Gestational diabetes mellitus and risk of incident primary cancer: A population-based retrospective cohort study

Associations between Diabetes Mellitus and Selected Cancers

Cancer is one of the major causes of mortality and is the second leading cause of death. Diabetes mellitus is a serious and growing problem worldwide, and its prevalence continues to grow; it is the 12th leading cause of death. An association between diabetes mellitus and cancer has been suggested for more than 100 years. Diabetes is a common disease diagnosed among patients with cancer, and evidence indicates that approximately 8-18% of patients with cancer have diabetes, with investigations suggesting an association between diabetes and some particular cancers, increasing the risk for developing cancers such as pancreatic, liver, colon, breast, stomach, and a few others. Breast and colorectal cancers have increased from 20% to 30% and there is a 97% increased risk of intrahepatic cholangiocarcinoma or endometrial cancer. On the other hand, a number of cancers and cancer therapies increase the risk of diabetes mellitus. Complications due to diabetes in patients with cancer may influence the choice of cancer therapy. Unfortunately, the mechanisms of the associations between diabetes mellitus and cancer are still unknown. The aim of this review is to summarize the association of diabetes mellitus with selected cancers and update the evidence on the underlying mechanisms of this association.

The Relationship Between Gestational Diabetes and the Risk of Cancer: A Systematic Review

Gestational diabetes mellitus (GDM) is one of the most common endocrine disorders to occur during pregnancy due to the increase in circulating human placental lactogen (hPL) and possible beta-cell sensitivity. While GDM can be managed either with diet and exercise or pharmacological interventions, it is associated with significant maternal and neonatal complications. Maternal complications include short- and long-term conditions such as pre-eclampsia, preterm birth, arrest of labor, future development of type 2 diabetes mellitus (T2DM), and cardiovascular disorders. Neonates can develop hypoglycemia and hypocalcemia and have a large gestational age (LGA). New research has also highlighted another possible long-term complication for both mothers and offspring, which is the development of cancer. Cancer has various types of progression, but most cause systemic symptoms leading to a reduced quality of life. Cancer can be terminal and can affect the majority of the population; thus, significant effort is being employed to try and reduce its occurrence. This systematic review was conducted with adherence to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines using PubMed, ScienceDirect, and ProQuest databases. Initially, 136,019 publications were identified. Through the screening process, a total of 27 publications were finalized within the scope of this paper. Most studies observing maternal cancer with a history of GDM found that there was an association between the increased risk of cancer and GDM. Specifically, these studies identified the association of GDM with breast, ovarian, cervical, and uterine cancer, as well as other non-reproductive organs such as the thyroid and pancreas. Cancer development in the offspring also presented an association with mothers who developed GDM. The most prevalent cancer evaluated was leukemia, and it was specifically associated with a maternal history of GDM. With the consistent rise in the incidence of cancer, any attempts to reduce its development are imperative to assess. While GDM is essentially a temporary condition that resolves following pregnancy in most patients, the possibility of contributing to future conditions years after its occurrence creates a sense of urgency and necessity to reduce the incidence of GDM. Researchers should be able to identify other unknown biomarkers that contribute to the development of cancer in mothers who experienced GDM as well as their infants.

Long-Term Follow-Up on Morbidity Among Women With a History of Gestational Diabetes Mellitus: A Systematic Review

BACKGROUND

Gestational diabetes mellitus (GDM) complicates up to 10% of pregnancies and is a well-known risk factor for type 2 diabetes mellitus (T2DM) and cardiovascular disease. Little is known about possible long-term risks of other diseases.

BACKGROUND

The aim was to review the literature for evidence of associations with morbidity other than T2DM and cardiovascular disease and with long-term mortality.

METHODS

A systematic review based on searches in Medline, Embase, and Cochrane Library until March 31, 2021, using a broad range of keywords. We extracted study characteristics and results on associations between GDM and disease occurrence at least 10 years postpartum, excluding studies on women with diabetes prior to pregnancy or only diabetes prior to outcome. The results are reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Newcastle-Ottawa Scale was used to assess risk of bias.

