Mammograms have become a rite of passage for 40-year-old American women, and a compulsory exercise for those over 40.

But as rote as those annual screenings might seem, there’s nothing routine about a diagnosis of breast cancer.

As scientists make strides to improve diagnostic imaging, testing and treatment, however, the disease is becoming more survivable.

“Early diagnosis is definitely associated with a high cure rate,” said Dr. Debu Tripathy, director of the Komen/University of Texas Southwestern Breast Cancer Research Program at the UT Southwestern Medical Center in Dallas.

In the United States, widespread awareness of the importance of screening mammography means most patients are diagnosed with early-stage breast cancer, and three quarters of them are cured, he said.

Women who haven’t been instilled with the importance of early screening likely will be bombarded with reminders throughout October, National Breast Cancer Awareness Month.

Breast cancer is still the second leading cause of cancer-related deaths in women, after lung cancer, government statistics show. But thanks to better detection and treatment, breast cancer death rates in women declined by 2.3 percent a year from 1990 to 2000, according to a news release from the coordinators of National Breast Cancer Awareness Month.

Approximately 215,990 women in the United States will be diagnosed with invasive breast cancer this year, and about 40,110 will die from the disease. There are slightly more than 2 million American women who have been treated for breast cancer, according to the American Cancer Society.

And while it’s rare, men can develop malignancies in their breasts. Some 1,450 men will be diagnosed with breast cancer this year, the American Cancer Society estimates, and about 470 will die from it.

Mammography screening is the gold standard for detecting abnormalities in the breast, but it’s not foolproof. It may miss 20 percent of cancers, depending on breast density, said Dr. Judy Destouet, chairwoman of the American College of Radiology’s Mammography Accreditation Commission.

“In younger women who have very dense breast tissue, the cancer may be obscured by the breast tissue,” Destouet explained. That’s why monthly self-examinations and annual clinical breast exams are so important.

And when a doctor or patient feels something unusual in the breast but the mammogram comes back negative, there’s always ultrasound. Ultrasound testing should be widely used as an adjunct to mammography, Destouet said, because it is inexpensive and, unlike mammography, won’t expose the patient to radiation because it uses sound waves to capture images of the breast.

Any woman can get breast cancer, although her risk rises as she grows older. Women with a family history of the disease also face a heightened risk. A simple blood test can tell women whether they are carrying the BRCA1 or BRCA2 gene mutations that make them more susceptible to breast cancer.

A debate still swirls over whether women who take hormone replacement therapy (HRT) to ease menopausal symptoms should stop taking those drugs. Recent studies have linked HRT to an increased risk for breast cancer and other diseases. Each woman and her doctor should make that decision after weighing possible risks and benefits, says the American Cancer Society. Still, most breast cancer specialists do not recommend HRT for women with a personal history of the disease.

Since there’s no one-size-fits-all strategy for breast cancer, one woman’s treatment regimen may differ markedly from a friend’s or family member’s experience. The main options include surgery, radiation, chemotherapy and hormonal therapy.

“The treatment is based on several factors, the stage, of course, but also some of the tumor characteristics,” Tripathy said.

Women whose tumor cells contain estrogen and progesterone receptors, for example, may be given hormone therapy after surgery to prevent cancer cells from getting the hormones they need for the cancer to grow. Tamoxifen is the most common drug treatment for estrogen-receptor positive cancers.

Another class of drugs, called aromatase inhibitors, stops estrogen production in postmenopausal women and is becoming the treatment of choice for these women, Tripathy said.

Advances in chemotherapy may also contribute to better results for breast cancer patients. The drug Herceptin (trastuzumab), approved for treating patients with metastatic breast cancer, is now being tested to see whether it can help early-stage breast cancer patients, he noted.

Through continued scientific advances, breast cancer is becoming a disease that more patients can survive. “Our hope is most people diagnosed with cancer won’t die of it,” Tripathy said.