Serum protein profiling reveals an inflammation signature as a predictor of early breast cancer survival.

BACKGROUND: Breast cancers exhibit considerable heterogeneity in their biology, immunology, and prognosis. Currently, no validated, serum protein-based tools are available to evaluate the prognosis of patients with early breast cancer. METHODS: The study population consisted of 521 early-stage breast cancer patients with a median follow-up of 8.9 years. Additionally, 61 patients with breast fibroadenoma or atypical ductal hyperplasia were included as controls. We used a proximity extension assay to measure the preoperative serum levels of 92 proteins associated with inflammatory and immune response processes. The invasive cancers were randomly split into discovery (n = 413) and validation (n = 108) cohorts for the statistical analyses. RESULTS: Using LASSO regression, we identified a nine-protein signature (CCL8, CCL23, CCL28, CSCL10, S100A12, IL10, IL10RB, STAMPB2, and TNFß) that predicted various survival endpoints more accurately than traditional prognostic factors. In the time-dependent analyses, the prognostic power of the model remained rather stable over time. We also developed and validated a 17-protein model with the potential to differentiate benign breast lesions from malignant lesions (Wilcoxon p < 2.2*10- 16; AUC 0.94). CONCLUSIONS: Inflammation and immunity-related serum proteins have the potential to rise above the classical prognostic factors of early-stage breast cancer. They may also help to distinguish benign from malignant breast lesions.

PErsonalized TReatment for Endometrial Carcinoma (PETREC): study design and methods of a prospective Finnish multicenter trial.

BACKGROUND: Endometrial carcinomas can be classified into four molecular subgroups - mismatch repair deficient (MMRd), p53 abnormal (p53abn), polymerase-ϵ (POLE) ultramutated, and 'no specific molecular profile' (NSMP). Retrospective data imply that the response to adjuvant therapies may depend on the molecular subgroup. These findings emphasize the need for adjuvant therapy trials where patients are randomized to treatment arms separately within each molecular subgroup. PRIMARY OBJECTIVE: The PErsonalized TReatment for Endometrial Carcinoma (PETREC) trial clarifies the value of molecular classification in the determination of adjuvant therapies of high-intermediate risk and early-stage high-risk endometrial carcinoma. STUDY HYPOTHESIS: Compared with vaginal brachytherapy, the utilization of whole pelvic radiotherapy may result in improved outcomes for either MMRd or NSMP high-intermediate risk carcinomas. Early-stage high-risk p53abn and nonendometrioid carcinomas are postulated to gain benefits from chemoradiotherapy, as opposed to chemotherapy alone. POLE ultramutated carcinomas harboring high-intermediate or high-risk clinicopathologic features are speculated to have favorable prognosis without any adjuvant therapy. TRIAL DESIGN: This prospective, multicenter, phase 3 trial compares the efficacy of vaginal brachytherapy vs whole pelvic radiotherapy in high-intermediate risk MMRd and NSMP molecular subgroups, and chemotherapy vs chemoradiotherapy in early-stage high-risk p53abn subtype and nonendometrioid carcinomas. Eligible women who consent to participation in the trial are randomly allocated (1:1) to treatment arms. MAJOR INCLUSION/EXCLUSION CRITERIA: Women with stages I-II molecular integrated high-intermediate risk or high-risk endometrial carcinoma will be included. PRIMARY ENDPOINT: The primary endpoint is the 5 year cumulative incidence of disease recurrence. SAMPLE SIZE: A total sample size of 294 patients (49 subjects in each treatment arm of the three subgroups intended for randomization) was estimated to be sufficient. ESTIMATED DATES FOR COMPLETING ACCRUAL AND PRESENTING RESULTS: Patient recruitment will be completed in 2025, and follow-up will be completed in 2030. TRIAL REGISTRATION: NCT05655260.

The Association of Metformin, Other Antidiabetic Medications, and Statins With the Prognosis of Colon Cancer in Patients With Type 2 Diabetes: A Retrospective Cohort Study.

