Chemotherapy is highly effective in some cancers, useless in others, and unnecessary in still others.
Taking all forms of cancer together, people who receive chemotherapy increase their odds of living five years after diagnosis by about two percentage points (e.g., from about 61% being alive after five years to about 63% of them being alive after five years).^[34] However, this overall rate obscures the wide variation. Cytotoxic chemotherapy produces much larger gains for some forms of cancer, including testicular cancer (about 40% of the men who live five years after diagnosis are alive because of chemotherapy), lymphomas (about 13%), and cervical cancer (12%).^[34] By contrast, chemotherapy is essentially useless in other cancers, including prostate cancer, melanoma of the skin, multiple myeloma, bladder cancer, kidney cancer, and pancreatic cancer: people who receive chemotherapy for these conditions are just as likely to die within five years as people who do not.^[34] Chemotherapy only slightly improves survival for some of the most common forms of cancer, including breast cancers (1.5%) and lung cancers (1.5%).^[34]