Beyond diabetes mellitus: role of metformin in non-muscle invasive bladder cancer

Nonintravesical Interventions for Preventing Intravesical Recurrence in Patients With Nonmuscle-Invasive Bladder Cancer: A Systematic Review and Meta-Analysis

Despite currently used intravesical therapies in non-muscle-invasive bladder cancer (NMIBC), the rate of intravesical recurrence remains very high. We aimed to evaluate the effectiveness of adding nonintravesical interventions to standard intravesical therapies to prevent intravesical recurrence. In April 2024, 3 databases were queried for prospective studies evaluating nonintravesical interventions in addition to standard intravesical therapies for NMIBC (CRD42024490988). The primary outcome was intravesical recurrence-free survival (iRFS). Standard pairwise meta-analyses were performed using hazard ratios (HR) and 95% confidence intervals (95% CI) with a random-effects model. We identified 18 eligible studies (14 RCTs and 4 prospective trials) comprising 4,593 NMIBC patients, which investigated pharmacological interventions (eg, selenium, vitamins, Lactobacillus casei, celecoxib, metformin, mistletoe lectin) and lifestyle modifications (diet). The addition of Lactobacillus casei significantly improved iRFS (HR: 0.50; 95% CI: 0.34-0.73; P < .001). A high western diet pattern significantly worsened iRFS (HR:1.48, 95%CI:1.06-2.06, P = .03). The other nonintravesical interventions were not associated with iRFS. Our comprehensive review of the published literature highlights the need for further research into the efficacy of nonvesical interventions for NMIBC. While Lactobacillus was shown to improve iRFS in 2 RCTs, additional high-quality randomized studies are required to evaluate the effectiveness of other interventions.

Association Between Hypoglycemia Agents and Long-term Survival Outcomes for Patients with Non-muscle-invasive Bladder Cancer Treated with Intravesical Bacillus Calmette-Guérin Immunotherapy

BACKGROUND AND OBJECTIVE

There is a lack of data on the impact of hypoglycemia agents, especially metformin, on prognosis for non-muscle-invasive bladder cancer (NMIBC). Our aim was to investigate the association between hypoglycemia agents, especially metformin, and long-term survival outcomes for patients with NMIBC treated with bacillus Calmette-Guérin.

METHODS

All patients with NMIBC treated with intravesical BCG therapy from 2001 to 2020 were identified in a territory-wide database in Hong Kong. Patients were stratified into two groups according to whether or not they were taking a hypoglycemia agent at BCG treatment initiation. We analyzed data for overall survival (OS), cancer-specific survival (CSS), recurrence-free survival (RFS), and progression-free survival (PFS) using the Kaplan-Meier method. Multivariable Cox regression analysis was used to adjust for potential confounding factors and estimate hazard ratio (HRs) and 95% confidence intervals (CIs). Subgroup analyses were conducted to assess the specific influence of metformin on survival outcomes.

KEY FINDINGS AND LIMITATIONS

Of 2602 patients with NMIBC treated with intravesical BCG, 19.5% (n = 507) were taking a hypoglycemia agent at BCG initiation (treatment group) and 80.5% (n = 2095) were not (control group). At median follow-up of 11 yr, Kaplan-Meier analysis revealed a significant difference in OS between the groups (p < 0.01), but not in CSS (p = 0.36), RFS (p = 0.19), or PFS (p = 0.05). Subgroup analysis comparing outcomes for patients taking metformin, patients taking a hypoglycemia agent other than metformin, and control subjects revealed significant differences in OS (p < 0.01) and RFS (p = 0.02), but not in CSS (p = 0.59) or PFS (p = 0.08). Multivariable Cox regression analysis identified metformin-based treatment for hypoglycemia as an independent risk factor for RFS (HR 1.22, 95% CI 1.02-1.46), whereas hypoglycemia agents other than metformin were not significantly associated with RFS (HR 0.71, 95% CI 0.47-1.06).

CONCLUSIONS AND CLINICAL IMPLICATIONS

Metformin-based hypoglycemia treatment was an independent risk factor for RFS in BCG-treated NMIBC. Hypoglycemia treatment with an agent other than metformin was not related to long-term survival outcomes.

