Colon CancerDILEMMANCT04364373
D2 vs D3 Lymph Node Dissection for Left Colon Cancer
A study testing Left colon resection, Sigmoid colon resection and Distal sigmoid colon resection or anterior resection in people with Colon Cancer, run by Russian Society of Colorectal Surgeons at 1 site in Russia.
Trial summary
The efficiency of the D3 lymph node dissection is still controversial for left colon cancer patients. This study will try find difference in 5-year overall survival between D2 and D3 lymph node dissection. Investigation of the functional and short-term outcomes will clarify safety of the D3 lymph node dissection. Read more about this study
- Who is it for?
- Ages 18 to 75 years
- Conditions the study is for
- Colon Cancer
- What is being tested?
- Left colon resection, Sigmoid colon resection and Distal sigmoid colon resection or anterior resection
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 1,381 participants
- Where
- 1 siteRussia
- Study dates
- 31 Mar 2020to 31 Dec 2033
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 75 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Agreement of the patient to participate in trial
- Colon cancer (only adenocarcinoma )
- The tumor located between the splenic flexure and rectosigmoid junction
- cT3-Т4а,b
- cN0-2
- cM0
- Tolerance of chemotherapy
- ASA 1-3
Who cannot join
- сТis - Т2, сТ4b (tail of the pancreas, stomach, small bowel, ureter, urinary bladder)
- Preoperative complications of the tumor (perforation and full bowel 3. obstruction)
- Previous radiotherapy or chemotherapy
- Synchronous or metachronous tumors
- Women during Pregnancy or breast feeding period
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Russia1 site, 1 recruiting
- Recruiting
Clinic of coloproctology and minimally invasive surgery
Moscow, 119435
Vladimir Balaban, Ph.D, +79889478358, balaban@kkmx.ru
Inna Tulina, Ph.D, +79264086672, tulina@kkmx.ru
About this study
Official title: D2 vs D3 Lymph Node Dissection for Left Colon Cancer: Multicenter Randomize Control Trial (DILEMMA)
The efficiency of the D3 lymph node dissection is still controversial for left colon cancer patients. This study will try find difference in 5-year overall survival between D2 and D3 lymph node dissection. Investigation of the functional and short-term outcomes will clarify safety of the D3 lymph node dissection.
Read the detailed description
Discussion about optimal type of lymph node dissection in colorectal cancer continues during last 15 years, when in Europe was presented concept of complete mesocolic excision. However, this concepts is very close to Japanese D3 lymph node dissection and in the first view it seems the same but principal differences were found. Japanese concept is partial resection of the bowel according feeding artery (short bowel specimen, long lymphovascular pedicle), opposite European concept is wide resection of the bowel like hemicolectomy or extended hemicolectomy, sigmoidectomy. In complete mesocolic excision anatomical landmarks are still unclear but in Japanese guidelines it has anatomical margins which can standardize this procedure. Also nerve sparing technique around root of inferior mesenteric artery was described. One more difference is in histological examination of the specimen. European concept is to pay more attention to the quality of complete mesocolic excision and less - to the number of investigated lymph nodes. In Japan lymph node extraction is performed by surgical team from the fresh specimen and send to pathologist separately (each group of lymph nodes). Considering the absence of randomized control trials for patients with left colon cancer DILEMMA trial was started using Japanese approach
- Conditions
- Colon Cancer
- Being tested
- Left colon resection, Sigmoid colon resection, Distal sigmoid colon resection or anterior resection
- Keywords
- D2, D3, lymph node dissection, complete mesocolic excision, left colon cancer, CME
- Medical subject headings
- Colonic Neoplasms
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Left colon resectionProcedure or surgery
This procedure is performed for tumours in splenic flexure and proximal and descending colon.
Left colic artery is divided at its origin. Sigmoid arteries and superior rectal arteries are preserved. Inferior mesenteric vein is divided at the lower border of the pancreas. The colon is divided about 10 cm proximal and distal to the tumour. Mesocolic fascia is preserved and the length of the "vessel trunk" of the mesocolon corresponds to the level of lymph node dissection. After removal of the resected colonic segment a handsewn or stapler end-to-end or side-to-side colonic anastomosis is performed.
