Patients diagnosed with locally advanced very low rectal cancer were chosen to participate in a comprehensive neoadjuvant therapy (TNT) protocol. This treatment regimen consisted of preoperative fractionated radiotherapy (5×7Gy) combined with 6 cycles of CAPOX chemotherapy and enverolimab. For patients who achieved clinical complete response (cCR) or near-clinical complete response (ncCR) after undergoing TNT, an organ-preserving strategy involving local full-thickness resection was implemented.
Locally advanced very low rectal cancer poses significant challenges in rectal cancer treatment. Presently, the prevailing approach in clinical practice involves neoadjuvant chemoradiotherapy in conjunction with total mesorectal excision (TME). Historically, abdominoperineal resection (APR) has been the conventional surgical procedure for managing locally advanced very low rectal cancer. However, the long-term presence of a colostomy following an abdominoperineal resection (APR) significantly impacts the quality of life for patients. Additionally, studies have revealed that 11.8-22% of rectal cancer patients who underwent APR after neoadjuvant chemoradiotherapy (nCRT) achieved a pathological complete response (pCR). Conversely, 11-52% of patients with pCR after nCRT for rectal cancer ultimately underwent APR surgery. Intersphincter resection (ISR) offers a highly beneficial surgical approach that preserves the anal sphincter, particularly for individuals with locally advanced very low rectal cancer. The patient's postoperative quality of life was significantly affected by severe low anterior resection syndrome (LARS), sexual dysfunction, and voiding dysfunction. This study represents an exploratory phase II clinical trial in which patients diagnosed with locally advanced very low rectal cancer were chosen to undergo a total neoadjuvant therapy (TNT) regimen. This regimen consisted of preoperative fractionated radiotherapy (5×7Gy) combined with 6 cycles of CAPOX chemotherapy and enverolimab. For patients who achieved clinical complete response (cCR) or near-clinical complete response (ncCR) after undergoing TNT, an organ-preserving strategy involving local full-thickness resection was implemented. Patients who achieve non-clinical complete response are subjected to traditional TME surgery. This study aims to investigate the effectiveness and safety of organ preservation using the local resection approach in patients with locally advanced very low rectal cancer. By implementing this approach, the study aims to improve the quality of life for patients who achieve pathological complete response (pCR), thereby avoiding the need for conventional abdominoperineal resection (APR) and intersphincteric resection (ISR) procedures. Additionally, this study aims to address the issue of local regrowth associated with the "watch \& wait" strategy and propose a novel treatment strategy for rectal-sparing surgery in patients with locally advanced very low rectal cancer.
After reaching a cumulative radiotherapy dose of 25Gy in the entire pelvic cavity (PTV1), the treatment field was subsequently narrowed to solely focus on the primary tumor (PTV2), with a total dose of 35Gy administered. All patients will undergo fractionated radiotherapy, following a regimen of 7Gy per fraction, delivered every 3 weeks for five cycles.
Drug: Oxaliplatin,130mg/m2,ivgtt,d1,for 6 cycles. Drug: Capecitabine,1000mg/m2,po,bid,d1-14, for 6 cycles.
Envafolimab is administered by subcutaneous injection. The recommended dose is 300 mg per 3 weeks (Q3W) for 6 cycles.
Pan Chi
Fuzhou, Fujian, China
Organ preservation
The rectum is intact, owing to no radical total mesorectal excision (TME), curative (R0) salvage surgery by local excision (LE), and no permanent stoma (including a never reversed protective stoma or a stoma owing to toxicities and/or poor functional outcomes).
Time frame: 36 months
ypT0-1 rate
The proportion of subjects with primary rectal cancer assessed by hematoxylin and eosin staining including no evidence of primary tumor (T0) or carcinoma in situ: intramucosal carcinoma (invading lamina propria, not infiltrating muscularis mucosa) (Tis) or tumor invading submucosa (T1) (ypT0-1 based on the latest UICC/AJCC staging system)
Time frame: 36 months
Pathological complete response (pCR) rate
Proportion of subjects with primary rectal cancer and all sampled lymph nodes who did not find any invasive carcinoma and high-grade intraepithelial neoplasia/severe dysplasia after assessment by hematoxylin and eosin staining (Judged as ypT0N0 stage according to the latest UICC/AJCC staging system)
Time frame: 36 months
Acute and late toxicity
Acute and late toxicity, Incidence of Treatment-Emergent Adverse Events assessment according to NCICTCAE V.5.0
Time frame: 36 months
Local recurrence rate
The proportion of patients in all subjects within 3 years from the start of the surgery to detection of a tumor involving the bowel wall only that occurs after LE or TME
Time frame: 36months
Local regional recurrence rate
The proportion of patients in all subjects within 3 years from the start of the surgery to detection of a tumor involving either the bowel wall, mesorectum, and/or pelvic organs that occurs after LE or TME
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
TREATMENT
Masking
NONE
Enrollment
72
Local full-thickness resection is employed for patients with clinical complete response (cCR) or near-clinical complete response (ncCR) following TNT.
Time frame: 36 months
Disease-free survival
The proportion of patients in all subjects within 3 years from the start of the surgery to recurrence, distant metastsis, or death from any cause (whichever occurs first)
Time frame: 36 months
Quality of life-based on EORTC QLQ-C30 and EORTC QLQ-CR29
Quality of life measured using EORTC QLQ-C30 and EORTC QLQ-CR29
Time frame: baseline, 3 months, 12 months, 24 months, and 36 months after LE or TME
Anorectal function
Anorectal function based on LARS score
Time frame: baseline, 3 months, 12 months, 24 months, and 36 months after LE or TME