Reproductive factors and histologic subtype in relation to mortality after a breast cancer diagnosis.

Evidence suggests that certain reproductive factors are more strongly associated with the incidence of lobular than of ductal breast cancer. The mechanisms influencing breast cancer incidence histology may also affect survival. Women with invasive breast cancer (N = 22,302) diagnosed during 1986-2005 were enrolled in a series of population-based studies in three US states. Participants completed telephone interviews regarding reproductive exposures and other breast cancer risk factors. Histologic subtype was obtained from state cancer registries. Vital status and cause of death were determined through December 2006 using the National Death Index. Women were followed for 9.8 years on average with 3,050 breast cancer deaths documented. Adjusted hazard rate ratios (HR) and 95% confidence intervals (95% CI) were calculated using Cox proportional hazards regression models for breast cancer-specific and all-cause mortality. Parity was inversely associated with breast cancer-specific mortality (P (Trend) = 0.002). Associations were similar though attenuated for all-cause mortality. In women diagnosed with ductal breast cancer, a 15% reduction in breast cancer-specific mortality was observed in women with five or more children when compared to those with no children (HR = 0.85, 95% CI: 0.73-1.00). A similar inverse though non-significant association was observed in women with lobular subtype (HR = 0.70, 95% CI: 0.43-1.14). The trend did not extend to mixed ductal-lobular breast cancer. Age at first birth had no consistent relationship with breast cancer-specific or all-cause mortality. We found increasing parity reduced mortality in ductal and lobular breast cancer. The number of full-term births, rather than age at first birth, has an effect on both breast cancer-specific and overall mortality.

Birth defects in the sons and daughters of women who were exposed in utero to diethylstilbestrol (DES).

Prenatal exposure to diethylstilbestrol (DES) is associated with adverse health outcomes, including anatomic anomalies of the reproductive tract in women and of the genitourinary tract in men. The mouse model, which replicates many DES-related effects seen in humans, suggests that prenatal DES exposure causes alterations that may affect the next generation of offspring. We asked women participating in a large, multi-centre study of prenatal DES exposure to report birth defects occurring among 4029 sons and 3808 daughters (i.e., the third generation). A subcohort of 793 third generation daughters was also queried for birth defects. We used logistic regression models to generate odds ratio and 95% confidence intervals for the association between prenatal DES exposure in the mother and birth defects in the offspring. Based on the mothers' reports, overall birth defects were elevated in the sons (OR = 1.53; 95% CI = 1.04, 2.23) and in the daughters (OR = 2.35; 95% CI = 1.44, 3.82). Most estimates of association were imprecise, but daughters appeared to have an excess of heart conditions (OR = 4.56; 95% CI = 1.27, 16.34). Our data suggest a possible association between the mother's prenatal DES exposure and birth defects in their offspring, particularly in daughters. We cannot, however, rule-out the possible influence of reporting bias. In particular, the exposed daughters' elevated risk of cardiac defects may be as a result of the underreporting of these conditions by unexposed mothers.

Validating genetic risk associations for ovarian cancer through the international Ovarian Cancer Association Consortium.

The search for genetic variants associated with ovarian cancer risk has focused on pathways including sex steroid hormones, DNA repair, and cell cycle control. The Ovarian Cancer Association Consortium (OCAC) identified 10 single-nucleotide polymorphisms (SNPs) in genes in these pathways, which had been genotyped by Consortium members and a pooled analysis of these data was conducted. Three of the 10 SNPs showed evidence of an association with ovarian cancer at P< or =0.10 in a log-additive model: rs2740574 in CYP3A4 (P=0.011), rs1805386 in LIG4 (P=0.007), and rs3218536 in XRCC2 (P=0.095). Additional genotyping in other OCAC studies was undertaken and only the variant in CYP3A4, rs2740574, continued to show an association in the replication data among homozygous carriers: OR(homozygous(hom))=2.50 (95% CI 0.54-11.57, P=0.24) with 1406 cases and 2827 controls. Overall, in the combined data the odds ratio was 2.81 among carriers of two copies of the minor allele (95% CI 1.20-6.56, P=0.017, p(het) across studies=0.42) with 1969 cases and 3491 controls. There was no association among heterozygous carriers. CYP3A4 encodes a key enzyme in oestrogen metabolism and our finding between rs2740574 and risk of ovarian cancer suggests that this pathway may be involved in ovarian carcinogenesis. Additional follow-up is warranted.

