Reproductive factors, exogenous hormone use, and risk of pancreatic cancer in postmenopausal women

Association of Menopausal Hormone Therapy with Risk of Pancreatic Cancer: A Systematic Review and Meta-analysis of Cohort Studies

BACKGROUND

Although menopausal hormone therapy (MHT) is commonly prescribed, little is known about the association between MHT use and risk of pancreatic cancer.

METHODS

We searched PubMed, Embase, and Cochrane Library, from inception until April 20, 2022. The risk of bias was assessed with the Newcastle-Ottawa Quality Assessment Scale. Pooled relative risks (RR) for pancreatic cancer risk were calculated using random-effects models. We computed prediction intervals (PI) and performed subgroup meta-analyses. Meta-regression was performed to investigate the sources of heterogeneity.

RESULTS

This study included 2,712,313 women from 11 cohort studies. There was no association between MHT and pancreatic cancer risk (RR, 0.92; 95% confidence interval (CI), 0.83-1.02; I2, 64%; 95% PI, 0.68-1.25). Subgroup meta-analyses of four studies stratified by MHT formulations showed inverse associations with the risk of pancreatic cancer (women receiving estrogen-only MHT: RR, 0.77; 95% CI, 0.64-0.94; I2, 57%; estrogen plus progestin MHT: RR, 0.85; 95% CI, 0.75-0.96; I2, 0%). Subgroup analysis defined by recency and duration of treatment did not reveal evidence of associations between MHT and pancreatic cancer risk.

CONCLUSIONS

This study found no association between the overall use of MHT and risk of pancreatic cancer. However, among four studies with data on MHT formulations, subgroup analysis showed a decreased risk of pancreatic cancer among users of estrogen-only and combined estrogen-progestin therapy. Owing to the inconsistent findings between our main and subgroup analyses, future studies stratified by MHT formulations are warranted.

IMPACT

The findings of this study indicate that future investigation should focus on MHT formulations.

Common variability in oestrogen-related genes and pancreatic ductal adenocarcinoma risk in women

The incidence of pancreatic ductal adenocarcinoma (PDAC) is different among males and females. This disparity cannot be fully explained by the difference in terms of exposure to known risk factors; therefore, the lower incidence in women could be attributed to sex-specific hormones. A two-phase association study was conducted in 12,387 female subjects (5436 PDAC cases and 6951 controls) to assess the effect on risk of developing PDAC of single nucleotide polymorphisms (SNPs) in 208 genes involved in oestrogen and pregnenolone biosynthesis and oestrogen-mediated signalling. In the discovery phase 14 polymorphisms showed a statistically significant association (P < 0.05). In the replication none of the findings were validated. In addition, a gene-based analysis was performed on the 208 selected genes. Four genes (NR5A2, MED1, NCOA2 and RUNX1) were associated with PDAC risk, but only NR5A2 showed an association (P = 4.08 × 10-5) below the Bonferroni-corrected threshold of statistical significance. In conclusion, despite differences in incidence between males and females, our study did not identify an effect of common polymorphisms in the oestrogen and pregnenolone pathways in relation to PDAC susceptibility. However, we validated the previously reported association between NR5A2 gene variants and PDAC risk.

Use of oral contraceptives and risk of pancreatic cancer in women: A recalculated meta-analysis of prospective cohort studies

In a recent systematic review and meta-analysis of observational studies, the author found potential errors in the selection and extraction processes. The recalculated summary relative risks and the results of a dose-response meta-analysis showed that oral contraceptive use may not be associated with the risk of pancreatic cancer in women.

Association between oral contraceptive use and pancreatic cancer risk: A systematic review and meta-analysis

BACKGROUND

Studies on the association of oral contraceptive (OC) use and pancreatic cancer showed inconsistent findings.

AIM

To evaluate the relationship between OC use and pancreatic cancer risk.

METHODS

A literature search for observational studies (case-control and cohort studies) was conducted up to December 2020. A meta-analysis was performed by calculating pooled relative risks (RRs) and 95% confidence intervals (CIs). Heterogeneity was assessed using Cochran’s chi-square test and I² statistic. Subgroup analyses were performed by study design, source of controls in case-control studies, number of cases of pancreatic cancers, study quality according to Newcastle-Ottawa Scale score, geographical region and menopausal status. All analyses were performed using Review Manager 5.3 (RevMan 5.3).

