Abstract 2747
Background
Guidelines for rectal cancer treatment differ in Japan, Europe, and the United States. Neoadjuvant chemoradiotherapy (CRT) has been used to control lateral lymph nodes (LLNs) in the West. The usefulness of LLN dissection (LLND) has been discussed in Japan, and a randomized study stated the possible advantage of local control. However, it is still unclear whether adding LLND to CRT is beneficial.
Methods
To investigate the effectiveness of LLND on rectal cancer patients who underwent neoadjuvant CRT, we retrospectively collected magnetic resonance images (MRIs) in a cohort of 1500 patients with cStage II/III lower rectal cancer below the peritoneal reflection and centrally reviewed MRIs. We measured short-axis LLN sizes on pre- and post-CRT images and evaluated patients’ prognosis according to LLN size and whether LLND was performed.
Results
MRIs were collected from 752 patients, of whom 189 underwent neoadjuvant CRT. Both pre- and post-CRT MRIs were available in 155 patients, of whom 66 underwent LLND (LLND group) and 89 did not (non-LLND group). The LLND and non-LLND group showed the following differences: positive circumferential resection margin by MRI after CRT: 53.0% vs. 32.6%; positive extramural venous invasion: 36.4% vs. 24.7%; laparoscopic surgery: 39.4% vs. 88.8%; and mean pre-CRT LLN size: 5.2 mm vs. 3.6 mm. Five-year relapse-free survival (5y-RFS) was 73.8% and 66.1% in the LLND and non-LLND groups, respectively (p = 0.38). Two local recurrences occurred in the LLND group. In stratified analysis, 5y-RFS of 40 patients whose LLN size was ≥5 mm in pre-CRT images was 77.8% in the LLND group and 46.2% in the non-LLND group (p = 0.06). On the other hand, 115 patients whose LLN size was <5 mm in pre-CRT images showed almost no difference between the LLND and non-LLND group (5y-RFS: 71.1% vs. 69.5%, p = 0.85).
Conclusions
Our data indicated that adding LLND to CRT may have survival benefits on those who had LLN size of ≥ 5 mm before CRT. Stratification by short-axis LLN size using pre-CRT MRIs may facilitate optimal multidisciplinary treatment strategies for low rectal cancer.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
Department of Surgery, Kyoto University Graduate School of Medicine.
Funding
The Japanese Foundation for Research and Promotion of Endoscopy, The Japan Society of Clinical Oncology, and Kondou Kinen Medical Foundation.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
5134 - Early prediction of the platinum-resistant relapse risk using the CA125 modeled kinetic parameter KELIM: a pooled analysis of AGO-OVAR 7 & 9; ICON 7 (AGO/GINECO/ MRC CTU/GCIG trials).
Presenter: OLIVIER COLOMBAN
Session: Poster Display session 2
Resources:
Abstract
4410 - Mirvetuximab soravtansine, a folate receptor alpha (FRa)-targeting antibody-drug conjugate (ADC), in combination with carboplatin and bevacizumab: Initial results from a Phase 1b study in patients (pts) with ovarian cancer
Presenter: David Omalley
Session: Poster Display session 2
Resources:
Abstract
5077 - Response to Pegylated Liposomal Doxorubicin (PLD) and Weekly Paclitaxel (wpac) in Platinum Resistant (PR) Ovarian Cancer (OC) by BRCA mutation status
Presenter: Louise Bremer
Session: Poster Display session 2
Resources:
Abstract
3483 - Impact of prior pegylated liposomal doxorubicin (PLD) treatment in recurrent ovarian cancer (ROC): Sub-group analysis from a randomized, open-label study comparing trabectedin (T) and PLD versus PLD alone in ROC (ET743-OVC-3006)
Presenter: Bradley Monk
Session: Poster Display session 2
Resources:
Abstract
5423 - OCTAVE - A phase I study of enadenotucirev, an oncolytic group B adenovirus, in combination with weekly paclitaxel in platinum-resistant epithelial ovarian cancer
Presenter: Iain McNeish
Session: Poster Display session 2
Resources:
Abstract
1385 - Phase I study of low dose whole abdominal radiation therapy (LDWART) in combination with weekly paclitaxel (wP) for platinum resistant ovarian cancer (PROC)
Presenter: Natalie Ngoi
Session: Poster Display session 2
Resources:
Abstract
2090 - Phase 1b/2a study assessing the safety and efficacy of adding AL3818 (Anlotinib) to standard platinum-based chemotherapy in subjects with recurrent or metastatic endometrial, ovarian or cervical carcinoma
Presenter: David Miller
Session: Poster Display session 2
Resources:
Abstract
1960 - Phase I Study of Intraperitoneal TRX-E-002-1 in Subjects with Persistent or Recurrent Ovarian, Fallopian Tube or Primary Peritoneal Cancer: Three-month Follow-up Results of the Dose Escalation Phase
Presenter: Jermaine Coward
Session: Poster Display session 2
Resources:
Abstract
4288 - Hybrid capture-based genomic profiling of circulating tumor DNA (ctDNA) from patients with ovarian cancer
Presenter: Mi Yang
Session: Poster Display session 2
Resources:
Abstract
3433 - Tumor Microvessel Density for predicting Nintedanib activity: data from the randomized CHIVA trial (a GINECO study)
Presenter: Maud Villemin
Session: Poster Display session 2
Resources:
Abstract