Whole genome amplification of buccal cytobrush DNA collected for molecular epidemiology studies.

When cytobrush buccal cell samples have been collected as a genomic DNA (gDNA) source for an epidemiological study, whole genome amplification (WGA) can be critical to maintain sufficient DNA for genotyping. We evaluated REPLI-g WGA using gDNA from two paired cytobrushes (cytobush 'A' kept in a cell lysis buffer, and 'B' dried and kept at room temperature for 3 days, and frozen until DNA extraction) in a pilot study (n=21), and from 144 samples collected by mail in a breast cancer study. WGA success was assessed as the per cent completion/concordance of STR/SNP genotypes. Locus amplification bias was assessed using quantitative PCR of 23 human loci. The pilot study showed > 98% completion but low genotype concordance between cytobrush wgaDNA and paired blood gDNA (82% and 84% for cytobrushes A and B, respectively). Substantial amplification bias was observed with significantly lower human gDNA amplification from cytobrush B than A. Using cytobrush gDNA samples from the breast cancer study (n =20), an independent laboratory demonstrated that increasing template gDNA to the REPLI-g reaction improved genotype performance for 49 SNPs; however, average completion and concordance remained below 90%. To reduce genotype misclassification when cytobrush wgaDNA is used, inclusion of paired gDNA/wgaDNA and/or duplicate wgaDNA samples is critical to monitor data quality.

Children with a TV in their bedroom at higher risk for being overweight.

OBJECTIVE: We examined having a TV in the bedroom as a risk factor for child overweight. DESIGN: Cross-sectional study. SETTING: School- and telephone-based surveys in New Hampshire and Vermont between 2002 and 2004. PARTICIPANTS: Two thousand three hundred and forty-three children enrolled in public schools, aged 9-12 years, and one of their parents. MAIN EXPOSURES: The child having a TV in the bedroom. MAIN OUTCOME MEASURES: Age- and gender-standardized child body mass index (zBMI). Overweight was defined as equal to or above the 95th percentile for zBMI. RESULTS: Overall, 22.3% (N=523) of the children were overweight, and almost half of all children (48.2%, N=1130) had a TV in their bedroom. Children with a TV in their bedroom had a higher zBMI and were significantly more likely to be overweight compared to those without a TV in their bedroom (27.3 versus 17.7%, respectively; P<0.05). After controlling for sociodemographics, physical activity, frequency of TV or movie watching and internet use, children with a TV in their bedroom who watched at least one session of TV or movies per day were more likely to be overweight compared to those without a TV in their bedroom (odds ratio=1.32, 95% confidence interval: 1.03, 1.70). CONCLUSIONS: Having a TV in the bedroom is a risk factor for child overweight, independent of reported physical activity, participation in team sports, TV or movie watching time and internet use at home. Further study is needed to fully understand the mechanism by which having a TV in the bedroom increases children's risk for overweight.

Mortality in women given diethylstilbestrol during pregnancy.

We used Cox regression analyses to assess mortality outcomes in a combined cohort of 7675 women who received diethylstilbestrol (DES) through clinical trial participation or prenatal care. In the combined cohort, the RR for DES in relation to all-cause mortality was 1.06 (95% CI = 0.98-1.16), and 1.11 (95% CI = 1.02-1.21) after adjusting for covariates and omitting breast cancer deaths. The RR was 1.07 (95% CI = 0.94-1.23) for overall cancer mortality, and remained similar after adjusting for covariates and omitting breast cancer deaths. The RR was 1.27 (95% CI = 0.96-1.69) for DES and breast cancer, and 1.38 (95% CI=1.03-1.85) after covariate adjustment. The RR was 1.82 in trial participants and 1.12 in the prenatal care cohort, but the DES-cohort interaction was not significant (P = 0.15). Diethylstilbestrol did not increase mortality from gynaecologic cancers. In summary, diethylstilbestrol was associated with a slight but significant increase in all-cause mortality, but was not significantly associated with overall cancer or gynaecological cancer mortality. The association with breast cancer mortality was more evident in trial participants, who received high DES doses.

Birth weight and breast cancer risk.

