Initial experience of preoperative short-course radiotherapy followed by oxaliplatin-based consolidation chemotherapy for locally advanced rectal cancer

Preoperative sequential short-course radiation therapy and FOLFOX chemotherapy versus long-course chemoradiotherapy for locally advanced rectal cancer: a multicenter, randomized controlled trial (SOLAR trial)

BACKGROUND

Preoperative (chemo)radiotherapy has been widely used as an effective treatment for locally advanced rectal cancer (LARC), leading to a significant reduction in pelvic recurrence rates. Because early administration of intensive chemotherapy for LARC has more advantages than adjuvant chemotherapy, total neoadjuvant therapy (TNT) has been introduced and evaluated to determine whether it can improve tumor response or treatment outcomes. This study aims to investigate whether short-course radiotherapy (SCRT) followed by intensive chemotherapy improves oncologic outcomes compared with traditional preoperative long-course chemoradiotherapy (CRT).

METHODS

A multicenter randomized phase II trial involving 364 patients with LARC (cT3-4, cN+, or presence of extramural vascular invasion) will be conducted. Patients will be randomly assigned to the experimental or control arm at a ratio of 1:1. Participants in the experimental arm will receive SCRT (25 Gy in 5 fractions, daily) followed by four cycles of FOLFOX (oxaliplatin, 5-fluorouracil, and folinic acid) as a neoadjuvant treatment, and those in the control arm will receive conventional radiotherapy (45-50.4 Gy in 25-28 fractions, 5 times a week) concurrently with capecitabine or 5-fluorouracil. As a mandatory surgical procedure, total mesorectal excision will be performed 2-5 weeks from the last cycle of chemotherapy in the experimental arm and 6-8 weeks after the last day of radiotherapy in the control arm. The primary endpoint is 3-year disease-free survival, and the secondary endpoints are tumor response, overall survival, toxicities, quality of life, and cost-effectiveness.

DISCUSSION

This is the first Korean randomized controlled study comparing SCRT-based TNT with traditional preoperative LC-CRT for LARC. The involvement of experienced colorectal surgeons ensures high-quality surgical resection. SCRT followed by FOLFOX chemotherapy is expected to improve disease-free survival compared with CRT, with potential advantages in tumor response, quality of life, and cost-effectiveness.

TRIAL REGISTRATION

This trial is registered at Clinical Research Information under the identifier Service KCT0004874 on April 02, 2020, and at Clinicaltrial.gov under the identifier NCT05673772 on January 06, 2023.

Single-Port Robotic Intersphincteric Resection for the Treatment of Rectal Cancer

BACKGROUND

The da Vinci Single-port (SP) system is designed to facilitate single-incision robotic surgery in a narrow space. We developed a new procedure of intersphincteric resection (ISR) using the SP platform and evaluated the technical safety and feasibility of this procedure for the treatment of very low rectal cancer.

MATERIALS AND METHODS

Eleven rectal cancer patients who underwent SP robotic ISR between August 2020 and July 2021 were included. Patients' clinical characteristics, operative and pathologic findings of the patients were retrospectively analyzed.

RESULTS

The median tumor height was 3 cm (range, 2-4 cm). A single docking was performed, and the median docking time was 3 min 10 sec (range, 2 min 50 sec-3 min 30 sec). The median total operation time was 210 min (range, 150-280 min), and the median time of pelvic dissection was 57 min (range, 45-68 min). All patients presented with negative distal resection margins [median 1 cm (range, 0.5-2.0 cm)], and only one patient had less than 1mm of circumferential resection margin (0.9 mm).

CONCLUSIONS

Our initial experience suggests that SP robotic ISR is safe and feasible.