The Insulin–Urothelial Axis: Evaluating Insulin Resistance as a Convergent Driver of Bladder Cancer Across Diverse Risk Factor Profiles

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

• The authors are encouraged to follow PRISMA guidelines to strengthen the methodological rigor and transparency of the review.
• The title could be more informative and specific, as it currently does not fully reflect the scope and content of the review.
• Although the title suggests a focus on the association between bladder cancer and insulin resistance, the manuscript also discusses associations with other types of cancer, which creates some inconsistency 
• The subsection headings are single-word and therefore somewhat vague; more descriptive titles would improve clarity and readability.
• Pathophysiological mechanisms are not adequately presented (see Table 1), and this limits the scientific depth of the review.
• Figure 1 is not sufficiently clear and may be difficult for readers to interpret.

Minnor commnt

Overall, the authors should improve the clarity, focus, and scientific quality of the manuscript.

Author Response

Reply to Reviewer 1

We would like to express our sincere gratitude for your insightful and constructive feedback on our manuscript. Your suggestions have been instrumental in elevating the clarity, focus, and overall scientific quality of this work.

 

 

Comment: The authors are encouraged to follow PRISMA guidelines to strengthen the methodological rigor and transparency of the review.

 

Answer: This paragraph according to PRISMA guidelines was added: The review was conducted following established methodological standards to ensure transparency and reproducibility. The search strategy utilized keywords and synonyms related to hyperinsulinemia, insulin sensitivity/resistance, BMI, obesity, abdominal adiposity, metabolic syndrome, and BC risk factors. The searched  databases were PubMed, Scopus, Web of Science, and Google Scholar. Gray literature sources, such as government reports and conference proceedings, were not considered. This  complete electronic search strategy for multiple databases was applied to enable verification and replication of the evidence‑retrieval process. Study selection followed a predefined and transparent workflow, detailing the screening phases, eligibility criteria, and procedures used to resolve disagreements between reviewers. All included studies underwent a structured assessment of risk of bias, providing a clear appraisal of the internal validity of the evidence base. Protocol registration was not undertaken because the scope of the review evolved iteratively during its early conceptualization, making prospective registration impractical and potentially misleading with respect to the final methodological approach.

 

Comment : The title could be more informative and specific, as it currently does not fully reflect the scope and content of the review.

Answer:  Title was changed in one more risk factor centric, and more specific: The Insulin-Urothelial Axis: Evaluating Insulin Resistance  as a Convergent Driver of Bladder Cancer Across Diverse Risk Factor Profiles

Comment :  Although the title suggests a focus on the association between bladder cancer and insulin resistance, the manuscript also discusses associations with other types of cancer, which creates some inconsistency 

Answer:  In the context of our review, the "hypothetical" part is determining if the bladder urothelium is as sensitive some systemic signals as other cancer. For example, given that bladder cancer is heavily influenced by chemical exposures (smoking/dyes), insulin resistance might act as the "promoter" that allows those chemical "initiators" to take hold more effectively. 

The reason insulin resistance is frequently cited as a "universal" mechanism across various cancers (like breast, colorectal, and pancreatic) is that it creates a systemic environment that is essentially “pro-growth.” This last sentence was added in the beginning of the Discussion section  and was stressed successively when dealing with insulin sensitizers.

Comment: The subsection headings are single-word and therefore somewhat vague; more descriptive titles would improve clarity and readability.

Answer: The titles of the subsection were  transformed from a narrow, binary question or single words into a capturing, mechanistic hypothesis by shifting the focus of our review from just listing risk factors to proposing a clear, biological reason why they all lead to bladder cancer.

 

Comment: Pathophysiological mechanisms are not adequately presented (see Table 1), and this limits the scientific depth of the review.

Answer: 

The legend for Table 1 has been expanded to provide a more comprehensive synthesis, ensuring readers can immediately grasp the mechanistic connections presented. By moving the detailed molecular descriptions—specifically the convergence of risk factors on pathways like DNA damage response, oncogenic signaling, and metabolic activation—into the legend, the table transforms from a simple data list into an integrated map of bladder carcinogenesis. 

 

Comment: Figure 1 is not sufficiently clear and may be difficult for readers to interpret.

Answer: The original flowchart was substantially redesigned and expanded to more accurately 

capture the complex pathophysiological mechanisms connecting metabolic dysfunction to malignancy. By integrating new stages—such as the transition from uncontrolled cell cycling to angiogenesis (VEGF upregulation) and the subsequent development of a tumor microenvironment—the updated figure provides a more rigorous and complete visual map.

