Linear reduction in thyroid cancer risk by oral contraceptive use: a dose-response meta-analysis of prospective cohort studies

Women consuming oral contraceptives containing cyproterone acetate and ethinylestradiol show a higher risk of thyroid cancer than nonusers

This study explored whether the risk of thyroid cancer in Asian women is associated with consumption of oral contraceptives (Diane-35). We conducted a population-based, retrospective cohort study using the Taiwan National Health Insurance Research Database. From the database, 9865 women aged 18 to 65 years who were prescribed Diane-35 between 2000 and 2012 were included in the Diane-35 group, and 39,460 women who were not prescribed Diane-35 were included in the comparison group and were frequency-matched by age and index year. Both groups were followed until 2013 to calculate the incidence of thyroid cancer. Hazard ratios (HR) and 95% confidence intervals (CI) were estimated using Cox proportional hazard model. The median (standard deviation) follow-up duration was 7.08 (3.63) and 7.04 (3.64) years in the Diane-35 and the comparison group, respectively. The incidence of thyroid cancer was 1.80-fold higher in the Diane-35 group than in the comparison group (2.72 vs 1.51 per 10,000 person-years). The cumulative incidence of thyroid cancer was significantly higher in the Diane-35 group than in the comparison group (log-rank test, P = .03). An elevated hazard ratio of thyroid cancer was observed in the Diane-35 group than in the comparison group (HR: 1.91, 95% CI: 1.10-3.30). In subgroup analysis, patients aged 30 to 39 years showed a higher hazard ratio of developing thyroid cancer after consuming Diane-35 than those in the comparison group (HR: 5.58, 95% CI: 1.84-16.91). The study provides evidence that women aged 30 to 39 years consuming Diane-35 are at increased risk of thyroid cancer. Nevertheless, a larger population with a longer follow-up may be necessary to confirm causality.

DNMT3B-mediated FAM111B methylation promotes papillary thyroid tumor glycolysis, growth and metastasis

Over the past decades, the incidence of thyroid cancer (TC) rapidly increased all over the world, with the papillary thyroid cancer (PTC) accounting for the vast majority of TC cases. It is crucial to investigate novel diagnostic and therapeutic targets for PTC and explore more detailed molecular mechanisms in the carcinogenesis and progression of PTC. Based on the TCGA and GEO databases, FAM111B is downregulated in PTC tissues and predicts better prognosis in PTC patients. FAM111B suppresses the growth, migration, invasion and glycolysis of PTC both in vitro and in vivo. Furthermore, estrogen inhibits FAM111B expression by DNMT3B methylation via enhancing the recruitment of DNMT3B to FAM111B promoter. DNMT3B-mediated FAM111B methylation accelerates the growth, migration, invasion and glycolysis of PTC cells. In clinical TC patient specimens, the expression of FAM111B is inversely correlated with the expressions of DNMT3B and the glycolytic gene PGK1. Besides, the expression of FAM111B is inversely correlated while DNMT3B is positively correlated with glucose uptake in PTC patients. Our work established E2/DNMT3B/FAM111B as a crucial axis in regulating the growth and progression of PTC. Suppression of DNMT3B or promotion of FAM111B will be potential promising strategies in the estrogen induced PTC.

Hormonal Crosstalk Between Thyroid and Breast Cancer

Differentiated thyroid cancer and breast cancer account for a significant portion of endocrine-related malignancies and predominately affect women. As hormonally responsive tissues, the breast and thyroid share endocrine signaling. Breast cells are responsive to thyroid hormone signaling and are affected by altered thyroid hormone levels. Thyroid cells are responsive to sex hormones, particularly estrogen, and undergo protumorigenic processes upon estrogen stimulation. Thyroid and sex hormones also display significant transcriptional crosstalk that influences oncogenesis and treatment sensitivity. Obesity-related adipocyte alterations-adipocyte estrogen production, inflammation, feeding hormone dysregulation, and metabolic syndromes-promote hormonal alterations in breast and thyroid tissues. Environmental toxicants disrupt endocrine systems, including breast and thyroid homeostasis, and influence pathologic processes in both organs through hormone mimetic action. In this brief review, we discuss the hormonal connections between the breast and thyroid and perspectives on hormonal therapies for breast and thyroid cancer. Future research efforts should acknowledge and further explore the hormonal crosstalk of these tissues in an effort to further understand the prevalence of thyroid and breast cancer in women and to identify potential therapeutic options.

