Purpose: To investigate potential prognostic factors, including hemoglobin levels before and during radiotherapy, for associations with survival and local control in patients with unirradiated locally recurrent rectal cancer.
Patients and methods: Ten potential prognostic factors were investigated in 94 patients receiving radiotherapy for recurrent rectal cancer: age (<or=68 vs. >or=69 years), gender, Eastern Cooperative Oncology Group performance status (0-1 vs. 2-3), American Joint Committee on Cancer (AJCC) stage (<or=II vs. III vs. IV), grading (G1-2 vs. G3), surgery, administration of chemotherapy, radiation dose (equivalent dose in 2-Gy fractions: <or=50 vs. >50 Gy), and hemoglobin levels before (<12 vs. >or=12 g/dL) and during (majority of levels: <12 vs. >or=12 g/dL) radiotherapy. Multivariate analyses were performed, including hemoglobin levels, either before or during radiotherapy (not both) because these are confounding variables.
Results: Improved survival was associated with better performance status (p<0.001), lower AJCC stage (p=0.023), surgery (p=0.011), chemotherapy (p=0.003), and hemoglobin levels>or=12 g/dL both before (p=0.031) and during (p<0.001) radiotherapy. On multivariate analyses, performance status, AJCC stage, and hemoglobin levels during radiotherapy maintained significance. Improved local control was associated with better performance status (p=0.040), lower AJCC stage (p=0.010), lower grading (p=0.012), surgery (p<0.001), chemotherapy (p<0.001), and hemoglobin levels>or=12 g/dL before (p<0.001) and during (p<0.001) radiotherapy. On multivariate analyses, chemotherapy, grading, and hemoglobin levels before and during radiotherapy remained significant. Subgroup analyses of the patients having surgery demonstrated the extent of resection to be significantly associated with local control (p=0.011) but not with survival (p=0.45).
Conclusion: Predictors for outcome in patients who received radiotherapy for locally recurrent rectal cancer were performance status, AJCC stage, chemotherapy, surgery, extent of resection, histologic grading, and hemoglobin levels both before and during radiotherapy.