Sigmoid colon resectionProcedure or surgery
This procedure is performed for tumours in sigmoid colon. Corresponding sigmoid arteries are divided at their origin. Left colic artery and superior rectal artery are preserved. Inferior mesenteric vein is divide close to the left colic artery. Proximal and distal margin compose 10 cm from the tumour. Mesocolic fascia is preserved and the length of the "vessel trunk" of the mesocolon corresponds to the level of lymph nodes dissection. After removal of the resected colonic segment a handsewn end-to-end or side-to-side or stapler colonic anastomosis is performed.
Distal sigmoid colon resection or anterior resectionProcedure or surgery
This procedure is performed for tumours in distal sigmoid colon or rectosigmoid junction. Superior rectal artery is divided below the origin of left colic artery. Left colic artery is preserved. Inferior mesenteric vein is divide close to the left colic artery. The colon is divided about 10 cm proximal and 5 cm distal to the tumour. Mesocolic fascia is preserved and the length of the "vessel trunk" of the mesocolon corresponds to the level of lymph node dissection. After removal of the resected colonic segment handsewn or stapler colo-rectal anastomosis is performed.
| Study group | Role | What they receive |
|---|---|---|
| D2 lymph node dissection | Active comparator | For tumours in splenic flexure and proximal and mid part of descending colon lymph nodes 232 and 231 will be removed.
For tumours in distal part of descending colon and proximal sigmoid lymph nodes 231, 232 and partially 241, 242 (considering variation of the feeding artery) will be removed.
For tumours in the mid part of sigmoid colon lymph nodes 241, 242 will be removed.
For tumours in the rectosigmoid junction 251, 252 groups of the lymph node will be removed. Receives: Procedure: Left colon resection; Procedure: Sigmoid colon resection; Procedure: Distal sigmoid colon resection or anterior resection |
| D3 lymph node dissection | Experimental | For tumours in splenic flexure and proximal and mid part of descending colon lymph nodes 232, 231 and 253 will be removed.
For tumours in distal part of descending colon and proximal sigmoid lymph nodes 231, 232 and 253 and partially 241, 242 (considering variation of the feeding artery) will be removed.
For tumours in the mid part of sigmoid colon lymph nodes 241, 242 and 253 will be removed.
For tumours in the rectosigmoid junction 251, 252 and 253 groups of the lymph node will be removed. Receives: Procedure: Left colon resection; Procedure: Sigmoid colon resection; Procedure: Distal sigmoid colon resection or anterior resection |
What is being measured
The primary outcome is the main question the study is designed to answer.
5-year overall survival
Probability to be alive measured in %, where 100% means that patients have a 100% probability to be alive and 0% means that patients have 0% probability to be alive
Measured: Up to 5 years post-operatively
Secondary outcomes (7)
5-year disease free survival
Probability to be alive with no signs of local or distant recurrence measured in %, where 100% means that patients have a 100% probability to be alive with no signs of local or distant recurrence and 0% means that patients have 0% probability to be alive with no signs of local or distant recurrence
Measured: Up to 5 years post-operatively
Postoperative sexual dysfunction
The rate of ejaculation problems in sexually active men and the rate of decreased vaginal lubricant production in sexually active women, measured in % from the total number of male/female patients
Measured: Up to 1 year post-operatively
Apical lymph node involvement rate
The rate of lymph nodes 253 with metastatic cells among all lymph nodes 253, measured in %
Measured: 1 month after surgery
Intraoperative complications rate
The rate of any complications within the course of surgery
Measured: Day 0
Early postoperative complications rate
The rate of surgical and infectious complications
Measured: 1-30 days after surgery
Mortality
The rate of death from all causes
Measured: 0-30 days after surgery
Late postoperative complications rate
The rate of surgical and infectious complications
Measured: 30-180 days after surgery
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted28 Apr 2020
- Study start31 Mar 2020
- Primary completion31 Dec 2028 (estimated)