RESULTS

We screened 3084 titles, 81 articles were assessed full-text, and 15 included in the review. The strongest evidence for an association was for kidney diseases, particularly in Black women. We found indication of an association with liver disease, possibly restricted to women with T2DM postpartum. The association between GDM and breast cancer had been studied extensively, but in most cases based on self-reported diagnosis and with conflicting results. Only sparse and inconsistent results were found for other cancers. No study on thyroid diseases was found, and no study reported on short-term or long-term mortality in women with a history of GDM.

CONCLUSION

Given the frequency of GDM, there is a need for better evidence on possible long-term health consequences, in particular, studies based on comprehensive records of diagnosis of GDM and long-term health outcomes.

Different types of diabetes mellitus and risk of thyroid cancer: A meta-analysis of cohort studies

OBJECTIVE

Sex-specific thyroid cancer risk exists in patients diagnosed with diabetes mellitus (DM). However, thyroid cancer risk in different types of DM is still unclear. This meta-analysis aims to identify the real correlation between different types of DM and thyroid cancer risk in both sexes.

METHODS

Studies were identified by an electronic search of PubMed, EMBASE, and Cochrane Library on 16 January 2022. A random-effects model was used to estimate the relative risks (RRs). The Cochran's Q and I² statistics were computed to detect heterogeneity between studies.

RESULTS

In comparison with non-DM counterparts, patients with DM had a 1.32-fold higher risk of thyroid cancer (95% CI, 1.22-1.44) with 1.26-fold (95% CI, 1.12-1.41) in men and 1.36-fold (95% CI, 1.22-1.52) in women, respectively. Subgroup analysis by the type of DM showed that the RR of thyroid cancer in patients with type 2 diabetes was 1.34 (95% CI, 1.17-1.53) in the study population with 1.32 (95% CI, 1.12-1.54) in men and 1.37 (95% CI, 1.12-1.68) in women, respectively; the RR of thyroid cancer was 1.30 (95% CI, 1.17-1.43) in patients with gestational diabetes; the risk of thyroid cancer in patients with type 1 diabetes was 1.51-fold in women but not in men. Although there were some heterogeneities, it did not affect the above results of this study.

CONCLUSION

This study indicates that, compared with non-DM individuals, patients with any type of DM have an elevated thyroid cancer risk. This positive correlation between type 2 diabetes and thyroid cancer risk exists in both men and women.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/prospero/, CRD42022304028.

Is Gestational Diabetes Mellitus a Risk Factor of Maternal Breast Cancer? A Systematic Review of the Literature

The association between gestational diabetes mellitus (GDM) and breast cancer (BC) risk is complex. We aimed to examine this association in a systematic review of the literature. This review was done using the PubMed/Medline and Web of Science databases, in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The Newcastle-Ottawa Scale was used for the assessment of bias and quality of studies. Only English-language articles published before 1 June 2021, were included. Fourteen studies were included in this systematic review. Among them, eight did not find statistically significant results. Three studies showed a statistically significant increased risk of BC after GDM, and they explained this potential increased risk by hyperinsulinemia, hyperglycemia, and low-grade inflammation. However, three studies showed a statistically significant decreased risk of BC after GDM, suggesting a possible protective effect of hormonal changes induced by GDM during pregnancy. These controversial results should be interpreted with caution due to both quantitative and qualitative methodological shortcomings. Further investigations are thus needed in order to gain a better understanding of the associations between GDM and BC, and their underlying mechanisms.

Correlation Analysis of Breast and Thyroid Nodules: A Cross-Sectional Study

Objective

Based on physical examination, to explore the relationship between breast mass (BM) and thyroid nodule (TN) prevalence, and to further explore other related factors that affect the occurrence of BM and TN.

