Not yet recruitingNCT07928180ClinicalTrials.gov record

Oral B-Complex Vitamin (B6, B9 and B12) Prevents Low Anterior Resection Syndrome in Rectal Cancer Patients With Hyperhomocysteinemia

Low Anterior Resection Syndrome · Hyperhomocysteinemia · Rectal Cancer

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THE QUICK READ

What this study involves

The registry does not currently label this study as recruiting. Ask about its status before planning a screening visit.

Study type: Interventional
Phase: Not applicable
Age range: 18 years - 75 years
Sex eligible: All sexes
Healthy volunteers: Not accepted
Participants: 277 Estimated

These are starting points, not an eligibility decision. The research team must review the full requirements.

About the research

The goal of this clinical trial is to investigate if taking Oral B-Complex Vitamin (B6, B9 and B12) can help prevent low anterior resection syndrome (LARS) in rectal cancer patients with hyperhomocysteinemia after sphincter-preserving surgery for rectal cancer. LARS is a group of bowel problems that can occur after rectal cancer surgery, including frequent bowel movements, an urgent need to have a bowel movement, constipation, and loss of bowel control.

Our previous research suggests that hyperhomocysteinemia increased the occurrence of LARS. Folic acid, vitamin B6 and vitamin B12 are a safe, widely used way to treat hyperhomocysteinemia.

The main questions this study aims to answer are:

Does taking Oral B-Complex Vitamin (B6, B9 and B12) lower the rate of LARS 6 months after surgery?
How does this treatment affect internal anal sphincter (IAS) function?

Researchers will compare Oral B-Complex Vitamin (B6, B9 and B12) with a placebo (a look-alike tablet that contains no vitamins) to see if Oral B-Complex Vitamin (B6, B9 and B12) can help prevent LARS.

Participants will:

Take B-Complex Vitamin (B6, B9 and B12) every day for 6 months
Visit the clinic twice ( 3 months and 6 months after surgery) for checkups and tests
Complete the LARS score questionnaire 6 months after surgery

Read the full description

Low anterior resection syndrome (LARS) is a cluster of bowel dysfunction symptoms after sphincter-preserving surgery for rectal cancer, including incontinence, urgency, and frequent bowel movements. The Chinese Expert Consensus on the Diagnosis and Treatment of LARS (2025 edition) reports an incidence of 69.8% at 3 months and 62.3% at 6-9 months after low anterior resection. LARS may persist for years and substantially impair quality of life. LARS is multifactorial, involving reduced rectal capacity and compliance, internal anal sphincter dysfunction and nerve injury. No drug or treatment is currently available to prevent LARS.

Hyperhomocysteinemia (HHcy) is defined as a serum homocysteine (Hcy) level above 15 μmol/L. The pooled prevalence of hyperhomocysteinemia (Hcy \>15 μmol/L) in China was 25.9%. The prevalence of hyperhomocysteinemia is higher in cancer patients. Hyperhomocysteinemia increases the risk of various cardiovascular and cerebrovascular diseases, including coronary heart disease and stroke.

Our preliminary data showed that, in a single-center cohort of 530 patients who underwent low anterior resection for rectal cancer at Qilu Hospital of Shandong University between December 2023 and December 2025, hyperhomocysteinemia was present in 105 of 205 patients with LARS (51.2%) and in 95 of 325 patients without LARS (29.2%). This suggests hyperhomocysteinemia may be a risk factor of LARS.

In a Sprague-Dawley rat model of low anterior resection, hyperhomocysteinemia shortened colonic transit time and increased fecal water content. Postoperative supplementation with folic acid, vitamin B6 and vitamin B12 lowered serum Hcy and reversed these changes.

In our prospective single-arm pilot study, 80 patients who met the same eligibility criteria received Oral B-Complex Vitamin treatment. No adverse events were observed. After 6 months, majority of patients' Hcy levels returned to normal. LARS occurrence was much lower than 62.3%.

Who may be able to participate?

The list below is the sponsor’s full registry wording. It can include conditions, prior treatment, test results and other requirements. A match in search does not mean you qualify.