 

Minor comment

Overall, the authors should improve the clarity, focus, and scientific quality of the manuscript.

Answer: By refining the manuscript's focus onto the systemic-local axis of carcinogenesis and integrating complex molecular interactions with practical clinical surveillance strategies, we have transformed the paper into a cohesive resource that addresses the multi-dimensional nature of bladder cancer. By emphasizing the need for non-invasive follow-up tools the manuscript offers a practical solution to the problem of managing high-risk metabolically compromised patients.

Reviewer 2 Report

Comments and Suggestions for Authors

The approach taken in this review is interesting; the authors seek to identify insulin resistance as a pathophysiological mechanism related to cancer and various risk factors already associated with bladder cancer. However, it is necessary to integrate general basic concepts related to this type of tumor.

Page 2 introduction,

You should discuss what insulin resistance is and which tissues or cell lines are involved in generating this resistance. You could to show the mechanism by which chronically elevated glucose levels in the body can wear down the system and generate insulin resistance. In addition, it would be convenient to include the proteins involved in insulin signaling, the translocation of glucose transporters, and the autocrine, paracrine, or endocrine regulation of the participating cell tissues. It should describe the pathophysiology of bladder cancer, its classification, diagnosis, and existing treatments. It would also be convenient to describe the mechanism of how bladder cancer generates an environment of constant chronic inflammation in the body (low-grade chronic inflammation) of these patients.

Page 2 aim and methods, It is necessary to check the author's guide and take into account the structure for a review that includes, Abstract, Keywords, Introduction, Relevant Sections, Discussion, Conclusions, and Future Directions.

Page 2 results, the results section is not required in review articles.

Page 13 discussion figure 1, In your Figure 1 you refer to insulin resistance as a causal element for the development of bladder cancer and subsequently low-grade inflammation. In the existence of any comorbidity that involves a low-grade inflammatory process, what would the outcome be? Similar to Figure 1 or different? Please integrate information about these cases into the manuscript.

You need two important sections in this manuscript, you need a discussion about the findings of different studies, is important add information about insulin resistance  a potential pathophysiological mechanism underlying the association between bladder cancer and its known risk factors, the second section is the conclusion about your research question.

Comments on the Quality of English Language

It would be appropriate to review the English writing again

Author Response

Reply to Reviewer 2

We would like to express our sincere gratitude for your insightful and constructive feedback on our manuscript. Your suggestions have been instrumental in elevating the clarity, focus, and overall scientific quality of this work.

 

Comment 

The approach taken in this review is interesting; the authors seek to identify insulin resistance as a pathophysiological mechanism related to cancer and various risk factors already associated with bladder cancer. However, it is necessary to integrate general basic concepts related to this type of tumor.

Answer: Indeed, the authors thank this reviewer for the positive judgement. They have followed the suggestion integrating general basic concept related to bladder cancer.

Page 2 introduction,

Comment: You should discuss what insulin resistance is and which tissues or cell lines are involved in generating this resistance.You could to show the mechanism by which chronically elevated glucose levels in the body can wear down the system and generate insulin resistance. In addition, it would be convenient to include the proteins involved in insulin signaling, the translocation of glucose transporters, and the autocrine, paracrine, or endocrine regulation of the participating cell tissues. It should describe the pathophysiology of bladder cancer, its classification, diagnosis, and existing treatments. It would also be convenient to describe the mechanism of how bladder cancer generates an environment of constant chronic inflammation in the body (low-grade chronic inflammation).

Answer: A comprehensive layout  (Figure1) ensures that readers can clearly trace the biological progression from systemic insulin resistance through to the localized cellular shifts that define bladder cancer.  Anew  section in the Introduction provides a comprehensive overview of bladder cancer, tracing its progression from molecular origins to clinical management. It details the pathophysiology of the disease, its standardized classification and diagnostic protocols, and the current landscape of treatments. Furthermore, it explores the systemic impact of the disease, specifically the mechanism by which bladder cancer fosters a state of chronic low-grade inflammation.

 Comment: Page 2 aim and methods, It is necessary to check the author's guide and take into account the structure for a review that includes, Abstract, Keywords, Introduction, Relevant Sections, Discussion, Conclusions, and Future Directions.

