SAN ANTONIO--Screening mam-mography significantly improves breast cancer survival in women ages 40 to 49, compared with other methods of cancer detection, a Minnesota study suggests.
Women whose cancers were detected by mammograms had a 94% five-year survival, compared with 84% for breast self-examination (BSE), 79% for patient incidental discovery, and 75% for clinical breast examination.
Detection by clinical exam or incidental discovery doubled the odds for death within 5 years of discovery, Charles L. Murray, MD, reported at the San Antonio Breast Cancer Symposium. The study was performed by Carol McPherson and colleagues at Methodist Hospital, Health-System Minnesota.
The study involved 969 breast cancer patients who were between the ages of 40 and 49 at the time of diagnosis. The patients were identified through an upper midwestern tumor registry and came from 23 hospitals located in Minnesota, North Dakota, and South Dakota.
Only invasive cancers were included in the analysis. Patients were followed up to 8 years after treatment, with a mean follow-up of almost 3 years.
The largest number of patients (363) detected their breast cancers incidentally. Almost a third of the cancers were detected by screening mammog-raphy. The fewest were identified via clinical examination.
Breast cancers detected by mammog-raphy were significantly smaller, averaging 1.85 cm, compared with 2.32 cm for clinical exam, 2.79 cm for BSE, and 2.91 for incidental discovery. With mammog-raphy, the likelihood of detecting cancers while still localized was significantly greater, 75.8% versus 52% to 56% for the other detection modalities, said Dr. Murray, a medical oncologist at Park Nicollet Cancer Center, HealthSystem Minnesota, St. Louis Park.