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PubMed2002

Breast cancer risk in healthy and symptomatic women: results of a multivariate analysis. A case-control study.

Several risk factors for breast cancer (BC) have been investigated in different reports, but none has been really useful in preventing BC development. The aim of this study was to evaluate the risk of BC in self-selected symptomatic women in comparison with the healthy population residing in an urban area of Italy. A group of 404 women (median age 59 years, range 26-89 years) with confirmed BC (cases) were age-matched with 389 healthy women (Group A), and 391 (Group B) symptomatic non-screened patients without BC, who were referred to our Breast unit. The results of univariate analysis showed a significant (P < 0.01) difference between cases and controls in (1) age at menarche, (2) number of birth and age at first births, (3) lactation and months of lactation, and (4) estrogen replacement therapy (ERT) and duration of ERT. Multivariate analysis using a logistic regression model adjusted for age showed that five independent parameters (no pregnancy, age at first birth > 30 years, no lactation, use of ERT, ERT > 40 months) significantly (P < 0.01) correlated with BC onset. The relative odds ratios (ORs) at 95% confidence interval (95% CI) were 5.25, 2.47, 2.82, 2.80, and 5.56, respectively. The cumulative OR (95% CI) calculated from the observed vs. predicted values was 7.15. No differences (P = NS) were found between groups A and B. In conclusion, in our study population, the prolonged use (> 40 months) of ETR in menopausal women resulted in an increased risk of BC, and represented the only risk factor that could be removed.

Adult↗
PubMed1997

Pregnancy and risk of non-Hodgkin's lymphoma: a prospective study.

The etiology of non-Hodgkin's lymphomas (NHL), including chronic lymphocytic leukemia (CLL), is likely to be related to immune function. In the light of the established immunologic effects of a pregnancy, we decided to examine the risk of NHL and CLL in relationship to full-term pregnancies. Within a nationwide cohort we identified 1,546 women with NHL and 198 women with CLL, all 15 years or older, born 1925-1972. Five age-matched controls were selected for each case patient. Conditional logistic regression was used to estimate the odds ratios after mutual adjustment for number of births and age at first birth. We found a weak, negative association between parity and risk of NHL (p for trend 0.11) and a transient, 10-40% decrease in risk within 5-14 years after the last birth among women with various parity status. The risk of CLL decreased more markedly, and orderly with increasing parity, but the trend was not significant (p = 0.18). Small numbers of cases with CLL prevented more detailed analyses of temporal relationships. Age at first birth appeared unrelated to the risk of both NHL and CLL. We conclude that the immunologic alterations associated with a pregnancy have limited, if any, relevance to the etiology of NHL and CLL; changing reproductive pattern is an unlikely contributor to the marked increase in incidence of NHL seen in many populations.

Adult↗
PubMed1989

Reproductive factors and breast cancer: an overview.

Despite extensive research, there is still uncertainty on the separate effects of parity and age at first birth on breast cancer risk. Thus, information on these variables from formal epidemiological articles published in English since 1970 is reviewed in the present article. Among 26 studies considered, one found no significant association with either variable, seven showed an association between age at first birth but not parity and breast cancer risk, six an association with parity but not age at first birth, and in twelve studies both variables appeared to be independently related with breast cancer risk. Various reasons for these apparent differences can be considered, including heterogeneity between various populations (for instance, the proportion of multiparous women in studies showing no association with parity tended to be higher than in studies finding an inverse relation with parity), criteria for selection of cases and controls, influence of age and other covariates (among which the interval between pregnancies is of particular interest) and, of course, the role of chance. The data reviewed suggest, from an aetiological viewpoint, that both parity and age at first birth have some independent effect on breast carcinogenesis. From a public health viewpoint, however, it appears that the importance of age at first birth is greater, since the trend is linear across subsequent age levels, while the protection of parity seems to be quantitatively relevant only for women with four or five births or more.

Breast Neoplasms↗
PubMed2005

Fertility behavior and reproductive outcomes among young Guatemalan adults.

