Psychoneurological Symptoms and Biomarkers of Stress and Inflammation in Newly Diagnosed Head and Neck Cancer Patients: A Network Analysis

Round 1

Reviewer 1 Report

Review of: Pshychoneurological symptoms and biomarkers of stress and inflammation in newly diagnosed head and neck cancer patients a network analysis

This research paper aimed to group pshychoneurological factors and inflammatory factors by network analysis in order to identify important links between the two systems.  The group have published previously on similar findings but have this time included the diurnal cortisol slope as a novel component in their studies. The paper is well laid out and well written with detailed statistical analyses.  The findings add to the knowledge of how various factors which are experienced by newly diagnosed cancer patients can influence systemic indicators which may then influence the cancer progression.  It is assumed that this work will be followed up with further analyses looking at patient outcome in the future. This is not made clear in the paper and perhaps should be addressed in terms of the “so what” element of the results.

Abstract

Clearly written, concise and to the point

Line 41 – there is a different font size here which needs to be resolved

Line 44 – should read an important role

Introduction

Provides adequate background of the research area, however the novelty of the research should be highlighted more

Materials and methods

Standard measures of sleep quality, anxiety, pain and fatigue have been used appropriately.  Clearly written methods with sufficient detail for reproduction. Statistics appear to be robust.

Question – were salivettes used or did the patients simply drool into the tube? This needs to be made clear

Line 38 – should read: upon receipt

It is not clear why four different MSD kits were required, the final one being a non-human kit? The K15049 contains all three of the cytokines investigated, therefore it is not clear why the other three kits have been included. 

It is also not clear why the authors have not included the other data from the MSD kits, for example the IFNγ, IL1β, IL2, IL4, IL8, IL12p70 and IL13 data that would be available from kit K15049? Surely these would have added further strands to the network.

Results

Question – the difference in age between the complete and incomplete groups produced a significant result, I find that hard to believe that the difference between 62 and 65 with SD of 8.2 and 10.4 would be significant. Can this be double checked please.

Line 235 – reads depressiom instead of depression

Question - Have the authors investigated the subgroups of head and neck cancer patients separately eg the oral cancer patients alone, as these patients may experience a worse sleep quality compared to those with hyphopharyngeal cancer for example.  This would add an interesting angle to the data perhaps?

Discussion

A nice round up of the data and comparison to the other literature

Line 310 – “IL6 seemed to be produced not only by tumour cells to induce HNC proliferation…..” this sentence is worded as such that it sounds like the group have done this in the current paper, which is not the case – please reword.

 

Overall a sound research paper which needs to highlight the novelty of the research more.

Author Response

Response to reviewer 1 comments

Point 1. This research paper aimed to group psychoneurological factors and inflammatory factors by network analysis in order to identify important links between the two systems.  The group have published previously on similar findings but have this time included the diurnal cortisol slope as a novel component in their studies. The paper is well laid out and well written with detailed statistical analyses.  The findings add to the knowledge of how various factors which are experienced by newly diagnosed cancer patients can influence systemic indicators which may then influence the cancer progression.  It is assumed that this work will be followed up with further analyses looking at patient outcome in the future. This is not made clear in the paper and perhaps should be addressed in terms of the “so what” element of the results.

Response 1. Thank you for this suggestion. We now address the potential impact of our findings in the Conclusion section (Line 364 – 366) : “Our findings may assist future studies to disentangle the role of inflammation and psychoneurological symptoms in progression of HNC-related outcomes over time.”

 

Abstract

Point 2. Line 41 – there is a different font size here which needs to be resolved

Response 2. We corrected the font size accordingly.

 

Point 3. Line 44 – should read an important role

Response 3. As suggested, we corrected the phrase accordingly.

Introduction

Point 4. Provides adequate background of the research area, however the novelty of the research should be highlighted more

Response 4. For more clarity, we adjusted the following sentence of Introduction section (Line 89 – 93): “Therefore, we used this novel approach to examine the associations between psychoneurological symptoms (poor sleep quality, anxiety, depression, fatigue, and oral pain), and biomarkers of stress (diurnal cortisol slope) and inflammation (CRP, IL-6, interleukin-10 [IL-10], and tumor necrosis factor alpha [TNF-α]) among newly diagnosed HNC patients.”

 

Materials and methods

Point 5. Question – were salivettes used or did the patients simply drool into the tube? This needs to be made clear

Response 5. We used salivettes to obtain the saliva samples. For more clarity we added this information in Patients and methods section, subsection Measures (Line 153 – 154): “Patients were given 4 salivette tubes (one for each saliva collection) and were instructed to note the exact time of saliva collection.”

 

Point 6. Line 38 – should read: upon receipt

Response 6. As suggested, we corrected the word accordingly.

Point 7. It is not clear why four different MSD kits were required, the final one being a non-human kit? The K15049 contains all three of the cytokines investigated, therefore it is not clear why the other three kits have been included. 

