Time Trends and Geographic Patterns of Mortality Due to Tracheal, Bronchus, and Lung Cancer in Portugal

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This is a study whose objective was to describe both the geographic patterns and temporal trends in the trachea, bronchus a lung cancer observed in Portugal in the last years. I still have some concerns about improving the manuscript quality.

 

1. Review all citations in the manuscript. These must come before the point.

2. Material and Methods, Data Collection: the study design is not clear, is it a descriptive study? Analytical? Cross? Longitudinal? Does the study have approval from an ethical board? What were the selection criteria?

3. Material and Methods, Statistical Analysis: were all the data normally distributed?  If not, what statistical tests were used?

4. Material and Methods, Statistical Analysis: Evidently, the authors performed linear regression. The authors must declare it explicitly since there are also logistic regression models.

5. The legend of all figures should be more informative. For example, what is shown in the left panel? What is displayed in the right panel?

Author Response

Comments 1: “Review all citations in the manuscript. These must come before the point.”

 

Authors answer:

We revised the manuscript and we performed the changes according to your report.

 

Comments 2: “Material and Methods, Data Collection: the study design is not clear, is it a descriptive study? Analytical? Cross? Longitudinal? Does the study have approval from an ethical board? What were the selection criteria? “

 

Authors answer:

Please, see in lines 81-82, we included a sentence about type of the study. In lines 83-84 we provided information about the database used. This database is publicly available, therefore there are no ethical concerns. 

 

Comments 3: “Material and Methods, Statistical Analysis: were all the data normally distributed?  If not, what statistical tests were used?”

 

Authors answer:

We appreciated your comments about statistical approach. As we explained in lines 104-113 we modeled aggregated data: annual deaths count and population estimates, by using joinpoint regression models as recommended by the International Agency of Research on Cancer for cancer surveillance over time.  According to the following reference:  Kim HJ, Fay MP, Feuer EJ, Midthune DN. Permutation tests for joinpoint regression with applications to cancer rates. Sta-tistics in medicine 2000;19:335-51.

 

Comments 4: “Material and Methods, Statistical Analysis: Evidently, the authors performed linear regression. The authors must declare it explicitly since there are also logistic regression models.”

 

Authors answer:

Thank you for your suggestion. However, we did not conduct logistic regression analysis. As we explained above we used joinpoint regression for assessing time-trends of cancer rates. Then we obtained Standardized Mortality Rates for comparison of cancer rates between regions.

 

Comments 5: “The legend of all figures should be more informative. For example, what is shown in the left panel? What is displayed in the right panel?”

 

Authors answer:

Thank you for your comment. We introduced changes we hope make figures more informative.

 

Reviewer 2 Report

Comments and Suggestions for Authors

Reviewer’s Comments:

Title: Trends and geographic pattern of mortality due to trachea, 2 bronchi and lung cancer in Portugal

 The authors have studied the trends of mortality due to trachea, bronchi and lung cancer (TBLC) in Portugal across genders and geographical regions using joinpoint regression models. The manuscript (MS) may be recommended for publication after addressing following comments:

1.     The manuscript has been well written, however, the study seems small with respect to the publication in the peer reviewed journal. Use of additional multivariate data analysis tools can add more data and value to the paper.

2.     The introduction section seems very short. Some more information on position of Portugal globally on TBLC with respect to other countries would add value.

3.     Authors should check the citation format for the MS as the references (e.g. [1,2]) are cited after the fullstop for every statement.

4.     The line spacing between the heading, subheadings and the text is not consistent at some places. It is advised to check it thoroughly.

5.     Figure 2, ‘time trend’ column under ‘Women, Sub-urban Area’ is slightly misaligned.

Author Response

Comments 1: “The manuscript has been well written, however, the study seems small with respect to the publication in the peer reviewed journal. Use of additional multivariate data analysis tools can add more data and value to the paper.”

 

Authors answer:

 

Thank you for your comment. We agree with you that multivariate analysis could give use more insights about lung cancer in our setting. However, we used aggregated data for this analysis. We aimed to provide information about time-trends in rates of lung cancer, based on aggregated data and we believe is useful for cancer surveillance in our setting. Therefore, we can stratify results according to the gender and the geographic region, nevertheless we cannot conduct multivariate analysis

 

Comments 2: “The introduction section seems very short. Some more information on position of Portugal globally on TBLC with respect to other countries would add value. “

 

Authors answer:

Thank you for your comment. We agree with you, therefore we introduced more information in the introduction section mainly about the TBLC rates observed in Portugal (Lines 47–54 and lines 65-70).

