The postoperative adjuvant radiation therapy and radiochemotherapy for UICC stage II and III rectal cancer - A retrospective analysis

Aim: This analysis was undertaken to review the outcome and toxicity of postoperative adjuvant therapy for Stage II and III rectal cancer. Patients and Methods: We reviewed 112 patients treated with radiotherapy (44 patients) and radiochemotherapy (68 patients) after potentially curative (RO) surgery for rectal cancer (UICC Stages II and III), between 1983 and 1994 at the University Clinic of Wurzburg. Median radiation dose was 56 Gy (range: 45 to 66 Gy). Chemotherapy consisted of 4 to 6 courses of 5-fluorouracil (5-FU) (420 mg/m(2)/d) and leucovorin (200 mg/m(2)/d). Median follow-up was 37 months. Results: The overall survival was 84% for patients with UICC Stage II and 45% for patients with UICC Stage III disease (p = 0.0045). There were no statistically significant differences between patients treated with radiochemotherapy vs radiotherapy in terms of 5-year survival (63% after radiochemotherapy vs 53% after radiotherapy, p = 0.16), relapse-free survival (52% vs 50%) and locoregional control (69% vs 67%). UICC Stage III disease was associated with high failure rates (40% pelvic recurrences and 53% distant metastases). There was a statistically significant difference in terms of the incidence of distant metastases between the 2 treatment modalities for patients with Stage III disease (49% 5-year probability for developing distant metastases after radiochemotherapy vs 66% after radiotherapy, p = 0.047). In a multivariate analysis, the addition of chemotherapy, lymph node stage and grading were independent prognostic factors for survival. Severe late toxicity was documented in 5% of treated patients. Conclusions: Prognosis of patients with UICC Stage III rectal cancer remains poor after "standard" surgery followed by postoperative adjuvant treatment (pelvic radiotherapy and bolus intravenous injection of 5-FU and leucovorin). Major efforts should be made in order to improve prognosis for these patients, including optimization of surgical treatment and systemic treatment. More effective multimodality treatment strategies should be investigated in prospective randomized trials.