Nutritional Support for Gastrointestinal Cancer Patients: New (and Old) Frontiers in Management, a Narrative Review

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The authors present an interesting, well structured review which is much broader than expected from the title. While "nutritional prehabilitation" focuses on the preoperative period , the article globally addresses many perioperative aspects of nutritional care and management in gastrointestinal cancer patients. It is more rehabilitation than prehabilitation. 

-The role of  perioperative Medical Nutrition Therapy (MNT) is missing and should be discussed.

Proposal to modify the title: "Nutritional management in patients with gastrointestinal cancer"

Author Response

We appreciate the reviewers’ comments. Our objective with this review was not to try to recreate ASPEN or ESPEN guidelines for nutritional support on cancer patients. We do recognize that adding some details on guideline recommendation for Medical Nutrition Therapy recommendation could be helpful and have added a paragraph regarding the value of MNT and a summary of the ESPEN guidelines for nutrition for cancer patients. See below and table 4.

“Medical nutrition interventions

Evidence based approaches to decrease the development of malnutrition during the different periods of the continuum of cancer care have been published.^18,36,37 They include some the aforementioned dietary based interventions to address the common challenges and symptoms associated with cancer and its therapies.³⁶ The European Society for Clinical Nutrition and Metabolism (ESPEN) has done a very review of the evidence for medical nutrition recommendations for cancer patients using the GRADE method to achieve the recommendations level based on strength or recommendation (weak to strong) level of evidence (low to high) and degree of consensus  with strong consensus denoted when reaching at least 80% of the panel. The following table (Table 4) summarizes the medical therapy recommendations for cancer patients.³⁶  “    

Reviewer 2 Report

Comments and Suggestions for Authors

The manuscript addresses an important and timely topic, highlighting nutritional challenges and emerging strategies for patients with gastrointestinal cancers. The authors provide a comprehensive and clinically relevant overview. However, substantial revisions are required before the manuscript can be considered for publication. While the topic is of high value, the current structure and methodology do not fully meet the standards of a scoping review, and the breadth of content at times detracts from the focus on nutritional prehabilitation.

1. Methods: Although the manuscript is labeled as a scoping review, it does not describe essential methodological components such as databases searched, search terms/keywords, inclusion and exclusion criteria, study selection process, or data charting and synthesis methods. This makes it difficult to evaluate the rigor and reproducibility of the review. Please revise the Methods section to follow PRISMA-ScR guidelines and include a flow diagram.

2. Overall: The paper covers malnutrition, cancer-related symptoms, pharmacologic management, digital health, behavioral science, and machine learning. While informative, much of this content extends beyond the core topic. The manuscript should be reorganized to prioritize definition and components of nutritional prehabilitation, specific evidence supporting prehabilitation in GI cancers, and gaps and future directions specific to prehabilitation. General nutritional management and cachexia pharmacotherapy can be summarized more concisely or moved to supplementary material.

3. Results: Many studies are cited, but the current narrative does not distinguish levels of evidence, heterogeneity across study designs, effect sizes or strengths of associations, and consistency (or lack thereof) across findings. Consider adding a summary table of key prehabilitation studies (design, sample size, outcomes, major findings). This would substantially improve clarity and usefulness.

4. “Pharmacologic Interventions Section Is Only Loosely Connected to Prehabilitation”: The discussion of megestrol, corticosteroids, olanzapine, and ponsegromab focuses primarily on cachexia treatment and symptom management, not prehabilitation. Recommend condensing this section and explicitly linking its relevance to the prehabilitation framework (e.g., “role as adjunctive therapy to optimize nutritional status before surgery or treatment”).

5. “Digital Health, Behavioral Science, and Machine Learning Sections Require Streamlining”: These sections provide interesting perspectives but are lengthy and at times tangential. Suggest integrating these into a single “Future Directions” section, highlighting their potential role specifically in nutritional prehabilitation rather than general oncology care.
6. Consider adding a dedicated section summarizing which patient groups benefit most from prehabilitation, optimal timing (pre-diagnosis, pre-surgery, early therapy, etc.), recommended intervention components (nutrition counseling, supplements, physical activity, psychosocial care), or implementation challenges in real-world settings. This addition would significantly enhance the clinical utility.

Author Response

1. 