BACKGROUND: Use of metformin and statins have been associated with improved prognosis of colon cancer (CC) in patients with type 2 diabetes (T2D). We examined the survival from CC in relation to the use of metformin, other oral antidiabetic medications (ADM), insulin, and statins in T2D patients. MATERIALS AND METHODS: A cohort (n = 2252) of persons with pre-existing T2D diagnosed with incident CC between 1998 and 2011 was identified from several Finnish registers. Cox models were fitted for cause-specific mortality rates to obtain adjusted estimates of the hazard ratios (HR) with 95% confidence intervals (CI) in relation to use of ADM and statins before the CC diagnosis. Cox models were also fitted for mortality in relation to post-diagnostic use of the medications treating these as time-dependent exposures, and starting follow-up 1 year after the CC diagnosis. RESULTS: Pre- and post-diagnostic metformin use was weakly associated with the risk of CC-related death (HR .75; 95% CI .58-.99, and HR .78; 95% CI .54-1.14, respectively) compared to the use of other oral ADMs. Pre- and post-diagnostic statin use predicted a reduced risk of CC-related death (HR .83; 95% CI .71- .98, and HR .69; 95% CI .54-.89, respectively). CONCLUSION: Additional evidence was found for use of statins being associated with an improved survival from CC in patients with pre-existing T2D, but for metformin use the evidence was weaker.

Survival after breast cancer in women with type 2 diabetes using antidiabetic medication and statins: a retrospective cohort study.

Background: We assessed survival of breast cancer in women with type 2 diabetes (T2D) treated with metformin, other types of antidiabetic medication (ADM) and statins.Materials and Methods: The study cohort consisted of women with T2D and diagnosed with breast cancer in Finland in 1998─2011. Mortality rates from breast cancer and other causes were analysed by Cox models, and adjusted hazard ratios (HRs) with 95% confidence intervals (Cls) were estimated in relation to the use of different types of medication.Results: The final cohort consisted of 3,533 women. No clear evidence was found for breast cancer mortality being different in metformin users (HR 0.86, 95% Cl 0.63-1.17), but their other-cause mortality appeared to be lower (HR 0.73, 95% Cl 0.55-0.97) in comparison with women using other types of oral ADM. Other-cause mortality was higher among insulin users (HR 1.45, 95% Cl 1.16-1.80) compared with users of other oral ADMs, other than metformin. Prediagnostic statin use was observed to be associated with decreased mortality from both breast cancer (HR 0.76, 95% Cl 0.63-0.92) and other causes (HR 0.75, 95% Cl 0.64-0.87).Conclusions: We did not find any association between ADM use and disease-specific mortality among women with T2D diagnosed with breast cancer. However, interestingly, prediagnostic statin use was observed to predict reduced mortality from breast cancer and other causes. We hypothesise that treating treatment practices of T2D or hypercholesterolaemia of breast cancer patients might affect overall prognosis of women diagnosed with breast cancer and T2D.

Association of antidiabetic medication and statins with breast cancer incidence in women with type 2 diabetes.

PURPOSE: To address the possible association between the use of metformin, other forms of antidiabetic medication (ADM) and statins with the incidence of breast cancer in women with type 2 diabetes (T2D). METHODS: Data were collected from a Finnish nationwide diabetes database (FinDM). The study cohort consisted of women diagnosed with T2D in 1996-2011 in Finland. In full-cohort analysis, Poisson regression was used to estimate hazard ratios (HRs) in relation to use of metformin, insulin, other forms of oral ADM and statins. In nested case-control analysis, up to 20 controls were matched for age and duration of diabetes to each case of breast cancer. Conditional logistic regression was used to estimate HRs in relation to medication use and cumulative use of different forms of ADM, and statins. RESULTS: 2300 women were diagnosed with breast cancer during follow-up. No difference in breast cancer incidence was observed between metformin users [HR 1.02, 95% confidence interval (CI) 0.93-1.11] or statin users (HR 0.97, 95% CI 0.89-1.05) compared with non-users. In nested case-control analysis the results were similar. Use of insulin (HR 1.18, 95% CI 1.03-1.36) was associated with a slightly increased incidence of breast cancer. CONCLUSIONS: No evidence of an association between the use of metformin or statins and the incidence of breast cancer in women with T2D was found. Among insulin users, a slightly higher incidence of breast cancer was observed.

Metformin diminishes the unfavourable impact of Nrf2 in breast cancer patients with type 2 diabetes.

Nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is a major regulator of the oxidative stress response and it is negatively regulated by Kelch-like ECH-associated protein 1 (Keap1). The Keap1-Nrf2 axis has a fundamental role in carcinogenesis. In previous studies, the widely used diabetes drug metformin has appeared to have a critical role in the regulation of Nrf2 function. In this study, we assessed the expression of Nrf2 and Keap1 immunohistochemically in 157 patients with type 2 diabetes who underwent breast cancer surgery with curative intent. In total, 78 (49.7%) of these patients were taking metformin alone or combined with other oral anti-diabetic medication at the time of breast cancer diagnosis. We found that high-level cytoplasmic Nrf2 expression predicted dismal overall survival and breast cancer-specific survival, but only in the patients who were not taking metformin at the time of diagnosis. Similarly, low-level nuclear Keap1 expression had an adverse prognostic value in terms of overall survival and breast cancer-specific survival in patients without metformin. On the other hand, high-level nuclear Keap1 expression was associated with prolonged overall survival and breast cancer-specific survival. The results may be explained in terms of non-functioning or displaced Keap1, although more mechanistic pre-clinical and prospective clinical studies are warranted.

Prognosis of ovarian cancer in women with type 2 diabetes using metformin and other forms of antidiabetic medication or statins: a retrospective cohort study.

BACKGROUND: Ovarian cancer is one of the most lethal cancers and women with type 2 diabetes (T2D) have even poorer survival from it. We assessed the prognosis of ovarian cancer in women with type 2 diabetes treated with metformin, other forms of antidiabetic medication, or statins. METHODS: Study cohort consisted of women with T2D diagnosed with ovarian cancer in Finland 1998-2011. They were identified from a nationwide diabetes database (FinDM), being linked to several national registers. Patients were grouped according to their medication in the three years preceding ovarian cancer diagnosis. The Aalen-Johansen estimator was used to describe cumulative mortality from ovarian cancer and from other causes in different medication groups. Mortality rates were analysed by Cox models, and adjusted hazard ratios (HR) with 95% confidence intervals (95% CIs) were estimated in relation to the use of different forms of medication. Main outcome measures were death from ovarian cancer and death from other causes. RESULTS: During the accrual period 421 newly diagnosed ovarian cancers were identified in the FinDM database. No evidence was found for any differences in mortality from ovarian cancer or other causes between different antidiabetic medication groups. Pre-diagnostic use of statins was observed to be associated with decreased mortality from ovarian cancer compared with no such use (HR 0.72, 95% CI 0.56-0.93). CONCLUSIONS: Our findings are inconclusive as regards the association between metformin and ovarian cancer survival. However, some evidence was found for improved prognosis of ovarian cancer with pre-diagnostic statin use, requiring cautious interpretation, though.

Redox-state-regulating enzymes have prognostic value in diabetic endometrial cancer patients: impact of statin use?

Objective: The incidence of endometrial cancer is increasing, and oxidative stress has been suggested to play a vital role in its carcinogenesis. Statins have an impact on the cellular redox-state. The aim of this study was to determine the effects of statin use on redox-state regulating enzymes in endometrial cancer in women with type 2 diabetes. Materials and methods: This retrospective study consisted of 119 women with type 2 diabetes who were diagnosed with endometrial cancer at Oulu University Hospital in Finland between 2007 and 2014. There were 58 statin users and 61 non-users based on medication use at the time of endometrial cancer diagnosis. The expression of redox-state regulating proteins nuclear factor erythroid 2-related factor 2 (Nrf2) and Kelch-like ECH-associated protein 1 (Keap1) in the tumor samples was assessed immunohistochemically, and manganese superoxide dismutase (MnSOD) levels were measured both immunohistochemically and from serum samples. Results: High MnSOD expression predicted better progression-free survival (PFS) in statin non-users in a univariate analysis (p=0.02). There was no statistical difference in overall survival (OS) or PFS between strong and weak expression of Nrf2 and Keap1. After adjusting for stage and statin use, the results were similar. Conclusion: Statin non-users with strong MnSOD expression had better PFS compared to statin users which proves that statins have impact on redox-state regulating enzymes. However, these findings are preliminary and require further research.

The association of breast cancer patients survival and prior menopausal hormone therapy in women with type 2 diabetes.