Association of Hormonal Contraceptive Use With Adverse Health Outcomes: An Umbrella Review of Meta-analyses of Randomized Clinical Trials and Cohort Studies

IMPORTANCE

Meta-analyses have reported conflicting data on the safety of hormonal contraception, but the quality of evidence for the associations between hormonal contraceptive use and adverse health outcomes has not been quantified in aggregate.

OBJECTIVE

To grade the evidence from meta-analyses of randomized clinical trials (RCTs) and cohort studies that assessed the associations between hormonal contraceptive use and adverse health outcomes among women.

DATA SOURCES

MEDLINE, Embase, and the Cochrane Database of Systematic Reviews were searched from database inception to August 2020. Search terms included hormonal contraception, contraceptive agents, progesterone, desogestrel, norethindrone, megestrol, algestone, norprogesterones, and levonorgestrel combined with terms such as systematic review or meta-analysis.

EVIDENCE REVIEW

The methodological quality of each meta-analysis was graded using the Assessment of Multiple Systematic Reviews, version 2, which rated quality as critically low, low, moderate, or high. The Grading of Recommendation, Assessment, Development and Evaluations approach was used to assess the certainty of evidence in meta-analyses of RCTs, with evidence graded as very low, low, moderate, or high. Evidence of associations from meta-analyses of cohort studies was ranked according to established criteria as nonsignificant, weak, suggestive, highly suggestive, or convincing.

RESULTS

A total of 2996 records were screened; of those, 310 full-text articles were assessed for eligibility, and 58 articles (13 meta-analyses of RCTs and 45 meta-analyses of cohort studies) were selected for evidence synthesis. Sixty associations were described in meta-analyses of RCTs, and 96 associations were described in meta-analyses of cohort studies. Among meta-analyses of RCTs, 14 of the 60 associations were nominally statistically significant (P ≤ .05); no associations between hormonal contraceptive use and adverse outcomes were supported by high-quality evidence. The association between the use of a levonorgestrel-releasing intrauterine system and reductions in endometrial polyps associated with tamoxifen use (odds ratio [OR], 0.22; 95% CI, 0.13-0.38) was graded as having high-quality evidence, and this evidence ranking was retained in the subgroup analysis. Among meta-analyses of cohort studies, 40 of the 96 associations were nominally statistically significant; however, no associations between hormonal contraceptive use and adverse outcomes were supported by convincing evidence in the primary and subgroup analyses. The risk of venous thromboembolism among those using vs not using oral contraception (OR, 2.42; 95% CI, 1.76-3.32) was initially supported by highly suggestive evidence, but this evidence was downgraded to weak in the sensitivity analysis.

CONCLUSIONS AND RELEVANCE

The results of this umbrella review supported preexisting understandings of the risks and benefits associated with hormonal contraceptive use. Overall, the associations between hormonal contraceptive use and cardiovascular risk, cancer risk, and other major adverse health outcomes were not supported by high-quality evidence.

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.

Analysis of the Association between Female Medical History and Thyroid Cancer in Women: A Cross-Sectional Study Using KoGES HEXA Data

The purpose of this study was to evaluate the association between female medical history and thyroid cancer. Methods: Data from the Korean Genome and Epidemiology Study were collected from 2004 to 2016. Among a total of 1303 participants with thyroid cancer and 106,602 control (non-thyroid cancer) participants, the odds ratios (ORs) with 95% confidence intervals (CIs) of hysterectomy, oophorectomy, use of oral contraceptives, and number of children were evaluated. Results: The adjusted OR of hysterectomy for thyroid cancer was 1.73 (95% CI = 1.48-2.01, p < 0.001) in the minimally adjusted model. The adjusted ORs for thyroid cancer were 1.89 (95% CI = 1.06-3.37, p = 0.031), 0.89 (95% CI = 0.83-0.94, p < 0.001), and 0.85 (95% CI = 0.73-0.99, p = 0.040) for bilateral oophorectomy, number of children, and use of oral contraceptives, respectively, in the fully adjusted model. In the subgroup analysis, the adjusted ORs of bilateral oophorectomy were significant in the younger age (OR = 3.62, 95% CI = 1.45-9.03, p = 0.006), while the number of children was significant in the older age (OR = 0.86, 95% CI = 0.80-0.93, p < 0.001). Conclusions: The ORs of hysterectomy and bilateral oophorectomy were significantly higher in the thyroid cancer group in the younger age group. The adjusted ORs of the number of children were significantly low in the older age group.

