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.     

Menstrual and reproductive factors and pancreatic cancer risk in women

To investigate possible correlates of the systematically higher pancreatic cancer rates in males than in females, the role of menstrual, reproductive and hormonal factors in females have been assessed using data from a case-control study conducted in Northern Italy. Cases were 133 women with histologically confirmed incident cancer of the pancreas, and controls were 377 women in hospital for acute, non-neoplastic, non-digestive-tract disorders. After allowance for age, education, area of residence and smoking habit, an increased risk of pancreatic cancer was observed in women with early menarche (? 13 years) (OR = 1.9; 95% Cl; 1.0–3.6), but no significant association was observed with age at menopause or length of fertile life. Parous women were at reduced risk as compared to nulliparous women (OR = 0.7), although the trend in risk with number of births was not significant. No association with spontaneous or induced abortions was observed. Pancreatic cancer risk was inversely related to early age at first birth (first birth < 25 versus nulliparae: OR = 0.5; 95% C1: 0.3–0.9; p-value for trend < 0.01) and to age at last birth (last birth < 25 versus nulliparae: OR = 0.3; 95% C1: 0.1–0.8; p-value for trend < 0.05). Ever-users of estrogen replacement therapy showed a non-significantly increased risk (OR = 2.2). Although no clear pattern of association is evident, the present results are in agreement with previous epidemiological observations and experimental research indicating that hormonal (menstrual and reproductive) factors could explain part of the male-to-female differential in incidence and mortality from pancreatic cancer. © 1995 Wiley-Liss Inc.     

Serum leptin,adiponectin and endometrial cancer risk in Chinese women

Objective

To investigate the relationship between serum concentrations of leptin or adiponectin, and endometrial carcinoma in Chinese women.

Methods

We conducted a case-control study of a total of 516 Chinese women to detect the relationships between serum concentrations of leptin or adiponectin, and endometrial carcinoma in Chinese women. The study subject constituted 206 cases of endometrial cancer and 310 normal controls.

Results

Patients with endometrial carcinoma had higher serum leptin concentrations than controls (28.8±2.2 ug/L vs. 19.8±1.4 ug/L; p<0.001). The adiponectin levels in patients were lower than in controls with borderline statistical significance (2,330.7±180.5 ug/L vs. 2,583.9±147.2 ug/L; p=0.078). Logistic regression analysis confirmed the associations between leptin or adiponectin, and endometrial carcinoma after adjustment for age, body mass index, fasting insulin, serum glucose, cholesterol, triglycerides, and high-density lipoprotein cholesterol (odds ratio for the top tertile vs. the bottom tertile: leptin 2.05; 95% confidence interval [CI], 1.28 to 3.29; p<0.001; adiponectin 0.52; 95% CI, 0.32 to 0.83; p<0.001).

Conclusion

Increased leptin or decreased adiponectin levels are associated with endometrial carcinoma.     

Temporal pattern of recurrence of stage I endometrial cancer in relation to histological risk factors

Objective

To study the temporal pattern of endometrial cancer recurrence in relation to histological risk factors in a large multicenter setting.

Methods

843 patients with apparent stage I endometrial cancer were followed for a median time of 38 months, documenting all recurrences. Patients were stratified as high risk based on the presence of at least one of the established histological risk factors: high tumor grade, penetration to the outer half of the myometrium, lymphvascular space involvement, lower uterine segment involvement and non endometroid histology. Survival analysis, including Kaplan–Meier curves, log-rank tests and multi-variate Cox proportional hazard regression were used to evaluate the equality of recurrence-free distributions for different levels of risk.

Results

Recurrence was documented in 66 cases. The presence of one or more of the histological risk factors was associated with significantly shorter recurrence free survival, not attenuating over time (p < 0.001). Age-adjusted Cox regression model demonstrated a significantly decreased recurrence-free survival (HR = 2.8 95% CI 1.5, 5.1) in the presence of risk factors.

Conclusions

In patients with stage I endometrial cancer, the presence of histological risk factors is associated with a significantly higher recurrence rate, which does not attenuate over follow up time. This may allow for a selective approach in the follow- up of endometrial cancer patients.     