We investigated the association of prediagnostic use of menopausal hormone therapy (MHT) with breast cancer survival among women with type 2 diabetes (T2D). The study cohort was identified from a Finnish nationwide diabetes database, and consisted of women with T2D, who were diagnosed with breast cancer between 2000 and 2011 (n = 3189). The patients were classified according to their previous MHT use: systemic MHT, local MHT, and no history of any MHT. The cumulative mortality from breast cancer, cardiovascular diseases, and other causes in three MHT groups was described by the Aalen-Johansen estimator. The cause-specific mortality rates were analyzed by Cox models, and adjusted hazard ratios (HRs) were estimated for the use of MHT. The breast cancer mortality appeared to be lower among systemic MHT users (HR 0.49, 95% Cl 0.36-0.67) compared with non-users of MHT. The mortality from cardiovascular diseases and from other causes of death was found to be lower among systemic MHT users, (HR 0.49, 95% Cl 0.32-0.74), and (HR 0.51, 95% Cl 0.35-0.76), respectively. In conclusion, prediagnostic systemic MHT use is associated with reduced breast cancer, cardiovascular, and other causes of mortality in women with T2D.

The Association of Metformin, Other Antidiabetic Medications, and Statins with the Prognosis of Hepatocellular Carcinoma in Patients with Type 2 Diabetes: A Retrospective Cohort Study.

This study aimed to explore whether the prediagnostic use of metformin and statins is associated with the prognosis of patients with hepatocellular carcinoma (HCC) and type 2 diabetes. We identified 1383 eligible individuals who had both type 2 diabetes and HCC diagnosed between 1998 and 2017 from several Finnish registers. Cox models were fitted for cause-specific and all-cause mortality in relation to the use of antidiabetic medications and statins prior to the HCC diagnosis. Prediagnostic metformin use was associated with decreased overall mortality (hazard ratio 0.84, 95% confidence interval 0.74-0.94) compared with nonuse in patients with type 2 diabetes. Similarly, slightly decreased HCC mortality and other-cause mortality were observed among metformin users. The results were inconclusive regarding metformin use and both overall and HCC mortality among patients with localized HCC. No discernible contrast between statin users and nonusers was found in overall mortality nor HCC mortality in either the whole cohort or patients with localized cancer.

Oxidative Stress-regulating Enzymes and Endometrial Cancer Survival in Relation to Metformin Intake in Diabetic Patients.

BACKGROUND/AIM: Metformin inhibits tumorigenesis in endometrial carcinoma and interferes with the expression of oxidative stress-regulating proteins, such as nuclear factor erythroid 2-related factor 2 (Nrf2) and Kelch-like ECH-associated protein 1 (Keap1). Although manganese superoxide dismutase (MnSOD) is vital for withstanding mitochondrial oxidative stress, it has also been linked with chemoresistance and poorer outcomes in several cancer types. However, data on endometrial cancers are limited. This study aimed to highlight the relationship between mitochondrial redox regulation and endometrial cancer survival in relation to metformin consumption in women with type 2 diabetes mellitus (T2DM). PATIENTS AND METHODS: Our retrospective hospital-based cohort study included 121 patients diagnosed with endometrial carcinoma and T2DM between 2007 and 2014. Fifty-eight patients were using metformin at the time of diagnosis. Nrf2 and Keap1 expression levels in the tumor samples were assessed immunohistochemically, and MnSOD levels were measured both immunohistochemically and from the serum samples. RESULTS: High MnSOD tissue expression was associated with better overall survival among metformin users in the univariate analysis (p=0.03). When adjusted for histology and stage, high serum MnSOD was associated with better overall survival (HR=0.22, 95%CI=0.07-0.71, p=0.01). No association was found between MnSOD, Nrf2, or Keap1 and overall survival among metformin non-users. CONCLUSION: Higher expression of MnSOD in patients with endometrial cancer and T2DM is associated with better overall survival if the patient is consuming metformin.

Immunological Markers of Chlamydia trachomatis Infection in Epithelial Ovarian Cancer.