Reproductive Factors and Risk of Thyroid Cancer in Women: An Analysis in the Nurses' Health Study II

BACKGROUND

The incidence of thyroid cancer in women is increasing at an alarming rate, with greatest risk in the reproductive years. Establishing relationships of hormonally related reproductive factors with thyroid cancer has been difficult. We aimed to elucidate potential risk factors for thyroid cancer in a large cohort of women.

METHODS

Among 116,228 women in the Nurses' Health Study II followed from 1989 to 2013, 620 cases of thyroid cancer were identified. We examined reproductive and hormone-related factors, including age at menarche, age at menopause, parity, oral contraceptive use, and postmenopausal hormone therapy use. Pregnancy, reproductive years, and months of breastfeeding were used as surrogate markers for exposure to endogenous reproductive hormones. We used multivariable Cox models to calculate relative risks and 95% confidence intervals for the associations between these factors and risk of thyroid cancer.

RESULTS

Number of reproductive years of 41 years or more was associated with more than double the risk of thyroid cancer compared with 30 years or fewer (relative risk, 2.20; 95% confidence interval, 1.19-4.06). The other variables analyzed (parity number, months of breastfeeding, age at menarche, menopausal status, and postmenopausal hormone therapy) were not associated with the risk of thyroid cancer. Women who entered menopause at age 45 years or older had a higher risk of thyroid cancer compared with women who entered menopause at a younger age. This result did not reach statistical significance; however, there was a linear trend between later age at menopause and increased risk of thyroid cancer (p_trend = .009).

CONCLUSIONS

This study used a unique large, longitudinal dataset to assess thyroid cancer risk factors and potential confounders over an extended time frame. Our key finding suggests increased risk of thyroid cancer may be associated with a variety of indicators of longer reproductive years. The Nurses' Health Study II has provided new insights into the hormonal risks associated with thyroid cancer.

The risk of extra-ovarian malignancies among women with endometriosis: A systematic literature review and meta-analysis

We conducted a meta-analysis of studies reporting on the risk of extra-ovarian malignancies among women with endometriosis. Summary relative risk (SRR) and 95% confidence intervals (CI) were calculated through random effect models. We explored causes of between-studies heterogeneity and assessed the presence of publication bias. We included 32 studies published between 1989 and 2018. We found an increased risk of endometrial (SRR 1.38, 95%CI 1.10-1.74) and thyroid cancer (SRR 1.38, 95%CI 1.17-1.63), and inverse association with cervical cancer (SRR 0.78, 95%CI 0.60-0.95). No association emerged for breast cancer (SRR 1.04, 95%CI 0.99-1.09) and melanoma (SRR 1.31, 95%CI 0.86-1.96). Between-study heterogeneity was large for breast and endometrial cancer and melanoma. Associations were generally stronger in case-control, cross-sectional, and cohort studies with internal control group, compared to cohort studies with external control group. No indication for publication bias was found. Our conclusions need to be confirmed in properly designed cohort studies with clinical confirmation of endometriosis.

Association of Combined Estrogen-Progestogen and Progestogen-Only Contraceptives with the Development of Cancer

Combined estrogen-progestogen contraceptives (oral contraceptives or OCs) and progestogen-only contraceptives (POCs) are synthetic steroids that bind to steroid hormone receptors, which are widespread throughout the body. They have a profound effect on cellular physiology. Combined OCs have been classified by the International Agency for Research on Cancer (IARC) as Group 1 carcinogens, but their findings have not been updated recently. In order to update the information and better understand the impact that OCs and POCs have on the risk of development of cancers, a comprehensive literature search was undertaken, focusing on more recently published papers. In agreement with the IARC, the recent literature confirms an increased risk of breast cancer and cervical cancer with the use of OCs. The recent literature also confirms the IARC conclusion that OCs decrease the risk of ovarian and endometrial cancers. However, there is little support from recent studies for the IARC conclusion that OCs decrease the risk of colorectal cancer or increase the risk of liver cancer. For liver cancer, this may be due to the recent studies having been performed in areas where hepatitis is endemic. In one large observational study, POCs also appear to increase the overall risk of developing cancer. OCs and POCs appear to increase the overall risk of cancer when carefully performed studies with the least intrinsic bias are considered.

