A pooled multisite analysis of the effects of female reproductive hormones on glioma risk

Nero. Society of Family Planning Clinical Recommendation: Contraceptive considerations for individuals with cancer and cancer survivors part 3 - Skin, blood, gastrointestinal, liver, lung, central nervous system, and other cancers: Joint with the Society of Gynecologic Oncology

This Clinical Recommendation provides evidence-informed, person-centered, and equity-driven recommendations to facilitate the management of and access to contraception care for individuals who are diagnosed with, being actively treated for, or who have previously been treated for skin, blood, gastrointestinal, liver, lung, central nervous system, and other cancers. For individuals with a history of nonmelanoma skin cancers, we recommend clinicians provide access to all available contraceptive methods utilizing a person-centered approach (GRADE 1B). Based on expert opinion, for individuals with a history of melanoma who are considering hormonal contraception, we suggest shared decision-making with the individual and their oncologist (GRADE 2C). For individuals with a history of myeloproliferative neoplasms, lymphatic or hematopoietic cancer, and hematopoietic stem cell transplantation, we recommend clinicians provide access to all contraceptive methods (GRADE 1B); we suggest shared decision-making in those with follicular lymphoma subtype of non-Hodgkin lymphoma who are considering hormonal contraception (GRADE 2C). For individuals with a history of colorectal, pancreatic, esophageal, and gastric cancer, we recommend clinicians provide access to all available contraceptive methods (GRADE 1C). We recommend clinicians provide access to all available contraceptive methods in individuals with a history of primary hepatocellular carcinoma with normal liver function (GRADE 1C); with severely altered liver function, we recommend nonhormonal and progestin-only contraceptives as first-line contraceptive methods (GRADE 1B). For individuals with a history of glioma, we recommend clinicians provide access to all available contraceptives (GRADE 1B). For individuals with a history of meningioma who request hormonal contraception, we recommend shared decision-making with the individual and their oncologist (GRADE 2B). We recommend clinicians provide access to all available contraceptive options for individuals with a history of or active bladder, kidney, thyroid, head and neck squamous cell, and soft tissue sarcomas (GRADE 1B). This document is part 3 of a three-part series that updates the Society of Family Planning's 2012 Cancer and contraception clinical guidance. It builds upon the considerations outlined in the Society of Family Planning Committee Statement: Contraceptive considerations for individuals with cancer and cancer survivors part 1 - Key considerations for clinical care and parallels recommendations outlined in the Society of Family Planning Clinical Recommendation: Contraceptive considerations for individuals with cancer and cancer survivors part 2 - Breast, ovarian, uterine, and cervical cancer. Readers are encouraged to review parts 1 and 2 for this additional context.

Association between hormone therapy and glioma risk in US women: a cancer screening trial

OBJECTIVE

Gliomas are the most common primary brain tumors in adults, and the role of hormone therapy (HT) in their development remains controversial. This study with a cohort design aimed to investigate the association between HT use and glioma risk using the data from the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial.

METHODS

We analyzed data from 75,335 women, aged 50-78, who were enrolled between 1993 and 2001. The median follow-up period was 11.82 years. Cox proportional hazard models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the relationship between HT use and glioma risk, adjusting for various potential confounders.

RESULTS

Over the follow-up period, 101 participants were diagnosed with glioma. After adjusting for relevant variables, there was no significant association between HT use and glioma risk (HR, 1.16; 95% CI, 0.75-1.81). Similarly, no significant associations were found when considering HT status or duration of use. However, in subgroup analysis by education, marital status, body mass index, oral contraceptive, hysterectomy, ovariectomy, ever been pregnant, age at menarche, and age at menopause, we found that a significant positive association was only observed in the group with at least college graduate (HR, 3.00; 95% CI, 1.02-8.84). The interaction effect for education was not significant ( P = 0.056).

CONCLUSIONS

Our findings suggest no overall link between HT use and glioma risk. Further research is needed to confirm these results.

Does exogenous hormonal therapy affect the risk of glioma among females: A systematic review and meta-analysis

Background

The effect of exogenous hormone replacement therapy (HRT) and oral contraceptive pills (OCPs) on glioma risk in females is unclear despite numerous studies; hence, we conducted a meta-analysis to evaluate this relationship.

Methods

Studies investigating the impact of exogenous female hormones on glioma risk were retrieved by searching 4 databases from inception until September 2022. Articles of any design, such as case-control and cohort studies, proving the relative risk (RR), odds ratio (OR), or hazard ratio were included. Summary OR values were calculated using a random effects model.