PATIENT SUMMARY

We investigated the relationship between treatment for high blood sugar and long-term survival for patients with intermediate-risk or high-risk non-muscle-invasive bladder cancer. The patients had received BCG (bacillus Calmette-Guérin) treatment in Hong Kong for their bladder cancer over the past two decades. Our results show that metformin, but not other drugs used to treat high blood sugar, was associated with poorer survival free from bladder cancer recurrence for these patients.

Prognostic value of the triglyceride-glucose index in non-muscle-invasive bladder cancer: a retrospective study

Background

Bladder carcinoma is a type of urological tumor with high risks of recurrence and progression. The triglyceride-glucose (TyG) index has demonstrated significant promise as a prognostic marker for metabolic health in different types of cancer. Further research is needed to explore the relationships among non-muscle-invasive bladder cancer (NMIBC), the TyG index, and its prognostic importance. Purpose of this preliminary research is to assess the predictive significance of the TyG index for recurrence and progression risk in NMIBC patients.

Methods

Data from patients admitted between October 2018 and July 2021 were reviewed, and there are 198 patients in total were included. The experimental data were supplied by medical records. In addition, patient prognoses were followed up via telephone. Furthermore, patients were separated into two groups: the high and low TyG groups, using X-tile software. Apart from recurrence-free survival (RFS), progression-free survival (PFS) was the main outcome. According to the TyG index, nomograms were also established.

Results

The cohort consisted of 93 patients in the high TyG group and 105 patients in the low TyG group. The TyG index was a key prognostic factor for postoperative RFS (HR = 2.726, 95% CI = 1.474-5.041, p = 0.001) and PFS (HR = 2.846, 95% CI = 1.359-5.957, p = 0.006) among patients with NMIBC. The log-rank test revealed a notable disparity between the low and high TyG groups regarding RFS (p = 0.0025) and PFS (p = 0.0110). Moreover, it was strongly connected to well-known NMIBC risk factors. Because the TyG index exhibited good predictive value, the nomogram models were formulated.

Conclusion

The TyG index serves as an isolated predictor of both RFS and PFS among patients with NMIBC, revealing new insights into disease treatment mechanisms. Indeed, the TyG index serves as a credible indicator of risk classification while facilitating early intervention among patients with NMIBC.

Metformin: A promising clinical therapeutical approach for BPH treatment via inhibiting dysregulated steroid hormones-induced prostatic epithelial cells proliferation

The occurrence of benign prostate hyperplasia (BPH) was related to disrupted sex steroid hormones, and metformin (Met) had a clinical response to sex steroid hormone-related gynaecological disease. However, whether Met exerts an antiproliferative effect on BPH via sex steroid hormones remains unclear. Here, our clinical study showed that along with prostatic epithelial cell (PEC) proliferation, sex steroid hormones were dysregulated in the serum and prostate of BPH patients. As the major contributor to dysregulated sex steroid hormones, elevated dihydrotestosterone (DHT) had a significant positive relationship with the clinical characteristics of BPH patients. Activation of adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) by Met restored dysregulated sex steroid hormone homeostasis and exerted antiproliferative effects against DHT-induced proliferation by inhibiting the formation of androgen receptor (AR)-mediated Yes-associated protein (YAP1)-TEA domain transcription factor (TEAD4) heterodimers. Met's anti-proliferative effects were blocked by AMPK inhibitor or YAP1 overexpression in DHT-cultured BPH-1 cells. Our findings indicated that Met would be a promising clinical therapeutic approach for BPH by inhibiting dysregulated steroid hormone-induced PEC proliferation.

High risk of non-cancer mortality in bladder cancer patients: evidence from SEER-Medicaid

PURPOSE

The objective of this study was to investigate non-cancer causes of death and associated risk factors after bladder cancer (BC) diagnosis.

METHODS

Eligible BC patients were obtained from the SEER database. SEER*Stat software 8.3.9.2 was used to calculate the standardized mortality ratios (SMRs). The proportions of different non-cancer cause of death were calculated and analyzed in different follow-up periods. Multivariate competing risk model was used to analyze the risk factors for death of BC and non-cancer diseases.

