In the treatment of low rectal cancer, the “watch and wait” strategy has sparked a compelling debate between organ preservation and radical resection. With the advancement of neoadjuvant therapies, some patients achieve clinical complete response (cCR) following chemoradiotherapy, opening the door to non-operative management and the possibility of avoiding a permanent stoma. However, concerns over local regrowth, subjective response assessment, and the psychological burden on patients continue to challenge the broader application of this approach.At the 9th Annual Meeting of the Chinese Medical Doctor Association Colorectal Oncology Committee, Professor Aiwen Wu from Peking University Cancer Hospital delivered a keynote presentation titled “Decision-Making Before Treating Low Rectal Cancer: Should We Choose Watch and Wait?” In this talk, Professor Wu provided a comprehensive review of the clinical evidence, technical limitations, and decision-making pathways surrounding the watch-and-wait strategy. His insights aim to support shared decision-making between physicians and patients, and to help guide rectal cancer management toward a new era of precision and organ preservation.
I. Limited Sphincter Preservation in Low Rectal Cancer
Sphincter preservation has long been a key concern for both physicians and patients facing low rectal cancer. Unfortunately, the outcomes in this regard are often suboptimal. For instance, the LASRE trial, published in JAMA Oncology in 2022, reported a sphincter preservation rate of 71.7% in the laparoscopic surgery group compared to 65.0% in the open surgery group. While the laparoscopic approach showed a slight advantage in preservation rates, it also exhibited a higher rate of local recurrence (3.7% vs. 2.3%) and a significant difference in postoperative complications (13.0% vs. 17.2%). These findings highlight the inherent challenges of achieving sphincter preservation in low rectal cancer and underscore the importance of setting realistic expectations with patients.
Moreover, the quality of life following sphincter-preserving surgery often does not meet the expectations of patients—or even clinicians. Several studies have shown that patients with a permanent stoma do not necessarily experience a lower quality of life compared to those who undergo low anterior resection. This reflects the clinical dilemma of choosing between oncologic cure and functional preservation—finding the optimal balance between the two remains at the core of treatment decisions.
To quantify the risk of developing low anterior resection syndrome (LARS), researchers have developed the PORTLARS predictive model. By inputting five clinical variables—such as pathological lymph node stage, choice of proximal colon, and distal rectal length—the model estimates the likelihood of major LARS. For example, when the distal rectal length is 0 cm, the risk of major LARS is as high as 82.2%, but it drops significantly to 8.7% when the length reaches 5 cm (Figure 1). Patients suffering from severe LARS endure substantial—and often invisible—distress. In some cases, patients may even opt for a permanent stoma after initially undergoing a preservation procedure. As such, the PORTLARS tool provides a scientific foundation for preoperative discussions and personalized follow-up strategies.
Importantly, the treatment goals for low rectal cancer often differ between doctors and patients. These differences typically stem from varying perceptions of the disease, expectations of treatment, and the weight placed on quality of life. For many patients, the anus is not merely a functional organ—it symbolizes dignity and a better life. As a result, patients frequently prioritize sphincter preservation, even if it comes with an increased risk of recurrence. In contrast, physicians tend to focus more on perioperative safety, oncologic radicality, and long-term survival outcomes. Therefore, aligning treatment goals through thorough doctor–patient communication is essential before initiating any therapy.
II. Non-Surgical Management: A Safer Path to Sphincter Preservation in Low Rectal Cancer
In recent years, the watch-and-wait (W&W) approach following neoadjuvant therapy has emerged as a widely discussed strategy in rectal cancer care—and one that has already benefited a subset of patients. Compared to surgery, successful implementation of W&W can significantly reduce postoperative complications and functional impairment, markedly improving patients’ quality of life.
International multicenter studies have shown that for patients who achieve a clinical complete response (cCR) or near-complete response (near-cCR) following neoadjuvant therapy, the 5-year overall survival rate with W&W (85%) is comparable to that of surgery, with an organ preservation rate of 85.3%. For example, in China’s first multicenter registry study, among 318 patients who achieved cCR or near-cCR after treatment, the 5-year cumulative organ preservation rate was 85.3%, with a local regrowth rate of 18.5% and a distant metastasis rate of 8.2%. These findings suggest that with careful patient selection and close follow-up, the W&W approach can be safely applied in clinical practice.
Still, challenges remain. Local regrowth, distant metastasis, and uncertainty in decision-making continue to hinder broader implementation. Studies show that up to 36% of patients under W&W experience recurrence, 52% of whom had only achieved near-cCR. Most recurrences occurred within the first 2 to 3 years post-treatment and were closely tied to tumor stage: cT4 patients had a local regrowth rate of 31%, significantly higher than the 18% observed in cT1–2 tumors. These findings underscore the need for careful evaluation, individualized treatment planning, and stringent post-treatment monitoring.
To address these issues, Professor Aiwen Wu highlighted four key strategies:
- Long-course vs. Short-course Radiotherapy in Non-surgical Treatment During the COVID-19 pandemic, MSKCC shifted from long-course chemoradiotherapy (LCCRT) to short-course chemoradiotherapy (SCRT) for low rectal cancer. Subsequent research revealed that the 2-year organ preservation rate was lower in the SCRT group (70%) compared to LCCRT (89%), while local regrowth was significantly higher (36% vs. 19%). These results suggest that LCCRT remains the preferred protocol for patients pursuing a W&W strategy aimed at organ preservation.
