An international team conducted a pooled analysis of adjuvant chemotherapy for resected colon cancer in elderly patients.
Adjuvant chemotherapy is standard treatment for patients with resected colon cancer, who are at high risk for recurrence. However, the efficacy and toxicity of such treatment in patients over 70 years of age are controversial.
Individual patient data from 7 phase III randomized trials (involving 3351 patients) was collected. In these, the effects of postoperative fluorouracil plus leucovorin (5 trials), or fluorouracil plus levamisole (2 trials), were compared with the effects of surgery alone, in patients with stage II or III colon cancer.
Individuals were grouped into 4 age categories of equal size. Analyses were repeated with 10-year age ranges (<50, 51-60, 61-70, and >70 years).
The toxic effects measured in all trials were nausea or vomiting, diarrhea, stomatitis, and leukopenia.
|5-year overall survival:|
With adjuvant therapy: 71%
Without adjuvant therapy: 64%
| New England Journal of Medicine |
Patients in the fluorouracil-plus-leucovorin and fluorouracil-plus-levamisole groups were combined for the efficacy analysis, but kept separate for toxicity analyses.
Adjuvant treatment was found to have a significant positive effect on both overall survival and time to tumor recurrence (hazard ratios of death and recurrence of 0.76 and 0.68, respectively).
The 5-year overall survival was 71% for those who received adjuvant therapy, as compared with 64% for those untreated.
No significant interaction was observed between age and the efficacy of treatment.
The researchers found that the incidence of toxic effects was not increased among the elderly (age >70 years), except for leukopenia in one study.
Author Daniel J. Sargent, of the Mayo Clinic, Rochester, Minnesota, USA, concluded on behalf of his team, "Selected elderly patients with colon cancer can receive the same benefit from fluorouracil-based adjuvant therapy as their younger counterparts, without a significant increase in toxic effects."