RESULTS

In total, 240,954 BC patients were included and 106,092 patients experienced death, with 37,205 (35.07%), 13,208 (12.45%) and 55,679 (52.48%) patients experienced BC, other cancer and non-cancer disease-related deaths, respectively. Overall SMR for BC patients who died from non-cancer diseases was 2.42 (95% CI [2.40-2.44]). Cardiovascular diseases were the most common non-cancer cause of death, followed by respiratory diseases, diabetes mellitus, and infectious diseases. Multivariate competing risk analysis identified the following high-risk factors for non-cancer mortality: age > 60 years, male, whites, in situ stage, pathological type of transitional cell carcinoma, not receiving treatment (including surgery, chemotherapy, or radiation), and widowed.

CONCLUSIONS

Cardiovascular diseases are the leading non-cancer cause of death in BC patients, followed by respiratory disease, diabetes mellitus and infectious diseases. Physicians should pay attention to the risk of death from these non-cancer diseases. Also, physicians should encourage patients to engage in more proactive self-surveillance and follow up.

Metformin and Cancer, an Ambiguanidous Relationship

The deregulation of energetic and cellular metabolism is a signature of cancer cells. Thus, drugs targeting cancer cell metabolism may have promising therapeutic potential. Previous reports demonstrate that the widely used normoglycemic agent, metformin, can decrease the risk of cancer in type 2 diabetics and inhibit cell growth in various cancers, including pancreatic, colon, prostate, ovarian, and breast cancer. While metformin is a known adenosine monophosphate-activated protein kinase (AMPK) agonist and an inhibitor of the electron transport chain complex I, its mechanism of action in cancer cells as well as its effect on cancer metabolism is not clearly established. In this review, we will give an update on the role of metformin as an antitumoral agent and detail relevant evidence on the potential use and mechanisms of action of metformin in cancer. Analyzing antitumoral, signaling, and metabolic impacts of metformin on cancer cells may provide promising new therapeutic strategies in oncology.

Metformin Use on Incidence and Oncologic Outcomes of Bladder Cancer Patients With T2DM: An Updated Meta-Analysis

Background: The incidence rate and mortality of bladder cancer are increasing year by year. Interestingly, the commonly used metabolic regulatory drug metformin has been reported to have anti-tumor effect in recent years. Nevertheless, it keeps unclear whether the usage of metformin is beneficial or unbeneficial in treating bladder cancer. Thus, a meta-analysis was conducted to explore the long-term effect of metformin on the incidence of bladder cancer and OS, PFS, DSS and RFS in bladder cancer patients with T2DM.

Method: We aim to collect evidence of the association between the usage of metformin and the incidence and treatment outcome of bladder cancer. We searched PubMed, Embase, Ovid Medline and Cochrane Library up to February 2021 to get effective literature reporting the effects of metformin in bladder cancer. The main outcomes were the protective effects of metformin on the incidence, overall survival (OS), recurrence-free survival (RFS), progression-free survival (PFS), and disease-specific survival (DSS) of bladder cancer. And OR (odds ratio) and HR (hazard ratio) with their 95%CI were pooled. Two independent researchers assessed the quality of included studies using the Newcastle-Ottawa Scale (NOS).

Results: We involved 12 studies meeting the inclusion criteria, including a total of 1,552,773 patients. The meta-analysis showed that use of metformin could decrease the incidence (OR = 0.45, 95%CI = 0.37–0.56; p &lt; 0.01) and prolong recurrence-free-survival (HR = 0.56, 95%CI = 0.41–0.76; p = 0.91) of bladder cancer. However, there were no significant protective effects in the overall survival (HR = 0.93, 95%CI = 0.67–1.28, p = 0.05), disease-specific-survival (HR = 0.73, 95%CI = 0.47–1.16; p = 0.01), and progression-free-survival (HR = 0.78, 95%CI = 0.53–1.15, p = 0.34).

Conclusion: The results revealed that the usage of metformin could reduce the incidence of bladder cancer and prolong the prognosis of bladder cancer in T2DM patients, respectively. More prospective studies are needed to prove the protective role of metformin on bladder cancer.