Chinese Herbal Formula Faces Its Toughest Test: Landmark Trial Targets Precancerous Colon Polyps

Every year, millions of people who undergo colonoscopy walk out of the clinic with a sense of relief: the polyp has been removed, the threat has been extinguished. For a substantial fraction of them, however, that relief is premature. High-risk colorectal adenomas — the lesions that gastroenterologists watch most closely — are the recognized precursors of colorectal cancer, and between 25 and 40 percent of patients who have one surgically resected through the endoscope will grow a new one within just three years. This stubborn tendency of the colon to regenerate its own danger zones, known as metachronous adenoma formation, is one of the central unsolved problems in cancer prevention, and it is the problem that a newly launched clinical trial in China is now attacking with an unexpected weapon: a traditional herbal formula delivered as granules dissolved in water.

The trial, described in a study protocol published in BMC Complementary Medicine and Therapies, will test Shenbai granules, a compound formulation rooted in traditional Chinese medicine, against a placebo in 450 patients whose high-risk adenomas have been removed endoscopically. The design is deliberately rigorous: a multicentre, randomised, double-blind, placebo-controlled study — the same architecture used to license modern pharmaceuticals. Participants will be allocated one to one between the herbal treatment and an indistinguishable placebo, and neither the patients nor the clinicians assessing outcomes will know who is receiving which. The trial is registered with ClinicalTrials.gov under identifier NCT07129499 and is supported by China’s National Science and Technology Major Project for the prevention and treatment of major diseases.

The stakes are considerable. Colorectal cancer remains one of the most common and lethal malignancies worldwide, and the adenoma-to-carcinoma sequence — the slow accumulation of mutations that transforms a benign glandular polyp into an invasive cancer — offers one of medicine’s best windows for intervention. Removing adenomas during colonoscopy demonstrably reduces cancer incidence, but surveillance colonoscopy exists precisely because the field of colonic mucosa that produced one lesion remains prone to producing others. A safe, well-tolerated agent that could suppress that field effect would fundamentally change prevention strategy, reducing both the burden of repeated procedures and the anxiety that shadows every post-polypectomy patient.

At present, the pharmacological cupboard is nearly bare. Low-dose aspirin is the only agent supported by high-level evidence for reducing the incidence of metachronous high-risk adenomas, and its utility is constrained by a well-known liability: bleeding. In a population of middle-aged and older adults already undergoing periodic endoscopy, the risk of gastrointestinal hemorrhage is not a trivial consideration, and it has kept aspirin chemoprevention from becoming universal practice. Non-steroidal anti-inflammatory drugs face similar limitations. This therapeutic vacuum is what makes the Shenbai granule trial noteworthy — if the formula demonstrates genuine efficacy under blinded, placebo-controlled conditions, it would offer a chemopreventive option with, in principle, a very different safety profile.

The trial’s structure reflects a careful, phased logic. It opens with a 14-day screening period to confirm eligibility, followed by a six-month treatment phase in which participants take their assigned granules daily. What follows is the scientifically decisive portion: a 30-month surveillance phase, encompassing four on-site visits and one telephone follow-up, during which patients undergo the colonoscopic monitoring that will reveal whether new lesions have emerged. The primary endpoint is unambiguous — the detection rate of metachronous high-risk colorectal adenomas within three years of the first dose. A superiority design has been adopted, meaning the investigators are testing whether the herbal formula outperforms placebo, not merely whether it is equivalent or non-inferior.

Beyond the primary endpoint, the protocol specifies an unusually rich set of secondary outcomes that should give researchers a granular picture of any treatment effect. These include the detection rate of metachronous low-risk adenomas and serrated lesions — a second, morphologically distinct class of precancerous polyps — as well as the cumulative number of detection episodes, total lesion counts, lesion size, distribution, anatomic location within the colon, and pathological characteristics. The trial will also track the incidence of outright colorectal cancer within three years of the first dose. This level of detail matters because chemopreventive agents can act in subtle ways: a drug might not eliminate new adenomas entirely but could reduce their number, shrink them, or shift them toward less aggressive pathology, and only comprehensive endpoints can capture such effects.

Safety monitoring has been built into the protocol with the same seriousness applied in pharmaceutical trials. Adverse events will be systematically recorded, with laboratory surveillance encompassing complete blood counts and liver and kidney function markers, including alanine aminotransferase, aspartate aminotransferase, and alkaline phosphatase. A Data Monitoring Committee will oversee the trial’s conduct, and the study will adhere to Good Clinical Practice standards, with source-data verification and standard operating procedures governing the participating centres. Analyses are planned on both intention-to-treat and per-protocol bases, and an Interactive Web Response System will handle randomisation, minimising the risk of allocation bias across the many sites involved.

The geographic and institutional breadth of the study is itself significant. The trial draws together investigators from Nanjing University of Chinese Medicine and its affiliated hospitals alongside gastroenterology and oncology departments at institutions across China, including Southern Medical University’s Shenzhen Hospital, Renji Hospital of Shanghai Jiao Tong University, Shandong University’s Second Qilu Hospital, Union Hospital of Huazhong University of Science and Technology, Harbin Medical University, and West China Hospital of Sichuan University, among others. This multicentre footprint is essential for a trial of this size, but it also serves a scientific purpose: results that hold across diverse patient populations and endoscopic practices are far more convincing than findings from a single centre, however well run.

The investigators have also framed the trial with an eye toward precision prevention. Beyond simply asking whether Shenbai granules work, the study aims to identify clinical predictors of treatment response, with the goal of defining the optimal target population for therapy. This is a sophisticated framing that acknowledges a hard truth in chemoprevention research: agents that show modest average effects may nonetheless be highly effective in identifiable subgroups. If certain clinical characteristics — perhaps related to a patient’s adenoma history, pathology, or baseline features — predict who benefits most, the eventual clinical recommendation could be tailored rather than blanket, maximising benefit while exposing fewer people to unnecessary treatment.

For the broader field, the trial represents a test case for how traditional medicine compounds can be evaluated under modern evidence standards. Previous studies of Shenbai granules have suggested potential in preventing metachronous high-risk adenomas, but as the protocol’s authors note, evidence from randomised controlled trials has been lacking — the gap that separates promising observation from clinical practice. If the trial succeeds, it would establish objective clinical evidence for both the therapeutic benefit and safety of the formula in preventing malignant transformation of high-risk colorectal adenomas, potentially opening a new chapter in colorectal cancer prevention. If it fails, the result will still be valuable, closing off a hypothesis with data rather than tradition. Either way, the 450 participants who swallow their granules over six months and return for three years of vigilant colonoscopic surveillance will have helped answer a question that matters to millions: whether the herbs of classical Chinese pharmacopoeia can earn a place in the evidence-based arsenal against one of the world’s most common cancers.

Subject of Research: A randomised controlled trial evaluating Shenbai granules for preventing metachronous high-risk colorectal adenomas after endoscopic resection

Article Title: Shenbai granules for preventing malignant transformation of high-risk colorectal adenomas: protocol of a multicentre, randomised, double-blind, placebo-controlled trial

Article References: Shenbai granules for preventing malignant transformation of high-risk colorectal adenomas: protocol of a multicentre, randomised, double-blind, placebo-controlled trial. (n.d.). https://doi.org/10.1186/s12906-026-05615-9

Image Credits: AI Generated

DOI: 10.1186/s12906-026-05615-9

Keywords: colorectal cancer, colorectal adenoma, chemoprevention, Shenbai granules, traditional Chinese medicine, randomised controlled trial, colonoscopy, metachronous adenomas, cancer prevention, clinical trial protocol, placebo-controlled, gastroenterology