Reproductive factors and risks of biliary tract cancers and stones: a population-based study in Shanghai, China

Abstract

BACKGROUND: Parity has been linked to gallbladder cancer and gallstones, but the effects of other reproductive factors are less clear. METHODS: We examined 361 incident biliary tract cancer cases, 647 biliary stone cases, and 586 healthy women in a population-based study in Shanghai. RESULTS: The effects of parity (odds ratios, OR X3 vs 1 child ¼ 2.0, 95% confidence interval (CI) 0.7 -5.1), younger age at first birth (OR per 1-year decrease ¼ 1.2, 95% CI 0.99 -1.6), and older age at menarche (OR per 1-year increase ¼ 1.4, 95% CI 1.1 -1.8) on gallbladder cancer risk were more pronounced among women with stones, but the interactions were not significant. CONCLUSION: Our results provide support for high parity, younger age at first birth, and late age at menarche in the development of gallbladder cancer, particularly among women with biliary stones.

Number of parity and the risk of gallbladder cancer: a systematic review and dose–response meta-analysis of observational studies

“…Recent evidence from epidemiological studies has suggested that reproductive factors may be an important risk factor for GBC development [7,8]. A recent populationbased study in Sweden confirmed that high parity and sex hormones may play a role in the etiology of GBC [9].…”

“…After the initial screening, eighteen potentially relevant full publications [8][9][10][11][12][13][18][19][20][21][22][23][24][25][26][27][28][29] were identified from 1412 articles. One publication [24] was considered a conference abstract and was, therefore, excluded from the analysis.…”

“…In another epidemiological cohort in 2015, a positive association was observed between parity and mortality risk for GBC among young parous women [7]. Additionally, several studies have been published on parity and risk of GBC, but the results of these studies have not been consistency [8,[10][11][12][13][14][15]. Hence, the relationship between parity and GBC still remains controversial.…”

Exogenous estrogen and the risk of biliary tract cancer – a population-based study in a cohort of Swedish men treated for prostate cancer

“…Most epidemiological studies assessing the association of endogenous estrogen and BTC have found that factors associated with prolonged exposure to estrogen, i.e. high parity, younger age at birth of the first child, younger age at menarche, increase the risk of BTC [8,9,12].…”

“…The mechanism behind this sex difference is unknown but it has been hypothesized that exposure to female sex hormones, such as estrogen, might increase this risk [8]. Previous epidemiologic studies addressing this hypothesis have mainly investigated reproductive factors or menstrual history in women, and it seems that high parity and young age at the first birth may increase the risk of BTC [8][9][10][11][12]. However, a recent study by our research group did not support this hypothesis for EHCC, but the role of sex hormones in the risk of GBC could not be ruled out [13].…”