Title: Impact of Chemotherapy and Radiotherapy on the Survival of Elderly Esophageal Cancer
Patients Undergoing Surgery: A SEER Database Analysis
Version: 7 Date: 25 Aug 2021
Reviewer's report:
This is a retrospective study examining the benefit of additional radiotherapy or chemotherapy
after surgery of esophageal cancer in 1221 elderly patients.  Although various statistical methods
have been applied to reduce selection bias, this type of study is not free from inherent limitation.
1. first of all, I wonder if it is appropriate to include M1 patients for this study.
2. how the authors verify that radiotherapy or chemotherapy had been performed after surgery?
It is believed that the present conclusion can be maintained under the title presented only when
this problem is properly resolved.
3. Can patients with both radiotherapy and chemotherapy be considered patients treated with
concurrent chemoradiation? It is thought that comparison of chemoradiation vs. chemotherapy
would be important for choosing radiotherapy in situations where chemo is more commonly
administered when adjuvant Tx is required.
4. also, perioperative treatment usually differed by the primary tumor location, but the analysis
according to this had not been performed
5. margin status was also unknown, but the analysis is thought to be limited because there is no
appropriate record in SEER database. It should be further described in discussion and limitation
with more detail.
6. in fig 3 nomogram, why are Tx factors (radiotherapy/chemotherapy) missing?
minor point
1. many figures : fig 4,5, and one of 6/7 may be moved to supplementary figures.
2. some typos, e.g. trail -> trial
Title: Impact of Chemotherapy and Radiotherapy on the Survival of Elderly Esophageal Cancer
Patients Undergoing Surgery: A SEER Database Analysis
Version: 7 Date: 25 Aug 2021
Reviewer's report:
This is a retrospective study examining the benefit of additional radiotherapy or chemotherapy
after surgery of esophageal cancer in 1221 elderly patients.  Although various statistical methods
have been applied to reduce selection bias, this type of study is not free from inherent limitation.
1. first of all, I wonder if it is appropriate to include M1 patients for this study.
2. how the authors verify that radiotherapy or chemotherapy had been performed after surgery?
It is believed that the present conclusion can be maintained under the title presented only when
this problem is properly resolved.
3. Can patients with both radiotherapy and chemotherapy be considered patients treated with
concurrent chemoradiation? It is thought that comparison of chemoradiation vs. chemotherapy
would be important for choosing radiotherapy in situations where chemo is more commonly
administered when adjuvant Tx is required.
4. also, perioperative treatment usually differed by the primary tumor location, but the analysis
according to this had not been performed
5. margin status was also unknown, but the analysis is thought to be limited because there is no
appropriate record in SEER database. It should be further described in discussion and limitation
with more detail.
6. in fig 3 nomogram, why are Tx factors (radiotherapy/chemotherapy) missing?
minor point
1. many figures : fig 4,5, and one of 6/7 may be moved to supplementary figures.
2. some typos, e.g. trail -> trial
Please review this paper.
user
Title: Impact of Chemotherapy and Radiotherapy on the Survival of Elderly Esophageal Cancer
Patients Undergoing Surgery: A SEER Database Analysis
Version: 7 Date: 25 Aug 2021
Reviewer's report:
This is a retrospective study examining the benefit of additional radiotherapy or chemotherapy
after surgery of esophageal cancer in 1221 elderly patients.  Although various statistical methods
have been applied to reduce selection bias, this type of study is not free from inherent limitation.
1. first of all, I wonder if it is appropriate to include M1 patients for this study.
2. how the authors verify that radiotherapy or chemotherapy had been performed after surgery?
It is believed that the present conclusion can be maintained under the title presented only when
this problem is properly resolved.
3. Can patients with both radiotherapy and chemotherapy be considered patients treated with
concurrent chemoradiation? It is thought that comparison of chemoradiation vs. chemotherapy
would be important for choosing radiotherapy in situations where chemo is more commonly
administered when adjuvant Tx is required.
4. also, perioperative treatment usually differed by the primary tumor location, but the analysis
according to this had not been performed
5. margin status was also unknown, but the analysis is thought to be limited because there is no
appropriate record in SEER database. It should be further described in discussion and limitation
with more detail.
6. in fig 3 nomogram, why are Tx factors (radiotherapy/chemotherapy) missing?
minor point
1. many figures : fig 4,5, and one of 6/7 may be moved to supplementary figures.
2. some typos, e.g. trail -> trial
assistant