Answer: The structure for the review was strictly adhered to, ensuring a logical and comprehensive progression of the topic. Moreover, the manuscript was reassembled with some paragraphs transposed and the reference list fully reorganized.

Comment: Page 2 results, the results section is not required in review articles.

Answer: The Results section was substituted by Relevant Sections as suggested.

Comment: Page 13 discussion figure 1, In your Figure 1 you refer to insulin resistance as a causal element for the development of bladder cancer and subsequently low-grade inflammation. In the existence of any comorbidity that involves a low-grade inflammatory process, what would the outcome be? Similar to Figure 1 or different? Please integrate information about these cases into the manuscript.

Answer: This information was integrated in the text before Figure 1.

 

Comment: You need two important sections in this manuscript, you need a discussion about the findings of different studies, is important add information about insulin resistance  a potential pathophysiological mechanism underlying the association between bladder cancer and its known risk factors, the second section is the conclusion about your research question.

Answer:  Authors fully agree that the heterogeneity of the available literature—stemming from differences in study design, population characteristics, and the metabolic markers assessed—requires careful interpretation. Although certain carcinogenic pathways are well established, the extent to which systemic factors such as insulin resistance contribute remains debated and cannot be overstated. For this reason, I have explicitly added this consideration as a note of caution in the Conclusions, emphasizing the need for prudence when interpreting associative findings and highlighting the gaps that future research must address.

Comments on the Quality of English Language

It would be appropriate to review the English writing again

Answer: We restructured the manuscript by repositioning certain paragraphs and performing a complete overhaul of the references. Furthermore, we tried to eliminate typos and language mistakes.

Reviewer 3 Report

Comments and Suggestions for Authors

This manuscript is timely, ambitious, and intellectually stimulating. Its main strength is the attempt to frame insulin resistance as a unifying biological node linking several environmental, dietary, and lifestyle exposures to bladder cancer through chronic hyperinsulinemia, PI3K/AKT/mTOR signaling, oxidative stress, and low-grade inflammation. That central hypothesis is plausible and the review is generally well structured, but for a major journal the paper still needs a more rigorous hierarchy of evidence and a more cautious tone. At present, the title, highlights, abstract, and conclusion present insulin resistance too strongly as the primary common mechanism and move too quickly toward prevention and clinical application, whereas much of the review remains associative and hypothesis-generating rather than definitive. This is particularly relevant because the manuscript places well-established risk factors such as smoking and occupational exposure alongside more preliminary domains such as microplastics, air pollution, chlorinated water, sleep disorders, and microbiome shifts without consistently distinguishing strong epidemiologic support from emerging biologic plausibility.

The manuscript would be substantially strengthened by deeper clinical contextualization. If insulin resistance is proposed as a meaningful determinant of bladder-cancer risk and progression, the review should better explain how this concept might influence contemporary surveillance and treatment frameworks, especially in metabolically compromised patients. In this context, the authors should discuss the need for sensitive non-invasive follow-up tools and cite doi: 10.3390/diseases12090219. PMID: 39329888; PMCID: PMC11431392. The discussion on inflammation, tumor microenvironment, and GLP-1 receptor agonists would also benefit from a more direct connection to immune checkpoint biology, particularly PD-L1 expression and its clinical relevance in advanced urothelial carcinoma. This would give the review a more modern translational dimension and improve its relevance for readers dealing with real urothelial oncology practice. The paper also requires tightening at the level of presentation and internal consistency. Some tables and figures are overly linear and simplify complex biology too aggressively, while several textual problems weaken confidence in the manuscript, in addition pay attention to several sentences with mistakes. The therapeutic section is likewise too expansive and partly speculative, particularly where it moves from insulin resistance biology to GLP-1 receptor agonists, supportive care, and cannabinoids. Overall, I see value in the review and in its central hypothesis, but in its current form it reads more as an interesting conceptual narrative than as a mature high-impact synthesis. The authors should focus on evidence stratification, clinical integration, and sharper editorial control would markedly improve the manuscript.

Author Response

Reply to Reviewer 3

We would like to express our sincere gratitude for your insightful and constructive feedback on our manuscript. Your suggestions have been instrumental in elevating the clarity, focus, and overall scientific quality of this work.