BACKGROUND/AIM: Pelvic inflammatory disease (PID) is a risk factor for epithelial ovarian cancer (EOC). Chlamydia trachomatis infection, a major cause of PID, may persist in some women. Serum IgG antibodies to chlamydial TroA and HtrA are more common in ascending or repeat chlamydial infection than in uncomplicated infection. The aim of this study was to explore the role of C. trachomatis infection in EOC by analyzing chlamydial TroA, HtrA and major outer membrane protein (MOMP) IgG serum antibody responses. PATIENTS AND METHODS: The study is based on the review of Oulu University Hospital medical records of 162 women diagnosed with EOC between March 2008 and May 2018. Serum IgG antibody responses to recombinant C. trachomatis TroA, HtrA and MOMP were analyzed using enzyme-linked immunoassay. Complete response to the first line therapy and the three-year survival were the study endpoints. RESULTS: Altogether, 16.7%, 11.1% and 12.3% women were C. trachomatis TroA, HtrA and MOMP IgG positive, respectively. Women with these antibodies were more likely to have a complete response to the first-line treatment, compared to women without these antibodies (63.0% vs. 34.1% for TroA IgG, 50.0% vs. 37.5% for HtrA IgG and 50% vs. 37.3% for MOMP IgG, respectively). The presence of these antibodies predicted better three-year survival. CONCLUSION: Women with EOC and positive markers of persistent C. trachomatis infection have better response to the first-line treatment and seem to have better three-year survival.

The Association of Metformin, Other Antidiabetic Medications and Statins on the Prognosis of Rectal Cancer in Patients with Type 2 Diabetes: A Retrospective Cohort Study.

Metformin and statin use have been associated with an improved prognosis for colorectal cancer in persons with type 2 diabetes (T2D). Data regarding rectal cancer (RC) have been inconclusive; therefore, we investigated the issue with high-quality data and a robust study design. We identified 1271 eligible patients with T2D and incident RC between 1998 and 2011 from the Diabetes in Finland (FinDM) database. Cox models were fitted for cause-specific mortality rates to obtain adjusted estimates of the hazard ratios (HR) with 95% confidence intervals (CI) in relation to use of antidiabetic medication (ADM) and statins before the RC diagnosis and for post-diagnostic use in a time-dependent exposure manner. No sufficient evidence was found for either pre- or post-diagnostic metformin use and RC mortality (HR 0.96, 95% CI 0.67-1.38, and 0.70, 95% CI 0.45-1.10, respectively) when compared to other oral ADMs. Both pre- and post-diagnostic statin use appeared to be inversely associated with mortality from RC (HR 0.77 95% CI 0.63-0.94, and 0.57, 95% CI 0.42-0.78, respectively). Our study was inconclusive as to the association of metformin use with the prognosis of RC, but statin use was found to predict reduced mortality, both from RC and from other causes of death in persons with T2D.

No Association Between Statin Use and the Prognosis of Endometrial Cancer in Women With Type 2 Diabetes.

Preclinical studies have suggested statins have antiproliferative and anti-metastatic effects on endometrial cancer cells. Similarly, most previous epidemiological studies have reported a better prognosis of endometrial cancer in patients who used statins. In this study, we explored the role of statins in the prognosis of endometrial cancer in women with type 2 diabetes in a hospital-based cohort. This retrospective cohort consisted of 119 women with type 2 diabetes who were diagnosed and treated for endometrial cancer at Oulu University Hospital, Finland, between 2007 and 2014. The patients were classified as statin users (n = 58) and nonusers (n = 61) based on the type of medication they were using at the time of endometrial cancer diagnosis. Statin use showed no association with progression-free survival or overall survival in the whole cohort nor the subgroups with type I or type II histology, in lower or higher body mass index groups, or at an early or advanced stage. The results remained similar in the multivariate analysis after adjusting for the patient's age, cancer stage, and histology. Furthermore, statin use seemed not to have any association with most of the prognostic factors at the time of endometrial cancer diagnosis.

Metformin Associates With Aggressive Features of Endometrial Cancer in Women With Type 2 Diabetes.

BACKGROUND/AIM: Preclinical studies on metformin use and endometrial cancer have been promising but epidemiological studies have reported variable results. This study aimed to assess if metformin use is associated with endometrial cancer aggressiveness and survival in women with type 2 diabetes (T2D). PATIENTS AND METHODS: This retrospective hospital-based cohort consisted of women with T2D who were treated for endometrial cancer at the Oulu University Hospital, Finland, between 2007 and 2014. RESULTS: The sample size was 121 patients: 58 metformin users and 63 metformin non-users. Intriguingly, type 2 histology, deep myometrial invasion and the presence of lymphovascular invasion were more common in the metformin user group. However, metformin use showed no association with overall survival and progression-free survival. CONCLUSION: Metformin use was associated with poorer prognostic factors in endometrial cancer patients with T2D.