Exploring whether the positive association between birth weight and breast cancer risk differs by other breast cancer risk factors may help inform speculation about biological mechanism. In these data, high birth weight was associated with breast cancer risk in younger and in more educated women, but was not associated overall.

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.

Carotenoids, antioxidants and ovarian cancer risk in pre- and postmenopausal women.

An inverse association between ovarian cancer risk, carotenoids and antioxidant vitamins has been suggested by several epidemiologic studies and 1 experimental trial of a vitamin A analogue. From a population-based study of 549 cases of ovarian cancer and 516 controls, we estimated the consumption of the antioxidant vitamins A, C, D and E and various carotenoids, including alpha- and beta-carotene and lycopene, using a validated dietary questionnaire. Multivariate logistic regression was used to calculate the exposure odds ratios adjusted for established ovarian cancer risk factors. Intakes of carotene, especially alpha-carotene, from food and supplements were significantly and inversely associated with risk for ovarian cancer, predominantly in postmenopausal women. Intake of lycopene was significantly and inversely associated with risk for ovarian cancer, predominantly in premenopausal women. Food items most strongly related to decreased risk for ovarian cancer were raw carrots and tomato sauce. Consumption of fruits, vegetables and food items high in carotene and lycopene may reduce the risk of ovarian cancer.

Electric blanket or mattress cover use and breast cancer incidence in women 50-79 years of age.

Previous research has demonstrated inconsistent associations between electromagnetic radiation, especially from electric blanket use, and breast cancer. Breast cancer risk according to electric blanket or mattress cover use was examined as part of a multicenter population-based case-control study. Breast cancer patients 50-79 years of age (N = 1949) were identified from statewide tumor registries in Massachusetts, New Hampshire, and Wisconsin from the period June 1994 to July 1995. Women of similar age were randomly selected from population lists as controls. Information regarding electric blanket and mattress cover use and breast cancer risk factors was obtained through telephone interviews. After adjustment for age, body mass index, and other breast cancer risk factors, the risk of breast cancer was similar among ever-users (relative risk = 0.93; 95% confidence interval = 0.82-1.06) and lower among current users than among never-users (relative risk = 0.79; 95% confidence interval = 0.66-0.95). There was no evidence of a dose-response relation with increasing number of months that electric blankets had been used. This study provides evidence against a positive association between electric blanket or mattress cover use and breast cancer.

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.

Collection of genomic DNA from adults in epidemiological studies by buccal cytobrush and mouthwash.

Blood samples are an excellent source of large amounts of genomic DNA. However, alternative sources are often needed in epidemiological studies because of difficulties in obtaining blood samples. This report evaluates the buccal cytobrush and alcohol-containing mouthwash protocols for collecting DNA by mail. Several DNA extraction techniques are also evaluated. The study was conducted in two phases. In phase 1, we compared cytobrush and mouthwash samples collected by mail in two different epidemiological studies: (a) cytobrush samples (n = 120) from a United States case-control study of breast cancer; and (b) mouthwash samples (n = 40) from a prospective cohort of male United States farmers. Findings from phase 1 were confirmed in phase 2, where we randomized cytobrush (n = 28) and mouthwash (n = 25) samples among participants in the breast cancer study to directly compare both collection methods. The median human DNA yield determined by hybridization with a human DNA probe from phenol-chloroform extracts was 1.0 and 1.6 microg/2 brushes for phases 1 and 2, respectively, and 27.5 and 16.6 microg/mouthwash sample for phases 1 and 2, respectively. Most (94-100%) mouthwash extracts contained high molecular weight DNA (>23 kb), in contrast to 55-61% of the brush extracts. PCR success rates for amplification of beta-globin gene fragments (268, 536, and 989 bp) were similar for cytobrush and mouthwash phenol-chloroform extracts (range, 94.4-100%). Also, we obtained high success rates in determining the number of CAG repeats in the androgen receptor gene, characterizing tetranucleotide microsatellites in six gene loci, and screening for mutations in the BRCA1/2 genes in a subset of phenol-chloroform DNA extracts. Relative to DNA extracted by phenol-chloroform from cytobrush samples, DNA extracted by NaOH had lower molecular weight, decreased PCR success rates for most assays performed, and unreliably high spectrophotometer readings for DNA yields. In conclusion, although DNA isolated from either mouthwash or cytobrush samples collected by mail from adults is adequate for a wide range of PCR-based assays, a single mouthwash sample provides substantially larger amounts and higher molecular weight DNA than two cytobrush samples.

