PONE-D-21-00937

Trends in Extent of Surgical Cytoreduction for Patients with Ovarian Cancer

PLOS ONE

Dear Dr. Cohen,

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Both reviewers found the manuscript interesting and valuable overall. Only minor criticisms were made. I am very confident that once these are incorporated, the manuscript can be published and look forward to the revised version.

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PLOS ONE

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Reviewers' comments:

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Comments to the Author

1. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Partly

Reviewer #2: Yes

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2. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #2: Yes

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3. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #2: Yes

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4. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

Reviewer #2: Yes

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5. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: Data from NIS has been analyzed in order to examine the trend of ECR for patients with ovarian cancer. The reviewer has some minor points that need to be addressed:

1. Has there been exclusion criteria? Was invalid, duplicated or missing data detected?

2. In 2015 a transition to ICD 10 took place due to update of a coding system. Has this database change affected the data collected for this research? Has the algorithm for data collection been modified?

3. Although patient characteristics are considered in the study objective, authors have not included this aspekt in their hypothesis.

The authors hypothesize, that ECR is associated with a higher risk of perioperative mortality and length of stay. It is very likely that this effect will occur, when comparing extended surgery procedures against minor ones.

4. Please describe how the reference groups in the multivariate regression were determined.

5. In order to determine if the relative number of ECR procedures has decreased 2013- 2017 it is necessary to indicate the number of new diagnosed ovarian cancer per year. The decrease of the absolute ECR number is most significant since 2016. This coincides with the database change mentioned in item 2 above. Could this have interfered in the results?

6. Which data in this research supports the statement that socioeconomic factors influence the access of surgery? Or is this statement supported by a citation?

7. The increase of neoadjuvant chemotherapy has been observed (cited) between 2004 and 2013. Does recent data support this trend? Moreover the observation in the reviewed research starts at 2013.

8. The decrease in bowel resection could reflect the increasing use of neoadjuvant therapy, but there are also other explanations. As previously mentioned the number of new diagnosed ovarian cancer ist needed in oder to confirm a decrease in bowel resection.

9. How the decrease of ECR relates to the quality of care provided to ovarian cancer patient?

Reviewer #2: I found this manuscript excellent and very interesting to read. It highlights differences in the management of ovarian cancer depending on certain demographic and hospital characteristics.

The only correlation that is difficult to understand is how patients with increased comorbidities had more chances of undergoing extensive surgery for ovarian cancer. The index used in this study is complex with a lot of parameters contributing to the final score and this might account for the finding. If the PS was available it would have made more sense in interpreting the comorbidity index used in this study.

Also I am not familiar with the data base used for extracting data for this study, however its limitations are thoroughly discussed by the author and I don't think these are reducing the value of the results.

I think it should be published at its current form in PLOS ONE

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Reviewer #1: Yes: Elena Junghans MD

Reviewer #2: Yes: Ioannis Biliatis

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Trends in Extent of Surgical Cytoreduction for Patients with Ovarian Cancer

PONE-D-21-00937R1

Dear Dr. Joshua Garrett Cohen,

We’re pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements.

Within one week, you’ll receive an e-mail detailing the required amendments. When these have been addressed, you’ll receive a formal acceptance letter and your manuscript will be scheduled for publication.

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Kind regards,

Xiaodong Cheng

Academic Editor

PLOS ONE

Additional Editor Comments (optional):

All comments have been addressed.

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation.

Reviewer #2: All comments have been addressed

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2. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #2: Yes

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3. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #2: I Don't Know

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4. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #2: Yes

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5. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #2: Yes

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6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #2: As I have already described in my initial review of this manuscript I find it excellent and very interesting. I think the authors addressed all issues raised appropriately

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7. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files.

If you choose “no”, your identity will remain anonymous but your review may still be made public.

Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #2: No