A powerful ad that ran on the radio some years ago described the symptoms of an all-too-common medical condition: sleeplessness, anxiety, loss of appetite, inability to concentrate. Then the announcer intoned, "These are not the signs of breast cancer. They are the symptoms of fearing you have breast cancer."

Cancer can be a fearful disease, and treatment, especially chemotherapy, has dangers and side effects of its own. Now, however, there will be less to fear for more than 60,000 women a year in the United States and many more in other countries. The findings of a newly announced study of breast cancer patients indicate that women with the most common type of early-stage breast cancer can forego chemotherapy without raising their chances that the disease will recur.

This is good news and great medicine. Genetic testing of more than 10,000 women over a nine-year period has made it possible to predict that the 67 percent of women at intermediate risk of recurrence can follow courses of treatment that do not include chemotherapy. Until now, only about 16 percent were judged at sufficiently low risk to forego chemo; now it is 83 percent overall, an overwhelming majority.

Those who could safely skip chemotherapy, according to the results released at the recent American Society of Clinical Oncology conference and published in the New England Journal of Medicine, are women with early-stage disease that has not spread to lymph nodes, is hormone-positive and is not the type targeted by the drug Herceptin.

To determine their individual genetic risk of the cancer recurring, women in the study were evaluated by a test of the genes involved in cell growth and response to hormone therapy, which is the standard long-term treatment after surgery.

The value of chemotherapy was already uncertain in the treatment of many women, but it was a "better safe than sorry" situation until medicine had the tools to figure out which ones. Knowing who needs chemo and who doesn't is a critical piece of evidence, and oncologists will be recommending the test for many patients.

The test costs about $4,000, and many insurers, including Medicare, pay for it. They recognize that it can be a money saver as well as a life saver, compared to multiple rounds of chemotherapy.

Although laypeople tend to think of cancer as a single disease, scientists and physcians have long known that it is a collection of diseases that behave differently in different people. Some drugs, including chemotherapy drugs, work well in some patients; in others they fail to halt the progress of the disease.

Most families have had experience with a loved one who began the cancer journey not knowing which treatment might heal them and sometimes had to go back to square one with a new approach. Genetic testing can rule out courses of action that would take a long time and great financial and physical cost before they show they are not working. For women whose cancer matches the diagnoses of those in the study, the decision can now be made with a clear idea of the odds as to whether it is the right way to go.

Because of genetic testing, gene targeting therapies, the hormone blockers that are now standard treatment in many breast cancers, and new techniques of activating a patient's immune system to fight tumors, the dreaded diagnosis no longer presumes the same old treatments.

And that invites a change in how we think about cancer screening. Early diagnosis can mean far less of an ordeal. The women in the study were all early-stage patients who qualified for the non-chemo route because their disease had not spread to lymph nodes. Sooner is far better. 

Humankind has a a long history of dreading cancer and the radical treatments developed to fight it. The use of these new medical tools allows physicians and patients ways of fighting smarter, not just harder.

The Day editorial board meets with political, business and community leaders to formulate editorial viewpoints. It is composed of President and Publisher Timothy Dwyer, Executive Editor Izaskun E. Larraneta, Owen Poole, copy editor, and Lisa McGinley, retired deputy managing editor. The board operates independently from The Day newsroom.