- Subjectivity in Endoscopic and MRI Assessments Clinical judgment remains crucial in evaluating treatment response. The team at Peking University Cancer Hospital has observed instances where patients assessed as cCR via endoscopy were found to have more advanced disease postoperatively (e.g., ypT2N1a or ypT3N1a). Similarly, MRI-based mrTRG scoring is not always reliable; some cases scored as mrTRG2 or 3 were confirmed to be pathological complete responses (pCR) after surgery. This highlights the risks of both false negatives and false positives. Hence, a multimodal approach, incorporating endoscopic evaluation, MRI, rectal ultrasound, serum CEA, and PET-CT, is essential for improving diagnostic accuracy.
- Variation in Local Regrowth Rates Across Centers Significant discrepancies in local regrowth rates—ranging from 5.9% to 40%—have been reported among different institutions. These differences often stem from inconsistent patient selection and evaluation standards. The OPRA trial, led by MSKCC, demonstrated a 36% overall regrowth rate, with 40% in the induction therapy group and 27% in the consolidation group. Of 123 patients with cCR, 27 (22%) relapsed; among 94 near-cCR cases, 49 (52%) relapsed; and among 8 incomplete responders, 5 (63%) experienced recurrence. These findings illustrate the urgent need for standardized definitions and evaluation criteria.
- Organ-specific Responses to Immunotherapy in dMMR Tumors A study from Peking University Cancer Hospital involving 37 patients with dMMR/MSI-H gastrointestinal malignancies treated with neoadjuvant PD-1 blockade showed a pCR rate of 56.7% in colorectal cancer, and an impressive 80% pCR rate in locally advanced rectal cancer. These results suggest that dMMR rectal cancers respond exceptionally well to neoadjuvant immunotherapy. In contrast, response rates in gastric and duodenal adenocarcinomas were also notable but lower. Furthermore, combining chemoradiotherapy with immunotherapy (NAICRT) may further increase cCR rates, offering hope for high-risk patients who do not respond well to conventional treatment.
III. When Is the Watch-and-Wait Strategy Not Suitable for Low Rectal Cancer?
Professor Aiwen Wu emphasized that as the watch-and-wait (W&W) approach gains popularity in rectal cancer management, it is critical to recognize the value of clinical expertise and avoid decisions driven purely by patient preference. She cautioned against adopting the strategy under pressure from patients when it may not be medically appropriate.
According to the 2024 Chinese Expert Consensus on Watch-and-Wait Strategy Following Neoadjuvant Therapy for Rectal Cancer, several patient-related factors make the W&W approach inadvisable. These include rectal cancers with a high risk of local recurrence, patients who are unable to tolerate neoadjuvant therapy, individuals who are either uncertain about or unwilling to accept the risks associated with W&W, and those with poor compliance, making them unsuitable for the rigorous follow-up required. This recommendation carries a Grade C level of strength and was supported by 83.87% of participating experts.
In evaluating the appropriateness of W&W for low rectal cancer patients, Professor Wu suggested taking a comprehensive view of each case. First, it is essential to assess whether conventional surgery—either upfront or following neoadjuvant treatment—can feasibly preserve the anal sphincter. Second, the risk of postoperative anastomotic leakage must be considered. Third, one must evaluate the potential for functional recovery of anal continence after surgery and how well the patient may tolerate neoadjuvant therapy. Furthermore, the biological characteristics of the tumor should be carefully reviewed to determine whether they signal a high risk of recurrence. Finally, the patient’s psychological resilience must be taken into account—particularly their ability to cope with the possibility of tumor recurrence and their willingness and capacity to adhere to a strict follow-up schedule.
In conclusion, the W&W strategy for low rectal cancer represents both a milestone in medical progress and a crucial test of shared decision-making between doctor and patient. The central principle should always be patient-centered care, supported by mutual understanding and transparent communication. It is equally important to distinguish between proactive W&W—based on thorough clinical judgment—and passive observation stemming from indecision or compromise.
Looking to the future, organ preservation will become an increasingly important goal in rectal cancer treatment. Achieving this will require ongoing research and refinement of treatment approaches, with careful attention to therapeutic simplicity, efficacy, and the differing side effect profiles across treatment modalities. By breaking through diagnostic bottlenecks through technological innovation, improving risk prediction through data sharing, and addressing patient anxiety through empathetic care, we move closer to a true win-win outcome—achieving both cancer cure and sphincter preservation
- Chief Physician, Professor, Doctoral Supervisor
- Director, Ward 3, Gastrointestinal Cancer Center, Peking University Cancer Hospital
- Executive Member, Chinese Anti-Cancer Association
- Standing Member, Beijing Anti-Cancer Association
- Chair, Colorectal Cancer Committee, Beijing Anti-Cancer Association
- Chair, Popular Science Committee, Beijing Anti-Cancer Association
- Member, Experimental and Translational Surgery Group, Chinese Society of Surgery
- Standing Member, Colorectal Cancer Committee, Chinese Anti-Cancer Association
- Member, Gastric Cancer Committee, Chinese Anti-Cancer Association
- Founding Member, China Watch and Wait Database (CWWD)
- Vice Chair, TaTME Committee, Chinese Medical Doctor Association Colorectal Oncology Branch
- Member, Colorectal Oncology Branch, Chinese Medical Doctor Association
- Member, Gastrointestinal Oncology Group, Chinese Society of Clinical Oncology
- Member, Anorectal Committee, Chinese Medical Doctor Association
- Member, Surgical Skills Research Group, Beijing Medical Doctor Association
- Secretary-General, 7th to 11th National Gastric Cancer Conferences (2013–2016)
- Secretary-General, 12th International Gastric Cancer Congress (2017)