Menstrual and reproductive factors and Gastric-cancer risk in women

To understand possible correlates of the systematically higher gastric-cancer rates in males than in females, we investigated the role of menstrual, reproductive and hormonal factors in females, using data from a case-control study conducted in Northern Italy. Cases were 229 post-menopausal women with incident, histologically confirmed gastric cancer, and controls were 614 post-menopausal women in hospital for acute, nonneoplastic, non-digestive-tract conditions. After allowance for age, education, family history, and selected dietary correlates of stomach cancer, a reduced gastric-cancer risk was observed in women with later menopause (odds ratio, OR = 0.6, p value for trend <0.05), and longer duration of fertile life (OR = 0.7, but the trend in risk was not significant). The risk of gastric cancer was elevated in multiparous women (OR = 1.7 for 3 and 1.9 for ≥ 4 births as compared to nulliparae). No association was observed with age at menarche, age at first birth, and with number of spontaneous or induced abortions. Ever-users of oral contraceptives had a non-significant increased risk (OR = 1.3), and users of oestrogen-replacement treatment a non-significant reduced risk (OR = 0.5). Although the association with each factor was moderate, and the interpretation of these findings is not straightforward, these results are compatible with the hypothesis that some role is played by (endogenous and exogenous) female hormones in the process of gastric carcinogenesis.     

Hormonal and reproductive factors in relation to melanoma in women: current review and meta-analysis

A number of studies have focused on possible relationships between characteristics of female endocrine status and melanoma (CM) risk; however, the link between melanoma, oral contraceptive (OC) and hormonal replacement therapy (HRT) use, and reproductive factors remains controversial. A comprehensive, systematic bibliographic search of the medical literature was conducted to identify relevant studies. Random effects models were used to summarise results. Subgroup, meta-regression and sensitivity analyses have been carried out to explore sources of between-study variation and bias. We included thirty-six observational studies published in the last 30 years. Summarising a total of 5626 melanoma cases, we did not find any significant melanoma risk associated with OC and HRT use. Several reproductive factors were also investigated, summarising data on 16787 melanoma cases. We found a significantly increased melanoma risk for late age at first birth, and women with more than one child may be at a lower risk for melanoma; however, socio-economic confounders were found to play a significant role in explaining this association. This study confirmed no increased risk of CM with the use of oral contraceptives and hormone replacement therapy: exogenous female hormones do not contribute to an increased risk of CM. In contrast, significant associations of CM with parity and age at first pregnancy were observed in this meta-analysis finds and warrant further research.     

Menstrual and reproductive factors and endometrial cancer risk: Results from a population-based case-control study in urban Shanghai

The purpose of our study was to evaluate the association of menstrual and reproductive factors with the risk of endometrial cancer. In a population-based case-control study conducted in urban Shanghai, in-person interviews were completed for 833 women aged 30-69 years and an equal number of controls frequency-matched to cases by age. All cases were newly diagnosed with endometrial cancer between January 1, 1997 and December 31, 2001. The unconditional logistic regression model was employed to derive the adjusted odds ratios (ORs) of endometrial cancer and 95% confidence intervals (CIs) in relation to menstrual and reproductive factors. Earlier menarche age, particularly among premenopausal women, and later menopausal age were associated with an elevated risk of endometrial cancer. A clear dose-response relation between endometrial cancer risk and years of menstruation was observed (p for trend < 0.01). Compared to women ever having a pregnancy and women ever having had a live birth, respectively, nulligravity and nulliparity were both associated with a more than one-fold elevated risk of endometrial cancer. Both completed (OR = 3.02, 95% CI 1.10-8.32 for women never having a complete pregnancy) and incomplete pregnancy (OR = 0.69, 95%CI 0.55-0.87) conferred a protective effect against endometrial cancer, and the protective effect appeared to increase with total number of pregnancies (p for trend = 0.01). The effect of pregnancy on endometrial cancer remained unchanged with increasing time since the last pregnancy. Stillbirth and age at first pregnancy was unrelated to endometrial cancer risk. Our study suggests that prolonged menstruation was related to an increased risk of endometrial cancer while pregnancy, including induced abortion, reduced the risk of endometrial cancer.     

