Dr. Seema Doshi was shocked and terrified when she found a lump in her breast that was eventually confirmed to be cancerous. "That rocked my world," said Dr. Doshi, a dermatologist in private practice. "I thought, 'That's it. I will have to do chemotherapy.'" She was wrong. Dr. Doshi was the beneficiary of a quiet revolution in breast cancer treatment, a slow chipping away at the number of people for whom chemotherapy is recommended. Chemotherapy for decades was considered "the rule, the dogma," for treating breast cancer and other cancers, said Dr. Gabriel Hortobagyi, a breast cancer specialist. But data from a variety of sources offers some confirmation of what many oncologists say anecdotally the method is on the wane for many cancer patients. Genetic tests can now reveal whether chemotherapy would be beneficial. For many there are better options with an ever-expanding array of drugs, including estrogen blockers and drugs that destroy cancers by attacking specific proteins on the surface of tumors. And there is a growing willingness among oncologists to scale back unhelpful treatments. The result spares thousands each year from the dreaded chemotherapy treatment, with its accompanying hair loss, nausea, fatigue, and potential to cause permanent damage to the heart and to nerves in the hands and feet. The diminution of chemotherapy treatment is happening for some other cancers, too, including lung cancer.