Review for 10.1186/s12876-021-01899-y (2021)

Reviewer’s report
Title: 
Long-term prognosis after endoscopic submucosal dissection for
colorectal tumors in patients aged over 80 years
Version: 
0 
Date: 
22 Apr 2021
Reviewer's report:
Colonoscopic procedures including ESD for large colorectal tumors become
recently standard treatment modalities. Because elderly patients had more
comorbidities and medication histories than young patients, decision making for
procedures in elderly could be challenging. More than 80 years is extremely old
age; therefore, evaluating the safety and efficacy of ESD for colorectal tumors is
valuable. I suggest some points for this study.
1. In your study, there were 15 patients who had followed-up without additional
surgery, although they were diagnosed with deep submucosal invasion. Why did
they refuse the surgery? Worried about their comorbidities? Or other causes?
Because the survival rate of patients who were not undergone additional surgery
was lower than that of patients who underwent surgery, the reason of refusal was
helpful to explain the lower survival rate. 
2. Because this study is retrospective analysis, there was limited to evaluate the
quality of life in elderly patients. A study evaluated the efficacy, safety, and
overall quality of life of ESD for ECC in over 70 years old patients
(Gastroenterol Res Prac. 2017;2017:2386291). Comparison of QOL between
patients with and without additional surgery might also be helpful.
3. The rate of metachronous tumors after ESD is very low in this study (9.4%).
In the method session, follow-up colonoscopy was performed once every 12
months after curative resection according to JSCCR guideline, Also, in case of
not performing curative resection, the interval of follow-up colonoscopy might
be shorter. How many patients were actually conducted the follow-up
colonoscopy in your study?
4. After considering risk and benefit in more than 80 years old, performing the
colonoscopy is needed. However, your opinion that follow-up colonoscopy may
be unnecessary after ESD for treatment-eligible lesion could cause controversy.
Follow-up colonoscopy might be required for detecting the recurrence of the
lesion.
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