Results

Both HRT and OCP use of any duration decreased the risk of developing glioma [HRT OR = 0.78, 95% CI 0.66-0.91, P = .00; OCP: OR = 0.80, 95% CI 0.67-0.96, P = .02]. When stratified by duration of use, HRT use >1 year significantly reduced glioma risk (<1 year: OR = 0.82, 95% CI 0.63-1.07, P = 0.15; 1-5 years: OR = 0.79, 95% CI 0.67-0.92, P = .00; 5-10 years: OR = 0.80, 95% CI 0.66-0.97, P = .02; >10 years: OR = 0.69, 95% CI 0.54-0.88, P = .00). In contrast, only OCP use for >10 years significantly reduced glioma risk (<1 year: OR = 0.72, 95% CI 0.49-1.05, P = .09; 1-5 years: OR = 0.88, 95% CI 0.72-1.02, P = .09; 5-10 years: OR = 0.85, 95% CI 0.65-1.1, P = 0.21; >10 years: OR = 0.58, 95% CI 0.45-0.74, P = .00).

Conclusions

Our pooled results strongly suggest that sustained HRT and OCP use is associated with reduced risk of glioma development.

Prospective investigation of herpesvirus infection and risk of glioma

Glioma is an aggressive neoplasm of the brain with poorly understood etiology. A limited number of pathogens have been examined as glioma risk factors, but data from prospective studies with infection status determined before disease are lacking. Herpesviruses comprise a large family of DNA viruses that infect humans and are linked to a range of chronic diseases. We conducted a prospective evaluation of the association between antibody to six human herpesviruses and glioma risk in the Janus Serum Bank (Janus) and the Cancer Prevention Study-II (CPS-II). In Janus and CPS-II, the risk for glioma was not related to seroprevalence of herpes simplex virus-1, varicella zoster virus, or human herpes viruses 6A or 6B. In Janus, seropositivity to either the Epstein Barr virus (EBV) EA[D] or VCAp18 antigen was associated with a lower risk of glioma (ORs: 0.55 [95% CI 0.32-0.94] and 0.57 [95% CI 0.38-0.85]). This inverse association was consistent by histologic subtype and was observed for gliomas diagnosed up to two decades following antibody measurement. In Janus, seropositivity to at least one of three examined cytomegalovirus (CMV) antigens (pp150, pp52, pp28) was associated with an increased risk of nonglioblastoma (OR: 2.08 [95% CI 1.07-4.03]). This association was limited to tumors diagnosed within 12 years of antibody measurement. In summary, we report evidence of an inverse association between exposure to EBV and glioma. We further report that CMV exposure may be related to a higher likelihood of the nonglioblastoma subtype.

Oral Contraceptive and Glioma Risk: A Prospective Cohort Study and Meta-Analysis

Background

Epidemiological evidence that glioma has a slight male predominance implies that factors associated with sex hormones may play a role in the development of glioma. The association between oral contraceptive (OC) use and glioma risk remains controversial.

Method

In the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial of 70,516 women in the USA, Cox proportional hazards regression analyses were adopted to calculate the crude and adjusted hazard ratios (HRs) and 95% confidence intervals (CIs). Additionally, a meta-analysis combining the PLCO findings with those of other prospective cohorts was performed.

Results

During a mean follow-up of ~11.7 years, 110 of 70,516 women aged 50–78 years at baseline were diagnosed with glioma in PLCO studies. Compared with never users, an inverse association of borderline significance was found for OC users (HR 0.67, 95% CI 0.44–1.04, P = 0.074). Analyses assessing glioma risk according to the duration of OC use yielded no significant association. When PLCO was combined with four other prospective studies, there was an inverse association between OC use and glioma risk (HR 0.85, 95% CI 0.75–0.97, I² = 0.0%). Further dose-response analysis showed a nonlinear, inverse relationship between OC use and glioma risk (P < 0.001).

Conclusions

This study provided some evidence of a nonlinear, inverse association between OC use and glioma risk. Future larger studies are warranted to validate this finding.

