Chemotherapy after surgery for stage II CRC can improve survival

December 14, 2007

NEW YORK (Reuters Health) - Treatment with adjuvant fluorouracil and folinic acid following resection of node-negative stage II colorectal cancer (CRC) provides a "small but definite benefit" in survival, an international team reports in the December 15th issue of The Lancet.

The advantages of chemotherapy following resection of stage II, node-negative cancers of the rectum and colon are debatable, members of the QUASAR (QUick And Simple And Reliable) Collaborative Study group point out.

The QUASAR trial included 3239 patients with CRC, median age 63 years, who were recruited from 150 centers in 19 countries between 1994 and 2003.

Seventy-one percent of patients had colon cancer and 91% had stage II disease.

Patients were randomized to chemotherapy or observation. Chemotherapy included fluorouracil 370 mg/m² plus low-dose L-folinic acid 25 mg or high-dose L-folinic acid 175 mg. Before 1997, levamisole or placebo was also administered. Patients were treated once-weekly for 30 weeks or 5 days a week every 4 weeks for six courses.

After a median follow-up of 5.5 years, 311 patients in the chemotherapy group and 370 in the observation group had died (relative risk 0.82; p = 0.008). There were 293 recurrences in the chemotherapy group and 359 in the observation group (relative risk 0.78; p = 0.001).

"Treatment efficacy did not differ significantly by tumor site, stage, sex, age, or chemotherapy schedule," the authors write.

However, the survival benefit was small. "If 5-year mortality without chemotherapy is 20%, a reduction in the relative risk of death of 18% translates into an absolute improvement in survival of 3.6%."

Still, they say, chemotherapy seemed to prevent, rather than just delay, many recurrences and deaths, suggesting more substantive survival benefits.

In an editorial, Dr. David Cunningham and Dr. Naureen Starling, at Royal Marsden Hospital, Sutton, UK, comment that the decision to use chemotherapy for stage II colorectal cancer must be made on a case-by-case basis. "In elderly patients," they add, "cognitive status, polydrug use, and psychosocial factors are also important in decision making."