Advanced Endoscopic Resection Enters the Rectal Cancer Response Setting
Locally advanced rectal cancer has long been managed with neoadjuvant therapy followed by radical surgery, a pathway designed to maximize oncologic control but often paid for with substantial functional cost. The operation can permanently alter bowel habits, sexual function, and quality of life, and even when cure is achieved, the price of cure can be steep. In patients who approach a near-complete clinical response after neoadjuvant treatment, the question becomes sharper: must every residual abnormality lead directly to radical resection, or can a more conservative strategy preserve the rectum without compromising safety?
This multicentre retrospective case series addresses that exact dilemma by examining advanced endoscopic resection for residual superficial rectal neoplasia after neoadjuvant therapy. The procedures included endoscopic submucosal dissection, endoscopic intermuscular dissection, and knife-assisted full-thickness resection. Each of these techniques is intended to remove localized residual disease while avoiding the morbidity of radical surgery or transanal local excision when possible.
The clinical logic is straightforward. If neoadjuvant therapy has already sterilized most of the tumor burden and left only a superficial remnant, a carefully performed endoscopic approach may be enough to clear the remaining lesion while preserving the rectum and the anal sphincter mechanism. In a disease where function matters as much as survival, the appeal is obvious.
Why Near-Complete Response Changes the Operative Question
Near-complete response after neoadjuvant therapy occupies an uneasy middle ground. The rectal lesion is no longer behaving like bulky, deeply invasive cancer, yet it cannot be dismissed as cured. Imaging, endoscopy, and clinical examination may show only a small residual area, but pathology can still reveal viable tumor. That uncertainty has traditionally pushed teams toward radical surgery, because missing residual cancer carries obvious oncologic risk.
Advanced endoscopic resection offers a different answer. Instead of removing the rectum or relying on transanal surgery with its own functional consequences, endoscopists can target the residual mucosal or superficial submucosal abnormality with precision. The tissue-sparing appeal is especially important in a setting where standard surgical local excision techniques, including transanal endoscopic microsurgery and transanal minimally invasive surgery, are associated with poor functional outcomes and high rates of major low anterior resection syndrome.
For patients who have already endured chemoradiation or other neoadjuvant treatment, an organ-preserving strategy can mean more than cosmetic anatomic conservation. It may mean avoiding bowel dysfunction severe enough to dominate daily life after the cancer diagnosis has otherwise been brought under control.
What This Multicentre Case Series Shows
The series evaluated advanced endoscopic resection specifically for residual superficial rectal neoplasia in patients with near-complete clinical response after neoadjuvant therapy. The inclusion of multiple techniques reflects the practical reality of endoscopic salvage: lesion morphology, depth of invasion, fibrosis, and the altered tissue planes left behind by radiation or chemotherapy determine which tool is most appropriate.
The overarching finding is cautious but important. The outcomes support advanced endoscopic resection as a viable and safe organ-preserving option, with a reasonable recurrence rate. In a field where the default response to residual rectal cancer has been aggressive surgery, that is a meaningful shift in concept. The study does not claim that endoscopic resection replaces radical surgery across the board. It does show that, in carefully selected patients, a less invasive pathway can be technically and clinically credible.
One sentence matters here.
These lesions are not being ignored; they are being removed with intent, precision, and pathologic confirmation.
The value of the case series lies in demonstrating that advanced endoscopic techniques can function not merely as diagnostic tools or rescue procedures, but as genuine organ-preserving treatment options in a high-stakes oncologic setting. That is especially relevant for rectal cancers where preserving function often matters as much as eradicating disease.
Functional Preservation Versus Radical Surgery
Rectal cancer surgery has always carried a dual burden: oncologic clearance and preservation of quality of life. The more distal the tumor, the more difficult that balance becomes. Radical surgery can save lives, but it can also leave patients with permanent stomas or chronic bowel dysfunction. Local excision has been used to reduce that burden, yet even transanal surgical techniques may still produce disappointing functional results, particularly when major low anterior resection syndrome develops.
Advanced endoscopic resection pushes preservation one step further. By staying within the endoluminal space and avoiding full pelvic dissection, these techniques may reduce the cascade of postoperative functional impairment. The biological rationale is not complicated: less tissue disruption means less neural injury, less distortion of the rectal reservoir, and less risk of the pelvic floor and sphincter dysfunction that often follow more extensive surgery.
At the same time, the oncologic tradeoff must be respected. The rectum is not a colon polyp, and residual cancer after neoadjuvant therapy exists in a field that has already been biologically stressed and anatomically altered. The acceptable margin for error is narrow. Any organ-preserving strategy must therefore be judged by both local control and the ability to avoid salvage surgery when disease recurs.
Where This Evidence Fits and What Still Needs Prospective Testing
This multicentre series should be read as a pilot signal rather than a final practice-changing verdict. Retrospective case series can establish feasibility, suggest safety, and identify a patient population worth studying more rigorously, but they cannot settle comparative effectiveness. The real unanswered question is not whether advanced endoscopic resection can be performed after near-complete response. It is whether it can reliably match radical surgery for disease control while preserving a better functional outcome over time.
Prospective trials are the necessary next step. Those studies will need to compare endoscopic resection-based organ-preserving strategies against standard surgical pathways in patients selected on the basis of response after neoadjuvant therapy. Endpoints should extend beyond technical success and recurrence alone to include bowel function, stoma avoidance, quality of life, and the need for subsequent salvage procedures. Without those data, the field can only infer benefit from a biologically plausible and technically attractive approach.
Still, the present series marks an important step in the evolution of rectal cancer care. It places advanced endoscopic resection squarely inside the conversation about organ preservation after neoadjuvant therapy, where the balance between oncologic certainty and functional harm is most difficult to strike. The study does not eliminate the need for radical surgery, and it does not claim universal applicability. It does, however, show that carefully selected patients with near-complete response may have another option beyond the operating room’s most invasive paths, and that option deserves prospective testing rather than anecdotal use alone.