Breast and Prostate Cancer Odds
Chances are most people know what pink ribbons mean. Advocates for breast cancer research, spearheaded by groups like Susan G. Komen for the Cure, have stamped the symbol into Americans’ consciousness as they combat the second-leading cause of cancer deaths in women. But what about prostate cancer, the second-leading cause of cancer deaths in men?
The incidence, or annual rate of diagnosis, has increased for both prostate cancer and breast cancer in women over the past three decades. In 1975, the odds a female would be diagnosed with breast cancer in a year were 1 in 951.5 compared to 1 in 812.7 in 2006. The odds of being diagnosed with prostate cancer increased from 1 in 1,064 in 1975 to 1 in 613.3 in 2006. Do these higher odds of being diagnosed with breast cancer (a 17% increase) or prostate cancer (a 73% increase) represent a true deterioration in health? Increased use of mammograms for women, including requirements that the cost of mammography be covered by public and private insurance plans, are credited for the higher incidence rates in breast cancer. The surge in prostate incidence is attributable to the development of the prostate-specific antigen blood tests for men. In both types of cancer, the increases in annual diagnosis rate driven by screening went down after reaching their respective peaks but never returned to the earlier levels. Both types of cancer are now detected at earlier stages than in the past.
The annual death rates for prostate and breast cancer are similar today—and both have improved over time. In 1975, the odds a female died of breast cancer were 1 in 3,185 but by 2006, those odds had dropped to 1 in 4,264—a reduction of 25% in the annual mortality. During the same period of time, the odds a man died of prostate cancer declined from 1 in 3,226 in 1975 to 1 in 4,244in 2006—a reduction of 24%.
Survival rates for both breast cancer and prostate cancer have also risen steadily, though prostate cancer survival has improved more. The odds a man diagnosed with prostate cancer in 2001 survived 5 or more years are 1 in 1 (100%); in 1985 those odds of survival had been 1 in 1.32 (76%), for an improvement of 32%. The odds a female diagnosed with breast cancer in 2001 survived 5 or more years are 1 in 1.11 (90%) versus the odds a female diagnosed in 1985 survived 5 or more years at 1 in 1.27 (79%), for an improvement of 11%. For both cancers, screening tests have detected malignant tumors sooner, before their cells have a chance to spread.
With the incidence of prostate cancer in men higher than breast cancer in women, why aren’t men’s outcomes worse? One reason might be age of onset. Prostate cancer is a disease of older men while breast cancer can occur in younger women, although risk increases with age. Prostate cancer can be indolent, sometimes spreading slowly enough that men die of other causes. That makes deciding on treatment more difficult for men, especially when such troubling side effects as incontinence or impotence are possible.
Breast and prostate cancer also look different on the federal research ledger. The National Cancer Institute devoted $572 million to breast cancer in fiscal 2008 but targeted $285 million to prostate cancer for the same year.
Prostate cancer advocacy groups have taken note. They now have their own ribbon—it’s blue.