Recurrence risk factors in stage IA grade 1 endometrial cancer

ObjectivesPatients with early-stage endometrial cancers (EC) with disease recurrences have worse survival outcomes. The purpose of this study was to identify clinical and pathologic factors that predict for all recurrences in stage IA grade 1 (IAG1) EC.MethodsRecords from patients diagnosed with EC were retrospectively reviewed. Baseline characteristics of 222 patients with IAG1 EC who underwent surgical resection were analyzed. Cox proportional hazard analysis was used to identify univariate and multivariate risk factors that predict for recurrence.ResultsSeventeen (7.65%) patients had recurrences. The 3-year cumulative incidence of recurrence were significantly higher for patients with time from biopsy to surgery ≥6 months (54% vs. 8%, p=0.003), simple hysterectomy with ovarian preservation vs. total hysterectomy and bilateral salpingo-oophorectomy (31% vs. 9%, p=0.032), any myometrial invasion vs. no invasion (18% vs. 2%, p=0.004), and tumor size ≥2 cm (15% vs. 2%, p=0.021). On, multivariate analysis, any myometrial invasion, increasing time from biopsy to surgery, and larger tumor size were independent predictors of any recurrence. Patients with recurrences had worse outcomes than those without (5-year overall survival [OS]=60%; 95% confidence interval [CI]=16%–86% vs. 5-year OS=95%; 95% CI=87%–99%, respectively, p=0.003).ConclusionTime from biopsy to surgery, larger tumors, and myometrial invasion are the most important predictors of recurrence. Though the recurrence rates are generally low in IAG1 EC, the survival rate for the patients with recurrences was worse than those without. Identification of additional recurrence risk factors can help select patients who may benefit from adjuvant treatment.     

Menstrual and reproductive factors and risk of breast cancer in Asian-Americans.

We conducted a population-based case-control study of breast cancer among Chinese-, Japanese- and Filipino-American women in Los Angeles County Metropolitan Statistical Area (MSA), San Francisco-Oakland MSA and Oahu, Hawaii. One objective of the study was to quantify breast cancer risks in relation to menstrual and reproductive histories in migrant and US-born Asian-Americans and to establish whether the gradient of risk in Asian-Americans can be explained by these factors. Using a common study design and questionnaire in the three study areas, we successfully conducted in-person interviews with 597 Asian-American women diagnosed with incident, primary breast cancer during the period 1983-87 (70% of those eligible) and 966 population-based controls (75% of those eligible). Controls were matched to cases on age, ethnicity and area of residence. In the present analysis, which included 492 cases and 768 controls, we observed a statistically non-significant 4% reduction in risk of breast cancer with each year delay in onset of menstruation. Independent of age at menarche risk of breast cancer was lower (odds ratio; OR=0.77) among women with menstrual cycles greater than 29 days. Parous Asian-American women showed a significantly lower risk of breast cancer then nulliparous women (OR=0.54). An increasing number of livebirths and a decreasing age at first livebirth were both associated with a lower risk of breast cancer, although the effect of number of livebirths was no longer significant after adjustment for age at first livebirth. Women with a pregnancy (spontaneous or induced abortions) but no livebirth had a statistically non-significant increased risk (OR=1.84), but there was no evidence that one type of abortion was particularly harmful. A positive history of breastfeeding was associated with non-significantly lower risk of breast cancer (OR=.78). There are several notable differences in the menstrual and reproductive factors between Asian-Americans in this study and published data on US whites. US-born Asian Americans had an average age at menarche of 12.12 years-no older than has been found in comparable studies of US whites, but 1.4 years earlier than Asian women who migrated to the US. Asian-American women, particularly those born in the US and those who migrated before age 36, also had a later age at first birth and fewer livebirths than US whites. A slightly higher proportion of Asian-American women breastfed, compared with US whites. The duration of breastfeeding was similar in US-born Asians and US whites, but was longer in Asian migrants, especially those who migrated at a later age. Menstrual and reproductive factors in Asian-American women are consistent with their breast cancer rates being at least as high as in US whites, and they are. However, the effects of these menstrual and reproductive factors were small and the ORs for migration variables changed only slightly after adjustment for these menstrual and reproductive factors. These results suggest that the lower rates of breast cancer in Asians must be largely as a result of other environmental/lifestyle factors.     

Isolated tumor cells and micrometastases in regional lymph nodes in stage I to II endometrial cancer

Objective

The aim of this study was to clarify the clinical significance of isolated tumor cells (ITCs) or micrometastasis (MM) in regional lymph nodes in patients with International Federation of Gynecology and Obstetrics (FIGO) stage I to II endometrial cancer.

Methods

In this study, a series of 63 patients with FIGO stage I to II were included, who had at least one of the following risk factors for recurrence: G3 endometrioid/serous/clear cell adenocarcinomas, deep myometrial invasion, cervical involvement, lympho-vascular space invasion, and positive peritoneal cytology. These cases were classified as intermediate-risk endometrial cancer. Ultrastaging by multiple slicing, staining with hematoxylin and eosin and cytokeratin, and microscopic examination was performed on regional lymph nodes that had been diagnosed as negative for metastases.

