Giving life to numbers
Authors: M. P. Cunningham
Journal: CA A Cancer Journal for Clinicians (1997)

This issue of CA again profiles the American Cancer Society's annual projection of cancer incidence and mortality.1 It is by far the most popular and most cited issue of CA. One might ask why this annual publication of cancer statistics makes such popular reading and referencing. After all, a casual glance at the raw tabular data is not really very stimulating. It is my supposition that these statistics are popular because they provide a proscenial view of the cancer problem at a particular point in time. They are a measure of the challenges, the triumphs, and the failures of the ongoing fight against cancer and are read with the hope that something new and better has happened since the last enumeration, that maybe this time our team is winning. It follows that part of the job of the American Cancer Society is to give meaning and life to the raw numbers, to recognize and share the urgency of their message, and to take from that message a renewed effort to change profoundly the statistics themselves. The reported number of new cancer cases for all sites is significantly higher in males than females, and there is a correspondingly higher mortality rate for males (reflecting higher lung and genital cancer mortality offsetting breast cancer mortality in females as well as incrementally higher mortality in males for almost all other sites). This observation is only minimally relevant without reference to total population numbers for each sex, but does assume there are fewer males at risk for cancer. The present lifetime risk of cancer for males is one out of two, essentially reflecting the high incidence rates of lung cancer and of prostate cancer in older age groups. African Americans continue to be diagnosed at less favorable stages of disease than whites and have uniformly lower survival for every major site (except stomach). Relative survival rates for virtually every major site (except, perhaps, non-Hodgkin's lymphoma) are improving, in some cases spectacularly (e.g., testis, Hodgkin's disease, and leukemia). Survival rates for children for all common pediatric sites have improved dramatically in the last 30 years. Cancer mortality in the United States compared with the world is about average for males (ranked 27 out of 48), but quite high for females (8 out of 48), reflecting the sad fact that American women have the highest death rates in the world from cancer of the lung and bronchus, a sorry commentary indeed on history's most technologically advanced society. Age-adjusted death rates for both sexes, for virtually all sites (except pancreas and non-Hodgkin's lymphoma) peaked around 1989 to 1990 and have trended consistently downward since. Cancer mortality rates in the United States from 1969 through 1995. Rates are age-adjusted to the 1970 US standard population. Provisional data from the National Center for Health Statistics and the National Cancer Institute.3 The importance of the last observation cannot be overemphasized. Recent data2, 3 have strongly corroborated these trends and suggest that cancer mortality is not only trending downward but will continue to do so and at an accelerating rate (Figure). The reasons for this are not altogether clear, but are almost certainly due, in part, to diminished mortality from lung cancer, itself a reflection of curtailed use of tobacco, especially by male smokers, in the last 25 years. Further, the unmistakable, across-the-board, sustained, steady, and sometimes spectacular improvement in case fatality rates argue for a definite treatment effect (i.e., a significant chemotherapy response as well as lowered treatment-related mortality). It is both exciting and seductive to anticipate a treatment-related “cancer breakthrough,” especially one promised by the ongoing discoveries of molecular biology. It is perhaps more prudent and productive to continue with renewed effort in what we know already works: absolute elimination of tobacco; adoption of well-recognized, health-ensuring lifestyles; and early detection and intervention for the common solid tumor sites aided, perhaps, by highly targeted and intense screening for truly high-risk populations identified by genetic profiling. These statistics, then, are an annual snapshot of a slowly moving, ever-changing mosaic of cancer events that, for the first time are unmistakably trending favorably. Keep your fingers on these figures: they are the quickening pulse of an evolving revolution in cancer biology, epidemiology, and cancer control.