Parity, reproductive factors, and the risk of pancreatic cancer in women.
ABSTRACT Incidence rates for pancreatic cancer are consistently lower in women than in men. Previous studies suggest that reproductive factors, particularly parity, may reduce pancreatic cancer risk in women. We examined parity, breast feeding history, age at first birth, menstrual factors, and exogenous hormone use in relation to pancreatic cancer risk in a prospective cohort study of women. Information on parity and other reproductive factors was assessed by questionnaires in 1976 and updated biennially. Multivariate relative risks were adjusted for cigarette smoking, body mass index, diabetes, and height. During 22 years of follow-up (1976-1998), 115,474 women contributed 2.4 million years of person time, and 243 cases of pancreatic cancer were identified. Compared with nulliparous women, the relative risk of pancreatic cancer was 0.86 [95% confidence interval (CI), 0.55-1.36] for women with 1-2 births, 0.75 (95% CI, 0.48-1.17) for 3-4 births, and 0.58 (95% CI, 0.34-0.98) for those with >/=5 births after adjusting for other factors. An analysis for linear trend indicates a 10% reduction in risk for each birth (P(trend) = 0.008). Other reproductive factors and exogenous hormone use were not significantly related to pancreatic cancer risk. In this large prospective cohort of women, parity was associated significantly with a reduced risk of pancreatic cancer. Additional studies should examine the physiological or hormonal changes underlying pregnancy or childbirth that may explain this finding.
- SourceAvailable from: Ali Mohammad Alizadeh[Show abstract] [Hide abstract]
ABSTRACT: Oxytocin (OT) is the first peptide hormone structurally assessed and chemically synthesized in biologically active form. This hormone acts as an important factor in human reproductive system particularly during pregnancy and lactation in women. So far, different therapeutic roles for OT have been identified as a spectrum from central and peripheral actions on male and female reproductive systems, circulatory system, musculoskeletal system, etc. Some in vitro and in vivo studies also revealed that OT is responsible for bivariate biological functions involved in cancer as following. By activating OT receptor in tumoral cells, OT enacts as a growth regulator, whether activator or inhibitor. Regarding the increase of OT in some conditions such as breastfeeding, exercise, and multiparity, we can relate the effect of these conditions on cancer with OT effects. Based on this hypothesis, we present a review on the effects of this neuropeptide on various types of cancer and also the influence of these conditions on the same cancer.European Journal of Pharmacology 08/2014; 741. DOI:10.1016/j.ejphar.2014.07.053 · 2.68 Impact Factor
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ABSTRACT: Multiple studies have hypothesized parity is associated with pancreatic cancer risk but obtained conflicting results. We conducted a meta-analysis (including a dose-response approach) of current available epidemiologic studies to investigate the association between parity and risk of pancreatic cancer. Ten cohort studies and ten case-control studies including 8205 cases were eligible for inclusion. The combined RR (relative risk) of pancreatic cancer for the parous vs. nulliparous was 0.91 (95% CI, confidence interval = 0.85-0.97, I(2) = 39.0%, Ph = 0.01). We observed an inverse association between giving birth to two children pancreatic cancer risk with RR of 0.86 (95% CI = 0.80-0.93, I(2) = 8.7%, Ph = 0.36). And no evidence supported there was non-linear (P = 0.33) or linear relationship (P = 0.14) between number of parity and risk of pancreatic cancer. Findings from this meta-analysis indicate that giving birth to two children has the lowest pancreatic cancer risk, mechanism of this protective effect needs further investigation.Scientific Reports 06/2014; 4:5313. DOI:10.1038/srep05313 · 5.08 Impact Factor
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ABSTRACT: The aim of this study is to evaluate the significance of grand multiparous (GM) status in the mortality from cancers of the digestive system among a cohort of GM women in Taiwan during the period 1978-2008. The study cohort consisted of 144,922 women with at least five children (GM women) in the Taiwan Birth Register between 1 January 1978 and 31 December 2003. Standardized mortality ratios (SMRs) for cancers of the digestive system including esophagus, stomach, colon, rectum, liver, and pancreas were calculated by dividing the numbers of observed cancer deaths to the expected numbers of deaths based on the rates of national female population. Among the 144,922 GM women, a total of 23, 220, 213, 92, 397, and 65 deaths were caused by cancers of the esophagus, stomach, colon, rectum, liver, and pancreas, respectively. The SMRs among GM women were 1.61 (95% confidence intervals (CI): 0.95-2.27) for esophageal cancer, 1.15 (95% CI: 1.00-1.31) for stomach cancer, 1.07 (95% CI: 0.93-1.22) for colon cancer, 0.94 (95% CI: 0.75-1.14) for rectal cancer, 1.18 (95% CI: 1.06-1.30) for liver cancer, and 0.79 (95% CI: 0.60-0.98) for pancreatic cancer. This study provides evidence that grand multiparity may confer a protective effect on the risk of death from pancreatic cancer. However, the results suggest that GM women may increase the risk of death from cancers of the liver and stomach.International Journal of Environmental Research and Public Health 04/2014; 11(4):4374-83. DOI:10.3390/ijerph110404374 · 1.99 Impact Factor