Adjuvant Treatment of Concurrent RT and CAPOX or Capecitabine Alone for Stage II and III Rectal Cancer

Prospective Randomized Phase III Study of Concurrent Capecitabine and Radiotherapy With or Without Oxaliplatin as Adjuvant Treatment for Stage II and III Rectal Cancer

The purpose of this study is:

• To compare the long-term of survival and local/regional control between the two postoperative concurrent chemoradiotherapy regimens: capecitabine vs. oxaliplatin and capecitabine,for stage II and III rectal cancer
• To compare the toxicity profile between the two different concurrent chemoradiotherapy regimens.

Adjuvant 5-FU based concurrent chemoradiotherapy and chemotherapy is the standard care for locally advanced stage II-III rectal cancer, based on several randomized Phase III clinical trials. With this standard treatment, 5-year local failure rate and distant metastasis rate is 10% and around 35%, respectively. Capecitabine, an analog of 5-fluoruracil (5FU), was demonstrated to have similar treatment results compared to 5-FU, but have much lower toxicities. Oxaliplatin based chemotherapy, also showed a better disease-free survival rate compared with 5-FU based-regimen. So far, some Phase I/II studies have shown the safety and preliminary results of either concurrent chemotherapy of capecitabine or oxaliplatin and capecitabine. The long-term results in comparison of capecitabine concurrent chemoradiotherapy with oxaliplatin/capecitabine concurrent chemoradiotherapy need to be further analyzed.

Inclusion Criteria:

• 18-75 years old,male or female
• R0 surgery
• Pathologically approved as stage II or stage III
• Enrolled within 6 months from the date of surgery
• Upper border of tumor before surgery was under L5
• KPS>70% or ECOG 0-2
• No prior radiotherapy in the past 6 months
• Received chemotherapy no more than 4 cycles after surgery
• HGB>100 g/L, WBC≥3.5x109 /L, PLT≥100x109 /L; CR<1.5 x Upper normality，TB<2.5 X Upper normality，AST or ALT<2.5 x Upper normality，AKP<2.5 X Upper normality
• Signed consent

Exclusion Criteria:

• Other malignancies simultaneously except in situ cervix or nonmelanoma skin cancer
• Pregnancy or in lactation
• HGB<100 g/L, WBC<3.5x109 /L, PLT<100x109 /L; CR≥1.5 x Upper normality，TB≥2.5 X Upper normality，AST or ALT≥2.5 x Upper normality，AKP≥2.5 X Upper normality