Inclusion Criteria:

Aged 18 to 75 years
Body mass index (BMI) of 18.5 to 28 kg/m2
Low anterior resection performed for rectal cancer
Serum homocysteine level between 15 and 50 μmol/L both before and after surgery
No evidence of tumor recurrence or distant metastasis
No short-term postoperative complications at the time of enrollment
Able to resume oral intake after surgery
Signed written informed consent

Exclusion Criteria:

History of, or planned, neoadjuvant or adjuvant radiotherapy or chemotherapy
Other severe chronic diseases, such as cardiovascular or cerebrovascular disease, diabetes mellitus or chronic respiratory disease
Renal insufficiency, epilepsy, or other gastrointestinal diseases
Hyperhomocysteinemia caused by inherited defects, such as cystathionine beta-synthase deficiency, methylenetetrahydrofolate reductase (MTHFR) deficiency or hereditary folate malabsorption, screened by detailed medical and family history; highly suspected cases will be referred for specialist diagnosis and excluded
Participation in any other clinical study within the past 3 months

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Treatment, groups and participation

The registry may describe treatments and study duration without a complete visit calendar. Ask the study team for the exact schedule, procedures, risks, costs and alternatives. Keep your usual care plan unless your treating clinician tells you otherwise.

Assignment: Random assignment
Masking: Quadruple masked

Oral B-Complex Vitamin (B6, B9 and B12)

Participants will take Oral B-Complex Vitamin (B6, B9 and B12) tablets, one tablet orally twice daily, starting after resumption of oral intake following surgery. Serum homocysteine (Hcy) will be measured at 3 months after surgery: if Hcy remains above 15 μmol/L, the full dose will continue for another 3 months; if Hcy has returned to normal, the dose will be reduced to one tablet once daily.Treatment will continue until the 6-month postoperative visit.

Dietary Supplement: Oral B-Complex Vitamin (B6, B9 and B12)

Placebo

Participants will take placebo tablets identical in appearance, color, odor and packaging to the Oral B-Complex Vitamin (B6, B9 and B12) tablets, one tablet orally twice daily, starting after resumption of oral intake following surgery. The same homocysteine-based dose-adjustment rules as in the experimental arm will apply, and treatment will continue until the 6-month postoperative visit.

Other: Placebo

Oral B-Complex Vitamin (B6, B9 and B12) DIETARY_SUPPLEMENT

Film-coated oral tablet (0.3 g) registered as a health food in China (filing No. G201937000905), manufactured by Dongying Guangyuan Biotechnology Co., Ltd. Each tablet contains vitamin B6 (pyridoxine hydrochloride) 1.38 mg, folic acid (vitamin B9) 286 μg and vitamin B12 (cyanocobalamin) 3.05 μg. Excipients include corn starch, maltodextrin, microcrystalline cellulose, silicon dioxide, magnesium stearate, calcium carbonate and a film-coating premix.

Placebo OTHER

Oral placebo tablet (0.3 g) containing corn starch and maltodextrin, with no active vitamins, manufactured by Dongying Guangyuan Biotechnology Co., Ltd. under good manufacturing practice. The placebo tablets are identical in appearance, color, odor and packaging to the Oral B-Complex Vitamin (B6, B9 and B12) tablets.

Prepare your questions

What researchers are measuring

Outcome measures describe what is being studied. They are not proof that a treatment works.

Primary measures

Incidence of Low Anterior Resection Syndrome (LARS)

Time frame: 6 months after surgery (3 months after stoma closure for participants whose protective stoma has not been closed by 6 months after surgery)

Proportion of participants with LARS, defined as a total score of 21 or higher on the LARS score questionnaire. The LARS score is a validated 5-item questionnaire on bowel function (Emmertsen and Laurberg, 2012), with a total score ranging from 0 to 42; higher scores indicate worse bowel function (0-20: no LARS; 21-29: minor LARS; 30-42: major LARS).

Secondary measures

LARS Score

Time frame: 6 months after surgery (3 months after stoma closure for participants whose protective stoma has not been closed by 6 months after surgery)

Total LARS score (range 0-42; higher scores indicate worse bowel function), compared between groups as a continuous variable.

Serum Homocysteine Concentration

Time frame: Baseline (preoperative), and 3 and 6 months after surgery

Serum homocysteine concentration (μmol/L).

Systolic Blood Pressure