Review Reports

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The aim of the study was checking in clinical practice the usefulness of the new frailty scoring system in predicting the results of esophagectomy in patients older than 65 y. To do this they used previously validated frailty assessment instrument and significantly high group of 447 patients subjected esophagectomy for testing, what increases the value of the study. Up to my opinion, the statistical methods used in this research were properly selected and exhausted the requirements of the study. And, what is very important, the conclusions are consistent with the evidence and arguments presented. We still are in need for such scoring systems to enable more elderly patients with esophageal cancer be subjected esophagectomy instead of palliative treatment only.

Congratulations, well documented and very useful study worth testing in clinical practice in other cancer centers.

Author Response

Reviewer Comment:

The aim of the study was checking in clinical practice the usefulness of the new frailty scoring system in predicting the results of esophagectomy in patients older than 65 y. To do this they used previously validated frailty assessment instrument and significantly high group of 447 patients subjected esophagectomy for testing, what increases the value of the study. Up to my opinion, the statistical methods used in this research were properly selected and exhausted the requirements of the study. And, what is very important, the conclusions are consistent with the evidence and arguments presented. We still are in need for such scoring systems to enable more elderly patients with esophageal cancer be subjected esophagectomy instead of palliative treatment only.
Congratulations, well documented and very useful study worth testing in clinical practice in other cancer centers. 

Response:

Thank you for reviewing our manuscript.

 

Reviewer 2 Report

Comments and Suggestions for Authors

Congratulations to Boerner et al. The authors conducted an investigation on a new frailty index as a predictor of perioperative outcomes in esophageal cancer. Overall, the study is well-written with a well-designed methodology. Additionally, the topic is quite relevant. I have some remarks:

Methods:
The diagram of patient selection should be in the Results section and not in the Methods. Moreover, it appears that the design of this flowchart was adapted from PRISMA for systematic reviews. This seems inappropriate, as there is no identification and screening for a cohort study.

Use vs. in italics.

The statistical analysis section should be more detailed. What significance level was adopted? What kind of effect measure was used? Etc.

Neoadjuvant Treatment:
Could you provide more details regarding the neoadjuvant treatment, at least in terms of radiation, as it can affect postoperative risk?

Surgical Strategy:
Could you provide more details on the surgical strategy? You mentioned that 86% of patients underwent Ivor Lewis esophagectomy. What about the remaining patients? The type of surgery significantly affects the risk of complications.

Did you consider adjusting the regression analysis for the type of surgery or the use of preoperative radiation?

Author Response

Comment 1: Congratulations to Boerner et al. The authors conducted an investigation on a new frailty index as a predictor of perioperative outcomes in esophageal cancer. Overall, the study is well-written with a well-designed methodology. Additionally, the topic is quite relevant. I have some remarks:

Methods:
The diagram of patient selection should be in the Results section and not in the Methods. Moreover, it appears that the design of this flowchart was adapted from PRISMA for systematic reviews. This seems inappropriate, as there is no identification and screening for a cohort study.

Response 1: Thank you for this suggestion. We agree this is misleading and this diagram has been removed.

Comment 2: Use vs. in italics.

Response 2: Thank you for your feedback. This has been revised.

Comment 3: The statistical analysis section should be more detailed. What significance level was adopted? What kind of effect measure was used? Etc.

Response 3: We agree with the reviewer that further details could be included in the statistical analysis section. We have added the below test to our methods sections:

“From our logistic regression models, we reported the odds ratios (OR) and 95% confidence intervals (CI). All tests were 2-sided, and significance was set at p<0.05.” (Lines 110-111)

Comment 4: Neoadjuvant Treatment:
Could you provide more details regarding the neoadjuvant treatment, at least in terms of radiation, as it can affect postoperative risk?

Response 4: There were 360 overall patients that had neoadjuvant therapy. Of those, 348 patients underwent standard of care chemoradiation. This has been added to Table 1.

Comment 5: Surgical Strategy:
Could you provide more details on the surgical strategy? You mentioned that 86% of patients underwent Ivor Lewis esophagectomy. What about the remaining patients? The type of surgery significantly affects the risk of complications.

Response 5: Yes, and this has been added to Table 1. 32 patients underwent a 3 hole esophagectomy, 16 patients underwent transhiatal esophagectomy, and 5 underwent partial or completion gastrectomy with esophagectomy. There were 10 “other” operations, such as laryngo-pharyngo esophagectomy and open thoracoabdominal esophagectomy.

Comment 6: Did you consider adjusting the regression analysis for the type of surgery or the use of preoperative radiation

Response 6: Thank you for this question - We did not adjust our analysis for type of surgery or preoperative radiation. Our cohort is overwhelmingly composed of patients with adenocarcinoma (Table 1). Nearly all patients had an Ivor Lewis esophagectomy. Additionally, nearly all patients who had neoadjuvant therapy underwent standard of care chemoradiation prior to surgery.  All patients who did not undergo neoadjuvant therapy had clinical stage I or II disease. It would not be possible to adjust for radiation independently as this is highly correlated to clinical stage, and there were very limited patients who underwent neoadjuvant systemic therapy only.