really suffer from seizures. The original finding appeared to be the result of the use of transdermal scopolamine for "dizziness, rule out seizures"; the ICD-9-CM coding system does not include "rule out" diagnoses. Thus these data do not confirm the existence of an association between seizures and the use of transdermal scopolamine. In addition, this study demonstrates the usefulness of pharmacoepidemiology studies in documenting drug safety and the importance of obtaining primary medical records when performing pharmacoepidemiologic studies with claims data.

A population-based study of Stevens-Johnson syndrome. Incidence and antecedent drug exposures

To determine the incidence of Stevens-Johnson syndrome, a descriptive epidemiology study was performed using computerized Medicaid billing data from 1980 to 1984 from the states of Michigan, Minnesota, and Florida. The ratio of persons hospitalized with a discharge diagnosis of erythema multiforme (ICD-9-CM code 695.1) to persons with any claim for medical service was first used as an estimate of the incidence rate of the disease. Then, since the ICD-9-CM code for erythema multiforme includes other illnesses in addition to Stevens-Johnson syndrome and because these illnesses are frequently misdiagnosed, the information provided by a review of medical records for a subset of cases of erythema multiforme was used to determine the proportion of patients with true Stevens-Johnson syndrome. The incidence rates of Stevens-Johnson syndrome were 7.1 (6.1 to 8.2), 2.6 (1.6 to 4.0), and 6.8 (4.3 to 10.3) per million per year in each state, respectively. Penicillins, especially aminopenicillins, were frequently used in the 19 patients judged to be true cases of Stevens-Johnson syndrome. In conclusion, Stevens-Johnson syndrome is a uncommon condition. The excess risk of Stevens-Johnson syndrome due to any drug must, therefore, be very low.

Using a claims database to investigate drug-induced Stevens-Johnson syndrome

In order to explore a priori hypotheses about drug-induced Stevens-Johnson Syndrome (SJS), a case-control study was initiated using data from COMPASS, a computerized data base consisting of Medicaid claims data. The records of 3.8 million patients in five U.S. states were searched to identify patients with an inpatient diagnosis of ICD-9-CM code 695.1 (erythema multiforme-EM). Out of the total of 367 cases that were identified, primary medical records for 249 were sought and 128 (51.4 per cent) of these were obtained. The remainder could not be obtained because: in 36 (29.8 per cent) the hospital refused to provide medical records; in 33 (27.3 per cent) there were transcription errors; in 20 (16.5 per cent) the state could not translate the identification number, primarily because the patients lost Medicaid eligibility too long before our request; in 27 (22.3 per cent) the hospital could not locate the patient's record; and in 5 (4.1 per cent) there were other reasons. Of those with a medical record, 121 (94.5 per cent) had a skin diagnosis and 109 (85.2 per cent) had a diagnosis compatible with ICD-9-CM code 695.1 specified on their discharge summary. However, in 35 (27.3 per cent) an expert reviewer felt that the discharge diagnosis was incorrect. In 50 (39 per cent) the computer diagnosis was incorrect. Only 19 (14.8 per cent) were judged by the expert reviewer to truly have Stevens-Johnson Syndrome, and an additional 37 (28.9 per cent) were judged to have erythema multiforme minor. Thus, the computerized diagnosis agreed very well with the diagnoses specified on the discharge summary. However, EM is frequently misdiagnosed, ICD-9-CM code 695.1 contains multiple other diagnoses which are not EM, and much of hospitalized EM is EM minor. Thus, studies of SJS cannot be performed except in patients whose medical records are available.

The effect of indication on the risk of hypersensitivity reactions associated with tolmetin sodium vs other nonsteroidal antiinflammatory drugs

A retrospective cohort study using 1980-1984 Medicaid billing data from 3 US states was performed to assess the relative risk of hypersensitivity reactions from different nonsteroidal antiinflammatory drugs (NSAID). Comparing tolmetin sodium to other NSAID, pooling the data across the 3 US states using the Mantel-Haenszel procedure, gave an overall relative risk (95% confidence interval) of 1.1 (0.8-1.4). After adjusting for multiple potential confounding variables using logistic regression, an odds ratio (95% confidence interval) of 0.9 (0.6-1.2) was observed. These data do not confirm previous suggestions that use of tolmetin is associated with a higher risk of hypersensitivity reactions than use of other NSAID.

