The association of oral contraception with kidney cancer, colon cancer, gallbladder cancer (including extrahepatic bile duct cancer) and pituitary tumours

The Relationship Between Hormone Replacement Therapy and Risk of Kidney Cancer in Women: A Meta-Analysis

Results from the epidemiologic studies on the relationship between hormone replacement therapy (HRT) and the risk of kidney cancer in women were not completely consistent. This meta-analysis aimed to evaluate the relationship between HRT and risk of kidney cancer in women. We performed a meta-analysis of observational studies to assess this association. The PubMed and Embase databases were searched from their inception to January 29, 2020, to identify relevant studies that fit the pre-stated inclusion criteria; reference lists from the retrieved articles were also been reviewed. Relative risks (RRs) with corresponding 95% CIs were extracted and combined using random effects models. Furthermore, dose-response, sensitivity analyses, publication bias, and subgroup analysis by study design, regional location, and exposure assessment method were conducted. Thirteen articles involving 6 cohort studies and 8 case-control studies were included in our meta-analysis. Overall, 4194 women were diagnosed with kidney cancer among 648 107 participants. The pooled RR for kidney cancer was 1.08 (95% CI: 0.96-1.22) in those who were administered HRT compared to those who had not. Subgroup analysis indicated the overall result was not influenced by study type, regional location, or adjusted variables. Dose-response analysis showed a nonlinear relationship between HRT and kidney cancer (P = .0021) and the risk of kidney cancer decreased by 15% to 28% with 12 to 18 years of HRT use. No evidence of publication bias was found (P for Egger =.111). Our meta-analysis showed that HRT use is inversely associated with kidney cancer risk in a dose-dependent fashion.

Parity and risk of death from gallbladder cancer among a cohort of premenopausal parous women in Taiwan

Little epidemiologic research has been done on the etiology of gallbladder cancer (GC). This cohort study was undertaken to examine whether there is an association between parity and risk of death from GC. The study cohort consisted of 1,292,462 women who had a first and singleton childbirth between 1 January 1978 and 31 December 1987. We tracked each woman from the time of their first childbirth to 31 December 2009, and their vital status was ascertained by linking records with the computerized mortality database. Cox proportional hazard regression models were used to estimate the hazard ratios (HR) of death from GC associated with parity. There were 257 GC deaths during 34,980,246 person-years of follow-up. The mortality rate of GC was 0.73 cases per 100,000 person-years. As compared with women who had given birth to only one child, the adjusted HR was 1.20 (95% CI = 0.79–1.83) for women who had two children, 1.47 (95% CI = 0.95–2.29) for women who had three children, and 1.68 (95% CI = 0.99–2.85) for women with four or more births. There was a significant increasing trend in the adjusted HRs for GC with increasing parity. The findings suggested that premenopausal women of higher parity may increase the risk of death from GC.

Risk factors for gallbladder cancer and cholangiocarcinoma: similarities, differences and updates

INTRODUCTION

Far-ranging variation in the incidence of gallbladder cancer (GBC) and cholangiocarcinoma (CCA) in different geographic regions on the globe may reflect the risk factor distribution for these tumors

METHODS

The authors give a comprehensive review on the known risk factors for GBC and CCA, and analyze both similarities and differences between the risk factors for the two main types of biliary cancer

DISCUSSION AND CONCLUSION

Leading risk factors for GBC include gallstones, female gender, and advancing age. Primary sclerosing cholangitis, nitrosamine exposure, choledochal cysts, Clonorchis sinensis and Opisthorchis viverrini represent important risk factors for CCA, although a specific risk factor cannot be identified for many patients. While both cancers affect mostly individuals in their sixth decade or older, CCA has a male predominance and GBC--a predilection for females. Although the current level of understanding of the molecular pathogenesis of GBC and CCA at the interface with specific risk factors is significantly lower than for other gastrointestinal malignancies, it continues to evolve and may soon open new avenues for the therapy of biliary cancers.

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

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(> or =3 vs 1 child)=2.0, 95% confidence interval (CI) 0.7-5.1), younger age at first birth (OR(per 1-year decrease)=1.2, 95% CI 0.99-1.6), and older age at menarche (OR(per 1-year increase)=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.