Fertility rates have declined in many developing countries and this has implications for health and development of subsequent generations. Guatemala has the highest fertility rates in Central America. Reproductive histories were obtained by interview in 2002-04, in a cohort of 779 women and 647 men who had participated as young children in a nutrition supplementation trial in Guatemala conducted between 1969 and 1977. Most women (77%) and men (79%) are currently married. Among the 700 women and 524 men reporting at least one birth, mean age at first birth was 20.7 +/- 3.8 years and 23.1 +/- 3.9 years respectively. Knowledge (> 80%) and use (approximately 70%) of modern contraceptive methods is fairly high; knowledge increases with parental socioeconomic status (SES) as measured in 1975. Younger respondents have experienced fewer pregnancies and live births compared with older respondents; age-specific fertility rates between 20 and 24 years were 294, 249, 236, and 261 births per 1,000 women, respectively, for women born from 1962-65, 1966-69, 1969-73, and 1974-77. Women in the top tertile of parental SES have had significantly fewer pregnancies (3.3) compared with those in the middle (3.7) and lower (3.8) tertiles. Migrants to Guatemala City reported greater knowledge of contraceptive methods, fewer pregnancies and living children, higher age at first birth, and more pregnancy and newborn complications as compared with cohort members who remained in the original villages (p < .05 for each comparison). Fertility rates, especially between 20 and 24 years, have declined over time. Differences in reproductive behaviors by parental SES and current residence suggest the role of social transitions in determining family formation in Guatemala.

Abortion, Induced↗
PubMed1997

Attributable risks for breast cancer in Italy: education, family history and reproductive and hormonal factors.

The percent population attributable risk (AR) for breast cancer was estimated in relation to education, family history of the disease and some reproductive and hormonal factors, using data from a case-control study conducted between June 1991 and February 1994 in 6 Italian centres on 2,569 histologically confirmed incident breast cancer cases and 2,588 controls, admitted to hospital for a wide range of acute, non-neoplastic, non-hormone-related diseases. On the basis of multivariate odds ratios, a high level of education accounted for 20% of cases, elevated age at first birth and nulliparity for 38% and a family history of breast cancer in first-degree relatives for 7%. Education and nulliparity and age at first birth together explained 47% of all breast cancer cases, and the combination of these 2 factors plus a family history of the disease explained 50% of cases. In pre-menopausal women a high level of education accounted for 31% of all breast cancer cases, older age at first birth for 44% and the combination of the 2 factors for 49%. In post-menopausal women the corresponding values were 13%, 31% and 42%; further addition of risk associated with family history of the disease explained 52% of pre-menopausal cases. In post-menopausal women older age at menopause and the use of hormone replacement therapy accounted for 15% and 2% of breast cancer cases, respectively. The combination of risks associated with a high level of education, old age at first birth and nulliparity and older age at menopause accounted for 51% of cases; further inclusion of risk associated with use of hormone replacement therapy explained 52%, and the AR resulting from these 4 risk factors combined plus a family history of breast cancer was 56%. Thus, a few selected and well-identified risk factors explain about one-half the breast cancer cases in this Italian population.

Age Factors↗
PubMed1983

'Hormonal' risk factors, 'breast tissue age' and the age-incidence of breast cancer.

For most cancer sites there is a linear log-log relationship between incidence and age. This relationship does not hold for breast cancer, and certain 'key' breast cancer risk factors suggest that breast tissue does not 'age' in step with calendar time. A quantitative description of 'breast tissue age' is suggested which brings the age-incidence curve of breast cancer into line with the common log-log cancers and explains quantitatively the known key risk factors. The model also explains the 'anomalous' finding that although early first birth is protective, late first birth carries a higher risk than nulliparity. US breast cancer rates are some four to six times the rates in Japan--the model suggests that the key risk factors, when considered jointly with weight, can explain about 85% of the difference.

Adolescent↗
PubMed2004

Reproductive output, maternal age, and survivorship in captive common marmoset females (Callithrix jacchus).

