Abstract 2310
Background
Although the current standard preoperative chemoradiotherapy (PCRT) for stage II/III rectal cancer decreases the risk of local recurrence, it does not improve overall survival and increase the likelihood of preoperative overtreatment, especially in patients without the circumferential resection margin (CRM) involvement.
Methods
Stage II/III rectal cancer without CRM involvement and lateral lymph node metastasis was radiologically defined by preoperative magnetic resonance imaging (MRI). Patients who received either PCRT followed by TME (PCRT group) or upfront surgery with TME (US group) between 2011 and 2016 were analyzed. We derived cohorts of PCRT group versus US group using propensity-score matching using staging, age, and distance from anal verge). Three-year relapse-free survival rate, disease-free survival (DFS), and overall survival (OS) were compared between two groups.
Results
A total of 221 patients were analyzed after propensity score matching. There were no differences in baseline characteristics. The median follow-up was 75 months (range, 28-101). No difference in 3-year relapse-free survival rate was noted between PCRT and US groups (89% vs 92% with US; P = 0.657). Likewise, there was no statistically significant difference in DFS (7.7 years vs 8.0 years with US; P = 0.162) and OS (8.1 years vs 8.3 years with US; P = 0.431), respectively. The rates of locoregional recurrence (2.9% vs 0% with US, P = 0.301) and distant metastasis (7.4% vs 7.1%, P = 1.0) at 3-years were not significantly different between two groups. Interestingly, approximately half of patients had pathologic stage I cancer in both groups (56% with PCRT vs 45% with US; P = 0.167) and 69% of patients in US group had not received adjuvant treatment, suggesting that upfront surgery without neoadjuvant therapy can be considered in early stage patients with good prognosis.
Conclusions
PCRT may not be required for all stage II/III rectal cancer patients, especially for the MRI-based intermediate-risk group (cT1-2/N1, cT3N0) without CRM involvement and lateral lymph node metastasis. Further prospective studies are warranted.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
3353 - Results of the 3rd interim analysis of C-Patrol: A non-interventional study on olaparib in German routine clinical practice
Presenter: Jalid Sehouli
Session: Poster Display session 2
Resources:
Abstract
740 - A real-world analysis of the treatment of advanced ovarian cancer with PARPIs
Presenter: Alejandra Martinez de Pinillos
Session: Poster Display session 2
Resources:
Abstract
5867 - Incidence of tumour BRCA1/2 variants in relapsed, platinum-sensitive ovarian, fallopian tube and primary peritoneal cancer
Presenter: Robert Morgan
Session: Poster Display session 2
Resources:
Abstract
2966 - Frequency of mutations in 21 hereditary breast and ovarian cancer susceptibility genes among 882 high-risk individuals
Presenter: Jihong Liu
Session: Poster Display session 2
Resources:
Abstract
1687 - BRCA testing of 1,284 Brazilian patients for hereditary breast and ovarian cancer in a routine diagnostic setting
Presenter: Fernanda Milanezi
Session: Poster Display session 2
Resources:
Abstract
3162 - A multi-center integrative study on cancer predisposition genes in Chinese patients with epithelial ovarian carcinoma
Presenter: Changbin Zhu
Session: Poster Display session 2
Resources:
Abstract
5993 - Incidental Early Occult Ovarian Cancer after Risk-Reducing Salpingo-Oophorectomy in BRCA1/2 Mutation Carriers followed in a Community Public Hospital
Presenter: Begona Grana Suarez
Session: Poster Display session 2
Resources:
Abstract
5334 - Response to chemotherapy in ovarian cancer (OC) patients with or without prior breast cancer (BC), stratified by BRCA mutation (BRCAm) status
Presenter: Angela George
Session: Poster Display session 2
Resources:
Abstract
4565 - Advanced ovarian cancer: is residual disease after debulking surgery affected by genetics factors involved in angiogenesis and immunity pathways?
Presenter: Michele Bartoletti
Session: Poster Display session 2
Resources:
Abstract
3251 - Surrogate endpoint of progression-free (PFS) and overall survival (OS) for advanced ovarian cancer (AOC) patients (pts) treated with neo-adjuvant chemotherapy (NACT): Results of the CHIVA randomized phase II GINECO study
Presenter: Fabrice Lecuru
Session: Poster Display session 2
Resources:
Abstract