Use of oral contraceptives, intrauterine devices and tubal sterilization and cancer risk in a large prospective study, from 1996 to 2006

The association of contraceptive methods, including oral contraceptives (OC), intrauterine devices (IUD) and tubal sterilization (TS), with overall and site-specific cancer were prospectively investigated in a cohort of 66,661 Chinese women in Shanghai, 76.7% of whom used contraception. During a median follow-up time of 7.5 years, 2,250 women were diagnosed with cancer. Ever-use of any contraceptive method was not associated with overall cancer risk [adjusted hazard ratio (HR(adj)) = 1.02, 95% CI, 0.92-1.12]. Use of any contraceptive method was associated with increased risk of rectal cancer (HR(adj) = 1.68, 95% CI, 1.08-2.62) and reduced risk of thyroid cancer (HR(adj) = 0.63, 95% CI, 0.38-1.04). Risk of gallbladder cancer increased with ever use of OC (HR(adj) = 2.38, 95% CI, 1.26-4.49). IUD use was associated with a possible reduced risk of thyroid cancer (HR(adj) = 0.64, 95% CI, 0.38-1.07). Longer duration of IUD use decreased risk for breast, thyroid and lung cancers. Ever having a TS was associated with increased uterine body cancer (HR(adj) = 2.50, 95% CI, 1.47-4.25) and decreased risk of stomach cancer (HR(adj) = 0.59, 95% CI, 0.39-0.91). We did not find any contraceptive method to be related to the risk of ovarian cancer but the analyses were based on few events. Although chance findings are a likely explanation for some of the associations found in our study, these findings suggest that various contraceptive methods or reproductive patterns may play a role in the etiology of cancer.

Variants in hormone-related genes and the risk of biliary tract cancers and stones: a population-based study in China

Biliary tract cancers, encompassing gallbladder, extrahepatic bile duct and ampulla of Vater cancers, are uncommon but often fatal malignancies. Hormone-related factors, including parity, oral contraceptive use, obesity, and gallstones, have been implicated in the etiology of these cancers. To further clarify the role of hormones in biliary tract cancers and biliary stones, we genotyped 18 single-nucleotide polymorphisms (SNPs) in nine genes involved in steroid hormone biosynthesis, metabolism and transport in a population-based case-control study in Shanghai, China. This study included subjects who completed an interview and provided blood, which totaled 411 biliary tract cancer and 893 biliary stone patients and 786 healthy Shanghai residents. The CYP1A1 IVS1 + 606 (rs2606345) T allele was associated with gallbladder [odds ratio (OR) = 2.0, 95% confidence interval (CI), 1.3-3.0] and bile duct cancers (OR = 1.8, 95% CI = 1.1-3.1), whereas the CYP1A1 Ex7 + 131 (rs1048943) G allele was associated with ampulla of Vater cancer (OR = 2.9, 95% CI = 1.5-5.4). After taking into account multiple comparisons for SNPs within each gene, CYP1A1 was significantly associated with gallbladder (P = 0.004) and ampulla of Vater cancers (P = 0.01), but borderline with bile duct cancer (P = 0.06). The effect of CYP1A1 IVS1 + 606 on gallbladder cancer was more pronounced among non-obese (body mass index < 23) (OR = 3.3, 95% CI = 1.8-6.1; P interaction = 0.001). Among women taking oral contraceptives, the effect of SHBG Ex8 + 6 (rs6259) on gallbladder cancer (OR = 6.7, 95% CI = 2.2-20.5; P interaction = 0.001) and stones (OR = 2.3, 95% CI = 1.1-4.9; P-interaction = 0.05) was statistically significant. Our findings suggest that common variants in hormone-related genes contribute to the risk of biliary tract cancers and stones, possibly by modulating hormone metabolism.