Common marmosets (Callithrix jacchus) demonstrate significant variation in reproductive output on both a yearly and lifetime basis in comparison to other anthropoid primates. We explore the factors that may be most important in determining reproductive variation in captive common marmosets. Studies have found that maternal age, maternal condition, and dam survivorship are related to reproductive output; however, these reports are not in agreement and are far from conclusive. With the use of a large, multicolony, demographic database pooling data across five marmoset colonies, we examined litter information for 1,649 litters, and reproductive summaries for 400 dams to assess 1) how reproductive output variation (total production, total weaned production) is determined by litter size, interbirth interval (IBI), age at first birth, and dam survival age; 2) the relationship between maternal age and reproductive output variables; and 3) relationship between the reproductive output variables and survival. We used stepwise regression procedures to describe the amount of variation in lifetime reproductive output among dams, and found that mean litter size accounted for 18% of the variance in total production, survival age accounted for 10.6%, age at first birth accounted for 8.8%, and mean IBI accounted for 5%. For total (nonzero) weaned production, survival age accounted for 7.6% of variance, age at first birth accounted for 7.2%, mean IBI accounted for 2%, and mean litter size accounted for 1.6%. We identified significant effects (P<0.05) of maternal age on litter size and IBI length, but no effect of dam age on weaned litter size. Cox proportional hazards regression analyses revealed significant effects (P<0.01) of number of litters, age at first birth, and site on dam survivorship. Dams that produced more litters showed higher survivorship. Age at first birth showed a positive relationship with dam survivorship, i.e., dams that delayed first reproduction had higher survival. Our findings about reproductive variation in marmosets may have practical applications for the management of marmoset breeding colonies.

Animals↗
PubMed1983

Age at any birth and breast cancer risk.

In an effort to assess the relative importance of age at first birth, age at subsequent births, and total parity to the occurrence of breast cancer, reproductive data from 4,225 women with breast cancer and 12,307 hospitalized women without breast cancer were analyzed by a multiple logistic regression model. Age at first birth was confirmed to be the most important reproductive risk indicator; it was associated with a 3.5% increase of relative risk for every year of increase in age at first birth (the 95% confidence interval of this estimate was 2.3 to 4.7% increase per year). However, age at any birth after the first was also an independent and statistically significant risk indicator; it was associated with a 0.9% increase of relative risk for every year of increase in age at any (and every) birth (the 95% confidence interval of this estimate was 0.4 to 1.5% increase per year). There is evidence that the age of approximately 35 years represents for every birth a critical point; before this age any full-term pregnancy confers some degree of protection; after this age any full-term pregnancy appears to be associated with increase in breast cancer risk. The effect of parity is determined by the age of occurrence of the component pregnancies. While most pregnancies occur under the age of 35, the distribution varies from population to population, and this may account for the differences between populations in whether or not a protective effect is seen for births after the first, and if it is seen, its extent.

Adolescent↗
PubMed1987

A case-control study on breast cancer risk factors in a southern European population.

A case-control study has been carried out among women attending a screening service in Palermo (Sicily) from 1974 through 1983 to ascertain the distribution of the most frequently investigated risk factors for breast cancer in a southern European population. Information has been obtained from the archives of the screening service. The analysis was separately conducted for pre- and post-menopausal cases and non-cases. Risk factors for pre-menopausal women are: nulliparity (nulliparous versus parous: OR 2.17, 95% CI 1.41-3.32); age at first birth (25-29 versus less than 20: OR 2.16, 95% CI 1.17-4.00); interval between menarche and first birth (greater than 20 years versus less than 6: OR 5.34, 95% CI 2.08-13.66); number of births (greater than 4 versus 1-2: OR 1.98, 95% CI 1.10-3.50). Risk factors for post-menopausal women are: nulliparity (nulliparous versus parous: OR 2.18, 95% CI 1.59-2.99); age at first birth (greater than 29 versus less than 20: OR 1.84, 95% CI 1.13-2.99); interval between menarche and first birth (16-20 years versus less than 6: OR 2.15, 95% CI 1.20-3.85). Age at menarche, age at menopause, breast feeding and family history were not found to be risk factors for breast cancer in the investigated population. The existence of influencing differences between northern and southern populations has been postulated.

Adult↗
PubMed1984

What are the determinants of delayed childbearing and permanent childlessness in the United States?