RESULTS

A total of 21 studies (10 case-control studies and 11 cohort studies) were finally included in the present meta-analysis, comprising 7700 cases of pancreatic cancer in total. A significant association was observed between the ever use of OC and pancreatic cancer risk in the overall analysis (RR = 0.85; 95%CI = 0.73-0.98; P = 0.03). Duration of OC use (< 1 year, < 5 years, 5-10 years, > 10 years) was not significantly associated with the risk of pancreatic cancer. Subgroup analyses revealed a statistically significant subgroup difference for the geographic region in which the study was conducted (Europe vs Americas vs Asia; P = 0.07). Subgroup analyses showed a statistically significant decrease in pancreatic cancer risk and OC use in high-quality studies, studies conducted in Europe, and in postmenopausal women.

CONCLUSION

Despite the suggested protective effects of OC use in this meta-analysis, further epidemiological studies are warranted to fully elucidate the association between the use of OC and pancreatic cancer risk.

Reproductive Factors, Use of Exogenous Hormones, and Pancreatic Cancer Incidence: The Norwegian Women and Cancer Study

Introduction

The incidence of pancreatic cancer is increasing worldwide and characterized by a particularly low survival rate. Studies have reported weak and inconsistent evidence for associations among reproductive factors, use of exogenous hormones, and pancreatic cancer incidence in women.

Purpose

To investigate relationships between reproductive factors, exogenous hormones, and the rate of pancreatic cancer incidence in a large population-based prospective cohort of women in Norway.

Methods

We used data from the Norwegian Women and Cancer study on 588 incident cases of pancreatic cancer diagnosed among 165,419 women, with mean follow-up of 18.7 years. Cox proportional-hazard models were used to estimate HRs and 95% CIs for associations of interest.

Results

Cumulative breastfeeding duration >24 months was associated with 63% decreased incidence of pancreatic cancer compared to no breastfeeding. We observed an inverse linear dose–response trend between cumulative breastfeeding duration and pancreatic cancer incidence, which was confirmed in parous women and ever-smokers. Higher age at first birth and menopause were inversely associated with pancreatic cancer incidence, though with less precise effect estimates. Current use of oral contraceptives was associated with a doubling of pancreatic cancer incidence, but the analysis was hampered by a small number of cases. There was no evidence of any associations between age at menarche, parity or use of menopausal hormone therapy, and incidence of pancreatic cancer.

Conclusion

Our results suggest a potential protective effect of breastfeeding duration against pancreatic cancer incidence. Inconsistent results for the other reproductive factors suggested no important role of estrogens in pancreatic cancer etiology.

Gynecological and reproductive factors and the risk of pancreatic cancer: A case-control study

BACKGROUND

/Objectives: Pancreatic ductal adenocarcinoma (PDAC) has a higher incidence in men compared to women, although the difference in known risk factors cannot explain this disparity completely. Reproductive and hormonal factors have been demonstrated in pre-clinical studies to influence pancreatic carcinogenesis, but the few published data on the topic are inconsistent. The aim was to investigate the role of reproductive and hormonal factors on PDAC occurrence in women.

METHODS

We conducted a unicenter case-control study; PDAC cases were matched to controls by age with a 1:2 ratio. Risk factors were screened through questionnaires about gynecologic and medical history. Comparisons were made using Chi-square and Fisher's exact tests where appropriate for categorical variables and Student's t-test for continuous variables. Logistic regression was used to calculate Odds Ratios (ORs) and their 95% confidence intervals (CI). Multivariable logistic regression models were adjusted for potential confounders.

RESULTS

253 PDAC and 506 matched controls were enrolled. At logistic regression multivariable analysis adjusted for confounding factors, older age at menopause (OR:0.95 per year; 95% CI:0.91-0.98; p = 0.007), use of Oral Contraceptives (OR:0.52; 95% CI:0.30-0.89; p = 0.018), use of Hormonal Replacement Therapy (OR:0.31; 95% CI:0.15-0.64; p = 0.001), and having had two children (OR:0.57; 95% CI:0.38-0.84; p = 0.005) were significant, independent protective factors for the onset of PDAC.

CONCLUSIONS

These data confirm some previous findings on menopause age and number of births while, to our knowledge, this is the first study to show a protective effect of HRT and OC use. The results collectively support the hypothesis that exposure to estrogens plays a protective role towards PDAC.