International renal-cell cancer study. V. Reproductive factors, gynecologic operations and exogenous hormones

The relationships between reproductive factors, exogenous hormones and renal-cell cancer were examined in an international, multicenter, population-based, case-control study undertaken in 1989-1991. Data from 5 centers situated in Australia, Denmark, Germany, Sweden and the United States included for analysis 608 women with renal-cell cancer and 766 female controls. A significant trend in risk (p = 0.002) was associated with number of births, with an 80% excess risk for 6 or more births [RR = 1.8, 95% confidence interval (CI) = 1.1 to 2.9] compared with one birth. A decreasing risk was seen for increasing age at first birth, although this was confounded by body-mass index and number of births. A suggestive reduction of risk was also seen for increasing age at menarche. Age at menopause was unrelated to risk of renal-cell cancer. An increased risk was observed for women having had both a hysterectomy and an oophorectomy. Use of oral contraceptives in non-smoking women reduced the risk of renal-cell cancer (RR = 0.5, 95% CI = 0.4 to 0.8); this reduction increased with longer duration of use. No association was observed for estrogen replacement therapy. Our results indicate that certain hormonal and reproductive variables may be related to risk of renal-cell cancer and deserve further investigation, both epidemiologically and experimentally.

Reproductive factors and the risk of renal cell cancer among women

In etiologic studies of renal cell carcinoma the role of reproductive variables and the use of exogenous hormones have not been well examined. In a population-based case-control study including 165 female cases and 227 controls, we assessed the risk of renal cell cancer associated with reproductive factors and use of oral contraceptives and menopausal hormones. Odds ratios were computed using logistic regression analyses. Risk was positively associated with number of births and inversely associated with age at first birth, with the largest increases in risk (more than 2-fold) among women with 5 or more births after age 25. After adjustment for age, smoking status, body mass index and age at first birth, women with 5 or more births had a 2-fold risk (OR = 2.2, 95% CI = 1.2-4.0) relative to those with 1 or 2 births. Age at first birth, however, was no longer a risk factor when the number of births was adjusted for. The association with parity was considerably stronger among women with a history of hypertension or above-median body mass index than among those without these conditions. In addition, risk was reduced among long-term oral contraceptive users but elevated among women who had had a hysterectomy or used menopausal hormones. Our findings suggest that reproductive factors, particularly the number of births, may play an etiologic role in renal cell cancer among women and deserve further study.

Contraceptive choices for women with endocrine complications

Previous confusion regarding the interference by oral contraceptives in measurements of endocrine function have been largely eliminated by the advent of improved, more sensitive assays. There are few if any contraindications to oral contraceptive use in patients with thyroid disease. Patients with prolactinoma can be treated with bromocriptine to restore fertility and prevent mineral loss. However, as a less expensive alternative, oral contraceptives can be prescribed to correct mineral loss, because there is no convincing evidence of an adverse effect on prolactinomas by the steroidal content of the pill. Oral contraceptives comprise a near ideal treatment modality for women with polycystic ovary disease because, among other effects, oral contraceptives reduce synthesis of androgen by inhibiting pituitary gonadotropin secretion.

Risk factors for kidney cancer in New South Wales, Australia. II. Urologic disease, hypertension, obesity, and hormonal factors

In a population-based case-control study of kidney cancer in New South Wales, Australia, data from structured interviews with 489 cases of renal cell cancer (RCC) and 147 cases of renal pelvic cancer (CaRP) diagnosed in 1989 and 1990, and 523 controls from the electoral rolls, confirmed the link between obesity and RCC. In addition, regular consumption of 'diet' pills independently increased the risk for this cancer. A diagnosis of hypertension at least two years before interview raised the risk for RCC, and regular use of beta-blockers, a class of antihypertensive drug, independently increased the risk for RCC and CaRP (risk ratio = 1.5-1.8). No independent effect was found for use of diuretics. Additional information provided by this study includes increased risks associated with kidney injury (RCC, CaRP)--possibly attributed to recall bias--and kidney infection (CaRP), as well as a nonsignificantly raised risk linked with kidney stones (RCC, CaRP) and a significantly reduced risk for RCC in persons giving a history of lower urinary tract infection. No significant association of RCC was found with hormonal factors (age at menarche or menopause; child-bearing; regular use of oral contraceptives or estrogens; hysterectomy or oophorectomy).