 

Comment: This manuscript is timely, ambitious, and intellectually stimulating. Its main strength is the attempt to frame insulin resistance as a unifying biological node linking several environmental, dietary, and lifestyle exposures to bladder cancer through chronic hyperinsulinemia, PI3K/AKT/mTOR signaling, oxidative stress, and low-grade inflammation. That central hypothesis is plausible and the review is generally well structured, but for a major journal the paper still needs a more rigorous hierarchy of evidence and a more cautious tone. At present, the title, highlights, abstract, and conclusion present insulin resistance too strongly as the primary common mechanism and move too quickly toward prevention and clinical application, whereas much of the review remains associative and hypothesis-generating rather than definitive. This is particularly relevant because the manuscript places well-established risk factors such as smoking and occupational exposure alongside more preliminary domains such as microplastics, air pollution, chlorinated water, sleep disorders, and microbiome shifts without consistently distinguishing strong epidemiologic support from emerging biologic plausibility.

Answer: We modified the title and added a long paragraph in the conclusions

 

Comment: The manuscript would be substantially strengthened by deeper clinical contextualization. If insulin resistance is proposed as a meaningful determinant of bladder-cancer risk and progression, the review should better explain how this concept might influence contemporary surveillance and treatment frameworks, especially in metabolically compromised patients. In this context, the authors should discuss the need for sensitive non-invasive follow-up tools and cite doi: 10.3390/diseases12090219. PMID: 39329888; PMCID: PMC11431392. 

Answer: The review’s Future Directions highlight the urgent clinical need for the implementation of sensitive, non-invasive follow-up tools to monitor these high-risk individuals more effectively, as supported by recent diagnostic advancements (with suggested reference).

Comment: The discussion on inflammation, tumor microenvironment, and GLP-1 receptor agonists would also benefit from a more direct connection to immune checkpoint biology, particularly PD-L1 expression and its clinical relevance in advanced urothelial carcinoma. This would give the review a more modern translational dimension and improve its relevance for readers dealing with real urothelial oncology practice. 

Answer: The manuscript has been updated to include a direct connection between inflammation, GLP-1RAs, and immune checkpoint biology. We have specifically highlighted the clinical relevance of PD-L1 expression in the context of advanced urothelial carcinoma, ensuring the review reflects current translational oncology practices.

Comment: The paper also requires tightening at the level of presentation and internal consistency. Some tables and figures are overly linear and simplify complex biology too aggressively, while several textual problems weaken confidence in the manuscript, in addition pay attention to several sentences with mistakes. The therapeutic section is likewise too expansive and partly speculative, particularly where it moves from insulin resistance biology to GLP-1 receptor agonists, supportive care, and cannabinoids. Overall, I see value in the review and in its central hypothesis, but in its current form it reads more as an interesting conceptual narrative than as a mature high-impact synthesis. The authors should focus on evidence stratification, clinical integration, and sharper editorial control would markedly improve the manuscript.

Answer: Some paragraphs were drastically reduced, saving the core content. Authors warmly thank the esteemed reviewer for the positive judgement.

 

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The authors have improved the manuscript; for example, the addition of subtitles has made the structure clearer and more accurate.

However, the manuscript still lacks a strong focus on bladder cancer. In several instances, the authors rely on citations from other cancer types (e.g., colon and breast cancer), also in the tables, which weakens the relevance of the title.

Overall, the authors should ensure that the cited literature is directly relevant to bladder cancer, particularly in the tables.

In addition, the following minor issues were identified:

- One subtitle is titled “Relevant Section.” Does this imply that the previous text is not relevant?? Please clarify or revise.

- Subsections 2.1 and 2.2 lack clear context and should be better introduced.

- Table 1: The authors describe molecular signaling pathways. However Biochemical pathways are missing.

- Figure 1: The figure is improved. However the meaning of the different colors (red, green, yellow, and orange) is not explained and should be clarified in the legend.

- Line 396 (title of section 2.9): “Meat, Metabolism, and Malignancy". Please clarify what is meant by “meat” in this context.

Author Response

Reviewer 1

Dear Reviewer,

Thank you very much for your second review of our manuscript and for the extraordinary punctuality of your response. We truly appreciate the time and care you have invested in helping us refine this work.

We have carefully considered your latest feedback and have done our absolute best to address the remaining points in this revision. We believe these adjustments, all highlighted in blue and /or in different font/style, have significantly strengthened the paper and addressed your concerns. We hope that the manuscript is now in a form that meets your approval for publication.

Thank you again for your constructive guidance and your efficiency throughout this process.

Best regards,

Specifically, we have focused on:

Comment: 

The authors have improved the manuscript; for example, the addition of subtitles has made the structure clearer and more accurate.

