Invasive Colon Adenocarcinoma
Last Modified: November 1, 2001
Dear OncoLink "Ask the Experts,"
I have a friend in his low 40's with recent diagnosis of invasive colon adenocarcinoma. He underwent a colectomy with tumor resection. The tumor invade bladder but without penetration. Surgical margins clear of tumor. There are 3/31 mesenteric nodes positive. My questions what is his prognosis, what the treatment options are, is radiation treatment recommended, if so what the results are.
Li Liu, MD OncoLink Editorial Assistant, responds:
Thank you for your interest and question.
Standard treatment for colon cancer with positive nodes is adjuvant chemotherapy for several months. Chemotherapy may consist of 5-fluorouracil (5FU)/levamisole, for 12 months or 5FU/leucovorin for 6 months following surgery. Five year survival in patients with 1-4 nodes positive is approximately 60% and better than those patients with more than 4 nodes positive.
In contrast to rectal cancer, the role of adjuvant radiation therapy for cancers that arise above the pelvic peritoneal reflection has not been well established. Due to the anatomical locations of these cancers, particularly where the colon is attached to a mesentery, wide local resections are feasible. The primary failure pattern following potentially curative surgery is abdominal rather than local. When the tumor invades adjacent organs such as the bladder, the risk of local relapse increases.
Retrospective nonrandomized studies of radiation therapy following curative surgery of colon cancer with or without chemotherapy have suggested a potential benefit to both locoregional control and perhaps disease-free survival as well over surgical resection alone. Willett and colleagues (Journal of Clinical Oncology, 1993; 11:1112-1117) reported that radiation therapy in addition to surgery significantly improved local control and recurrence-free survival rates for patients with perforation or fistula associated with their tumor (stage B3) and stage C3 (B3 plus local lymph node spread). Concurrent administration of 5-FU with the radiation therapy appeared to improve local control compared to surgery plus radiation therapy only (79% vs. 67% for stage C3 cancer), but the difference was not statistically significant.
There are more than a dozen of clinical trials sponsored by National Cancer Institute. They can be searched at cancernet.nci.nih.gov/prot/patsrch.shtml.
You should ask your friend to talk to his oncologists to explore the treatment options.