Correlation of umbilical cord blood haematopoietic stem and progenitor cell levels with birth weight: implications for a prenatal influence on cancer risk.

We examined the relation with birth weight and umbilical cord blood concentrations of haematopoietic stem and progenitor populations in 288 singleton infants. Across the whole range of birth weight, there was a positive relation between birth weight and CD34+CD38(-) cells, with each 500 g increase in birth weight being associated with a 15.5% higher (95% confidence interval: 1.6-31.3%) cell concentration. CD34+ and CD34+c-kit+ cells had J-shaped relations and CFU-GM cells had a U-shaped relation with birth weight. Among newborns with >or=3000 g birth weights, concentrations of these cells increased with birth weight, while those below 3000 g had higher stem cell concentrations than the reference category of 3000-3499 g. Adjustment for cord blood plasma insulin-like growth factor-1 levels weakened the stem and progenitor cell-birth weight associations. The positive associations between birth weight and stem cell measurements for term newborns with a normal-to-high birth weight support the stem cell burden hypothesis of cancer risk.

The management of ASCUS cervical cytologic abnormalities and HPV testing: a cautionary note.

A recently published study of the management of low-grade cytologic smears compared immediate colposcopy to human papillomavirus (HPV) triage and entry cytology smears (conservative management) as three triage techniques for managing atypical squamous cells of undetermined significance (ASCUS) smears (Atypical Squamous Cells of Undetermined Significance/Low-grade Squamous Intraepithelial Lesion Triage Study [ALTS]). The study reported a high sensitivity (96.3%) for HPV testing using hybrid capture 2 to detect cervical intraepithelial neoplasia (CIN) III. The authors concluded that HPV testing is a viable option for managing ASCUS smears. We have reviewed the published data from the ALTS trial and have found a large excess of colposcopies and biopsies in the HPV arm in comparison with the conservative management (cytology) arm. In addition, the ALTS trial quality control and pathology review results raise doubts about the diagnostic validity of the study to establish standards of clinical practice. Furthermore, until the 2-year follow-up analysis of the conservative management arm is completed to detect CIN III, a valid comparison between HPV triage and conservative management is not possible. We conclude that, based on published data, HPV testing for routine clinical management of low-grade cytologic abnormalities (ASCUS smears) is not warranted, and that HPV testing is currently an investigational tool.

Incidence of squamous neoplasia of the cervix and vagina in women exposed prenatally to diethylstilbestrol (United States).

OBJECTIVES: Women exposed prenatally to diethylstibestrol (DES) have an excess risk of clear-cell adenocarcinoma of the vagina and cervix, but the effect on the incidence of squamous neoplasia is uncertain. The purpose of the current study was to evaluate the long-term risk of developing high-grade squamous neoplasia of the genital tract among women exposed prenatally to DES. METHODS: A cohort comprising 3,899 DES-exposed and 1,374 unexposed daughters was followed for 13 years (1982 1995) for pathology-confirmed diagnoses of high-grade squamous intraepithelial neoplasia (HSIL) of the genital tract. Poisson regression analysis was used to compute relative risks (RR) and 95% confidence intervals (95% CI), adjusting for age, calendar year, and other covariates. RESULTS: The RR (95% CI) among DES-exposed versus unexposed, based on 111 cases of high-grade disease, was 2.1 (1.2-3.8). Adjustment for screening history estimated by the number of years since the last Pap smear had little effect. Risk estimates were higher with earlier intrauterine exposure; the RR (95% CI) for exposure within 7 weeks of the last menstrual period was 2.8 (1.4-5.5). Only two cases of invasive squamous cervical cancer occurred in total, precluding separate analysis. CONCLUSIONS: The findings support an association between in-utero DES exposure and high-grade squamous neoplasia, although a role for more intensive screening among DES-exposed women in the production of this excess could not be completely ruled out.

Infertility among women exposed prenatally to diethylstilbestrol.