Summary

OCs have been classified as cancer-causing agents, especially leading to increases in breast cancer and cervical cancer. A review of the recent scientific literature was performed to see whether this still appears to be the case. The recent literature supports the cancer-causing role of OCs especially for breast cancer and cervical cancer. Studies also indicate that progesterone-only contraceptives (such as implants and vaginal rings) also can cause cancer. This is especially true for breast cancer and cervical cancer.

[Contraception and cancer: CNGOF Contraception Guidelines]

OBJECTIVES

To synthesize knowledge on cancer risks related to hormonal contraception and to propose recommendations on contraception during treatment and after cancer.

METHODS

A systematic review of the literature about hormonal contraception and cancer was conducted on PubMed/Medline and the Cochrane Library.

RESULTS

Overall, there is no increase in cancer (all types together) incidence or mortality among hormonal contraceptive users. Estroprogestin combined contraceptive use is associated with an increased risk of breast cancer (during use), and with a reduced risk of endometrial, ovarian, lymphatic or hematopoietic cancers that persist after discontinuation, and a decreased risk of colorectal cancer. Information on cancer risk is part of the systematic information given to patients wishing contraception. However, these data will not influence its prescription, considering the positive risk/benefit balance in women without specific cancer risk factor. Contraception is required during and after cancer treatment in every non-menopausal woman at cancer diagnosis. Specific thromboembolic, immunologic or vomiting risks due to the oncological context should be taken into account before the contraceptive choice. All hormonal contraceptives are contra-indicated after breast cancer, regardless of the delay since treatment, hormone receptor status and histological subtype. There is no data in the literature to limit hormonal or non-hormonal contraceptive use after colorectal or thyroid cancer. There was insufficient data in the literature to propose recommendations on contraceptive choice after cervical cancer, melanoma, lung cancer, tumor of the central nervous system, or after thoracic irradiation. If an emergency contraception is needed in a woman previously treated for a hormone-sensitive cancer, a non-hormonal copper intrauterine device should be preferred.

CONCLUSIONS

Information on cancer risk is part of the patient's information but does not influence the prescription of contraception in the absence of any specific risk factor. Contraception should be proposed in every woman treated or previously treated for cancer. The whole context should be taken into account to choose a tailored contraception.

Oral Contraceptive Use and Risks of Cancer in the NIH-AARP Diet and Health Study

Although use of oral contraceptives (OCs) is common, their influence on carcinogenesis is not fully understood. We used Cox proportional hazards models to examine OC use (never/<1 year (referent), 1-4, 5-9, ≥10 years) and development of incident cancers across body sites within the same base population: women in the prospective National Institutes of Health-AARP Diet and Health Study (enrolled 1995-1996 and followed until 2011). Adjustment for confounding varied by outcome; all models accounted for age, race, body mass index, and smoking status, and included at least 100,000 women. Any OC use conferred a 3% reduction in the risk for any cancer (hazard ratio = 0.97, 95% confidence interval: 0.95, 0.99). Expected risk reductions that strengthened with duration of use were identified for ovarian and endometrial cancers and were suggested for kidney cancer (all P for trend < 0.05). Non-Hodgkin lymphoma risk (hazard ratio = 0.79, 95% confidence interval: 0.64, 0.97) was reduced with 10 or more years of OC use. There was a 37% reduced risk for bladder cancer and 46% increased risk for pancreatic cancer among long-term OC users who were 60 years of age or younger at baseline. OC use did not influence risks for most other cancers evaluated. Given the high prevalence of use and changing formulations, additional studies are warranted to fully understand the chemopreventive effects of these medications.

