Abstract:

Background: Neoadjuvant chemoradiotherapy is the standard of care for Stage II/III rectal cancer. However, local relapse was not the main failures for these patients in TME era, especially in the low/intermediated-risk patients whose local recurrence rate was lower than 5%. As the Distant relapse was mainly due to the delayed initiation or elimination of systemic chemotherapy and insensitivity of the chemotherapeutic drug. So, this trial will explore the effect of Neoadjuvant chemotherapy in low/intermediated-risk rectal cancers, and also explore the possibility of early assessment of the chemosensitivity.

Methods/Design: This is a prospective, open-label, single group clinical trial. 60 low/intermediated-risk stage II/III rectal cancer patients will receive 4 cycles of standard CAPOX (oxaliplatin 130mg/m2, once daily on day 1, every 21 days; capecitabine 1000mg/m2, twice daily on days 1 to 14, every 21 days) neoadjuvant chemotherapy before surgery. The primary outcome of this trial is the clinical and pathological remission rate at the end of the second and fourth cycles of neoadjuvant chemotherapy. The secondary outcomes include disease-free survival, overall survival, toxic and side effects during treatment, toxicity of chemotherapy.

Discussion: This is the first clinical trial to early reevaluate the effect of NAC (with 2 cycle CAPOX, 6 weeks), and the results are believed to further confirm the feasibility of NAC and develop an early prediction model for the effect of NAC.