Answer:

  We sincerely thank the reviewer for this positive observation. We are pleased that the addition of subtitles has improved the clarity and structural accuracy of the manuscript. We have maintained this organized approach throughout the latest revision to ensure the narrative remains easy for the reader to follow.

Comment: 

However, the manuscript still lacks a strong focus on bladder cancer. In several instances, the authors rely on citations from other cancer types (e.g., colon and breast cancer), also in the tables, which weakens the relevance of the title.

Answer:

We appreciate this critical observation. We agree that maintaining a strict focus on bladder cancer is essential for the cohesion of the manuscript and its alignment with the title. In this revision, we have performed a comprehensive sweep of the text and tables to address this: Sentences in the text and related references referring to other cancers were deleted (16 and 17) and were listed two relevant ones. The reference 40 was eliminated and exchanged with a pertinent one. The reference 146 concerning breast cancer and reference 147 were deleted  and  substituted by two more proper ones; similarly the reference 165  in Table 3  was eliminated and replaced with  a fitting  one.

The  content of the reference  183 was modified  and another reference was chosen, i.e.,  Cherkasova V, Wang B, Gerasymchuk M, Fiselier A, Kovalchuk O, Kovalchuk I. Use of Cannabis and Cannabinoids for Treatment of Cancer. Cancers (Basel). 2022 Oct 20;14(20):5142. doi: 10.3390/cancers14205142. PMID: 36291926; PMCID: PMC9600568.

However, for the sake of clarity regarding our previous version, we would like to point out that the inclusion of breast cancer citations was initially intended to highlight shared molecular pathways that have been recently explored in both pathologies. Specifically, we were referring to: Xu W et al. in Exploration of genetics commonness between bladder cancer and breast cancer based on a silicio analysis on disease subtypes. Technol Health Care. 2018;26(S1):361-377. doi: 10.3233/THC-174699. PMID: 29758961; PMCID: PMC6027900. Their study identified some basal-related and luminal-related genes shared by two cancers,  helping shed light on the potential relationships between MIBC and breast cancer as a whole.

Comment: 

Overall, the authors should ensure that the cited literature is directly relevant to bladder cancer, particularly in the tables.

Answer:

 Cited literature was  opportunely modified. Table Update: The references in  Tables have been revised to remove data points from unrelated cancer types, ensuring that all presented evidence is now strictly relevant to bladder cancer.

In addition, the following minor issues were identified:

 

Comment: 

 One subtitle is titled “Relevant Section.” Does this imply that the previous text is not relevant?? Please clarify or revise.

Answer: The “Relevant Section” was commute in a new subtitle, more pertinent to the content of this section.

Comment: 

 Subsections 2.1 and 2.2 lack clear context and should be better introduced.

Answer: Subsection 2.1. was ameliorated in the subtitle and  introduction. Subsection 2.2. was  amplified, adding  an informative sentence. Consequently also subsection 2.3. was improved in the introduction.

Comment:

Table 1: The authors describe molecular signaling pathways. However Biochemical pathways are missing.

Answer: To ensure optimal clarity and avoid over-saturation of the existing data, the proposed integration of biochemical pathways for specific risk factors into Table 1 was deferred; instead, these comprehensive modifications have been consolidated into a dedicated, standalone new table  (Table 2 with title and legend) to better delineate the complex pathways involved.

Comment:  

 

Figure 1: The figure is improved. However the meaning of the different colors (red, green, yellow, and orange) is not explained and should be clarified in the legend.

Answer: A  clear (hoping more capturing) figure with details of colors was generated, and a short sentence was added in the Legend to Figure 1.

 

Comment:

Line 396 (title of section 2.9): “Meat, Metabolism, and Malignancy". Please clarify what is meant by “meat” in this context.

Answer:  The subtitle was clarified.

 

Comment:

The English is fine and does not require any improvement

Answer:  The phrasing underwent additional refinement.

Reviewer 2 Report

Comments and Suggestions for Authors

I don´t have any questions

Comments on the Quality of English Language

 The English could be improved 

Author Response

Reviewer 2 

Comment : The English could be improved 

Answer:  Thank you. The language was improved once more.

 

Reviewer 3 Report

Comments and Suggestions for Authors

The authors met the requests. Thank you. 

Author Response

Review 3 

 

Comment : The English could be improved to more clearly express the research.

 

Answer: Thank you. The language was improved once more.