Although it is well established that women exposed to diethylstilbestrol in utero have an increased risk of spontaneous abortion, ectopic pregnancy, and preterm delivery, it is not known whether they also have an increased risk of infertility. The authors assessed this question in data from a collaborative follow-up study of the offspring of women who took diethylstilbestrol during pregnancy. In 1994, 1,753 diethylstilbestrol-exposed and 1,050 unexposed women from an ongoing cohort study (National Cooperative Diethylstilbestrol Adenosis Study and Dieckmann cohorts) provided data on difficulties in conceiving and reasons for the difficulty. Age-adjusted relative risks were computed for the association of diethylstilbestrol exposure with specific types of infertility. A greater proportion of exposed than unexposed women were nulligravid (relative risk (RR) = 1.3, 95% confidence interval (CI): 1.1, 1.5), and a greater proportion had tried to become pregnant for at least 12 months without success (RR = 1.8, 95% CI: 1.6, 2.1). Diethylstilbestrol exposure was significantly associated with infertility due to uterine and tubal problems, with relative risks of 7.7 (95% CI: 2.3, 25) and 2.4 (95% CI: 1.2, 4.6), respectively. The present findings indicate that diethylstilbestrol-exposed women have a higher risk of infertility than do unexposed women and that the increased risk of infertility is primarily due to uterine or tubal problems.

Cancer risk in men exposed in utero to diethylstilbestrol.

BACKGROUND: An association between prenatal diethylstilbestrol (DES) exposure and cancer in men, especially testicular cancer, has been suspected, but findings from case-control studies have been inconsistent. This study was conducted to investigate the association between prenatal DES exposure and cancer risk in men via prospective follow-up. METHODS: A total of 3613 men whose prenatal DES exposure status was known were followed from 1978 through 1994. The overall and site-specific cancer incidence rates among the DES-exposed men were compared with those of the unexposed men in the study and with population-based rates. The relative rate (RR) was used to assess the strength of the association between prenatal DES exposure and cancer development. All statistical tests were two-sided. RESULTS: Overall cancer rates among DES-exposed men were similar to those among unexposed men (RR = 1.07; 95% confidence interval [CI] = 0.58 to 1.96) and to national rates (RR = 0.99; 95% CI = 0.65 to 1.44). Testicular cancer may be elevated among DES-exposed men, since the RRs for testicular cancer were 3.05 (95% CI = 0.65 to 22.0) times those of unexposed men in the study and 2.04 (95% CI = 0.82 to 4.20) times those of males in the population-based rates. The higher rate of testicular cancer in the DES-exposed men is, however, also compatible with a chance observation. CONCLUSIONS: To date, men exposed to DES in utero do not appear to have an increased risk of most cancers. It remains uncertain, however, whether prenatal DES exposure is associated with testicular cancer.

Cancer risk in women exposed to diethylstilbestrol in utero.

CONTEXT: The association between in utero exposure to diethylstilbestrol (DES) and clear cell adenocarcinoma (CCA) of the vagina and cervix is well known, yet there has been no systematic study of DES-exposed daughters to determine whether they have an increased risk of other cancers. As many as 3 million women in the United States may have been exposed to DES in utero. OBJECTIVE: To determine whether women exposed to DES in utero have a higher risk of cancer after an average of 16 years of follow-up. DESIGN: A cohort study with mailed questionnaires and medical record review of reported cancer outcomes. PARTICIPANTS: A cohort of 4536 DES-exposed daughters (of whom 81% responded) and 1544 unexposed daughters (of whom 79% responded) who were first identified in the mid-1970s. MAIN OUTCOME MEASURES: Cancer incidence in DES-exposed daughters compared with population-based rates and compared with cancer incidence in unexposed daughters. RESULTS: To date, DES-exposed daughters have not experienced an increased risk for all cancers (rate ratio, 0.96; 95% confidence interval [CI], 0.58-1.56) or for individual cancer sites, except for CCA. Three cases of vaginal CCA occurred among the exposed daughters, resulting in a standardized incidence ratio of 40.7 (95% CI, 13.1-126.2) in comparison with population-based incidence rates. The rate ratio for breast cancer was 1.18 (95% CI, 0.56-2.49); adjustment for known risk factors did not alter this result. CONCLUSIONS: Thus far, DES-exposed daughters show no increased cancer risk, except for CCA. Nevertheless, because exposed daughters included in our study were, on average, only 38 years old at last follow-up, continued surveillance is warranted to determine whether any increases in cancer risk occur during the menopausal years.

Environmental endocrine modulators and human health: an assessment of the biological evidence.

