ESD uptake in US continues to lag despite promise of improved colorectal cancer outcomes
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The American Cancer Society estimates 106,970 new cases of colon cancer and 46,050 new cases of rectal cancers in the United States in 2023, with colorectal cancer expected to result in approximately 52,550 deaths this year alone.
Today, so many efforts around CRC awareness focus on the importance of colonoscopy screening, which is critical and has contributed to a steady decrease in incidence and mortality of CRC over the past several decades.
While this progress is encouraging, an aging population paired with more screening exams means more premalignant and malignant polyps are being detected, and CRC remains the second most diagnosed cancer by volume of new cases. With that, clinicians are also seeking new methods and advances that can support removal of precancerous lesions and nonmetastatic cancers in a minimally invasive fashion, while also maximizing likelihood of completely curative intervention.
These efforts together — boosting CRC screening and arming clinicians with the methods and tools they need to catch cancers sooner and intervene more effectively, efficiently and safely — is how providers will ultimately improve overall outcomes for CRC.
Current options
Current treatment options include endoscopic techniques as well as surgical resection. The two techniques for endoscopic removal of large colonic polyps are endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD).
EMR is an endoscopic procedure to remove precancerous, early-stage cancer or other abnormal tissues (lesions) from the digestive tract. However, this technique may result in a “piecemeal” resection — removal of the lesion in several small pieces — especially for lesions larger than 2 cm in size. As a result, EMR has limitations, and studies have found higher rates of local recurrence (polyp regrowth) when comparing EMR to other treatment options.
ESD is a minimally invasive procedure that removes potentially cancerous tumors from the gastrointestinal tract, involving separation of a suspicious lesion from the surrounding healthy tissue, and removal of the lesion in one piece for further study and diagnosis.
The removal of a suspicious lesion in one piece, known as en bloc resection, is a key objective because it allows a pathologist to verify that negative margins are present around the lesion, meaning no precancerous cells were left behind. If negative margins cannot be confirmed, the likelihood of recurrence may be higher.
Surgical resection also has proven to be effective, but it is the most invasive treatment option. Surgery may be required for cancerous lesions that show signs of invasion deep into the colon wall or if the cancer has become metastatic. Otherwise, endoscopic removal is likely preferred, with lower risk of complication and/or significant quality of life implications after surgery.
Even so, data has shown that surgical removal of a colon segment (partial colectomy) is often performed, even for nonmalignant lesions for which a less invasive treatment option may have been appropriate.
EMR vs. ESD in the United States
As a safe and effective alternative to piecemeal endoscopic resection or invasive surgery, several countries have embraced ESD — but not the U.S. Moreover, some studies point to big benefits, like higher en bloc resection rate and lower local recurrence rate for the treatment of colorectal tumors.
From a pure resection standpoint, ESD is a better technique than EMR for the primary reason that it is a true oncological resection. Simply put, it is freehand resection of a lesion with removal of the lesion en bloc — that factor alone tends to guarantee a more optimal histological specimen evaluation of resection margins.
Furthermore, ESD is particularly beneficial in patients in whom early cancer is suspected. With early cancer, the goal is to achieve an oncological resection in one piece, which allows the pathologist to examine that specimen in its entirety and with clear margins to determine whether it has been adequately removed.
The downside of not doing so is that if you piecemeal a lesion it can lead to indeterminate resection margins. And that, unfortunately, can result in unnecessary surgery. Meanwhile, the patient could have been otherwise cured with en bloc resection.
While EMR is easier to learn and perform, has a lower risk for adverse events and carries a lower cost burden, ESD is associated with lower risk for recurrence and may reduce the need for subsequent intervention.
Addressing barriers, driving adoption
So why haven’t U.S. clinicians embraced the ESD technique? There are several reasons and chief among them is lack of four things: Training, mentors, reimbursement and the right technology.
Starting with training, one of the main limitations for the widespread adoption of ESD in the U.S. is that it is probably one of the most technically complex procedures we do.
ESD could be readily adopted in Japan because trainees had access to easier lesions compared with the West. Because of the high prevalence of gastric cancer in Asia over the years, the technique has been utilized regularly — and ultimately perfected — and now is the standard of care in Asia.
Utilizing ESD in the stomach tends to be one of the easier locations to start performing this technique. Clinicians who train in Asia have a good opportunity to perform ESD on easier, more approachable lesions and subsequently start developing and refining skills for ESD.
