Many of the therapies are still in clinical trials, and research is limited on handling side effects and determining proper dosage. Through their work with patients, nurses can help determine which patients benefit most from which drugs and in what amounts. This data can help control the considerable costs. One of the most popular targeted therapies, Avastin, when used for metastatic breast cancer, can cost $7,700 per month wholesale. Tarceva, when used for lung cancer, can cost $3,375 per month, says a spokesperson for pharmaceutical company Genentech. Nurses may need to work with pharmacies, social workers, and insurance companies to determine how a patient will pay for the treatments.