Cholesterol consumption and risk of endometrial cancer: a systematic review and dose-response meta-analysis of observational studies

In vivo and in vitro studies have indicated the link of cholesterol consumption and endometrial cancer risk, however, previous observational studies have yielded inconsistent results. Additionally, a previous meta-analysis published in 2007 found limited evidence of aforementioned association. Therefore, we performed the dose-response meta-analysis to address this concern. Studies were identified using the PubMed, EMBASE and Web of Science databases from the database inception to the end of June 2015 as well as by examining the references of retrieved articles. Two authors independently performed the eligibility evaluation and data extraction. The summary risk estimates and 95% confidence intervals (CIs) were summarized by the random-effects models. One cohort and nine case-control studies were included in the dose-response analyses. Risk of endometrial cancer increased by 6% for 100 mg/day increment in the dietary consumption of cholesterol (Odds ratio (OR) = 1.06; 95% CI = 1.00–1.12), with significant heterogeneity (I² = 64.2, P = 0.003). When stratified by study design, the result was significant in case-control studies (OR = 1.07; 95% CI = 1.01–1.13). Additionally, although the direction of the associations were consistent in the subgroup analyses stratified by study characteristics and adjustment for potential confounders, not all of them showed statistical significance. In summary, findings of the present dose-response meta-analysis partly support the positive association between dietary cholesterol consumption and risk of endometrial cancer. Since only one cohort study was included, more prospective studies and pooled analysis of observational studies are warranted to confirm our findings in the future.

Assessing the Role of Reversible Contraceptives in the Health Care of Women as it Pertains to Cancer Prevention

The use of effective and reversible contraception is characterized by many non-contraceptive benefits distinct from its ability to prevent pregnancy. Notably, the use of hormonal and non-hormonal birth control methods is known to impact the risk for developing certain female genital cancers as well as breast and colon cancers. We present here the current understanding of the role of effective and reversible contraceptives in the prevention and development of female genital cancers along with breast and colon cancers. Despite ongoing but unsubstantiated concerns regarding the use of hormonal and intrauterine contraceptives for a variety of clinical outcomes including cancer, contraceptive use in high- and low-risk reproductive-aged women remains an important part of cancer risk reduction for many malignancies.

Use of acetaminophen and risk of endometrial cancer: evidence from observational studies

Previous meta-analyses suggested that aspirin was associated with reduced risk of endometrial cancer. However, there has been no study comprehensively summarize the evidence of acetaminophen use and risk of endometrial cancer from observational studies. We systematically searched electronic databases (PubMed , EMBASE, Web of Science, and Cochrane Library) for relevant cohort or case-control studies up to February 28, 2017. Two independent authors performed the eligibility evaluation and data extraction. All differences were resolved by discussion. A random-effects model was applied to estimate summary relative risks (RRs) with 95% CIs. All statistical tests were two-sided. Seven observational studies including four prospective cohort studies and three case-control studies with 3874 endometrial cancer cases were included for final analysis. Compared with never use acetaminophen, ever use this drug was not associated with risk of endometrial cancer (summarized RR = 1.02; 95% CI: 0.93-1.13, I2 = 0%). Similar null association was also observed when compared the highest category of frequency/duration with never use acetaminophen (summarized RR = 0.88; 95% CI: 0.70-1.11, I2 = 15.2%). Additionally, the finding was robust in the subgroup analyses stratified by study characteristics and adjustment for potential confounders and risk factors. There was no evidence of publication bias by a visual inspection of a funnel plot and formal statistical tests. In summary, the present meta-analysis reveals no association between acetaminophen use and risk of endometrial cancer. More large scale prospective cohort studies are warranted to confirm our findings and carry out the dose-response analysis of aforementioned association.

Statin use and breast cancer survival and risk: a systematic review and meta-analysis

The purpose of this study is to determine the associations between statin use and breast cancer survival and risk by performing a systematic review and meta-analysis. We searched PubMed, Embase and Web of Science up to August 2015 for identifying relevant prospective or case-control studies, or randomized clinical trials. Five prospective studies involving 60,911 patients reported the association between statin use and breast cancer mortality. Eleven prospective studies, 12 case-control studies and 9 randomized clinical trials involving 83,919 patients reported the association between statin use and breast cancer risk. After pooling estimates from all available studies, there was a significantly negative association between pre-diagnosis statin use and breast cancer mortality (for overall survival (OS): hazard ratio (HR) = 0.68, 95% confidence interval (CI) 0.54–0.84; for disease specific survival (DSS): HR = 0.72, 95% CI 0.53–0.99). There was also a significant inverse association between post-diagnosis statin use and breast cancer DSS (HR = 0.65, 95% CI 0.43–0.98), although the association with breast cancer OS did not reach statistical significance (HR = 0.71, 95% CI 0.48–1.07). Additionally, there was a non-linear relationship for the duration of post-diagnosis statin use with breast cancer specific mortality. On the other hand, with regards to the relationship between statin use and breast cancer risk, no significant association was detected. Our analyses suggest that although statin use may not influence breast cancer risk, the use of statin may be associated with decrease mortality of breast cancer patients. Further large-scale studies are warranted to validate our findings.