Results

Among 61 patients in whom paraffin-embedded block was available, ITC/MM was identified in nine patients (14.8%). Deep myometrial invasion was significantly associated with ITC/MM (p=0.028). ITC/MM was an independent risk factor for extrapelvic recurrence (hazard ratio, 17.9; 95% confidence interval [CI], 1.4 to 232.2). The 8-year overall survival (OS) and recurrence-free survival (RFS) rates were more than 20% lower in the ITC/MM group than in the node-negative group (OS, 71.4% vs. 91.9%; RFS, 55.6% vs. 84.0%), which were statistically not significant (OS, p=0.074; RFS, p=0.066). Time to recurrence tended to be longer in the ITC/MM group than in the node-negative group (median, 49 months vs. 16.5 months; p=0.080).

Conclusions

It remains unclear whether ITC/MM have an adverse influence on prognosis of intermediate-risk endometrial cancer. A multicenter cooperative study is needed to clarify the clinical significance of ITC/MM.     

年轻妇女子宫内膜癌预后相关因素分析

目的探讨年轻妇女子宫内膜癌预后相关因素。方法回顾性分析2008年3月至2011年3月收治的年龄<40岁的年轻妇女子宫内膜癌患者185例,根据随访3年后的最终结果分为死亡组与生存组,对临床资料、预后相关因素进行分析。结果经随访3年发现,年轻妇女子宫内膜癌患者3年生存率为87.3%。死亡组与生存组患者比较,在BMI、ER(+)、PR(+)、合并PCOS、病理分期、肌层浸润深度、宫颈浸润情况和淋巴结转移方面差异有统计学意义(P<0.05)。结论 BMI、ER(+)、PR(+)、病理分期、淋巴结转移是影响子宫内膜癌预后的独立危险因素,BMI较大,ER(+)及PR(+)率较低,病理分期较晚,且有淋巴结转移的患者预后可能较差。     

Molecular and histopathologic predictors of distant failure in endometrial cancer

A case-cohort study was designed to correlate various histopathologic and molecular variables with distant failure in endometrial cancer by analyzing phenotypic and molecular indices in hysterectomy specimens. From an overall population of 283 patients with endometrial cancer, we selected a cohort including all 49 patients who experienced any recurrence and 76 randomly chosen patients without recurrence. Expression of nuclear proliferating cell nuclear antigen (PCNA), MIB-1 (a marker of cell proliferation), and p53 was determined with digital image analysis, and cell membrane HER-2/neu and bcl-2 were quantitated visually. Ploidy and DNA indices were determined with flow cytometry. Overall, 6 immunohistochemical and 11 flow cytometric cases were eliminated because of technical inadequacies. Distant failures were defined as primary recurrences that developed outside the pelvis or vagina. Median follow-up was 91 months. Distant failures occurred in 13% of the patients. Cervical stromal invasion, positive adnexae, myometrial invasion >50%, positive lymph nodes, positive peritoneal cytology, lymphovascular invasion, grade 3 histology, nonendometrioid subtype, p53 >33%, strong HER-2/neu membranous staining, aneuploidy, S-phase fraction > or =9%, proliferative index > or =14%, and DNA index > or =1.5 significantly (P<0.05) predicted distant failures. However, a logistic regression model identified only p53 (OR=43.73; P<0.005), lymphovascular invasion (OR=11.59; P<0.001), and cervical stromal invasion (OR=11.29; P=0.001) as cogent predictors of distant failures. Only 3% of patients without any of these three predictors developed distant failures compared with 36% of those with at least one of the three (P<0.01). Thus, locoregional therapy may be insufficient when at least one of these predictors is present.     