- Study completion31 Dec 2033 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Colon CancerStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 1,381 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Russian Society of Colorectal Surgeons
- Sponsor type
- University, hospital or other
- Collaborators
- I.M. Sechenov First Moscow State Medical University, G.V. Bondar Republican Cancer Center
- Responsible party
- Sponsor
- Investigators
- Peter Tsarkov, Ph.D, Study director, I.M. Sechenov First Moscow State Medical University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04364373
- Sponsor's protocol ID
- 0002
- Acronym
- DILEMMA
- Status last verified
- Aug 2026
- First submitted
- 1 Apr 2020
- Last updated
- 17 Aug 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 17 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- D2 vs D3 Lymph Node Dissection for Left Colon Cancer: Multicenter Randomize Control Trial (DILEMMA)
- ClinicalTrials.gov ID
- NCT04364373
- Acronym / sponsor ID
- DILEMMA / 0002
- Conditions
- Colon Cancer
- Keywords
- D2, D3, lymph node dissection, complete mesocolic excision, left colon cancer, CME
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 1,381 participants (estimated)
- Lead sponsor
- Russian Society of Colorectal SurgeonsUniversity, hospital or other
- Collaborators
- I.M. Sechenov First Moscow State Medical University, G.V. Bondar Republican Cancer Center
- Study start
- 31 Mar 2020 (actual)
- Primary completion
- 31 Dec 2028 (estimated)
- Study completion
- 31 Dec 2033 (estimated)
- First posted
- 28 Apr 2020 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The efficiency of the D3 lymph node dissection is still controversial for left colon cancer patients. This study will try find difference in 5-year overall survival between D2 and D3 lymph node dissection. Investigation of the functional and short-term outcomes will clarify safety of the D3 lymph node dissection.
Detailed description
Discussion about optimal type of lymph node dissection in colorectal cancer continues during last 15 years, when in Europe was presented concept of complete mesocolic excision. However, this concepts is very close to Japanese D3 lymph node dissection and in the first view it seems the same but principal differences were found. Japanese concept is partial resection of the bowel according feeding artery (short bowel specimen, long lymphovascular pedicle), opposite European concept is wide resection of the bowel like hemicolectomy or extended hemicolectomy, sigmoidectomy. In complete mesocolic excision anatomical landmarks are still unclear but in Japanese guidelines it has anatomical margins which can standardize this procedure. Also nerve sparing technique around root of inferior mesenteric artery was described. One more difference is in histological examination of the specimen. European concept is to pay more attention to the quality of complete mesocolic excision and less - to the number of investigated lymph nodes. In Japan lymph node extraction is performed by surgical team from the fresh specimen and send to pathologist separately (each group of lymph nodes). Considering the absence of randomized control trials for patients with left colon cancer DILEMMA trial was started using Japanese approach
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| D2 lymph node dissection | Active comparator | Procedure: Left colon resection, Procedure: Sigmoid colon resection, Procedure: Distal sigmoid colon resection or anterior resectionFor tumours in splenic flexure and proximal and mid part of descending colon lymph nodes 232 and 231 will be removed. For tumours in distal part of descending colon and proximal sigmoid lymph nodes 231, 232 and partially 241, 242 (considering variation of the feeding artery) will be removed. For tumours in the mid part of sigmoid colon lymph nodes 241, 242 will be removed. For tumours in the rectosigmoid junction 251, 252 groups of the lymph node will be removed. |
| D3 lymph node dissection | Experimental | Procedure: Left colon resection, Procedure: Sigmoid colon resection, Procedure: Distal sigmoid colon resection or anterior resectionFor tumours in splenic flexure and proximal and mid part of descending colon lymph nodes 232, 231 and 253 will be removed. For tumours in distal part of descending colon and proximal sigmoid lymph nodes 231, 232 and 253 and partially 241, 242 (considering variation of the feeding artery) will be removed. For tumours in the mid part of sigmoid colon lymph nodes 241, 242 and 253 will be removed. For tumours in the rectosigmoid junction 251, 252 and 253 groups of the lymph node will be removed. |
