Review for 10.1186/s12876-023-02989-9 (2024)

Title: Clinicopathological and molecular characteristics of colorectal adenosquamous
carcinoma in an Asian population
Version: 2 Date: 01 Jul 2023
Reviewer's report:
This is an interesting manuscript focusing on colorectal adenosquamous carcinoma, a rare form
of colorectal cancer, and examining KRAS and MMR. I recommended that this manuscript not
be accepted without major revision.
Major Comments
## In conclusion in the Abstract, the author concludes that adenosquamous cell carcinoma is
effective for targeted therapy, including immune checkpoint inhibitors. However, this is only
true for adenosquamous carcinomas with positive target factors, and the same can be said for
conventional cancers. Please change the wording here.
## The authors discuss Figure 1 in the Pathology Assessment section. Figure 1 should show
one representative case. In HE stains, adenocarcinoma and squamous cell carcinoma areas are
indicated by different colored arrows. Please add images immunostained with squamous cell
carcinoma markers (CK5/6, 34#E12, p40, p63) and adenocarcinoma markers (CK20, CDX2) to
provide evidence for a definitive diagnosis.
## For predominantly squamous type, please indicate in the pathology evaluation section what
percentage or more of the total tumor was squamous cell carcinoma.
## Adenosquamous carcinoma of the colon is most common in the left colon and is noted in
the results. However, Yokoi et al (J Nippon Med Sch. 2008 Aug;75(4):242-6.) report that it is
more common in the cecum and ascending colon. Please explain the reason for this difference
in your discussion.
## Generally, All RAS including NRAS as well as KRAS is examined in colorectal cancer. Why
did you limit yourself to KRAS in this study? Also, KRAS was only examined in 7 cases. Why
didn't you consider the remaining 4 cases?
## Please define the OS and DFS (time to recurrence) start and end dates in the Statistical analysis
section. Is the surgery date the starting date? Also, are you sure that the DFS statistics are correct
in determining that all 11 cases were operated on?
## Is it the OS that the author compared the surgery alone group (6 cases?) with the other group
(5 cases?) in a Log-rank test? Please specify in the text the number of cases in the surgery
alone group and the number of cases in the other group. If the author has reason to compare
the surgery-alone group with something else, please provide the Kaplan-Meier curve between
the two groups. Since the number of cases is small and the Stage is different, I think there is
no reason to compare them.
## Although four recurrent cases are listed, five cases (cases 3-7) are marked with * in Fig.
4 as recurrent cases. In addition, the Abstract shows 3 cases of distant metastasis, but Fig. 4
shows only case 10. Case 11 in Figure 4 has ICI even though it is not dMMR. What is the
reason for this? Please clarify the distinction between recurrence and metastasis. You mention
postoperative adjuvant chemotherapy, but you did not give systemic chemotherapy to the M1
case. Please change Fig. 4 to be much clearer.
Minor Comments
1. In Table 1, age is listed as the Median, but in reality, it is the mean. Due to the small number
of cases, Table 1 should, in principle, be consistent with the median value.
2. The text states that the mean tumor diameter is 6.21±3.77 cm, but this is not stated in Table
1. Please add it. Also, please use the median value.
3. The authors stated in the text that the nuclear proliferation index Ki67 of tumor cells ranges
from 25% to 70%, with a mean of 39%; please list this in Table 1 and use the median value.
4. Figure 3a and Figure 3b in the Oncological Outcomes and Prognostic Analysis section appear
to be incorrect. Please correct them.
5. In Figure 3, enter (Month) on the X-axis and (%) on the Y-axis.
6. The caption for Figure 3b should be Disease-free survival (DFS) as described in the text.
7. Please delete the superscript numeral 8 on line 18 of p7.
8. It is difficult to understand the number of cases in the classification of histological types in
lines 16-20 on p. 16. please describe clearly how the 11 cases were classified.
9. The author presents reference 24 and reports that there are no reports of KRAS being checked
in patients with CACS. But isn't reference 24 a paper that says KRAS was checked for mutations
in CACS and no mutations were found?