Cancer Mortality Continues to Decline Steadily
The trend for cancer, like the trend for longevity, is heading slowly in the right direction. Large investments in research produce incremental reductions in cancer mortality, but the shape of this relationship results from the present dominant approaches to cancer treatment, producing therapies that are each limited in their application to only one or a few narrow categories of cancer. Cancer is a spreading tree of variants, and all of the outer branches differ from one another in the details of their cellular biochemistry. Researchers tend to focus on attacking the particular distinctive biochemistry of one branch. This is inefficient and expensive, but it is going to change. The future of cancer treatment will hinge on approaches under development that are capable in principle of application to near all cancers, in particular methods of interfering in the lengthening of telomeres that all cancers rely upon. Once those treatments are a going concern, reduction in cancer mortality will no longer be an incremental trend.
Every year, the American Cancer Society estimates new cancer cases and deaths in the U.S. for the current year and compiles the most recent data on cancer incidence, mortality, and survival. Steady reductions in smoking combined with advances in cancer prevention, early detection, and treatment have resulted in a 23% drop in the cancer death rate since its peak in 1991. Overall cancer incidence is stable in women and declining by 3.1% per year in men (from 2009-2012), with one-half of the drop in men due to recent rapid declines in prostate cancer diagnoses as PSA testing decreases. Cancer mortality continues to decline; over the past decade of data, the rate dropped by 1.8% per year in men and 1.4% per year in women. The decline in cancer death rates over the past two decades is driven by continued decreases in death rates for the four major cancer sites: lung, breast, prostate, and colon/rectum.Death rates for female breast cancer have declined 36% from peak rates in 1989, while deaths from prostate and colorectal cancers have each dropped about 50% from their peak, a result of improvements in early detection and treatment. Lung cancer death rates declined 38% between 1990 and 2012 among males and 13% between 2002 and 2012 among females due to reduced tobacco use. Even as cancer remains the second leading cause of death nationwide, steep drops in deaths from heart disease have made cancer the leading cause of death in 21 states. Heart disease remains the top cause of death overall in the United States. "We're gratified to see cancer death rates continuing to drop. But the fact that cancer is nonetheless becoming the top cause of death in many populations is a strong reminder that the fight is not over. Cancer is in fact a group of more than 100 diseases, some amenable to treatment; some stubbornly resistant. So while the average American's chances of dying from the disease are significantly lower now than they have been for previous generations, it continues to be all-too-often the reason for shortened lives, and too much pain and suffering."