Adjuvant Chemotherapy Could Benefit Patients With Localised Colorectal Cancer (Quasar Trial)

Main Category: Colorectal Cancer
Also Included In: Cancer / Oncology
Article Date: 17 Dec 2007 - 2:00 PST

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Chemotherapy with fluorouracil and folinic acid could improve survival of patients with stage II colorectal cancer compared with observation alone, although the absolute improvements are small. These are the conclusions of an Article in this week's edition of The Lancet.

Colorectal cancer is the second most common malignant disease in developed countries, with 1 million new cases and 500 000 deaths worldwide every year. Cytotoxic chemotherapy after complete resection can lower the risk of recurrence, and flurouracil and folinic acid has become widely used for stage III (node positive) colorectal cancer. However, uncertainty remains regarding the value of this regimen in patients with stage II (node negative) colon cancer. The QUASAR (Quick and Simple and Reliable) trial was designed to provide large-scale randomised evidence on this issue.

Professor Richard Gray, Dr Jennifer Barnwell, and colleagues from the QUASAR Collaborative Group, Cancer Research UK Clinical Trial Unit, University of Birmingham, UK, studied 3239 patients who had had apparently curative resection of colon or rectal cancer, median age 63 years. The patients were recruited from 150 centres in 19 countries between 1994 and 2003. Around half the patients were randomised to receive chemotherapy with fluorouracil and folinic acid, with the other half observation alone. Chemotherapy was delivered as six 5-day courses every 4 weeks or as 30 once-weekly courses of intravenous fluorouracil with high-dose or low dose folinic acid.

The researchers found there were 293 recurrences of cancer in the chemotherapy group and 359 in the observation group, which meant the risk of recurrence was reduced by 22% by chemotherapy compared with observation alone. The numbers of deaths were also reduced, by 18%. The authors conclude: "Chemotherapy with flurouracil and folinic acid could improve survival of patients with stage II colorectal cancer, although the absolute improvements are small: assuming 5-year mortality without chemotherapy is 20%, the relative risk of death seen here translates into an absolute improvement in survival of 3•6%."

In an accompanying Comment*, Professor David Cunningham and Dr Naureen Starling, Royal Marsden Hospital, Sutton, Surrey, UK, say: "The decision to treat stage II colorectal cancer should be taken with the patient after consideration of the size of the benefit versus potential toxic effects." They also discuss the importance of identification of the patients most likely to benefit from therapy, and novel techniques in continuing development for this purpose, for example molecular markers.

*Comment: Professor David Cunningham, Royal Marsden Hospital, Sutton, Surrey, UK.

The Lancet