This paper presents estimates of delayed childbearing and permanent childlessness in the United States and the determinants of those phenomena. The estimates are derived by fitting the Coale-McNeil marriage model to survey data on age at first birth and by letting the parameters of the model depend on covariates. Substantively, the results provide evidence that the low first birth fertility rates experienced in the 1970s were due to both delayed childbearing and to increasing levels of permanent childlessness. The results also indicate that (a) delayed childbearing is less prevalent among black women than among nonblack women; (b) education is an important determinant of delayed childbearing whose influence on this phenomenon seems to be increasing across cohorts; (c) education is positively associated with heterogeneity among women in their age at first birth; (d) the dispersion of age at first birth is increasing across cohorts; (e) race has an insignificant effect on childlessness; and (f) education is positively associated with childlessness, with the effect of education increasing and reaching strikingly high levels for the most recent cohorts.

Adolescent↗
PubMed1986

Breast cancer risk in relation to early oral contraceptive use.

It has been suggested that the risk of breast cancer is increased by oral contraceptive use before the first birth, or by use before age 25, particularly if certain formulations are used. These hypotheses were evaluated in a hospital-based case-control study. A total of 521 patients under age 45 with breast cancer were compared with 521 controls matched for age, time of interview, and geographic area. Oral contraceptive use before the first birth was reported by 155 patients and 137 controls. With allowance for confounding by multivariate analysis, the estimated relative risk was 1.0 (95% confidence interval, 0.6-1.5). The estimate was 1.0 (0.2-3.9) for any use among nulliparous women and 0.6 (0.3-1.3) for use before the first birth among parous women. Use before age 25 was reported by 145 patients and 141 controls, and the multivariate relative risk estimate was 1.0 (0.7-1.6); the results were similar when use of specific formulations was examined. For oral contraceptive use before either the first birth or age 25, the relative risk estimates were compatible with 1.0 for use of five or more years' duration or an interval since first use of at least 15 years. There was also no evidence of an increased risk in any subgroup including those at increased underlying risk because of factors such as a family history of breast cancer or a history of cystic breast disease. The findings suggest that, up to age 45, the risk of breast cancer is not influenced by the use of oral contraceptives before the first birth or before age 25 even if the use lasted for five or more years.

Adult↗
PubMed2000

Reproductive factors and incidence of breast cancer: an international ecological study.

Ecological studies can help in understanding the relation of reproductive history of breast cancer. We analyzed data from 9416 women, comprising the control groups of seven countries (Australia, People's Republic of China, Colombia, (former) German Democratic Republic, Israel, Philippines, and Thailand) from the WHO international, multi-center case-control study of female cancers. Positive correlations with country-specific breast cancer incidence were observed for (median) duration of reproductive life (r > or = 0.95, p < 0.005), age at menopause (r > or = 0.84, p < 0.025) and delay to first birth (r > or = 0.59, p < 0.22) (when People's Republic of China was omitted, r > or = 0.85, p < 0.07). The association of age at first birth with breast cancer incidence was weakly positive in the whole sample (age-adjusted r = 0.18, p = 0.73), but weakly negative in the age groups 15-29 and 30-39 years and weakly positive in the age groups 40-49 and 50-64 years. A strong inverse correlation was observed between age at menarche and breast cancer incidence (r < or = -0.84, p < 0.03). These international ecological correlations agree with the associations previously reported for single populations, between higher incidence of breast cancer and younger age at menarche, older age at menopause, longer duration of reproductive life, and (possibly) longer delay to first birth. In contrast, age at first birth is only weakly related to breast cancer incidence across populations, indicating that this variable represents different constructs when measured ecologically versus individually.

Adolescent↗
PubMed2003

Association of age, race, and obstetric history with urinary symptoms among women in the Nurses' Health Study.

