The hard facts

For women worldwide, breast cancer is the most common cancer diagnosed and has the highest death toll. With improvements in screening and treatments over the past 50 years, more women are living longer, but the numbers reveal some tough challenges. By Amy Maxmen.

Age-standardized breast cancer incidence rates vary internationally by more than 13-fold. Disease diagnoses are more common in industrialized, Western countries that have high rates of screening; extremely low incidence rates in many developing countries in part reflect low screening rates and incomplete reporting. See Fig. 1

Figure 1

GLOBOCAN 2008, ACS GLOBAL CANCER FACTS & FIGURES 2ND EDITION, OECD INDICATORS 2011

Growing pains Women in the United States have a roughly 12% chance of developing breast cancer at some point in their life. But that risk increases when breast cancer runs in the family. Hereditary mutations in the tumour-suppressor genes BRCA1 and BRCA2 raise an individual’s risks of developing breast cancer to 60% and 85%, respectively. Disregarding heritable factors, the likelihood of breast cancer through the decades is as follows:

Credit: NATIONAL CANCER INSTITUTE, NATIONAL INSTITUTES OF HEALTH

Advances for some Increased screening and improved therapies have resulted in lower mortality rates in some population segments. But, although the decline is steep for white women, it is more gradual for African-Americans. The reasons range from inadequate access to healthcare services to biological differences that might reflect genes or environmental exposures.

Credit: NATIONAL CANCER INSTITUTE, NATIONAL INSTITUTES OF HEALTH

Survival factors Many factors influence a woman’s chance of survival, including how early the tumour is detected and the molecular profile of the tumour. Even so, women diagnosed now are much more likely to survive than women in decades past. See Fig. 2.

Figure 2

MD ANDERSON CANCER CENTER, NCI, PARISE, C. ET AL. THE BREAST CANCER JOURNAL 2009

Credit: ACS GLOBAL CANCER FACTS & FIGURES 2ND EDITION

The male factor Male breast cancer accounts for about 1% of all breast cancers. Although the incidence appears to be increasing, death rates have decreased by 3.3% a year since 2000.

Bittersweet success The cost of breast cancer is expected to rise as the population ages and patients live longer because of better — and more expensive — drugs. Because breast cancer is highly prevalent, it might have the highest price tag of any cancer by 2020. The chart projects the costs assuming a 2% increase in the initial treatment phase and a 2% increase in the final year of life.

Credit: NATIONAL CANCER INSTITUTE, NATIONAL INSTITUTES OF HEALTH