Italian NO-CUT Trial Shows Nonoperative Management Safe for Rectal Cancer Patients After Complete Response
核心洞察
The Italian NO-CUT phase II trial demonstrated that nonoperative management after total neoadjuvant therapy achieved 95% distant relapse-free survival at 30 months in rectal cancer (搜索) patients with complete response.
Among 179 patients with stage II-III rectal cancer (搜索), 26% achieved clinical complete response and successfully avoided surgery while maintaining excellent oncologic outcomes.
Circulating tumor DNA (搜索) analysis emerged as a powerful predictive biomarker, with ctDNA negativity after treatment strongly correlating with better outcomes and lower relapse risk.
The Italian NO-CUT phase II trial has demonstrated that nonoperative management following total neoadjuvant therapy can safely preserve organ function in select rectal cancer (搜索) patients without compromising long-term survival outcomes. Published in The Lancet Oncology, the multicenter study provides compelling evidence for organ preservation strategies in proficient mismatch repair (搜索)/microsatellite stable (搜索) (pMMR/MSS) stage II-III rectal cancer.
Study Design and Patient Population
The NO-CUT trial enrolled 179 patients with untreated pMMR/MSS stage II-III rectal adenocarcinoma (搜索) across four Italian cancer centers between June 2018 and August 2023. All participants received standardized total neoadjuvant therapy consisting of four cycles of capecitabine (1,000 mg/m² twice daily on days 1-14 every 3 weeks) and oxaliplatin (130 mg/m² on day 1 every 3 weeks), followed by concurrent chemoradiotherapy with capecitabine (825 mg/m² twice daily) and radiotherapy (50-54 Gy in 25 fractions over 5 weeks).
The study employed a structured three-step response evaluation process, with patients achieving clinical complete response entering nonoperative management while others proceeded to surgery. The primary endpoint was 30-month distant relapse-free survival in the nonoperative management cohort.
Efficacy Outcomes Exceed Expectations
Among the 179 patients, 165 (92%) completed total neoadjuvant therapy, with 47 patients (26%) achieving clinical complete response and entering nonoperative management. With a median follow-up of 35 months, the results demonstrated exceptional efficacy for the organ preservation approach.
Distant relapse-free survival at 30 months reached 95% (95% CI = 88%-100%) in the nonoperative management group, significantly exceeding the predefined efficacy benchmark. This compared favorably to 74% (95% CI = 66%-84%) in the surgery group and 74% (95% CI = 68%-82%) in the overall population.
The 2-year rectal surgery-free survival after nonoperative management was 83% (95% CI = 73%-95%), indicating that most patients successfully avoided surgical intervention long-term.
Local Control and Salvage Surgery
Local regrowth occurred in 7 of 47 patients (15%) in the nonoperative management group, with all cases occurring within two years and successfully salvaged with curative-intent surgery. The multidisciplinary algorithm correctly identified 82% of complete responders for nonoperative management, demonstrating the reliability of the response assessment protocol.
In the surgery cohort, local relapse risk was 11% at 2 years and 16% at 3 years, while distant progression during or immediately after total neoadjuvant therapy occurred in approximately 6% of patients.
Circulating Tumor DNA as Predictive Biomarker
The study's exploratory analysis revealed circulating tumor DNA (搜索) (ctDNA) as a powerful predictive tool. At baseline, ctDNA was positive in 95% of patients, falling to 24% after total neoadjuvant therapy and only 8% among patients with clinical complete response.
Circulating tumor DNA (搜索) positivity after total neoadjuvant therapy was associated with significantly poorer distant relapse-free survival (P = .0032). In multivariable models, post-treatment ctDNA negativity emerged as an independent predictor of reduced relapse risk, offering potential for personalized surveillance strategies.
Safety Profile
The treatment regimen demonstrated manageable toxicity, with grade 3 or 4 adverse events occurring in 31% of patients. The most common severe adverse events were diarrhea, lymphopenia, neutropenia, and bowel obstruction (4% each). Serious adverse events occurred in 17% of patients, with bowel obstruction being the most frequent (4%).
Treatment discontinuation due to adverse events occurred in 7% of patients, and importantly, no treatment-related deaths were reported throughout the study period.
Clinical Implications
As stated by the investigators, "In pMMR/MSS stage II–III rectal cancer (搜索), total neoadjuvant therapy followed by non-operative management allows organ preservation in some patients without compromising distant relapse–free survival, supporting non-operative management as a treatment option in clinical practice."
The study's findings strengthen nonoperative management as a guideline-supported option for rectal cancer (搜索) treatment, particularly when integrated with biological markers like ctDNA for enhanced patient selection and surveillance. The research suggests a future where organ preservation strategies are refined through personalized, biomarker-driven approaches, moving rectal cancer treatment toward less invasive, high-precision care.