Review for 10.1186/1471-230X-14-41 (2014)

Reviewer's report
Title:Short-term surgical and long-term survival outcomes after laparoscopic
distal gastrectomy with D2 lymphadenectomy for gastric cancer
Version: 1Date:26 August 2013
Reviewer: Guoxin Li
Reviewer's report:
Dear Dr. Mou,
This study evaluated the short-term surgical and long-term survival outcomes of
laparoscopic distal gastrectomy with D2 lymph node dissection in treatment of
gastric cancer. The authors should be congratulated on their achievements in
performing both laparoscopy-assisted distal gastrectomy and totally laparoscopic
distal gastrectomy within the past ten years. Judging from the 5-year survival
rates, LDG could yield acceptable oncologic outcomes. However, there’re still
some issues concerning the manuscript, which I believe should be better
demonstrated or revised in the future version:
Major Compulsory Revisions
1#What is the indications of performing TLDG over LADG? Since in the
manuscript, authors compared the short-term surgical outcomes of these two
LDG approaches, it’s better to clearly demonstrate under what conditions did the
author perform TLDG or LADG.
2#In the description of surgical procedures, it seems that in the authors’ clinical
practice, the lymph nodes along the superior mesenteric vein (No. 14v) were
routinely dissected. However, according to the Japanese Gastric Cancer
Treatment Guidelines (ver. 3) published in 2010, LN No.14v was no longer
included in the D2 lymphadenectomy range in distal gastrectomy. Did the authors
still dissect this group of LN even after 2010 in D2 lymph nodes dissection?
3#In the study, nearly half of the cases evaluated were either T1 or stage I
diseases. In the treatment guidelines and many phase II and III clinical trials, it is
not necessary to perform D2 lymphadenectomy to this group of patients.
However, the study reported only D2 lymphadenectomy, thus, it might not be
proper to conduct D2 lymphadenectomy in these early-staged patients. Maybe
the problem could be better explained by the authors.
4#In stage II tumor, the DFS is above the OS (72.7% vs. 67.6%), T3 tumor has
the similar issue (67.6% vs. 65.9%), which are quite rarely seen in other similar
reports. What causes does the authors think might contribute to this
phenomenon?
5#In the definitions of DFS and OS, both include the criteria of “from surgery to
the time of death from any causes”. This may result in overlapping of the cases
evaluated in survival analyses, which means that the definitions of DFS and OS
should be different from each other.
6#The title of the manuscript is "Short-term surgical and long-term survival
outcomes after laparoscopic distal gastrectomy with D2 lymphadenectomy for
gastric cancer", however, the median follow-up period was only 31.5 months,
which might be relatively short for "long-term", thus the words authors chose in
the manuscript title should be made more accurate.
7. I don't quite understand the first line in Table 2, especially B-I/B-II
reconstructions listed in LADG and TLDG groups don't add up 240. There may
be mistakes.
Minor Essential Revisions
1#Since in the Results and Discussion part of the study, recurrences were
demonstrated in both numbers and patterns, it is suggesting to the authors that in
the Method part, the clear definitions of recurrence patterns should be given.
2#In the design of Table 1, I do not think it is proper to list Mean±SD (Age, BMI,
Tumor size) beneath “Value (%)”.
3#Language polishing by a native speaker is strongly recommended.
Suggestion
In the study, the authors compared the short-term surgical outcomes of LADG
and TLDG. I believe it would be more interesting to also extend the comparison
into long-term oncologic outcomes.
Level of interest: An article of importance in its field
Quality of written English: Needs some language corrections before being
published
Statistical review: Yes, but I do not feel adequately qualified to assess the
statistics.
Declaration of competing interests:
I declare that I have no competing interests