Who may qualify
- Ages
- 18 to 75 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (8 listed)
- Agreement of the patient to participate in trial
- Colon cancer (only adenocarcinoma )
- The tumor located between the splenic flexure and rectosigmoid junction
- cT3-Т4а,b
- cN0-2
Key exclusion criteria (5 listed)
- сТis - Т2, сТ4b (tail of the pancreas, stomach, small bowel, ureter, urinary bladder)
- Preoperative complications of the tumor (perforation and full bowel 3. obstruction)
- Previous radiotherapy or chemotherapy
- Synchronous or metachronous tumors
- Women during Pregnancy or breast feeding period
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Left colon resectionThis procedure is performed for tumours in splenic flexure and proximal and descending colon. Left colic artery is divided at its origin. Sigmoid arteries and superior rectal arteries are preserved. Inferior mesenteric vein is divided at the lower border of the pancreas. The colon is divided about 10 cm proximal and distal to the tumour. Mesocolic fascia is preserved and the length of the "vessel trunk" of the mesocolon corresponds to the level of lymph node dissection. After removal of the resected colonic segment a handsewn or stapler end-to-end or side-to-side colonic anastomosis is performed. | Procedure or surgery | D2 lymph node dissection, D3 lymph node dissection |
| Sigmoid colon resectionThis procedure is performed for tumours in sigmoid colon. Corresponding sigmoid arteries are divided at their origin. Left colic artery and superior rectal artery are preserved. Inferior mesenteric vein is divide close to the left colic artery. Proximal and distal margin compose 10 cm from the tumour. Mesocolic fascia is preserved and the length of the "vessel trunk" of the mesocolon corresponds to the level of lymph nodes dissection. After removal of the resected colonic segment a handsewn end-to-end or side-to-side or stapler colonic anastomosis is performed. | Procedure or surgery | D2 lymph node dissection, D3 lymph node dissection |
| Distal sigmoid colon resection or anterior resectionThis procedure is performed for tumours in distal sigmoid colon or rectosigmoid junction. Superior rectal artery is divided below the origin of left colic artery. Left colic artery is preserved. Inferior mesenteric vein is divide close to the left colic artery. The colon is divided about 10 cm proximal and 5 cm distal to the tumour. Mesocolic fascia is preserved and the length of the "vessel trunk" of the mesocolon corresponds to the level of lymph node dissection. After removal of the resected colonic segment handsewn or stapler colo-rectal anastomosis is performed. | Procedure or surgery | D2 lymph node dissection, D3 lymph node dissection |
Primary outcome
5-year overall survival
Time frame: Up to 5 years post-operatively
Probability to be alive measured in %, where 100% means that patients have a 100% probability to be alive and 0% means that patients have 0% probability to be alive
7 secondary outcomes
5-year disease free survival
Time frame: Up to 5 years post-operatively
Postoperative sexual dysfunction
Time frame: Up to 1 year post-operatively
Apical lymph node involvement rate
Time frame: 1 month after surgery
Intraoperative complications rate
Time frame: Day 0
Early postoperative complications rate
Time frame: 1-30 days after surgery
Mortality
Time frame: 0-30 days after surgery
Late postoperative complications rate
Time frame: 30-180 days after surgery
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 17 Aug 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Peter Tsarkov, Ph.D study director
I.M. Sechenov First Moscow State Medical University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Left colon resection, Sigmoid colon resection and Distal sigmoid colon resection or anterior resection in people with Colon Cancer, run by Russian Society of Colorectal Surgeons at 1 site in Russia.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 8 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 17 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Russia. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Vladimir Balaban, Ph.D (+79889478358, balaban@kkmx.ru), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
5-year overall survival (time frame: Up to 5 years post-operatively). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 17 Aug 2026.