Association of antidiabetic medication and statins with survival from ductal and lobular breast carcinoma in women with type 2 diabetes.

We investigated the survival of female patients with pre-existing type 2 diabetes (T2D) diagnosed with invasive ductal carcinoma (IDC) and invasive lobular carcinoma (ILC) of breast, in relation to the use of metformin, other antidiabetic medication (ADM) and statins. The study cohort consisted of 3,165 women (2,604 with IDC and 561 with ILC). The cumulative mortality from breast cancer (BC) and from other causes was calculated using the Aalen-Johansen estimator. The cause-specific mortality rates were analysed by Cox models, and adjusted hazard ratios (HRs) were estimated for the use of different medications. No evidence of an association of metformin use with BC mortality was observed in either IDC (HR 0.92, 95% confidence interval [CI] 0.64-1.31) or ILC (HR 0.68, 95% CI 0.32-1.46) patients, when compared to other oral ADMs. The mortality from other causes was found to be lower amongst the IDC patients using metformin (HR 0.64, 95% CI 0.45-0.89), but amongst ILC patients the evidence was inconclusive (HR 1.22, 95% CI 0.64-2.32). Statin use was consistently associated with reduced mortality from BC in IDC patients (HR 0.77, 95% CI 0.62-0.96) and ILC patients (HR 0.59, 95% CI 0.37-0.96), and also mortality from other causes in IDC patients (HR 0.81, 95% CI 0.67-0.96) and in ILC patients (HR 0.66, 95% CI 0.43-1.01). We found no sufficient evidence for the possible effects of metformin and statins on the prognosis of BC being different in the two histological subtypes.

Association of Metformin, Other Antidiabetic Medications, and Statins With Incidence of Colon Cancer in Patients With Type 2 Diabetes.

BACKGROUND: Metformin and statins may have anticancer effects, with plausible cellular mechanisms. However, the association of these agents with the risk of colorectal cancer is unclear. PATIENTS AND METHODS: This was a retrospective cohort study on a large population (N = 316,317) of patients with type 2 diabetes. Data were obtained from the Diabetes in Finland database (FinDM). In a full cohort analysis, hazard ratios (HRs) with their 95% confidence intervals (CIs) for ever use versus never use were estimated using a multiple Poisson regression model. A nested case-control design within the cohort was used to examine the association of colon cancer (CC) with the defined daily dose of medication. The data were analyzed by conditional logistic regression. The analyses were adjusted for the patient's age, sex, and duration of diabetes. RESULTS: In total, 1351 CC cases were diagnosed during 1996-2011. The results revealed insufficient evidence for an association between metformin (HR, 1.01; 95% CI, 0.90-1.14), other oral antidiabetic medications (HR, 1.05; 95% CI, 0.93-1.19), insulin (HR, 1.02; 95% CI, 0.86-1.22), or statins (HR, 0.94; 95% CI, 0.84-1.05) and the incidence of CC in the full cohort analysis. The results from the case-control study were similar, with no consistent trend in the incidence of CC according to the cumulative dose of metformin or the other studied medications. CONCLUSION: This study found insufficient evidence for an association between metformin, insulin, other oral type 2 diabetes medications, or statins and the incidence of CC.

Low Expression of Stanniocalcin 1 (STC-1) Protein Is Associated With Poor Clinicopathologic Features of Endometrial Cancer.