Methods

From January 1, 2018, to January 1, 2021, 12,538 female subjects received breast and thyroid ultrasound examinations at the same time in the health examination center of the Affiliated Hospital of North Sichuan Medical College. Univariate analysis and multivariate logistic analysis were used to screen the relevant factors affecting TN and BM, and propensity score matching was used to further verify the results of the relationship between breast and thyroid.

Results

A total of 4975 (39.7%) of the included subjects have BM and a total of 6315 (50.4%) have TN,2557 (20.4%) had both BM and TN. The logistic regression results show that patients with TN are more likely to suffer from BM [OR = 1.185, 95% CI (1.099-1.278), p<0.0001]. In addition, age, free T4, HDL, height, BMI, systolic blood pressure, diastolic blood pressure, and albumin are independent factors affecting the occurrence of BM; patients with BM are more likely to have TN [OR = 1.180, 95% CI (1.094-1.272), p<0.0001], and age, free T3, free T4, AST, ALT, albumin, height, and BMI are independent influencing factors on the occurrence of TN. The result of propensity score matching confirmed the relationship between BM and TN.

Conclusion

There is a bidirectional pathogenic relationship between BM and TN, women with BM are at increased risk of TN, and women with TN are more likely to have BM. Thyroid hormone is not only related to the occurrence of TN but also affects the occurrence of BM.

Gestational diabetes mellitus and risks of gynecologic cancers: Results from a nationwide Swedish twin study

BACKGROUND

Type 2 diabetes has been associated with increased risk of gynecologic cancers, yet the effect of gestational diabetes mellitus (GDM) on gynecologic cancers is unclear.

OBJECTIVES

To examine associations between GDM history and subsequent gynecologic cancers in parous women, and to explore whether gestational hypertension (GH) plays a role in the associations.

STUDY DESIGN

The population-based cohort study included 15,941 individuals from the Swedish Twin Registry. The history of GDM and GH was ascertained based on self-reports. Incident cases of gynecologic cancers (including cancers of the cervix, uterus, ovaries and other female genitalia) were obtained from the National Patients Registry and the Swedish Cancer Registry. Generalized estimating equation models were applied to analyze associations between GDM and gynecologic cancers. Stratified analysis was used to explore whether associations between GDM and gynecologic cancers differed by GH. Additive and multiplicative interactions were calculated between GDM and GH.

RESULTS

Of all participants, 350 (2.2%) had GDM, and 1762 (11.1%) had incident gynecologic cancers. No statistically significant associations were found between GDM and risks of any gynecologic cancers. However, GDM was associated with an increased risk of ovarian cancer (OR = 5.29, 95% CI: 1.63-17.19) in women with GH. Interactions between GDM and GH were observed on the additive scale (Attributable proportion due to interaction: 0.86, 95% CI 0.42-1.30, P < 0.001).

CONCLUSIONS

The associations between GDM and risks of gynecologic cancers were not evident, but the effect of GDM on the risk of ovarian cancer was modified by GH. Further validation in larger cohorts is warranted.

Complications of Pregnancy and the Risk of Developing Endometrial or Ovarian Cancer: A Case-Control Study

BACKGROUND

The association of complications of pregnancy and the risk of developing gynecological cancer is controversial with the limited study. In this study, we investigated the association of preeclampsia, or gestational diabetes mellitus (GDM), or large for gestational age (LGA), or intrauterine growth restriction (IUGR) and the risk of endometrial or ovarian cancer.

METHODS

In this case-control study, 189 women with endometrial cancer and 119 women with ovarian cancer were included. 342 women without gynecological cancers were randomly selected as a control group. Data on the history of pregnancy and age at diagnosis of gynecological cancer as well as the use of intrauterine devices (IUDs) were collected.

RESULTS

Women with a history of preeclampsia or IUGR did not have an increased risk of developing endometrial or ovarian cancer. While women with a history of GDM or with the delivery of LGA infant increased the risk of developing endometrial cancer but not ovarian cancer. The odds of women with a history of GDM or with the delivery of LGA infant developing endometrial cancer was 2.691 (95% CI: 1.548, 4.3635, p=0.0003), or 6.383 (95% CI: 2.812, 13.68, p<0.0001) respectively, compared to the controls. The odds ratio of women who did not use IUDs developing ovarian cancer was 1.606 (95% CI: 1.057, 2.434), compared to the controls. There was no association of age at first birth and developing endometrial or ovarian cancer.