Hormonal contraceptive use and risk of pancreatic cancer-A cohort study among premenopausal women

IMPORTANCE

The association between the use of hormonal contraceptive and pancreatic cancer among premenopausal women has until now been unclear. This is the first study to investigate the risk of pancreatic cancer in pre-menopausal women.

OBJECTIVE

To determine whether hormonal contraception increases the risk of developing pancreatic cancer in pre-menopausal women.

DESIGN

A nationwide prospective cohort study followed all women in Denmark in the age range of 15-49 years without previous cancer or venous thrombosis from 1995 to 2014. The Danish National Prescription Registry provided individually updated exposure information on use of hormonal contraception. The Danish Cancer Registry provided cancer diagnoses, and the Danish National Patient Register containing clinical diagnoses and surgical codes at discharge from public and private hospitals.

SETTING

Population-based cohort study.

PARTICIPANTS

All women living in Denmark aged 15-49 years at January 1st, 1995, and those subsequently reaching age 15 years up to December 31st, 2014 were eligible for the study.

RESULTS

Among 1.9 million women who were followed on average for 11.4 years, 235 pancreatic cancers occurred. Compared to never users, ever users of any type of hormonal contraception had a relative risk (RR) of pancreatic cancer of 0.90 (95% confidence interval (CI) 0.68-1.19). No overall association between duration of hormonal contraceptive use and pancreatic cancer risk was found. Neither was long-term use of hormonal contraception associated with pancreas cancer, RR 0.83 (95% CI 0.47-1.50). The risk did not vary between users of combined and progestogen-only products. All models were adjusted for age, completed or ongoing education, polycystic ovary syndrome, endometriosis and among parous women; parity, age at first birth, smoking and body mass index.

CONCLUSIONS AND RELEVANCE

Compared to never users the risk of pancreatic cancer is not significantly higher among current and recent users of contemporary hormonal contraception and does not vary between users of combined and progestogen-only products. In conclusion, our study suggests no risk of pancreatic cancer with use of any type of hormonal contraception.

Pancreatic Cancer and Obesity: Molecular Mechanisms of Cell Transformation and Chemoresistance

Cancer and obesity are the two major epidemics of the 21st century. Pancreatic ductal adenocarcinoma (PDAC) is one of the leading causes of death, with a five-year overall survival rate of only 8%. Its incidence and mortality have increased in recent years, and this cancer type is expected to be among the top five leading causes of cancer-related death by 2030 in the United States (US). In the last three decades, the prevalence of overweight people has boosted with a consequent increase in obesity-related diseases. Considerable epidemiologic evidence correlates overweight and obese conditions to an increased risk of several types of cancer, including PDAC. Besides being a risk factor for multiple metabolic disorders, the tumor-promoting effects of obesity occur at the local level via inflammatory mediators that are associated with adipose inflammation and metabolic or hormones mediators and microbiota dysbiosis. Although an excess of body mass index (BMI) represents the second most modifiable risk factor for PDAC with an increased cancer related-death of more than 20–40%, still little is known about the molecular mechanisms that underlie this strong association. In this review, we focused on the role of obesity as a preventable risk factor of PDAC, discussing the molecular mechanisms linking obesity to cancer initiation and progression. Moreover, we highlighted the role of obesity in defining chemoresistance, showing how a high BMI can actually reduce response to chemotherapy.

Menstrual and Reproductive Factors and Risk of Pancreatic Cancer in Women

BACKGROUND

Pancreatic cancer (PC) is a deadly disease with a 5-year survival of less than 5%. Worldwide PC incidence rates are lower among women than men. While this suggests a protective role for steroid hormones in PC risk, results from epidemiological studies are not consistent.

METHODS

153 new incident PC cases and 202 controls were recruited from a prospective case–control study, running in a referral center for endoscopic ultrasonography during 2011-2017. A structured valid and reliable questionnaire was used for data collection by a few trained interviewers. Odds ratios and 95% confidence intervals for reproductive factors and PC were estimated using logistic regression methods.

RESULTS

Mean age (SD) of the cases and the controls were 63.18 (11.4) and 63.37 (12.0) years, respectively. Age at menarche, age at menopause, number of parity, gravidity, and abortion were not associated with PC risk.

CONCLUSION

This study does not support the hypothesis that menstrual and reproductive factors are associated with PC risk.