 We appreciate the reviews comment. This was not meant to a systematic review, and following  the reviewer’s recommendation a more appropriate definition  our manuscript would be a narrative review, we have modified the title and have added the following section of methods to reflect the review process.

“Methods: Pubmed, Medline, and Cochrane Review databases were queried for randomized clinical trials, meta-analyses and systematic reviews focusing on micronutrient and macronutrient deficiencies in patients with gastrointestinal malignancies, management of symptoms, clinical and pharmaceutical interventions. Similarly, the same approach was utilized to identify novel approaches to addressing nutritional deficits in cancer patients.”

2. 

Thank you for your feedback. As reflected above, the overall goal of the review is to provide a broad review of common nutritional alterations impacting patients who are diagnosed with GI malignancies and consolidate practice-based recommendations for addressing these issues. We have modified the tittle to make it more clear to readers and have added sections on medical nutritional therapy as well as reorganized the novel therapies and future directions section.

3. 

We appreciate the reviewers’ comments. Our objective was not to perform a systematic review of the evidence nor to develop a comprehensive guideline of management for GI cancer patients, but to highlight the emerging field of prehabilitation and new pharmacologic interventions.  We have changed the tittle to be more encompassing as we do cover multiple strategies for the management of those patients during their oncologic journey “Nutritional Support for Gastrointestinal Cancers: New (and old) frontiers in Management, a Narrative Review”. And have modified the manuscript to add more information on medical nutrition therapies

4. We appreciate the reviewers’ comments and have changed the tittle of the manuscript to better express the scope of our review. Additionally, we have restructured the manuscript to be better organized. Given the complexity of malnutrition in GI cancer patients, we aimed to first address interventions directly related to the disease process and consequences of treatment. Cancer related cachexia and anorexia is a major cause of malnutrition in any cancer diagnosis and further complicates management of malnutrition in patients with GI cancers. Pharmacologic interventions provide another channel of intervention to addressing nutritional deficiencies in this patient population

5. 

We appreciate the reviewer’s suggestion and have addressed this in our revision as possible future directions for addressing and better implementing interventions for malnutrition prehabilitation.

6. 

We appreciate the suggestion and have added a table including the ESPEN guidelines for nutrition of cancer patients, specifically regarding medical nutrition therapy recommendations.

Reviewer 3 Report

Comments and Suggestions for Authors

This is a good review of dietary therapy in patients with gastrointestinal symptoms from gastrointestinal cancers. There is not much in the way of outcomes data, but the review puts current practice-based recommendations in one place.

Missing is the most often utilized "prehabilitation" nutritional therapies for patients pre-operatively: enteral and parenteral nutritional support. Despite limited evidence of efficacy, most surgeons still place cancer patients on tube feeding or parenteral nutrition preoperatively, using the rationale that patients with overt malnutrition do worse than those who are reasonably well-nourished. This may be covered elsewhere in this special issue, but if not, should be covered here.

There are some oddities in the set-up of the pages that ought to be corrected before the papr is officially published:

1) Margins on the left are very large which makes for clumsy headers for the text

2) In Table 2, things that don't go together are in the same row. For example, under the Esophageal and Gastric section, "Gastric outlet obstruction" is next to "Odynophagia"--these two items do not go together. It would be better to set this table up verically, with a header (e.g., "Esophageal and Gastric Tumors") followed by two bullet points (e.g., "Nutrition challenges" and "Nutrition-impact symptoms") under each tumor type with the details filled in under each of those bullet points. There is nothing to be gained by comparisons up and down the existing columns; these are basically just lists.

Author Response

We appreciate the reviewers’ comments and have addressed the concerns by adding some evidence-based guidelines summary, additionally we reorganized the future directions section of the manuscript

1. 

We appreciate the reviewers’ comments. This oddity is part of the manuscript template provided by the submission website and recommended to be used. We agree that makes it very hard to read, not just that, it also makes it very hard to edit the text in real time. If the editors agree we would prefer to change to a normal word or PDF format. Thank you

2. 

Thank you for your feedback. We have maintained our formatting as in the required manuscript format from the editorial office. The table is not meant to show cause and effect or a direct relationship of challenges and onset of symptoms. Its objective is to aid summarize the common challenges and symptoms that occur with GI cancer diagnosis in a structured format than in written text.

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

well done