Alcohol consumption,cigarette smoking,and endometrial cancer risk: results from the Netherlands Cohort Study

Objective To examine the association between alcohol consumption, cigarette smoking, and endometrial cancer. Methods In 1986, the Netherlands Cohort Study was initiated. A self-administered questionnaire on dietary habits and other cancer risk factors was completed by 62,573 women. Follow-up for cancer was established by record linkage to the Netherlands Cancer Registry. Results After 11.3-years of follow-up, 280 incident endometrial cancer cases were available for analyses. In multivariate analysis, the rate ratio (RR) for alcohol users versus non-users was 1.06 (95% Confidence Interval (95% CI) = 0.78–1.43). There were neither dose-dependent trends nor associations with different types of beverages. The RR for former and current smokers versus never-smokers was 0.83 (95% CI = 0.58–1.20) and 0.59 (95% CI = 0.40–0.88), respectively. These estimates did not change significantly when body mass index (BMI) and age at menopause were added to the models. Conclusions There is no association between alcohol consumption and endometrial cancer. Current smoking is associated with a reduced risk of endometrial cancer. This association is neither mediated by BMI nor by age at menopause.     

Associations between obesity,metabolic syndrome,and endometrial cancer risk in East Asian women

ObjectiveThis study investigated the associations between obesity, metabolic syndrome (MetS), the combination of these two components as a metabolic obesity phenotype, and endometrial cancer risk in East Asian women.MethodsA total of 6,097,686 cancer-free women aged 40–74 years who underwent the National Health Insurance Service health examination between 2009 and 2010 were included. Cancer incidence was identified using the healthcare utilization database. Associations between baseline obesity (body mass index <23 kg/m², 23–24.9 kg/m², ≥25 kg/m²), MetS, each component of MetS, MetS stratified by obesity status, combination of obesity and MetS, and endometrial cancer risk were investigated using hazard ratios (HRs).ResultsObesity, each component of MetS, and MetS increased the endometrial cancer risk. After these factors were mutually adjusted for, the association did not change. When stratified by obesity, MetS and MetS components were not associated with endometrial cancer in normal-weight or overweight women. However, in obese women, MetS and MetS components increased the risk of endometrial cancer (HR=1.29; 95% confidence interval [CI]=1.20–1.39). Compared with normal-weight women without MetS, endometrial cancer risk was not increased in normal-weight women with MetS. Overweight women showed an increased risk of endometrial cancer irrespective of the presence of MetS (HR=1.37 and 1.38, respectively). The HR of obese women with MetS was higher than that of obese women without MetS (HR=2.18 and 1.75).ConclusionThe association between MetS and endometrial cancer was most prominent in obese women, suggesting that obese women with MetS would be more vulnerable to endometrial cancer.     

Role of reproductive factors on the risk of endometrial cancer

We analyzed the role of reproductive factors on the risk of endometrial cancer using data from a case-control study conducted in Italy. Cases were 752 women with histologically confirmed endometrial cancer <75 years of age. Controls were 2,606 patients <75 years of age admitted for acute, non-gynecological non-hormone-related, non-neoplastic conditions to the same network of hospitals where cases had been identified. In comparison with nulliparae, the risk of endometrial cancer tended to be lower in parous women, and the estimated multivariate odds ratios (ORs) were 0.9, 0.8 and 0.7, respectively, for women reporting 1, 2 and 3 or more births (χ₁² trend 10.21). In comparison with women reporting no induced abortion, the ORs of endometrial cancer were 0.6 in women reporting 1 and 0.4 in those reporting 2 or more induced abortions. When considering parous women only, in comparison with women reporting their last birth 20 years before or longer, the ORs of endometrial cancer were 0.6 in those reporting their last birth 10–19 years before and 0.3 in those reporting their last birth <10 years before. Our results confirm and further quantify a protective role of pregnancy on the risk of endometrial cancer and provide insights on the time-risk relationship between pregnancy and cancer of corpus uteri. Int. J. Cancer 76:784–786, 1998.© 1998 Wiley-Liss, Inc.     

Menstrual and reproductive factors and risk of gastric cancer: a Norwegian cohort study

Objective:To explore relations between menstrual and reproductive factors and incidence of gastric cancer in a cohort study of 63,090 Norwegian women, followed over a period of 29 years. Methods:Associations with potential risk factors were evaluated by Poisson regression analysis, considering 572 cases of gastric cancer diagnosed in women aged less than 80 years. Results:Age at menarche showed a moderate inverse association with overall risk of gastric cancer (incidence rate ratio 0.93 per year; 95% confidence interval 0.88–1.00). No association could be established with age at menopause. Among women aged less than 50 years, an old age at first delivery was related to an increased risk, mainly of cancer of the distal part of the stomach. In multiparous women aged 50 years or more, relations with childbearing history differed significantly between subsites. Women with many pregnancies over a short period of time had an increased risk of cancer of the proximal part of the stomach. In the distal part, pregnancies over a long period seemed to confer a higher risk. Conclusions:Relations between reproductive factors and risk of gastric cancer should be assessed separately for pre- and postmenopausal women and for subsites.     

