Abstract 97P
Background
Adjuvant chemotherapy has been recommended for patients who have locally advanced rectal cancer. However, the role of adjuvant chemotherapy in patients with positive surgical margin has not been clarified. We investigated the benefit of adjuvant chemotherapy according to the surgical margin in locally advanced rectal cancer.
Methods
A total of 1801 rectal cancer patients staging cT3-4N0-2M0 were included. The patients were eligible when tumors were pathologically confirmed adenocarcinoma, located within 10cm from anal verge, and staged cT3-4N0-2M0. Before surgery, all patients received radiation therapy at a dose of 50.4 Gy in 28 fractions with concurrent 5-fluorouracil or capecitabine. Curative surgery including TME was performed 4 to 8 weeks after radiotherapy. Adjuvant chemotherapy was performed after 4-6 weeks after surgery.
Results
Adjuvant chemotherapy was given to 1531 patients (85.0%). Patients with positive circumferential resection margin or distal resection margin were 205 (11.4%). With patients with positive surgical margin (n = 205), the 5-year recurrence-free survival (RFS) showed a significant difference between adjuvant chemotherapy group and no adjuvant chemotherapy group (50.3% vs. 30.9%, p = 0.01). The 5-year overall survival rate was 72.6% in adjuvant chemotherapy group and 57.2% in no adjuvant chemotherapy group (p = 0.09). With patients with the negative margin (n = 1596), the 5-year RFS rate did not show any difference between two groups (75.6% vs. 76.8%, p = 0.94). On multivariate analysis, adjuvant chemotherapy was significantly associated with RFS in patients who had the positive surgical margin (Hazard ratio (HR): 0.48, 95% confidence interval (CI): 0.25-0.94, p = 0.032). In contrast, there was no significant association between adjuvant chemotherapy and RFS in those with negative surgical margin (HR: 0.99, 95% CI: 0.72-1.35, p = 0.94).
Conclusions
Patients who received adjuvant chemotherapy showed a significantly improved 5-year RFS rate compared with those who did not receive adjuvant chemotherapy if the patients had positive surgical margin. The benefit of adjuvant chemotherapy was more remarkable in patients with positive surgical margin compared to those with negative surgical margin.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The author.
Funding
Has not received any funding.
Disclosure
The author has declared no conflicts of interest.
Resources from the same session
397P - Development of prediction model for hepatocellular carcinoma in chronic hepatitis B patients
Presenter: Teerapat Ungtrakul
Session: Poster display session
Resources:
Abstract
398P - Planning for future cancer control programs in Uganda: Projections of top five cancers’ incidence in the next decade
Presenter: Judith Asasira
Session: Poster display session
Resources:
Abstract
399P - Prevalence of colorectal cancer risk factors in apparently healthy adults in Suluhan Village, Bali
Presenter: Cindy Trisina
Session: Poster display session
Resources:
Abstract
400P - Female lung cancer: Emerging issue in Bangladesh
Presenter: Muhammad Rafiqul Islam
Session: Poster display session
Resources:
Abstract
402P - Work-related outcomes among cancer survivors in Singapore
Presenter: Chia Jie Tan
Session: Poster display session
Resources:
Abstract
407P - Focal treatments for metastatic soft tissue sarcoma (mSTS) is associated with improved overall survival
Presenter: Ching Tso Chen
Session: Poster display session
Resources:
Abstract
408P - The Asian sarcoma consortium sarcoma preceptorship program: A program evaluation study utilizing the Kirkpatrick model (Level 1 and 2)
Presenter: Fernando Gracieux Jr.
Session: Poster display session
Resources:
Abstract
409P - Integrated genomic and transcriptomic analysis revealed mutagenic patterns of dedifferentiated liposarcoma and leiomyosarcoma in Chinese patients
Presenter: Yuhong Zhou
Session: Poster display session
Resources:
Abstract
410P - Treatment patterns and outcomes of elderly patients with metastatic soft tissue sarcomas (mSTS)
Presenter: Yu-ju Kuo
Session: Poster display session
Resources:
Abstract
411P - Comparative analysis of protein profiles of prognosis-associated proteins and KIT-related proteins in gastrointestinal stromal tumour
Presenter: Yoshiyuki Suehara
Session: Poster display session
Resources:
Abstract