Palliative radiotherapy in patients with a symptomatic pelvic mass of metastatic colorectal cancer

BACKGROUND To evaluate the palliative role of radiotherapy (RT) and define the effectiveness of chemotherapy combined with palliative RT (CCRT) in patients with a symptomatic pelvic mass of metastatic colorectal cancer. METHODS From August 1995 to December 2007, 80 patients with a symptomatic pelvic mass of metastatic colorectal cancer were treated with palliative RT at Samsung Medical Center. Initial presenting symptoms were pain (68 cases), bleeding (18 cases), and obstruction (nine cases). The pelvic mass originated from rectal cancer in 58 patients (73%) and from colon cancer in 22 patients (27%). Initially 72 patients (90%) were treated with surgery, including 64 complete local excisions; 77% in colon cancer and 81% in rectal cancer. The total RT dose ranged 8-60 Gy (median: 36 Gy) with 1.8-8 Gy per fraction. When the α/β for the tumor was assumed to be 10 Gy for the biologically equivalent dose (BED), the median RT dose was 46.8 Gy10 (14.4-78). Twenty one patients (26%) were treated with CCRT. Symptom palliation was assessed one month after the completion of RT. RESULTS Symptom palliation was achieved in 80% of the cases. During the median follow-up period of five months (1-44 months), 45% of the cases experienced reappearance of symptoms; the median symptom control duration was five months. Median survival after RT was six months. On univariate analysis, the only significant prognostic factor for symptom control duration was BED ≥40 Gy10 (p < 0.05), and CCRT was a marginally significant factor (p = 0.0644). On multivariate analysis, BED and CCRT were significant prognostic factors for symptom control duration (p < 0.05). CONCLUSIONS RT was an effective palliation method in patients with a symptomatic pelvic mass of metastatic colorectal cancer. For improvement of symptom control rate and duration, a BED ≥ 40 Gy10 is recommended when possible. Considering the low morbidity and improved symptom palliation, CCRT might be considered in patients with good performance status.