Adjuvant chemotherapy of colon cancer: lymph node involvement without metastases

(1) The standard treatment for colon cancer is surgical excision, but without additional treatment nearly 50% of surgically treated patients die from relapse and metastatic disease progression. Adjuvant chemotherapy is designed to reduce the risk of post-surgical relapse. (2) The standard adjuvant chemotherapy is a combination of fluorouracil + folinic acid administered intravenously for 6 months (de Gramont protocol). (3) In patients with stage III disease (corresponding to Dukes stage C: lymph node involvement but no metastases), the 5-year survival rate after a 6-month course of fluorouracil + folinic acid is significantly higher than with placebo (63% versus 51%). The efficacy of this treatment has not been established in patients with stage II disease (no lymph node involvement or metastases), for whom the overall 5-year survival rate is about 80%. (4) In one trial a combination of oxaliplatin + fluorouracil + folinic acid (FOLFOX 4 protocol) failed to increase the overall 3-year survival rate more than the fluorouracil + folinic acid combination. It increased the event-free survival rate (72.2% versus 65.3%) but had more severe adverse effects, including: neuropathies (in about 12% of patients), neutropenia (41%), and gastrointestinal disturbances (5% to 10% of patients had nausea, vomiting and diarrhoea). (5) Capecitabine, a fluorouracil precursor, does not appear to be more effective than fluorouracil, but it does provide an alternative oral treatment with a slightly different profile of adverse effects (more frequent erythrodysesthesia, etc.). (6) In practice, adjuvant treatment with fluorouracil + folinic acid should be offered to patients with surgically treated stage-III colonic cancer.