Pneumonectomy for Primary Lung Tumors and Pulmonary Metastases: A Comprehensive Study of Postoperative Morbidity, Early Mortality, and Preoperative Clinical Prognostic Factors

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The interesting paper of Grapatsas et al. describes the in-hospital morbidity and 30- and 90-day mortality after pneumonectomy due to lung malignancy in a large tertiary center. The authors describe a high 90-day mortality associated with an ASA score of 4 or postoperative bronchus insufficiency. Age and cardiovascular comorbidities were not risk factors in the logistics regression analysis.

I have some questions regarding the manuscript:

A)  In Table 2 could the authors explain why the T and N stadium and the histology were classified as unknown postoperatively?

B) Do the authors have any data regarding the causes of 30- and 90-day mortality?

C) In table 6, could the authors add the effect of preoperative treatment on in-hospital mortality? I would suggest not only to divide these patients in two categories (chemo+rtx, chemo) but also to sum up these patients as one group. Moreover, was preoperative treatment as a whole a risk factor for postoperative morbidities?

D) Why did the authors did not perform a similar analysis as shown in table 6 for 90-day mortality?

E) The risk factors described in table 7 refer to 30-day, 90-day or total mortality?

F) The authors correctly state that pneumonectomy is a disease itself and they adequately comment on the increased 90-day mortality in their patient cohort. Therefore, I think the authors should more extensively describe the role of neoadjuvant chemotherapy in operable lung cancer and how it might be related to a decreased rate of pneumonectomies.  

Comments on the Quality of English Language

Minor editing of English language is required. 

Author Response

Τhank you very much for your comments and your recommendations for our article.

A The performance of the study was based on a prospective analysis of an institutional database. As a result, the TNM stadium of a number of patients was unknown. This aspect is mentioned in the section of Material and Methods. In addition, concerning this matter an additional mention is made in the section of limitations.

B Unfortunately, as our data are anonymized the reason of the patients’ death is not known for all patients. However, we calculated the patients’ death for any reason. This information is mentioned in the section of Material and Methods.

C As suggested, comparisons were made concerning preoperative treatment for postoperative morbidity and mortality. Details were added in table 4 and 6.

D The aim of this study was to investigate postoperative morbidity and early mortality for patients undergoing pneumonectomy. We added a comment in the Introduction to make it clearer. Another reason was to avoid repeating of the study’s results as the number of participants in our study was limited.

E The risk factors described in table 7 refer to 30-day mortality. A special reference was made in the table label and the section of limitations.

F As suggested, corrections were made and a new paragraph was added.

Reviewer 2 Report

Comments and Suggestions for Authors

I would like to congratulate the authors of an interesting article titled: “Pneumonectomy for primary lung tumors and pulmonary metastases: a comprehensive study of postoperative morbidity, early mortality and preoperative clinical prognostic factors”.

The paper is written according to the guidelines and includes all required sections. English quality is good, but professional proofreading could improve it. Introduction provides sufficient background for the study. Methodology is correct. Results are presented clearly. In the discussion, the authors refer to the current literature.

I have few comments to the article:

1.  Staging methods should be described briefly in the material and methods section (CT / PET-CT / invasive mediastinal staging).
2. Title of section 3.6 (“… 30-day mortality) and Table 6 (“… in-hospital mortality”) do not match, please correct it.
3. There are some minor errors in the tables, please check the tables carefully.

In general, the article does not contribute significant information to current medical knowledge, but it covers areas of interest to thoracic surgeons and oncologists.

Comments on the Quality of English Language

English proofreading required

Author Response

Thank you for you comments and suggestions. Corrections were made, as suggested.

1 Staging methods were described in Material and methods, as suggested.

2 Correction was made as suggested.

3 Corrections were made as suggested.

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The article can be published in the present form