A prospective study of reproductive factors and exogenous hormone use in relation to ovarian cancer risk among Black women

Purpose

Extensive data in White women have linked oral contraceptive use, tubal ligation, and parity to reduced risk of ovarian cancer; results on postmenopausal female hormone use are mixed. Few studies, all of which are case–control studies, have been undertaken among Black women. The aim of the present study was to prospectively assess associations of reproductive factors and exogenous hormones with ovarian cancer among Black women.

Methods

During follow-up from 1995 to 2013 in the Black Women’s Health Study, a prospective cohort study, 115 incident cases of ovarian cancer were identified. Cox proportional hazards models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for the relation of the factors of interest to risk of ovarian cancer, with control for covariates.

Result

Oral contraceptive use was inversely associated with ovarian cancer risk: The HR for ≥10 years of use relative to <1 year was 0.50 (95% CI 0.30–0.98). For postmenopausal female hormone use, the HRs for ever use of estrogen with progestin and of estrogen alone were 1.37 (0.73–2.55) and 1.66 (0.90–3.07), respectively. The HRs for parity and tubal ligation were below 1.0, but were not statistically significant.

Conclusion

Overall, the findings indicate that the relation of reproductive factors and exogenous hormone use to risk of ovarian cancer is similar among Black and White women. The results on estrogen-only supplements and estrogen with progestin supplements add to evidence from Whites, indicating that use of hormone supplements may be associated with increased risk of ovarian cancer.

     

Menstrual and reproductive factors and the mortality risk of gastric cancer in Japanese menopausal females

Objective: The relationship between gastric cancer and menstrual and reproductive history was investigated for 40,535 postmenopausal females from a large-scale prospective cohort in Japan (JACC: Japan Collaborative Cohort Study for Evaluation of Cancer Risk, sponsored by Monbusho). Methods: A Cox proportional hazard model was used to estimate risk with respect to menstrual and reproductive factors for gastric cancer mortality. The effects on risk of potential confounders such as lifestyle, dietary habits, and socioeconomic status were controlled for using a stepwise procedure. Results: During the study period (mean 8.2 years), 156 deaths due to gastric cancer were identified. Longer fertility tended to be inversely associated with risk of gastric cancer mortality, although the association was not significant. Late menopause had no obvious effect on gastric cancer risk. The risk ratio of delivery experience compared to no delivery was 0.62 (95% confidence interval 0.27–1.41), and this effect was consistent regardless of the number of deliveries. Early menarche was not associated with the risk of gastric cancer. The potential confounders were not seen to have distinct effects on the associations. Conclusions: Multiparity appears to confer a protective tendency on gastric cancer mortality; however, this result is inconsistent with previous reports. Further information needs to be accumulated from epidemiological studies in order to clarify the role of reproductive factors in gastric cancer.     

Menstrual and reproductive factors and risk of soft tissue sarcomas

BACKGROUND: Soft tissue sarcomas (STS) are a heterogeneous group of neoplasms whose etiology remains largely undefined. A role for female hormones in the development of STS has been suggested. To investigate this possibility, the authors analyzed data from a hospital-based case-control study conducted in Northern Italy between 1983 and 1998. METHODS: Cases were 104 women aged < 79 years with incident STS who were admitted to the cancer institutes and major teaching and general hospitals. Controls were 505 women admitted to the same network of hospitals for acute, nonneoplastic, nongynecologic, and nonimmune-related conditions. RESULTS: The multivariate odds ratio (OR) for women aged >/= 15 years compared with those aged < 12 years at menarche was 1.94 (95% confidence intervals [95% CI], 0.80-4.74). No association with STS risk was observed for menstrual cycle pattern, age at menopause, parity, and abortions. Late age at first pregnancy and birth were found to be related to an increased risk of STS, with an OR of 3.16 (95% CI, 0. 96-10.44) and 2.79 (95%% CI, 0.79-9.90) for women aged >/= 30 years at first pregnancy and birth compared with those aged < 20 years. The trend in risk was significant for age at first pregnancy. No relation with the risk of STS emerged for age at last birth and time since first or last birth. CONCLUSIONS: The risk of STS was found to be weakly related to late age at first pregnancy or birth, but not to other menstrual and reproductive factors.