Prognostic significance of postchemoradiation stage following preoperative chemotherapy and radiation for advanced/recurrent rectal cancers.

Abstract

To evaluate the prognostic significance of postchemoradiation pathologic stage and implications for further therapy following preoperative chemoradiation and surgery for advanced/recurrent rectal cancer. Seventy-seven patients with advanced (fixed or tethered T4) or recurrent rectal cancer were treated with preoperative chemoradation followed by surgical resection of disease. Chemotherapy consisted of either of bolus 5-FU 500 mg/m(2) per day or continuous venous infusion 225 mg/m(2) per day for the duration of radiation. Radiation therapy was planned to be delivered to the whole pelvis to a dose of 45 Gy followed by a boost to the area of the tumor of 5-15 Gy. Total radiation doses ranged from 40 to 63 Gy with a median of 55.8 Gy. Surgical resection was then carried out 6-10 weeks following the completion of treatment (median, 7 weeks). Twenty-eight patients underwent abdominoperineal resection and and 49 patients had sphincter-sparing surgical procedures. None of the patients received postoperative chemotherapy. Follow-up in these patients ranges from 1 year to 8 years with a median of 3 years. Significant downstaging of disease was observed with 12/77 (16%) having no residual disease(pT0) and 13% (10/77) found to have pT1-2, N0 disease, 31% (24/77) with pT3-4, N0 and 40% (31/77) for pT0-4, N1-2 cancers. Survival by pathologic stage was 100% for pT0-2, N0 cancers, 80% for pT3-4, N0 and 73% for pTx, N1-2. Local recurrence of disease was observed in 0% of patients with pT0-2, N0 as compared with 13% (3/24) in pT3-4, N0 and 16% (5/31) in pT0-4, N1-2 patients. Downstaging following preoperative chemoradiation is a significant prognostic factor. Patients with pT0, T1, or T2 disease have an excellent prognosis and are unlikely to fail locally or with systemic disease. However, patient with T3/T4 or N+ disease may benefit from further adjuvant chemotherapy.