Stanniocalcin-1 (STC-1) is a glycoprotein hormone involved in diverse biological processes, including regulation of calcium phosphate homeostasis, cell proliferation, apoptosis, inflammation, oxidative stress responses, and cancer development. The role of STC-1 in endometrial cancer (EC) is yet to be elucidated. In this study, we investigated the protein expression pattern of STC-1 in a tissue microarray (TMA) cohort of hysterectomy specimens from 832 patients with EC. We then evaluated the prognostic value of STC-1 expression regarding the clinicopathologic features and patients survival over a period of 140 months. Our results revealed that in EC tissue samples, STC-1 is mainly localized in the endometrial epithelium, although some expression was also observed in the stroma. Decreased STC-1 expression was associated with factors relating to a worse prognosis, such as grade 3 endometrioid tumors (p = 0.030), deep myometrial invasion (p = 0.003), lymphovascular space invasion (p = 0.050), and large tumor size (p = 0.001). Moreover, STC-1 expression was decreased in tumors obtained from obese women (p = 0.014) and in women with diabetes mellitus type 2 (DMT2; p = 0.001). Interestingly, the data also showed an association between DNA mismatch repair (MMR) deficiency and weak STC-1 expression, specifically in the endometrial epithelium (p = 0.048). No association was observed between STC-1 expression and disease-specific survival. As STC-1 expression was particularly low in cases with obesity and DMT2 in the TMA cohort, we also evaluated the correlation between metformin use and STC-1 expression in an additional EC cohort that only included women with DMT2 (n = 111). The analysis showed no difference in STC-1 expression in either the epithelium or the stroma in women undergoing metformin therapy compared to metformin non-users. Overall, our data may suggest a favorable role for STC-1 in EC behavior; however, further studies are required to elucidate the detailed mechanism and possible applications to cancer treatment.

Metformin and ovarian cancer: the evidence.

In recent decades, great interest in the off-label use of metformin has arisen as a result of its broad effects on different signaling pathways, with only a few side effects, and low cost. Metformin has been shown to have multiple, dose-dependent preclinical anticancer effects, which can be roughly divided into either direct effects via inhibition of mitochondrial respiratory chain complex I, or indirect effects through lowered glucose, insulin and insulin-like growth factor levels. Further details on in vitro and in vivo anticancer effects specifically in ovarian cancer are continuously reported. Preclinically metformin has clear chemosensitizing effects in ovarian cancer and it is an effective negative regulator of angiogenesis. There are also some epidemiological studies on metformin use in ovarian cancer, but the results of these studies are not as promising as those preclinical studies would indicate. Most preclinical studies have involved metformin concentrations that are many times higher than the pharmacological doses used in patients, which might confound the clinical use of metformin as regards the above-mentioned aspects. In this review we evaluate preclinical and clinical evidence concerning metformin in ovarian cancer treatment.

Antidiabetic Medication, Statins and the Risk and Prognosis of Non-endometrioid Endometrial Cancer in Women with Type 2 Diabetes.

AIM: To determine the incidence and prognosis of non-endometrioid endometrial cancer (EC) in relation to the use of metformin, other antidiabetic medication (ADM) and statins in patients with type 2 diabetes (T2D). MATERIALS AND METHODS: In order to analyze the incidence and prognosis of non-endometrioid EC, two cohorts were obtained from a nationwide diabetes database (FinDM); 57 non-endometrioid ECs were observed in a cohort of 92,366 women with newly-diagnosed T2D during the follow-up (1996 to 2011) to assess the incidence, and a retrospective cohort of 105 women with T2D diagnosed with non-endometrioid EC (1998 to 2011) was used to estimate cumulative mortality from EC and other causes of death. Hazard ratios (HRs) with 95% confidence intervals (CIs) for EC incidence were estimated in the full-cohort analysis and in the nested case-control analysis, matched for age and duration of T2D. Cumulative mortality was estimated by using the Aalen-Johansen estimator. Cause-specific mortality rates were analyzed by using Cox models regarding the pre-diagnostic use of different forms of ADM and statins. RESULTS: In the nested case-control analysis, the use of metformin was not associated with the risk of non-endometrioid EC (HR=1.09, 95% CI=0.59-2.00), whereas statin use was associated with a lower risk (HR=0.47, 95% CI=0.26-0.84). The results from the full-cohort analysis supported these findings. Mortality from non-endometrioid EC was not different between users of metformin and other types of oral ADM (HR=1.56, 95% CI=0.40-6.07) but was observed to be lower in statin users (HR=0.41, 95% CI=0.20-0.82). CONCLUSION: Our findings were inconclusive regarding the association of metformin with the risk and prognosis of non-endometrioid EC. However, statin use was associated with a lower incidence and mortality from this disease.