Parity and thyroid cancer risk: a meta-analysis of epidemiological studies

Although observational studies have assessed the relationship between parity and thyroid cancer risk, the findings are inconsistent. To quantitatively assess the association, we conducted a systematic review and meta-analysis. PubMed and Embase were searched up to January 2015. Prospective or case-control studies that evaluated the association between parity and thyroid cancer risk were included. We used the fixed-effects model to pool risk estimates. After literature search, 10 prospective studies, 12 case-control studies and 1 pooled analysis of 14 case-control studies including 8860 patients were identified. The studies had fair methodological quality. Pooled analysis suggested that there was a significant association between parity and risk of thyroid cancer (RR for parous versus nulliparous: 1.09, 95% CI 1.03-1.15; I2=33.4%). The positive association persisted in almost all strata of subgroup analyses based on study design, location, study quality, type of controls, and confounder adjustment, although in some strata statistical significance was not detected. By evaluating the number of parity, we identified that both parity number of 2 versus nulliparous and parity number of 3 versus nulliparous demonstrated significant positive associations (RR=1.11, 95% CI 1.01-1.22; I2=31.1% and RR=1.16, 95% CI 1.01-1.33; I2=19.6% respectively). The dose-response analysis suggested neither a non-linear nor linear relationship between the number of parity and thyroid cancer risk. In conclusion, this meta-analysis suggests a potential association between parity and risk of thyroid cancer in females. However, the lack of detection of a dose-response relationship suggests that further studies are needed to better understand the relationship.

Breastfeeding and thyroid cancer risk in women: A dose-response meta-analysis of epidemiological studies

BACKGROUND & AIMS

The association between breastfeeding and thyroid cancer risk is not consistent from epidemiological studies. To better clarify the association including assessing a potential dose-response relationship, we conducted a comprehensive meta-analysis.

METHODS

We searched PubMed (MEDLINE) up to November 2015 for prospective studies or case-control studies that evaluated the association between breastfeeding and risk of thyroid cancer. Effect estimates were pooled using a fixed-effects model.

RESULTS

Nine reports (2 prospective studies, 6 case-control studies and 1 pooled analysis of 14 case-control studies) involving 2423 cases and 350,081 non-cases were identified. After pooling relevant studies, there was a significant inverse association between ever breastfeeding and risk of thyroid cancer (RR = 0.91, 95% CI 0.83-0.99), with minor heterogeneity (I(2) = 10.1%). The dose-response analysis revealed a significant linear relationship between the duration of breastfeeding and risk of thyroid cancer. The summary RR for an increment of 1 month of breastfeeding with risk of thyroid cancer was 0.983 (95% CI 0.98-0.99). When focusing on cohort studies, a more prominent linear dose-response relationship was detected, with the combined RR for every increment of 1 month of breastfeeding to be 0.965 (95% CI 0.96-0.97).

CONCLUSIONS

This meta-analysis suggests that breastfeeding is potentially inversely associated with thyroid cancer risk. Also longer duration of breastfeeding may further decreases thyroid cancer risk. If validated in large-scale prospective studies, our findings may have implications for impacting women's decision in breastfeeding.

Efficacy of Ligustrazine Injection as Adjunctive Therapy for Angina Pectoris: A Systematic Review and Meta-Analysis

Background

In the past decades, a large number of randomized controlled trials (RCTs) on the efficacy of ligustrazine injection combined with conventional antianginal drugs for angina pectoris have been reported. However, these RCTs have not been evaluated in accordance with PRISMA systematic review standards. The aim of this study was to evaluate the efficacy of ligustrazine injection as adjunctive therapy for angina pectoris.