Recently, a great deal of attention and interest has been directed toward the hypothesis that exposure, particularly in utero exposure, to certain environmental chemicals might be capable of causing a spectrum of adverse effects as a result of endocrine modulation. In particular, the hypothesis has focused on the idea that certain organochlorine and other compounds acting as weak estrogens have the capability, either alone or in combination, to produce a variety of adverse effects, including breast, testicular and prostate cancer, adverse effects on male reproductive tract, endometriosis, fertility problems, alterations of sexual behavior, learning disability or delay, and adverse effects on immune and thyroid function. While hormones are potent modulators of biochemical and physiological function, the implication that exposure to environmental hormones (e.g., xenoestrogens) has this capability is uncertain. While it is reasonable to hypothesize that exposure to estrogen-like compounds, whatever their source, could adversely affect human health, biological plausibility alone is an insufficient basis for concluding that environmental endocrine modulators have adversely affected humans. Diethylstilbestrol (DES) is a potent, synthetic estrogen administered under a variety of dosing protocols to millions of women in the belief (now known to be mistaken) that it would prevent miscarriage. As a result of this use, substantial in utero exposure to large numbers of male and female offspring occurred. Numerous studies have been conducted on the health consequences of in utero DES exposure among the adult offspring of these women. There are also extensive animal data on the effects of DES and there is a high degree of concordance between effects observed in animals and humans. The extensive human data in DES-exposed cohorts provide a useful basis for assessing the biological plausibility that potential adverse effects might occur following in utero exposure to compounds identified as environmental estrogens. The effects observed in both animals and humans following in utero exposure to sufficient doses of DES are consistent with basic principles of dose response as well as the possibility of maternal dose levels below which potential non-cancer effects may not occur. Significant differences in estrogenic potency between DES and chemicals identified to date as environmental estrogens, as well as an even larger number of naturally occurring dietary phytoestrogens, must be taken into account when inferring potential effects from in utero exposure to any of these substances. The antiestrogenic properties of many of these same exogenous compounds might also diminish net estrogenic effects. Based on the extensive data on DES-exposed cohorts, it appears unlikely that in utero exposure to usual levels of environmental estrogenic substances, from whatever source, would be sufficient to produce many of the effects (i.e., endometriosis, adverse effects on the male reproductive tract, male and female fertility problems, alterations of sexual behavior, learning problems, immune system effects or thyroid effects) hypothesized as potentially resulting from exposure to chemicals identified to date as environmental estrogens.

Incident and demographic trends in cervical neoplasia.

During the past several years, information has been published that suggests that preinvasive cervical neoplasia may be increasing in the United States. Part of the increase can be explained by changes in disease definition, in disease reporting, and in screening patterns. However, a small increase may have occurred in certain population subsets.

The effect of changes in atmospheric pressure on the occurrence of the spontaneous onset of labor in term pregnancies.

OBJECTIVE: Our purpose was to determine whether there is a relationship between changes in atmospheric pressure and spontaneous onset of labor in term pregnancy. STUDY DESIGN: All women admitted to Medical Center of Central Massachusetts-Memorial Hospital with spontaneous onset of labor at term and who were delivered on the service during a 12-month period represent the cohort for this study. Each maternal chart was abstracted to ensure that each member of the cohort met the inclusion criteria. Hourly recordings of atmospheric pressure made at the Worcester Station of the National Weather Service, Department of Commerce, were used as the meteorologic data points of interest. Least-squares regression was used to determine an equation that expresses the probability of the onset of labor in this cohort as a function of gestational age, which was used to calculate expected numbers for the statistical analyses. Two relationships were studied: (1) the ratio of the observed to the expected number of onsets of labor and (2) the initiation of labor and atmospheric pressure changes in the preceding 3 hours. RESULTS: Three-hour periods of falling atmospheric pressure were less often followed by initiation of labor than were the periods with other types of pressure sequences. No association was observed between the onset of labor and days of low mean pressure. CONCLUSION: Although there was an observed statistically significant association between falling barometric pressure and onset of labor, the magnitude of the difference is not of clinical significance.

Role of colposcopy in the examination of diethylstilbestrol-exposed women.

Both epithelial and structural abnormalities of the lower genital tract are known to occur in women exposed in utero to DES with greater frequency than in the general population. These changes are usually easily identified by pelvic and colposcopic examination. In general, no treatment is suggested for benign changes. DES-exposed women, however, must be carefully followed-up because of the potential, although rare, of the development of clear cell adenocarcinoma and the increased incidence of squamous intraepithelial neoplasia. With rare exception, screening at yearly intervals is sufficient.

Increased risk of profound weight loss among women exposed to diethylstilbestrol in utero.

We surveyed 1711 women exposed to diethylstilbestrol in utero, and 919 women not exposed, concerning lifetime weight loss histories. The prevalence of a history of unexplained profoundly low body weight (weight less than or equal to 80% of expected weight for age, sex, and height) was 18.7 per 1000 in the exposed group compared to 3.3 per 1000 in the unexposed group; a 5.72 to 1 ratio of increased risk.