Fracture history and risk of breast and endometrial cancer.

Fractures in postmenopausal women may serve as a surrogate measure of bone density, reflecting long-term lower estrogen levels, and lower estrogen levels appear to be inversely associated with breast and endometrial cancer. Breast cancer cases aged 50-79 years (n = 5,559) and endometrial cancer cases aged 40-79 years (n = 739) were enrolled in a US case-control study in 1992-1994 to evaluate the relation between fractures and risk of breast and endometrial cancer. Controls for the breast cancer analysis (n = 5,829) and the endometrial cancer analysis (n = 2,334) were randomly selected from population lists (driver's license and Medicare files). Information on fracture history and other risk factors was obtained by telephone interview. Compared with women without a fracture in the past 5 years, the odds ratios for women with a history of fracture were 0.80 (95% confidence interval (CI): 0.68, 0.94) for breast cancer and 0.59 (95% CI: 0.40, 0.89) for endometrial cancer. Height loss (> or =2.5 cm) and recent fracture history were associated with the lowest risk of breast cancer (odds ratio = 0.62, 95% CI: 0.46, 0.83) and endometrial cancer (odds ratio = 0.15, 95% CI: 0.05, 0.43). These data suggest that the endogenous hormonal factors associated with increased fracture risk are also related to decreased breast cancer risk and, more strongly, to endometrial cancer risk.

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.

Menstrual and reproductive factors in relation to ovarian cancer risk.

We assessed menstrual and reproductive factors in relation to ovarian cancer risk in a large, population-based, case-control study. 563 cases in Massachusetts and New Hampshire were ascertained from hospitals and statewide tumour registries; control women (n = 523) were selected through random digit dialing and matched to case women by age and telephone sampling unit. We used multivariate logistic regression to evaluate factors in relation to risk of ovarian cancer and the major tumour histologic subtypes. Ovarian cancer risk was reduced among parous women, relative to nulliparous women (OR = 0.4; 95% CI = 0.3-0.6). Among parous women, higher parity (P = 0.0006), increased age at first (P = 0.03) or last (P = 0.05) birth, and time since last birth (P = 0.04) were associated with reduced risk. Early pregnancy losses, abortions, and stillbirths were unrelated to risk, but preterm, term, and twin births were protective. Risk was lower among women who had breast-fed, relative to those who had not (OR = 0.7; 95% CI = 0.5-1.0), but the average duration of breast-feeding per child was unrelated to risk (P for trend = 0.21). Age at menarche and age at menopause were unrelated to risk overall, although increasing menarcheal age was protective among premenopausal women (P = 0.02). Menstrual cycle characteristics and symptoms were generally unrelated to risk, although cycle-related insomnia was associated with decreased risk (OR = 0.5; 95% CI = 0.3-0.8). We found no association between the type of sanitary product used during menstruation and ovarian cancer risk. In analyses by histologic subtype, reproductive and menstrual factors had most effect on risk of endometrioid/clear cell tumours, and least influential with regard to risk of mucinous tumours. Overall, our findings offer some support to current hypotheses of ovarian pathogenesis, and show aetiologic differences among the tumour subtypes.

Loss of heterozygosity on chromosome 11q22-23 in melanoma is associated with retention of the insertion polymorphism in the matrix metalloproteinase-1 promoter.

Matrix metalloproteinase-1 (MMP-1, collagenase-1), which degrades interstitial collagen, is expressed at high levels by some tumor cells and is thought to enhance their invasiveness and metastatic potential. We recently described a common single nucleotide insertion polymorphism (2G allele) at -1,607 bp in the promoter of the MMP-1 gene that creates a binding site for the ETS family of transcription factors, and that is associated with enhanced transcription of this gene and increased enzyme activity. Allelic loss at the MMP-1 locus on chromosome 11 occurs in many tumors including melanoma, an invasive and aggressive cancer. We hypothesized that although loss of either the 1G or 2G allele from 1G/2G heterozygotes is random, retention of the transcriptionally more active 2G allele would favor tumor invasion and metastasis. As a result, a higher proportion of metastases would contain the 2G genotype than the 1G genotype. We report here the development of quantitative methods for assessing allelic loss at the MMP-1 locus, and demonstrate that 83% of the metastatic melanomas with loss of heterozygosity at this locus retained the 2G allele. This supports the hypothesis that retention of the 2G allele favors tumor invasion and metastasis in melanoma.

