Gains Against Cancer
Leading cancer organizations reported last week that mortality rates dropped an average of 2.1 percent a year between 2002 and 2004, almost double the average annual decrease from 1993 to 2002. That is a stunning reversal of the relentless increase in cancer death rates seen in the decades before the 1990s. The turnaround appears to be mainly a triumph in prevention and early detection rather than dazzling medical cures.
The main factor in the accelerated decline was a drop in the death rate from colorectal 節腸直腸cancer in men and women, mostly attributable to more widespread colonoscopy screening. The report also noted longer-term declines in the death rates from lung cancer in men, mostly because of reduced smoking; prostate cancer in men, for reasons that are unclear; and breast cancer in women, attributable to screening mammography and a large-scale exodus of women from the use of hormone replacement therapy.
There is clearly room for improvement. Only about half of American adults over 50 have been screened for colorectal cancer, far less than the percentage of women screened for cervical and breast cancer. Welcome as these gains may be, they pale in comparison with the remarkable turnaround in cardiovascular disease. By 2004, the death rate from coronary heart disease was 66 percent lower than in 1950, and the death rate from strokes was 72 percent lower. These gains have been attributed to impressive therapeutic advances and to lifestyle changes.
Although there have been improvements in treating cancer, only a minority of patients can be treated effectively once cancer has spread from its original site to distant points in the body. For now, the best hope lies in prevention and early detection.