OBJECTIVE: The purpose of this study was to better understand associations among age, race, obstetric history, and urinary incontinence in women. STUDY DESIGN: Race and obstetric history were assessed through the use of biennial mailed questionnaires from 1976 to 1996 among participants of the Nurses' Health Study. In 1996, 83,168 women aged 50 to 75 years reported their frequency of leaking urine and quantity leaked. We used logistic regression to calculate multivariate-adjusted odds ratios and 95% CIs for the relation of risk factors to leaking urine. RESULTS: Overall, 34.1% of the women reported leaking urine at least once per month during the previous 12 months; this prevalence was lowest in the black women (21.2%). After potential confounders were controlled, there were strong trends of increasing prevalence of occasional and frequent leaking with increasing age (P trend <.0001). There was also increasing prevalence of leaking urine with increasing parity; for example, compared with nulliparous women, the odds ratio for frequent leaking was 1.72 (95% CI, 1.55-1.90) among those with >/=5 births. Odds ratios that were associated with parity were higher in women aged <60 years than in women aged >/=60 years. Age at first birth of >35 years was associated with a slight elevation in frequent leaking compared with women with age at first birth from 21 to 25 years but was stronger for women with age at first birth of <21 years (OR, 1.27; 95% CI, 1.13-1.42). CONCLUSION: In these women, leaking urine is common; this condition is most prevalent in white women, in older women, in parous women, and in women with a younger age at first birth.

Black or African American↗
PubMed1994

Reproductive risk factors in a prospective study of breast cancer: the Nurses' Health Study.

A modification of the model of Pike et al. (Nature 1983;303: 767-70) was applied to 91,523 women in the Nurses' Health Study who did not report prevalent cancer initially and who were followed for 14 years (1,212,855 person-years and 2,341 incident breast cancers). The model took into account current age, age at all births, age at menopause, and age at menarche in predicting the annual and cumulative incidence of breast cancer. The authors found that ages both at first birth and at subsequent births have long-term influence on breast cancer incidence. The incidence density for parous women was greater than for nulliparous women for 20-30 years after the time of the first birth. However, cumulative incidence up to age 70 years was about 20% lower, 10% lower, or 5% higher for parous versus nulliparous women if their first birth was at age 20, 25, or 35 years, respectively. The authors also observed a significantly lower incidence after each additional birth as well as after menopause for women of the same age. Overall, the effect of reproductive factors (other than age at menarche) appears to influence cumulative incidence to age 70 years by a maximum of approximately 50% when women with multiple births with an early age at first birth are compared with women with a single birth at a late age.

Adult↗
PubMed2007

Incidence of hospitalization for postpartum psychotic and bipolar episodes in women with and without prior prepregnancy or prenatal psychiatric hospitalizations.

CONTEXT: Postpartum psychosis occurs in 1 to 2 cases per 1000 live births. Most studies have not distinguished postpartum psychosis from bipolar disorder or the proportion of the incidence attributable to prepregnancy psychiatric morbidity. OBJECTIVE: To determine the incidence of postpartum psychosis and bipolar disorder attributable to previous psychiatric hospitalization. DESIGN: Population-based study using linked registry data to determine postpartum onset of psychotic and bipolar episodes within 90 days after the first birth, by women with and without prepregnancy or prenatal psychiatric hospitalization. We assessed the type, number, and recency of previous hospitalizations on the incidence of hospitalization for postpartum psychotic and bipolar episodes. SETTING: Nationwide Swedish Hospital Discharge and Medical Birth registers. PATIENTS: Swedish women delivering a first live infant between January 1, 1987, and December 31, 2001. MAIN OUTCOME MEASURES: Postpartum hospitalization for psychosis or bipolar disorder. RESULTS: The cumulative incidences for postpartum psychotic and bipolar episodes (adjusted for age at first birth) were 0.07% and 0.03%, respectively. The incidence of psychiatric hospitalizations for postpartum psychotic or bipolar episodes among women without previous psychiatric hospitalizations was 0.04% and 0.01% of first births, respectively; for women with any psychiatric hospitalization before delivery, the incidence was 9.24% and 4.48%, respectively. For postpartum psychotic and bipolar episodes, the risk increased significantly with the recency of prepregnancy hospitalizations, number of previous hospitalizations, and length of most recent hospitalization. More than 40% of women hospitalized during the prenatal period for a bipolar or a psychotic condition were hospitalized again during the postpartum period. Approximately 90% of all postpartum psychotic and bipolar episodes occurred within the first 4 weeks after delivery. CONCLUSIONS: Almost 10% of women hospitalized for psychiatric morbidity before delivery develop postpartum psychosis after their first birth. This underscores the need for obstetricians to assess history of psychiatric symptoms and, with pediatric and psychiatric colleagues, to optimize the treatment of mothers with psychiatric diagnoses through childbirth.

