Status of Breast Cancer in California
Breast cancer remains the most common cancer among women of any race or ethnic group in California. It is the most common cause of death for women ages 15-54 and is second only to lung cancer for women over 55 years of age. In 1998, it is estimated that 19,300 women and men in California were diagnosed with breast cancer and 4,585 died of the disease. The incidence of breast cancer in the state climbed steadily until 1988 during the time data were being collected (since 1973 for the San Francisco Bay and Los Angeles areas). Since 1988, rates have decreased slightly and now appear to have leveled off. Age-adjusted rates dropped from 112.7 per 100,000 in 1988 to 104.9 per 100,000 in 1995.
These rates, however, varied markedly by race/ethnicity in the same time period, with non-Hispanic white women having the highest rate, followed by African American women, Hispanic women, and Asian American women, respectively. Among women younger than 50, however, African American women have a higher rate than white women. African American women also have the highest rates of more advanced disease, despite the fact that they have the highest incidence of mammograms in the previous 2 years. Roughly fifty per cent of breast cancers are diagnosed among women who are less than 65 years old (20 per cent are among women less than 50).
Rates of death due to breast cancer have remained relatively constant in the United States during the last three decades, but have decreased approximately 14% in California since 1985 (about 2% per year). Unfortunately, this decrease has only been consistent and statistically significant for non-Hispanic white women. In addition, although African American women have a lower incidence of breast cancer than white women, the death rate is higher for African American women.
Mammography usage has increased markedly in the past decade, probably accounting in part for both the increased incidence of breast cancer and the decreased mortality. In 1987, only 46.7% of California women aged 40 and over reported ever having had a mammogram. By 1994, this figure had increased to 82.8%. Asian and Hispanic women, less educated women and those reporting a lower income, however, are less likely to have been screened and are therefore at greater risk for being diagnosed with breast cancer at a later stage. While mammography has undoubtedly contributed to the decrease in mortality, no woman diagnosed with breast cancer today, no matter how small the tumor or how early it is detected, can be told that her cancer is cured.
The most promising aspect of this information is that the incidence of breast cancer is no longer increasing, as it did in every decade until the 1990's. Also encouraging is the increased proportion of breast cancers that are diagnosed at an early stage. This should translate into a decrease in mortality in years to come. Most disturbing is the lack of any dramatic changes in breast cancer incidence or mortality, and the increasing burden that breast cancer is placing on different populations of the state.
