Abstract 95P
Background
To compare the pathological complete response rates and toxicity in patients receiving long-course neoadjuvant chemoradiotherapy versus total neoadjuvant therapy in locally advanced carcinoma rectum.
Methods
Biopsy-proven newly diagnosed patients of locally advanced rectal adenocarcinoma clinical tumor stage were randomized. Arm A patients received short-course radiotherapy (25 Gy in 5 fractions over seven days) followed by six cycles of CAPEOX chemotherapy (Capecitabine 825 mg/m2 orally twice daily D1-D14 and oxaliplatin 130 mg/m2 on day 1) at intervals of 21 days. Arm B patients received concurrent chemoradiation (50.4 Gy in 28 fractions, five fractions in a week with concurrent tablet capecitabine 825 mg/m2 orally twice daily). Total Mesorectal Excision was done in both arms 6 to 8 weeks after completion of neoadjuvant treatment.
Results
60 patients were included in the study, 30 patients in each arm. Both arms were balanced in terms of the age of the patient, sex, stage of the disease, and tumor location. The median interval between randomization and surgery was 32 weeks and 20 weeks in the experimental arm and control arm, respectively. 9 out of 30 (33.3%) patients in the experimental arm and 6 out of 30 (20%) patients in the control arm had Pathological complete responses (p=0.682). At a median follow-up of 12 months, 6 out of 30 patients developed distant metastases in the standard arm as compared to 1 out of 15 patients in the experimental arm. Grade 3 or higher gastrointestinal adverse events were higher in the experimental arm (20%) as compared to (7%) in the standard arm (p-value=0.59). The requirement of colostomy during surgery was 46% in arm A as compared to 55.5% in arm B (p-value=1.0). Table: 95P
MRI response | ARM A | ARM B |
T3-> T1/2 | 33% | 26% |
T4-> T1/2 | 6.6% | - |
T4-> T3 | 26% | 20% |
T3-> T0 | 6.6% | - |
N2-> N0 | 26% | 20% |
N1-> N0 | 33% | 20% |
Pathological response | ARM A | ARM B |
pT0 | 33.3% | 20% |
pT1 | 20% | 20% |
pT2 | 6.6% | 13.3% |
pT3 | 26.6% | 20% |
pN0 | 80% | 53.3% |
pN1 | 13.3% | 40% |
pN2 | 6.6% | 6.6% |
Conclusions
Total neoadjuvant therapy in locally advanced carcinoma rectum had a higher complete pathological response than the standard arm. The survival analysis of the trial is awaited.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
All India Institute of Medical Sciences, Intramural Funding.
Disclosure
All authors have declared no conflicts of interest.
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