Material/Methods

The databases PubMed, Medline, Cochrane Library, Embase, Sino-Med, Wanfang Databases, Chinese Scientific Journal Database, Google Scholar, Chinese Biomedical Literature Database, China National Knowledge Infrastructure, and the Chinese Science Citation Database were searched for published RCTs. Meta-analysis was performed on the primary outcome measures, including the improvements of electrocardiography (ECG) and the reductions in angina symptoms. Sensitivity and subgroup analysis based on the M score (the refined Jadad scores) were also used to evaluate the effect of quality, sample size, and publication year of the included RCTs on the overall effect of ligustrazine injection.

Results

Eleven RCTs involving 870 patients with angina pectoris were selected in this study. Compared with conventional antianginal drugs alone, ligustrazine injection combined with antianginal drugs significantly increased the efficacy in symptom improvement (odds ratio [OR], 3.59; 95% confidence interval [CI]: 2.39 to 5.40) and in ECG improvement (OR, 3.42; 95% CI: 2.33 to 5.01). Sensitivity and subgroup analysis also confirmed that ligustrazine injection had better effect in the treatment of angina pectoris as adjunctive therapy.

Conclusions

The 11 eligible RCTs indicated that ligustrazine injection as adjunctive therapy was more effective than antianginal drugs alone. However, due to the low quality of included RCTs, more rigorously designed RCTs were still needed to verify the effects of ligustrazine injection as adjunctive therapy for angina pectoris.

Dietary fat intake and endometrial cancer risk: dose-response meta-analysis of epidemiological studies

Epidemiological studies have provided controversial evidence of the association between dietary fat intake and endometrial cancer (EC) risk. To address this inconsistency, we conducted this dose-response meta-analysis by total dietary fat intake, based on epidemiological studies published up to the end of June 2015 identified from PubMed, EMBASE and Web of Science. Two authors (RH and Q-JW) independently performed the eligibility evaluation and data extraction. All differences were resolved by discussion with the third investigator (LJ). Random-effects models were used to estimate summary relative risks (RRs) and 95% confidence intervals (CIs). Overall, the search yielded 16 studies (6 cohort and 10 case-control studies) that involved a total of 7556 EC cases and 563,781 non-cases. The summary RR for EC for each 30g/day increment intake was 0.98 (95%CI = 0.95–1.001; I² = 0%; n = 11) for total dietary fat. Non-significant results were observed in plant-based fat (summary RR = 1.05, 95%CI = 0.94–1.18; I² = 0%; n = 5) and animal-based fat (summary RR = 1.17, 95%CI = 0.92–1.36; I² = 85.0%; n = 6). Additionally, the null associations were observed in almost all the subgroup and sensitivity analyses. In conclusion, findings of the present meta-analysis suggested a lack of association between total dietary fat intake and EC risk. Further studies, especially prospective designed studies are warranted to confirm our findings.

Parity and endometrial cancer risk: a meta-analysis of epidemiological studies

The association between parity and endometrial cancer risk is inconsistent from observational studies. We aimed to quantitatively assess the relationship by summarizing all relevant epidemiological studies. PubMed (MEDLINE), Embase and Scopus were searched up to February 2015 for eligible case–control studies and prospective studies. Random-effects model was used to pool risk estimations. Ten prospective studies, 35 case-control studies and 1 pooled analysis of 10 cohort and 14 case-control studies including 69681 patients were identified. Pooled analysis revealed that there was a significant inverse association between parity and risk of endometrial cancer (relative risk (RR) for parous versus nulliparous: 0.69, 95% confidence interval (CI) 0.65–0.74; I² = 76.9%). By evaluating the number of parity, we identified that parity number of 1, 2 or 3 versus nulliparous demonstrated significant negative association (RR = 0.73, 95% CI 0.64–0.84, I² = 88.3%; RR = 0.62, 95% CI 0.53–0.74, I² = 92.1%; and RR = 0.68, 95% CI 0.65–0.70, I² = 20.0% respectively). The dose-response analysis suggested a nonlinear relationship between the number of parity and endometrial cancer risk. The RR decreased when the number of parity increased. This meta-analysis suggests that parity may be associated with a decreased risk of endometrial cancer. Further studies are warranted to replicate our findings.