Toxoplasma gondii infection and the risk of adult glioma in two prospective studies

Toxoplasma gondii (T gondii) is a common parasite that shows affinity to neural tissue and may lead to the formation of cysts in the brain. Previous epidemiologic studies have suggested an association between glioma and increased prevalence of T gondii infection, but prospective studies are lacking. Therefore, we examined the association between prediagnostic T gondii antibodies and risk of glioma in two prospective cohorts using a nested case-control study design. Cases and matched controls were selected from the American Cancer Society's Cancer Prevention Study-II Nutrition Cohort (CPSII-NC) (n = 37 cases and 74 controls) and the Norwegian Cancer Registry's Janus Serum Bank (Janus) (n = 323 cases and 323 controls). Blood samples collected prior to diagnosis were analyzed for antibodies to two T gondii surface antigens (p22 and sag-1), with individuals considered seropositive if antibodies to either antigen were detected. Conditional logistic regression was used to calculate odds ratios (OR) and 95% confidence intervals (95% CI) for each cohort. In both cohorts, a suggestive increase in glioma risk was observed among those infected with T gondii (OR: 2.70; 95% CI: 0.96-7.62 for CPSII-NC; OR: 1.32, 95% CI: 0.85-2.07 for Janus), particularly among participants with high antibody titers specific to the sag-1 antigen (CPSII-NC OR: 3.35, 95% CI: 0.99-11.38; Janus OR: 1.79, 95% CI: 1.02-3.14). Our findings provide the first prospective evidence of an association between T gondii infection and risk of glioma. Further studies with larger case numbers are needed to confirm a potential etiologic role for T gondii in glioma.

Prospective investigation of polyomavirus infection and the risk of adult glioma

Glioma is an aggressive primary tumor of the brain with a poorly understood etiology. We studied the association of 4 human polyomaviruses (HPyV)—JC virus (JCV), BK virus (BKV), human polyomavirus 6 (HPyV6), and Merkel cell polyomavirus (MCPyV) with glioma risk within the Cancer Prevention Study II in the US (CPS-II) and the Janus Serum Bank in Norway. Cohort participants subsequently diagnosed with glioma from the CPS-II (n = 37) and Janus Serum Bank (n = 323), a median of 6.9 and 15.4 years after blood collection, respectively, were matched to individual controls on age, sex, and date of blood draw. Serum antibodies to the major viral capsid protein (VP1) were used to establish infection history for each polyomavirus. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using conditional logistic regression. In the Janus Serum Bank, MCPyV infection was associated with a higher risk of glioma overall (OR: 1.56; 95% CI 1.10, 2.19). A modest, nonsignificant positive association with MCPyV infection was also observed in CPS-II (OR: 1.29; 95% CI 0.54, 3.08). In both cohorts, glioma risk was not significantly related to infection with JCV, BKV or HPyV6. The present study suggests that MCPyV infection may increase glioma risk.

Relationship Between Oral Contraceptives and the Risk of Gliomas and Meningiomas: A Dose-Response Meta-Analysis and Systematic Review

OBJECTIVE

Glioma and meningioma are the most common primary brain tumors in adults. Epidemiologic studies of the relationship between female hormone exposure and exogenous hormone use and the risk of meningioma and glioma in females have yielded inconsistent results.

METHODS

Two investigators comprehensively searched 3 electronic databases, including PubMed, Embase, and Cochrane Library. A total of 11 case-control studies were enrolled for meta-analysis. Dose-response meta-analyses were conducted.

RESULTS

Compared with the non-oral contraceptives (OCs) female users, the female OC users might have reduced risk of glioma (risk ratio [RR], 0.87; 95% confidence interval [CI], 0.77-0.97; I² = 42.6%). However, there was no obvious evidence of an association between OC use and the risk of meningioma in females (RR, 0.99; 95% CI, 0.87-1.13; I² = 42.7%). Using OCs for >10 years in females may significantly decrease the risk of glioma to 30% (RR, 0.7; 95% CI, 0.6-0.81; I² = 0%). The dose-response meta-analyses indicated that the risk of glioma in females significantly decreased when the duration of oral OC use was >7.5 years.

CONCLUSIONS

OC use may not increase the risks of glioma and meningioma in females. Instead, the long-term use of OCs may significantly decrease the risk of glioma, and the benefits are even more pronounced when the time window is >7.5 years. Nonetheless, the pooled results in this study suggest that OC use may not increase the risk of meningioma. Therefore, our conclusion should be validated and supplemented in future larger studies.

Sex Hormones and Optic Nerve Disorders: A Review

Aim: This review article presents a comprehensive overview of the literature on sex hormones (estrogens, androgens, progesterone) and optic nerve disorders, with a discussion of the implications for therapy and prevention.

