EP371 - Clinical outcomes of preoperative short-course RT and chemotherapy versus chemoradiotherapy in locally advanced rectal cancer: A single-center experience in Taiwan

Sunday, May 11, 2025

8:27 AM – 8:32 AM PT

Location: Monitor 10, Sails Pavilion, Upper Level

ePoster Presenter(s)

Yu-Hsin Hsieh, MD (she/her/hers)

Resident doctor
Taipei Veterans General Hospital
Taipei, Taipei, Taiwan (Republic of China)

All of the relevant financial relationships listed below have been mitigated.
This individual has no financial relationships with ineligible companies.

Senior Author(s)

HL

Hung-Hsin Lin, n/a

Visiting Staff
Taipei Veterans General Hospital
Taipei, Taipei, Taiwan (Republic of China)

All of the relevant financial relationships listed below have been mitigated.
This individual has no financial relationships with ineligible companies.

Author(s)

JJ

Jeng-Kai Jiang, n/a

Visiting staff
Taipei Veterans General Hospital
Taipei, Taipei, Taiwan (Republic of China)

Disclosure information not submitted.
SC

Shih-Ching Chang, n/a

Visiting staff
Taipei Veterans General Hospital
Taipei, Taipei, Taiwan (Republic of China)

Disclosure information not submitted.
HW

Huann-Sheng Wang, n/a

Visiting staff
Taipei Veterans General Hospital
Taipei, Taipei, Taiwan (Republic of China)

Disclosure information not submitted.
YL

Yuan-Tzu Lan, n/a

Visiting staff
Taipei Veterans General Hospital
Taipei, Taipei, Taiwan (Republic of China)

Disclosure information not submitted.
CL

Chun-Chi Lin, n/a

Visiting Staff
Taipei Veterans General Hospital
Taipei, Taipei, Taiwan (Republic of China)

Disclosure information not submitted.
sH

sheng-chieh Huang, n/a

Visiting Staff
Taipei Veterans General Hospital
Taipei, Taipei, Taiwan (Republic of China)

Disclosure information not submitted.
HC

Hou-Hsuan Cheng, n/a

Visiting Staff
Taipei Veterans General Hospital
Taipei, Taipei, Taiwan (Republic of China)

Disclosure information not submitted.

All of the relevant financial relationships listed below have been mitigated.

Yu-Hsin Hsieh, MD: This individual has no financial relationships with ineligible companies.

Hung-Hsin Lin, n/a: This individual has no financial relationships with ineligible companies.

Image or Table (Do Not add text here):

Purpose/Background: This study aims to compare the clinicopathological features and outcomes of patients with locally advanced rectal cancer (LARC) treated with short-course radiotherapy (SCRT) followed by chemotherapy and curative surgery versus those receiving preoperative chemoradiotherapy (LCRT) prior to surgery.

Methods/Interventions: Between January 2019 and December 2023, demographic and clinical data were collected from Taipei Veterans General Hospital, focusing on tumor characteristics, treatment regimens, and clinical outcomes. Eligible patients were those aged 18 years or older, and had a biopsy-proven, newly diagnosed locally advanced rectal adenocarcinoma. The SCRT prescription dose was 5 Gy x 5 to gross tumor and mesorectum, followed by ≥ 4 cycles of FOLFOX or ≥ 3 cycles of XELOX. Patients allocated to the chemoradiotherapy group received 28 daily fractions of 1.8 Gy up to 50.4 Gy with concomitant UFUR or FOLFOX/ XELOX. All patients received curative-intended rectal surgery.

Results/Outcomes: A total of 158 patients met the eligibility criteria for this retrospective analysis, including 100 patients in the SCRT group and 58 patients in the LCRT group. The cohort comprised predominantly male patients (69%) with a median age of 64.9 years and an average ASA score of 2.2. Both treatment groups exhibited a high proportion of stage III disease at diagnosis (94% in SCRT and 94.8% in LCRT). The distribution of rectal lesion locations revealed that in the SCRT group, 73% of lesions were located in the middle rectum, while 22% were found in the lower rectum. In the LCRT group, 55% had middle rectal lesions, and 40% had lower rectal lesions. Additionally, 13% of patients in the SCRT group underwent abdominoperineal resection, compared to 26% in the LCRT group. A pathological complete response (pCR) was observed in 17% of the SCRT group compared to 10.3% in the LCRT group. The three-year overall survival rates were comparable (SCRT: 89%, LCRT: 86.2%). Local recurrence rates at three years were 5% for SCRT and 3.4% for LCRT, with distant metastasis rates being 19% for SCRT and 32.8% for LCRT.

Conclusion/Discussion: This study indicates that while SCRT followed by chemotherapy yields comparable overall survival rates to LCRT, it is associated with a lower incidence of distant metastasis. These findings suggest that SCRT may offer a potential advantage in managing LARC.