Response 7. Thank you for the keen eye for detail. We cross-checked this issue with our technicians and we discovered a documentation error. In this study we only used kit K15049 to measure the cytokines of interest (IL-6, IL-10 and TNF-α.) We adjusted the Methods section accordingly (Line 178 – 181): “Each sample was analyzed using an ELISA based technology that uses electrochemiluminescence for detection with Meso Scale Discovery Quickplex SQ 120 Imager (cat. # K15049-Series, Meso Scale Discovery, Rockville MD).”

 

Point 8. It is also not clear why the authors have not included the other data from the MSD kits, for example the IFNγ, IL1β, IL2, IL4, IL8, IL12p70 and IL13 data that would be available from kit K15049? Surely these would have added further strands to the network.

Response 8. We selected IL-6, IL-10 and TNF-α as they were the most frequently studied markers and we did not measure the concentration of other cytokines. A further study including other cytokines such as IFN-γ, IL-1β, IL-8 and IL-13 could provide a more precise understanding on the inflammatory process in the network. We now acknowledge this issue in Discussion section (Line 352 - 356) “Third, we only measured IL-6, IL-10 and TNF-α as they were the most frequently studied markers and we did not measure the concentration of other cytokines. A further study including other inflammatory cytokines is needed for a deeper insight on the inflammatory process in the network.”

 

 

Results

Point 9. Question – the difference in age between the complete and incomplete groups produced a significant result, I find that hard to believe that the difference between 62 and 65 with SD of 8.2 and 10.4 would be significant. Can this be double checked please.

Response 9. We re-analyzed the samples using unpaired t-test and could confirm the statistically significant result, even after the correction for multiple testing (p-value < 0.05).

 

Point 10. Line 235 – reads depressiom instead of depression

Response 10. We corrected this accordingly.

 

Point 11. Question - Have the authors investigated the subgroups of head and neck cancer patients separately eg the oral cancer patients alone, as these patients may experience a worse sleep quality compared to those with hyphopharyngeal cancer for example.  This would add an interesting angle to the data perhaps?

Response 11. We did not analyze the network differences between different subgroups of head and neck cancer patients and we agree that this information may be interesting for the readers. We acknowledge this issue as a limitation of the study in the Discussion section (Line 356 – 359) “Fourth, we did not control for different subgroups of HNC patients, for example based on HNC location or stage. Future study is needed to examine whether the network of psychoneurological symptoms, cortisol diurnal slope and inflammation differ among these sub-populations.”

 

Discussion

A nice round up of the data and comparison to the other literature

Point 12. Line 310 – “IL6 seemed to be produced not only by tumour cells to induce HNC proliferation…..” this sentence is worded as such that it sounds like the group have done this in the current paper, which is not the case – please reword.

Response 12. We edited the sentence accordingly (Line 319 – 321) “A previous study hypothesized that IL-6 is produced not only by tumor cells to induce HNC proliferation, but also by host cells (e.g., endothelial cells, stromal cells, immune cells) as a response to tumor growth.”

 

Point 13. Overall a sound research paper which needs to highlight the novelty of the research more.

Response 13. Thank you for the compliment. In addition to our adjustment in Response 4, we highlighted the novelty of our research in the first sentence of Discussion section (Line 299 – 301) “To the best of our knowledge, this study is the first to use network analysis to examine associations between psychoneurological symptoms and biomarkers of stress and inflammation in newly diagnosed HNC patients.”.

 

 

Reviewer 2 Report

In the manuscript titled ‘Psychoneurological Symptoms and Biomarkers of Stress and 2 Inflammation in Newly Diagnosed Head and Neck Cancer Patients: A Network Analysis, the authors described the association of psychoneurological symptoms with the biomarkers of stress and inflammation in HNC. The authors explained the biomarkers of stress and inflammation via network analysis. Three indices of betweenness, closeness and degree were explored in the manuscript and the data is presented in tabular and graphical forms to highlight the findings. The interconnections between psychoneurological symptoms and biomarkers of inflammation and stress in HNC are evidenced by the novel findings of the study. The manuscript is written proficiently and can be recommended for publication in the journal of ‘Current Oncology’ if very minor revisions are performed.

 

 

Critique:

In the introduction, information regarding the types, sub-types, diagnostic presentations, and epidemiological features of HNC is missing.

The link between inflammation and HNC development is missing, and direct literature on psychoneurological symptoms of cortisol is provided.

Line 78-81 (Reference is missing)

The exclusion criteria of patients are mentioned but not well defined with reasoning.

Lines 165-174 can be placed in a separate heading before the measures to showcase the characteristics of patients (can be placed in section 2.1. Study Population).

Lines 325-330 present a sentence, which is not only long but complicated and needs to be broken down for easy understanding. The findings are sound and have connections to one another, therefore it is suggested to observe caution while stating a long conclusion in a single sentence as suppression of cancer-induced inflammation leading to fatigue is could be a wrong statement. Please revise.

The font of the conclusion is different from the rest of the manuscript.

Author Response

Please see the attachment.

Author Response File: Author Response.docx