Title: Clinical and Demographic Analysis of Patients with Colorectal Cancer Screened at a
Reference Hospital in Southern Brazil: Comparative Study Based on age (Retrospective Cohort
Study)
Version: 4 Date: 18 Oct 2024
Reviewer's report:
Dear Sir,
I read with much interest this manuscript on a hot topic regarding colorectal incidence among
younger age groups of patients.
I praise the significant collection of cases for this retrospective analysis.
That said, I would like to point out some significant topics that need revision/improvement:
Line 20: “with younger patients presenting more aggressive disease characteristics”
I recommend re-writing this statement as the concept of “aggressive” disease may be vague and
misguided. The authors base this assumption on a higher prevalence 2.3% vs 14.7% of occlusive
disease between the two age groups.
However, this may in fact not reflect a true “aggressiveness” of the disease. CRC screening is,
per international and national guidelines, offered to patients >50ys. Therefore, one should expect
a higher proportion of cases be diagnosed in earlier T stages resulting in a lower risk of occlusive/
subocclusive disease.  On the other hand, younger patients are more prone to present with
prolonged symptomatic disease before undertaking endoscopic examination (as the perceived
risk is lower).
Moreover the authors do not present data regarding biological aggressiveness / differentiation
of the disease. Is there any difference in WHO Tumor Grade (G); linfovascular or perineural
infiltration; adjuvant treatment disease free-survival or overall mortality (within the same TNM
sage group) ? All these (and other) variables are key to access whether younger patients really
have more aggressive tumors.
Line 62: “alcohol consumption, smoking”
Whether alcohol consumption does represent a serious risk factor for accelerated carcinogenesis
in CRC is at least debatable. Nonetheless, as smoking, the variable should be quantified (i.e.
in grams of alcohol per day or units pack years). The burden of these risk factors is strongly
related with this.
Line 105-106: . Among those under 50 years old, 19.3% had right-sided colon cancer and 80.7%
had left-sided colon cancer.
The higher incidence of right-sided CRC in older vs younger patients should be addressed as it
does not support current literature
I feel that addressing these points could greatly improve this manuscript.
Best regards
Title: Clinical and Demographic Analysis of Patients with Colorectal Cancer Screened at a
Reference Hospital in Southern Brazil: Comparative Study Based on age (Retrospective Cohort
Study)
Version: 4 Date: 18 Oct 2024
Reviewer's report:
Dear Sir,
I read with much interest this manuscript on a hot topic regarding colorectal incidence among
younger age groups of patients.
I praise the significant collection of cases for this retrospective analysis.
That said, I would like to point out some significant topics that need revision/improvement:
Line 20: “with younger patients presenting more aggressive disease characteristics”
I recommend re-writing this statement as the concept of “aggressive” disease may be vague and
misguided. The authors base this assumption on a higher prevalence 2.3% vs 14.7% of occlusive
disease between the two age groups.
However, this may in fact not reflect a true “aggressiveness” of the disease. CRC screening is,
per international and national guidelines, offered to patients >50ys. Therefore, one should expect
a higher proportion of cases be diagnosed in earlier T stages resulting in a lower risk of occlusive/
subocclusive disease.  On the other hand, younger patients are more prone to present with
prolonged symptomatic disease before undertaking endoscopic examination (as the perceived
risk is lower).
Moreover the authors do not present data regarding biological aggressiveness / differentiation
of the disease. Is there any difference in WHO Tumor Grade (G); linfovascular or perineural
infiltration; adjuvant treatment disease free-survival or overall mortality (within the same TNM
sage group) ? All these (and other) variables are key to access whether younger patients really
have more aggressive tumors.
Line 62: “alcohol consumption, smoking”
Whether alcohol consumption does represent a serious risk factor for accelerated carcinogenesis
in CRC is at least debatable. Nonetheless, as smoking, the variable should be quantified (i.e.
in grams of alcohol per day or units pack years). The burden of these risk factors is strongly
related with this.
Line 105-106: . Among those under 50 years old, 19.3% had right-sided colon cancer and 80.7%
had left-sided colon cancer.
The higher incidence of right-sided CRC in older vs younger patients should be addressed as it
does not support current literature
I feel that addressing these points could greatly improve this manuscript.
Best regards
Please review this paper.
user
Title: Clinical and Demographic Analysis of Patients with Colorectal Cancer Screened at a
Reference Hospital in Southern Brazil: Comparative Study Based on age (Retrospective Cohort
Study)
Version: 4 Date: 18 Oct 2024
Reviewer's report:
Dear Sir,
I read with much interest this manuscript on a hot topic regarding colorectal incidence among
younger age groups of patients.
I praise the significant collection of cases for this retrospective analysis.
That said, I would like to point out some significant topics that need revision/improvement:
Line 20: “with younger patients presenting more aggressive disease characteristics”
I recommend re-writing this statement as the concept of “aggressive” disease may be vague and
misguided. The authors base this assumption on a higher prevalence 2.3% vs 14.7% of occlusive
disease between the two age groups.
However, this may in fact not reflect a true “aggressiveness” of the disease. CRC screening is,
per international and national guidelines, offered to patients >50ys. Therefore, one should expect
a higher proportion of cases be diagnosed in earlier T stages resulting in a lower risk of occlusive/
subocclusive disease.  On the other hand, younger patients are more prone to present with
prolonged symptomatic disease before undertaking endoscopic examination (as the perceived
risk is lower).
Moreover the authors do not present data regarding biological aggressiveness / differentiation
of the disease. Is there any difference in WHO Tumor Grade (G); linfovascular or perineural
infiltration; adjuvant treatment disease free-survival or overall mortality (within the same TNM
sage group) ? All these (and other) variables are key to access whether younger patients really
have more aggressive tumors.
Line 62: “alcohol consumption, smoking”
Whether alcohol consumption does represent a serious risk factor for accelerated carcinogenesis
in CRC is at least debatable. Nonetheless, as smoking, the variable should be quantified (i.e.
in grams of alcohol per day or units pack years). The burden of these risk factors is strongly
related with this.
Line 105-106: . Among those under 50 years old, 19.3% had right-sided colon cancer and 80.7%
had left-sided colon cancer.
The higher incidence of right-sided CRC in older vs younger patients should be addressed as it
does not support current literature
I feel that addressing these points could greatly improve this manuscript.
Best regards
assistant