However, in the U.S., lesions that are generally targeted by ESD tend to be in the colon and rectum rather than in the stomach, which are significantly more complex and difficult to treat. From a training perspective, it has been more challenging to adopt ESD in the U.S. compared with Asia.
Another issue, closely allied to training, is the lack of mentorship. Because ESD is so underutilized here, there are few mentors to help guide beginners. Video coaching is one possible way to rectify that issue and help drive adoption of ESD.
For example, trainees could perform cases and then submit them to a mentor who can then remotely review their videos and provide feedback on their performance. Also, training on animal models is crucial to build confidence and muscle memory. The EndoGel training model (Sunarrow Ltd.) is another option to gain scope time; since it is a synthetic tissue, it could be used without the veterinary scopes and equipment.
Lack of reimbursement is another barrier to uptake in the U.S. For any procedure to gain widespread adoption, reimbursement is key. Without adequate reimbursement for the procedure, health care organizations will go with the reimbursable option, such as EMR.
However, reimbursement will eventually come. It will be largely based on the continued aggregation of evidence supporting the role of ESD for removing lesions — specifically in the Western hemisphere. Over the past few years, there have been several large, multicenter studies supporting the efficacy and safety of ESD. Overall, we are moving toward reimbursement.
There also remains a lack of proper tools to facilitate visualization, retraction and tissue manipulation during ESD. Performing ESD is no easy task, so any technology that can flatten the learning curve is going to help. We need technology that makes the procedure faster, more efficient and safer. That might mean different traction devices, different types of knives and different technology to help manage bleeding complications or perforations; these kinds of solutions increase our toolbox and make the procedure more approachable.
Study: traction technology
ESD still has its limitations, and many U.S. physicians are looking for technology solutions to help overcome existing challenges. There are studies from Japan, for example, that have shown that traction training improves ESD outcomes.
Recently, I led a study along the same lines, with results published in DEN Open in October 2022. Although small, it showed that traction technology during ESD may potentially improve learning, and that is expected to be translated into better efficacy and safety while making the procedures easier and less resource-, time- and labor-intensive. Specifically, ESD experts and trainees from three U.S. academic medical centers evaluated Tracmotion (Fujifilm), a single operator, 360-degree rotatable retraction device for performing ESD.
The goal of our study was to determine whether the introduction of this device would facilitate easier ESD in people who had not been otherwise exposed to using it. Five trainees performed two Tracmotion-assisted ESD procedures and two conventional ESD procedures, each in an ex vivo porcine stomach model, for a total of 20 procedures.
Our study found that Tracmotion-assisted ESD resulted in faster submucosal dissection and less physical demand when compared to conventional ESD. The key benefits were swifter, more efficient procedures for patients and less strain on clinicians.
When we evaluated the data comparing conventional ESD to Tracmotion, one of the parameters that improved was physical demand, and we believe it also was associated with a shorter dissection time.
Our study provides the first clinical data in the West for Tracmotion. Moreover, it demonstrated that ESD with Tracmotion was associated with high en bloc curative resection rates. While comparative studies will need to be done, we can say that at least in the selected lesions, Tracmotion was linked to higher resection outcomes than have been historically reported.
A promising future
From 2000 to 2014, there were more than 1.2 million colorectal surgeries for colorectal cancers and nonmalignant polyps. As a viable alternative to piecemeal resection or invasive surgery, ESD can be utilized for en bloc resection of large, potentially cancerous polyps or tumors in the GI tract.
As mentioned earlier, ESD has been shown to have a higher en bloc resection rate and lower local recurrence rate for the treatment of colorectal tumors, without increasing procedure-related complications, when compared with EMR. However, until recently, there was a lack of sufficient tools for physician training and education to master ESD in the U.S.
As an intuitive retraction tool, Tracmotion may enable endoscopists to reduce their time in both learning and performing ESD procedures. Increased utilization of ESD procedures as an alternative to EMR can, in turn, help save lives in the future.
References:
- Key statistics for colorectal cancer. https://www.cancer.org/cancer/types/colon-rectal-cancer/about/key-statistics.html.
- Yang D, et al. DEN Open. 2022;doi:10.1002/deo2.174.
For more information:
Dennis Yang, MD, is director of Third Space Endoscopy at the Center for Interventional Endoscopy at AdventHealth Orlando and professor of medicine at Loma Linda University Health.
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