Adult↗
PubMed1993

Determinants of invasive vulvar cancer risk: an Italian case-control study.

Risk factors for vulvar cancer have been evaluated in a case-control study conducted between 1987 and 1990 in northern Italy on 73 women with histologically confirmed invasive vulvar cancer and 572 control subjects in hospital for acute nongynecological, nonneoplastic non-hormone-related conditions. The risk of vulvar cancer was inversely related to education level: with reference to women reporting less than 7 years of schooling, the relative risk estimates were 0.6 and 0.4, respectively, in those reporting 7 to 11 and 12 or more years of schooling (chi 2(1) trend = 4.91 P = 0.03). No relationship emerged between number of births and spontaneous or induced abortions. Parous women reporting late first birth tended to be at lower risk (relative risk = 0.5, 95% confidence interval 0.3 to 1.1 for < 25 vs > or = 25 years at first birth), but there was no evidence of the risk to decrease with increasing age at first birth. The risk of vulvar cancer increased with body mass index, but the trend in risk was not significant after taking into account potential confounders in the multivariate analysis. No association emerged with indicators of sexual habits, menstrual history, and smoking. The risk of the disease was lower in women reporting Pap smears during their life and diminished with increasing number of cervical smears and decreasing recency of last Pap: compared to women reporting no Pap screening, it was 0.5 in those who reported one smear and 0.3 in those with two or more.

Adult↗
PubMed2002

The prognostic significance of Gail model risk factors for women with breast cancer.

BACKGROUND: Because many risk factors for breast cancer are related to hormonal factors and hormonal factors influence breast cancer prognosis, risk factors may have prognostic value. In order to assess the prognostic value of risk factors for breast cancer we divided patients with breast cancer into those at high risk and low risk using the Gail model. METHODS: Patients with available follow-up and information concerning age, age at menarche, number of children, age at first birth, number of first degree relatives with breast cancer, and number of previous breast biopsies were divided into low and high-risk groups by the average relative risk calculated using the Gail model. Risk factors, clinical presentations, pathologic findings, tumor characteristics, extent of disease, treatment and outcomes for the 106 high-risk women were compared with the 206 low-risk women. Stage IV patients were excluded. RESULTS: The average relative risk of breast cancer was 2.09. The 106 high-risk women were significantly older (58 years versus 53 years; P = 0.001), older at first live birth (30 years versus 23 years; P <0.001), more likely to have a first degree relative with breast cancer (57% versus 0%; P <0.001), and more likely to have previously had a breast biopsy (19% versus 1%; P <0.001). There was no difference in the average age at menarche. Low-risk patients were significantly more frequently nulliparous (40% versus 22%; P = 0.002). Clinical presentation, pathologic findings, extent of disease, and treatment were comparable in high and low-risk patients. Cancers of low-risk patients were more frequently poorly differentiated (39% versus 25%, P = 0.044). Tamoxifen was used more frequently in high-risk patients (56% versus 41%; P = 0.012). High-risk patients exhibited significantly better 5-year (95% versus 88%; P = 0.047) and 10-year distant disease-free survival than low-risk patients (88% versus 79%; P = 0.050). In multivariate analysis only the number of involved lymph nodes was related to local (P = 0.001) and distant (P <0.001) disease-free survival. CONCLUSIONS: Breast cancer patients considered high risk by the Gail model have significantly better disease-free survival than low-risk patients. This study does not support the notion that risk factors for breast cancer are prognostic factors.

Adult↗
PubMed2006

Risk of poor pregnancy outcomes: is it higher among multiparous teenage mothers?

It is commonly believed that pregnancy outcomes for multiparous teenage mothers are worse than those for teenage women experiencing a first birth. This article, based on a review of the literature, finds that when teenage mothers having a second birth are compared with those having a first birth, the second births often have worse outcomes. However, when the first and second birth to the same mother are compared, teenagers follow the pattern of older women, i.e., the second births usually have better outcomes than the first. This difference is probably due to selection bias.

Adolescent↗