Is Higher Efficacy Always at the Price of More Side Effects during Chemotherapy?

Breast cancer remains the most prevalent cancer diagnosed in women worldwide. The number of effective treatments for breast cancer is on the rise, however, the benefit from specific treatments to individual patients and the adverse events experienced vary considerably. Efficacy and safety of anticancer therapies may depend on tumor, treatment, and host characteristics. Advances in the adjuvant chemotherapy of operable breast cancer have come from the introduction of effective agents and the application of the principles of combination chemotherapy. Attempts to advance these principles by substantial escalation of drug dosage have proven unsuccessful with a potentially higher rate of side effects. Another concept to increase efficacy is dose density, the administration of drugs with shortened intertreatment interval, and sequential therapy. The dose-dense concept improved clinical outcome significantly and was not accompanied by an increase in toxicity.