CONCLUSION

Our observational data suggested that GDM and delivery of an LGA infant are associated with an increased risk of endometrial cancer.

Diabetes mellitus and the risk of ovarian cancer: a systematic review and meta-analysis of cohort and case-control studies

OBJECTIVE

Emerging evidence from observational studies (cohort and case-control studies) suggests that a history of diabetes mellitus (DM) has been linked to increased risk of ovarian cancer (OC), but the association between them remains inconclusive. The aim of this systematic review and meta-analysis of observational studies was to clarify this association.

DESIGN

Systematic review and meta-analysis.

METHODS

We searched PubMed, Embase and the Cochrane library databases published from the inception through 9 April 2020 without language restriction. Observational studies that evaluated the correlation between DM and the incidence of OC were included in our study. Relative risk (RR) with 95% CI was pooled by use of a random-effects model.

RESULTS

A total of 36 epidemiological articles, including 9 case-control and 27 cohort studies, were finally enrolled, consisting of 14 496 incident cases of OC. Synthesised RRs of developing OC by history of DM were 1.20 (95% CI=1.10 to 1.31) for all eligible studies, 1.08 (95% CI=0.77 to 1.53) for case-control studies and 1.22 (95% CI=1.11 to 1.33) for cohort studies. The above-mentioned positive association persisted across most of subgroup analyses, whereas it was not significant among studies from North American and European countries, level of unadjusted, and patients with low-quality and gestational DM group. The cumulative meta-analysis and sensitivity analysis showed pooled effect was stable and reliable, and no apparent publication bias was identified in this study.

CONCLUSIONS

Our study found weaker but still association between DM and OC risk. However, further well-designed prospective studies that control for potential confounders are warranted.

The association between gestational diabetes mellitus and cancer in women: A systematic review and meta-analysis of observational studies

AIM

Both type 1 and type 2 diabetes are associated with greater risk of a variety of cancers. However, the association between gestational diabetes mellitus (GDM) and risk of cancer has so far not been well addressed. This study aimed to summarize the epidemiological evidence of the association between GDM and subsequent risk of cancer.

METHODS

PubMed and Embase databases were searched for relevant studies, and a random-effects model was used to calculate the summary relative risks (RRs) along with the corresponding 95% confidence intervals (CIs).

RESULTS

A total of 17 observational studies were selected, comprising 7 case-control and 10 cohort studies. Pooled effect estimates retrieved from these 17 studies showed that GDM was associated with an increased risk of breast cancer in Asia (pooled RR: 1.31, 95% CI: 1.01-1.70), but not in other regions, and also with thyroid cancer (RR: 1.28, 95% CI: 1.16-1.42), stomach cancer (RR: 1.43, 95% CI: 1.02-2.00) and liver cancer (RR: 1.27, 95% CI: 1.03-1.55). However, GDM was not associated with any increased risk of colon (RR: 1.41, 95% CI: 0.90-2.21), colorectal (RR: 1.16, 95% CI: 0.95-1.41), ovarian (RR: 1.14, 95% CI: 0.90-1.44), cervical (RR: 1.02, 95% CI: 0.81-1.29), pancreatic (RR: 3.49, 95% CI: 0.80-15.23), brain and nervous system (RR: 1.26, 95% CI: 0.80-1.97), blood (leukaemia, RR: 0.77, 95% CI: 0.45-1.30), endometrial (RR: 0.77, 95% CI: 0.20-2.98), skin (RR: 1.13, 95% CI: 0.81-1.59) or urological (RR: 0.98, 95% CI: 0.73-1.31) cancers.

CONCLUSION

GDM is associated with a greater risk of cancer in women, including breast, thyroid, stomach and liver cancers. However, further investigation is nonetheless warranted.