Upper gastrointestinal tract bleeding from oral potassium chloride. Comparative risk from microencapsulated vs wax-matrix formulations

A retrospective cohort study was performed to assess the relative risk of upper gastrointestinal (UGI) tract bleeding from two formulations of potassium chloride. Relevant information was obtained from 1980 through 1984 Medicaid billing data from the states of Michigan, Minnesota, Florida, and Ohio. After patients with a history of UGI tract bleeding prior to their first prescription for either of the two potassium chloride preparations under study were excluded, data were analyzed for 28,790 patients (143,512 patient-months) dispensed a microencapsulated formulation exclusively and 76,118 patients (560,341 patient-months) dispensed a wax-matrix formulation exclusively. The risk of UGI tract bleeding within 30 days after each prescription for the drug of interest was examined. After sampling from the undiseased study subjects and adjusting for multiple potential confounding variables using logistic regression, an odds ratio (95% confidence interval) of 0.67 (0.52 to 0.85) was observed.

Does gallbladder removal protect against subsequent myocardial infarction?

It has been suggested that gallbladder removal may protect against subsequent development of myocardial infarction because of increased gastrointestinal cholesterol excretion resulting from increased enterohepatic cycling. To test this hypothesis, the authors used data from two large case-control studies of myocardial infarction--one conducted in 1976-1979 in 155 US hospitals and one conducted in 1980-1983 in 78 US hospitals. First, 550 female myocardial infarction cases were compared to 1,658 controls. Simultaneously adjusting for possible confounding variables using logistic regression, the odds ratio for development of a myocardial infarction subsequent to cholecystectomy was 0.8 (95% confidence interval, 0.5-1.1). Second, 1,511 male myocardial infarction cases were compared to 3,837 controls. With similar adjustments, the odds ratio was 0.8 (95% confidence interval, 0.5-1.2). The risk did not decline as the interval following cholecystectomy increased. The present data are compatible with a protective effect of cholecystectomy on the risk of subsequent myocardial infarction, but they are not conclusive.

Epidemiologic study of regular analgesic use and end-stage renal disease

A case-control study of the relationship between regular analgesic consumption and end-stage renal disease (ESRD) development was conducted and was made up of 527 patients with ESRD and 1,047 matched controls from southeastern Pennsylvania and southern New Jersey. The study was unable to demonstrate an increased risk of ESRD associated with use of analgesics either as single compounds or in combinations. In addition, no consistent dose or duration relationship was shown for users of specific analgesic combinations or for single compounds. We suggest that if there is an association between the use of analgesics and ESRD development, the risk is not large or at least not large in the geographic area where the study was carried out.

Trends in recent systemic lupus erythematosus mortality rates

National death rates from systemic lupus erythematosus (SLE) were calculated for the period 1972 to 1976 according to age, sex, and race and were compared to rates for 1968 to mid-1972. The time trend in the age-adjusted death rates from SLE was also analyzed for the entire period 1968 to 1977. The previously reported variable sex and race ratios persist through the recent period, particularly the greater mortality rates among black women during middle and early adulthood. An overall decline in the adjusted death rates in the younger age groups (1-49 years old) in each race-sex group is seen in the recent period.

Agreement rates between oral contraceptive users and prescribers in relation to drug use histories

A comparison between prescriber records and patient-reported oral contraceptive histories obtained during a case-control study of thromboembolism and oral contraceptive use served as the basis for evaluating the extent of agreement between these two sources of information. Agreement between oral contraceptive user and prescriber was highest on the name of the most recently-used product (89% agreement), and dropped to 62.5% on the name of the product taken before the more recent one. For total duration of oral contraceptive use (to within one month of hospital admission), agreement (defined as differences not exceeding one month) was 36%, while 39% showed the users reporting longer duration of use, and 25% showed users reporting shorter duration. Cases showed a higher rate of agreement with prescriber records than the controls on both the name of the product and the total duration of use. Disagreement from prescriber records in the direction of reporting longer duration of use was 45% for the controls compared to 27% for the cases. These results indicate that while user information in connection with the most recently used oral contraceptive can be acceptable in studies employing the case-control research strategy, user reports about previous oral contraceptive use may be less useful.