Title: Global burden of colon and rectal cancer and attributable risk factors in 204 countries and
territories from 1990 to 2021
Version: 0 Date: 19 Feb 2025
Reviewer:  Sina Azadnajafabad
Reviewer's report:
Thanks for the chance to review this study on the global burden of colorectal cancer and
attributable risk factors using the recent GBD 2021 data. The findings of this research is mostly
consistent with previous publications like the ones on the same topic using the GBD 2019 data.
I would like to ask authors to expand their analysis framework to address the emerging trends
in the colorectal cancer epidemiology to make this effort beneficial. Otherwise, publishing the
findings would not benefit the audience. See below for my comments and suggestions.
1. Recent trends show different patterns of colorectal cancer incidence and mortality in younger
population (age < 50 y) compared to older population. So, stratifying the analysis for this issue
could add to the research value.
2. Also, the recent diverging patterns of colorectal cancer in men and women necessitates to
focus more on the sex-specific results rather than overall estimates.
3. Considering the emerging concept of birth cohort effects in the incidence and mortality of
several cancer globally, it is highly suggested to add the age-period-cohort analysis to the study
methods and results.
4. Regarding the use of the World Bank’s income categorizations, it is not clear if authors
retrieved the data separately or just used the results extracted for WB income levels from GBD
data. In case of separate data extraction, authors need to mention the year for leveling and the
reason for separate data extraction.
5. Discussion: this section adds nothing specific to the body of literature. If authors consider the
major changes in the methods there might be some specific points to discuss in this section.
Title: Global burden of colon and rectal cancer and attributable risk factors in 204 countries and
territories from 1990 to 2021
Version: 0 Date: 19 Feb 2025
Reviewer:  Sina Azadnajafabad
Reviewer's report:
Thanks for the chance to review this study on the global burden of colorectal cancer and
attributable risk factors using the recent GBD 2021 data. The findings of this research is mostly
consistent with previous publications like the ones on the same topic using the GBD 2019 data.
I would like to ask authors to expand their analysis framework to address the emerging trends
in the colorectal cancer epidemiology to make this effort beneficial. Otherwise, publishing the
findings would not benefit the audience. See below for my comments and suggestions.
1. Recent trends show different patterns of colorectal cancer incidence and mortality in younger
population (age < 50 y) compared to older population. So, stratifying the analysis for this issue
could add to the research value.
2. Also, the recent diverging patterns of colorectal cancer in men and women necessitates to
focus more on the sex-specific results rather than overall estimates.
3. Considering the emerging concept of birth cohort effects in the incidence and mortality of
several cancer globally, it is highly suggested to add the age-period-cohort analysis to the study
methods and results.
4. Regarding the use of the World Bank’s income categorizations, it is not clear if authors
retrieved the data separately or just used the results extracted for WB income levels from GBD
data. In case of separate data extraction, authors need to mention the year for leveling and the
reason for separate data extraction.
5. Discussion: this section adds nothing specific to the body of literature. If authors consider the
major changes in the methods there might be some specific points to discuss in this section.
Please review this paper.
user
Title: Global burden of colon and rectal cancer and attributable risk factors in 204 countries and
territories from 1990 to 2021
Version: 0 Date: 19 Feb 2025
Reviewer:  Sina Azadnajafabad
Reviewer's report:
Thanks for the chance to review this study on the global burden of colorectal cancer and
attributable risk factors using the recent GBD 2021 data. The findings of this research is mostly
consistent with previous publications like the ones on the same topic using the GBD 2019 data.
I would like to ask authors to expand their analysis framework to address the emerging trends
in the colorectal cancer epidemiology to make this effort beneficial. Otherwise, publishing the
findings would not benefit the audience. See below for my comments and suggestions.
1. Recent trends show different patterns of colorectal cancer incidence and mortality in younger
population (age < 50 y) compared to older population. So, stratifying the analysis for this issue
could add to the research value.
2. Also, the recent diverging patterns of colorectal cancer in men and women necessitates to
focus more on the sex-specific results rather than overall estimates.
3. Considering the emerging concept of birth cohort effects in the incidence and mortality of
several cancer globally, it is highly suggested to add the age-period-cohort analysis to the study
methods and results.
4. Regarding the use of the World Bank’s income categorizations, it is not clear if authors
retrieved the data separately or just used the results extracted for WB income levels from GBD
data. In case of separate data extraction, authors need to mention the year for leveling and the
reason for separate data extraction.
5. Discussion: this section adds nothing specific to the body of literature. If authors consider the
major changes in the methods there might be some specific points to discuss in this section.
assistant