Long-term cancer risk in women given diethylstilbestrol (DES) during pregnancy.

From 1940 through the 1960s, diethylstilbestrol (DES), a synthetic oestrogen, was given to pregnant women to prevent pregnancy complications and losses. Subsequent studies showed increased risks of reproductive tract abnormalities, particularly vaginal adenocarcinoma, in exposed daughters. An increased risk of breast cancer in the DES-exposed mothers was also found in some studies. In this report, we present further follow-up and a combined analysis of two cohorts of women who were exposed to DES during pregnancy. The purpose of our study was to evaluate maternal DES exposure in relation to risk of cancer, particularly tumours with a hormonal aetiology. DES exposure status was determined by a review of medical records of the Mothers Study cohort or clinical trial records of the Dieckmann Study. Poisson regression analyses were used to estimate relative risks (RR) and 95% confidence intervals (CI) for the relationship between DES and cancer occurrence. The study results demonstrated a modest association between DES exposure and breast cancer risk, RR = 1.27 (95% CI = 1.07-1.52). The increased risk was not exacerbated by a family history of breast cancer, or by use of oral contraceptives or hormone replacement therapy. We found no evidence that DES was associated with risk of ovarian, endometrial or other cancer.

Metabolic disorders and breast cancer risk (United States).

OBJECTIVE: To clarify the hormonal context of breast cancer etiology we used data from a large, population-based case-control study to investigate the relationship between breast cancer risk and a history of diabetes mellitus, disorders associated with estrogen stimulation (uterine fibroids, endometriosis, gallstones), and disorders associated with androgen stimulation (acne, hirsutism, and polycystic ovaries). METHODS: Breast cancer patients between 50 and 75 years old were identified from state-wide tumor registries in Wisconsin, Massachusetts, and New Hampshire; controls were randomly selected from drivers' license lists (age less than 65) or Medicare enrollment files (age 65-74). Information on reproductive history, medical history, and personal habits was obtained by telephone interview. A total of 5659 cases and 5928 controls were interviewed and provided suitable data. RESULTS: There was no overall association between breast cancer risk and reported history of diabetes mellitus, endometriosis, uterine fibroids, gallstones, or cholecystectomy. However, the disorders with androgenic associations all conferred an increased risk: the overall odds ratio (OR) for a history of acne was 1.4 (95% CI 1.0-1.9), that for hirsutism was 1.2 (95% CI 0.81-1.8), and that for polycystic ovaries 1.6 (95% CI 0.8-3.2). Diabetes mellitus diagnosed before age 35 conferred an odds ratio of 0.52 (95% 0.25-1.1), while diabetes diagnosed at a later age was associated with an increased risk (OR = 1.2, 95% CI 1.0-1.4). CONCLUSIONS: Androgen-related phenomena are likely to be important in the etiology of breast cancer.

Incidence of squamous neoplasia of the cervix and vagina in des-exposed daughters.

PURPOSE: Women exposed to diethylstibestrol (DES) in utero are known to have an excess risk of clear cell adenocarcinoma of the vagina and cervix, in addition to vaginal epithelial changes, but the effect on the incidence of squamous neoplasia is uncertain. This study evaluated the long-term risk of developing high-grade squamous neoplasia of the genital tract among women exposed prenatally to diethylstilbestrol.METHODS: A cohort comprising 3899 DES-exposed and 1374 unexposed daughters was followed for thirteen years (1982-1995) for pathology-confirmed diagnoses of high-grade squamous neoplasia. A pathologist blinded to exposure status reviewed seventy-seven percent of cases. Poisson regression analysis was used to compute relative risks (RR) and 95% confidence intervals (CI) controlling for age, calendar year, screening history and other covariates.RESULTS: The RR (95% CI) among DES-exposed versus unexposed, based on 111 cases of high-grade disease, was 2.12 (1.19-3.77). Adjustment for screening history had little effect, but when the analysis was restricted to a group highly screened before 1982, the risk was reduced. Risk estimates were higher among women exposed earlier in gestation; the RR (95% CI) for exposure within 7 weeks of the last menstrual period was 2.82 (1.43-5.53).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.