 

Comments 3: “Authors should check the citation format for the MS as the references (e.g. [1,2]) are cited after the fullstop for every statement.”

 

Authors answer:

We revised the manuscript and we performed the changes according to your report.

 

Comments 4: “The line spacing between the heading, subheadings and the text is not consistent at some places. It is advised to check it thoroughly.”

 

Authors answer:

 

We revised the manuscript and we performed the changes according to your report.

 

Comments 5: “Figure 2, ‘time trend’ column under ‘Women, Sub-urban Area’ is slightly misaligned.”

 

Authors answer:

 

We performed the changes in the according to your report.

Reviewer 3 Report

Comments and Suggestions for Authors

The manuscript applsci-3043351 is a research paper about the environmental factors correlated with the bronchi and pulmonary cancer in Portugal. 

The subject is of great interest and this type of research advances the understanding of cancer pathology.

major comments:

Please check the L97-98 because the iThenticate report detects some similarities. 

The authors identify that the geographical has a role in the development of TBLC but, in my opinion,  the lecturer would like to know more about the nature of the environmental factors involved.- namely "geographical conditions" - L181-184, L201. The authors hypothesize an explanation for the differences in age rates (ASMR_50+) could be the frequency of unhealthy lifestyles (L 205, L212).

In my opinion, some correlations deserve more explanation. E.g. L201 - heterogeneity - in what sense could heterogeneity advance the understanding of the analyzed population groups? Also, for clarity, some lecturers would be interested in all aspects of unhealthy lifestyles other than smoking (L191, 213, L230, L248).

 

Author Response

Comments 1: “Please check the L97-98 because the iThenticate report detects some similarities.”

 

Authors answer:

 

Thank you for your comment. There may be some similarity, as it is a description of a data processing program used in different studies, and therefore the terms used may have some similarities.

 

Comments 2: “The authors identify that the geographical has a role in the development of TBLC but, in my opinion,  the lecturer would like to know more about the nature of the environmental factors involved.- namely "geographical conditions" - L181-184, L201. The authors hypothesize an explanation for the differences in age rates (ASMR_50+) could be the frequency of unhealthy lifestyles (L 205, L212).“

 

Authors answer:

 

Thank you for your comment and we appreciate your suggestions, therefore we introduced more information in lines 229-231.

 

Comments 3: “In my opinion, some correlations deserve more explanation. E.g. L201 - heterogeneity - in what sense could heterogeneity advance the understanding of the analyzed population groups? Also, for clarity, some lecturers would be interested in all aspects of unhealthy lifestyles other than smoking (L191, 213, L230, L248).”

 

Authors answer:

 

Thank you for your comment. Although some unhealthy lifestyles may explain our results, smoking is the one that best explains our results. Furthermore, as mentioned in lines 229-231, environmental quality may also be related to our results and in some way explain heterogeneity between population groups.

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The authors did a good job responding to my previous concerns, and the manuscript has been improved. I still have a concern.

Statistical analyses lack detail. Did the data follow a normal distribution? What statistical test did you use to analyse the results shown in Figures 4 and 5, for example? Is what is shown the mean ± SD or the mean ± SE?

Author Response

Comments 1: “Statistical analyses lack detail. Did the data follow a normal distribution? What statistical test did you use to analyse the results shown in Figures 4 and 5, for example? Is what is shown the mean ± SD or the mean ± SE?”

Response 1: Thank you for your comment. We introduced changes in methods section in order to clarify statistical approach. We computed standardized mortality rates: (observed number of deaths/expected number of deaths) *100. Please, see lines 116-117. Figures 4 and 5 present SMR and respective 95% confidence interval, please see Y axis title.

Reviewer 2 Report

Comments and Suggestions for Authors

Thanks for revising the manuscript. Adding a sentence on data type as aggregated justifies the data anaysis better to the readers. I would like to recommend the manuscript for publication.

Author Response

Comments 1: “Thanks for revising the manuscript. Adding a sentence on data type as aggregated justifies the data analysis better to the readers. I would like to recommend the manuscript for publication.”

Response 1: We appreciate the comment. The data in the INE database is available in the form of aggregates by NUTs, and is not individualized. We added information in lines 84 and 95.