Methods: Epidemiological, pre-clinical and clinical studies were reviewed.

Results: Analysis of the biological basis for a relationship between eye diseases and sex hormones showed that some types of hormones can exert a protective effect either directly on the retina and optic nerve or indirectly by modulating ocular blood flow. For example, it seems that estrogen exposure has a protective effect against glaucoma, whereas its deficit may lead to early onset of the disease. If further studies confirm the data in the literature, estrogen therapy, because of its antioxidant action, may be effective in the treatment of Leber's hereditary optic neuropathy, whereas, in the light of current studies, there does not seem to be an influence of estrogen on non-arteritic anterior ischemic optic neuritis (NAION).

Conclusions: Although there is some evidence that in some optic nerve pathologies the sex hormones seem to play an important role there are still too few studies providing evidence for its wider use in clinical practice.

Toenail selenium, genetic variation in selenoenzymes and risk and outcome in glioma

BACKGROUND

Selenium is an essential trace element obtained through diet that plays a critical role in DNA synthesis and protection from oxidative damage. Selenium intake and polymorphisms in selenoproteins have been linked to the risk of certain cancers though data for glioma are sparse.

METHODS

In a case-control study of glioma, we examined the associations of selenium in toenails and genetic variants in the selenoenzyme pathway with the risk of glioma and patient survival. A total of 423 genetic variants in 29 candidate genes in the selenoenzyme pathway were studied in 1547 glioma cases and 1014 healthy controls. Genetic associations were also examined in the UK Biobank cohort comprised of 313,868 persons with 322 incident glioma cases. Toenail selenium was measured in a subcohort of 300 glioma cases and 300 age-matched controls from the case-control study.

RESULTS

None of the 423 variants studied were consistently associated with glioma risk in the case-control and cohort studies. Moreover, toenail selenium in the case-control study had no significant association with glioma risk (p trend = 0.70) or patient survival among 254 patients with high grade tumors (p trend = 0.70).

CONCLUSION

The present study offers no support for the hypothesis that selenium plays a role in the onset of glioma or patient outcome.

Older age at the completion of linear growth is associated with an increased risk of adult glioma

PURPOSE

To examine the association of age when adult height was attained with glioma risk.

METHODS

We analyzed data from a US-based case-control study of glioma risk factors. Logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CI) associated between age at attainment of adult height and glioma risk. Multivariate models were adjusted for age, race, sex, education, and state of residence. We examined associations overall, and according to glioma grade, sex, and final adult height.

RESULTS

The study set included n = 951 controls and n = 776 cases, with a median age of 56 (18-92); the majority was male (53.8%) and identified as Caucasian. Older age at height completion was associated with an increased risk of glioma. A significant positive trend was observed both for glioblastoma (OR 1.10; 95% CI 1.04-1.17 per 1-year increase in age) and lower grade non-glioblastoma subtypes combined (OR 1.18; 95% CI 1.10-1.28 per year increase in age). The association was observed in men and women, and in all categories of final adult height.

CONCLUSIONS

We observed for the first time a positive association between glioma risk and a prolonged adolescent growth phase. Our results suggest a role for factors governing the timing and intensity of growth in adolescence as risk-determining exposures in adult glioma.

Descriptive epidemiology and risk factors of primary central nervous system tumors: Current knowledge

Although comparisons are difficult due to differences in methodologies, the annual incidence rates of central nervous system (CNS) tumors range from 8.5 to 21.4/100,000 population according to cancer registries, with a predominance of neuroepithelial tumors in men and meningiomas in women. An increase in the incidence of CNS tumors has been observed during the past decades in several countries. It has been suggested that this trend could be due to aging of the population, and improvements in diagnostic imaging and healthcare access, but these factors do not explain differences in incidence by gender and histological subtypes. Several etiological hypotheses related to intrinsic (sociodemographic, anthropometric, hormonal, immunological, genetic) and exogenous (ionizing radiation, electromagnetic fields, diet, infections, pesticides, drugs) risk factors have led to analytical epidemiological studies to establish relationships with CNS tumors. The only established environmental risk factor for CNS tumors is ionizing radiation exposure. However, for other risk factors, studies have been inconsistent and inconclusive due to systematic differences in study design and difficulties in accurately measuring exposures. Thus, the etiology of CNS tumors is complex and may involve several genetic and/or environmental factors that may act differently according to histological subtype.