RECENT CANCER TRENDS IN THE UNITED-STATES

Background: Cancer incidence rates have been reported to be increasing in the United States, although trends vary according to form of cance r, Purpose: We identify the cancers accounting for the rising incidenc e, quantify the changes that have occurred from the mid-1970s to the e arly 1990s, and contrast incidence and mortality trends to provide clu es to the determinants of the temporal patterns, Methods: Sex-, race-, and age-specific and age-adjusted incidence rates for the 5-year peri ods 1987-1991 versus 1975-1979 were calculated for 28 cancers among me n and 30 cancers among women using data from the Surveillance, Epidemi ology, and End Results (SEER) Program of cancer registration covering about 10% of the U.S. population, Similar rates were computed using na tional mortality data, Cancers were ranked according to the change in incidence rates over the two periods, Results: Age-adjusted incidence rates for all cancers combined increased by 18.6% among males and 12.4 % among females from 1975-1979 to 1987-1991, due large ly to rising ra tes for prostate cancer among men and for breast and lung cancers amon g women, National mortality rates for all cancers combined rose less s teeply, 3% and 6% among men and women, respectively, driven mostly by continuing increases in lung cancer mortality, while death rates for t he majority of the cancers were steady or declining, Total cancer inci dence rose at all ages, but with different tumors responsible for the increases at different ages: leukemia and brain/nervous system cancer among children; testicular cancer, nonmelanoma skin cancer (largely Ka posi's sarcoma), non Hodgkin's lymphoma, and melanoma noma among young and middle aged adults; and prostate, breast, and lung cancers among older individuals. In contrast, mortality rates for all cancers combin ed declined among both males and females under age 55 years, increasin g only among older persons, Conclusions: Trends in cancer incidence an d mortality differ, For most cancers, incidence rates are rising, whil e mortality rates are generally stable or declining, Implications: Muc h of the recent increase in cancer incidence can be explained by known factors, Improved proved detection appears to account for most of the in creases in breast cancer among women and prostate cancer among men , On the other hand, cigarette Smoking is the major determinant of the rise in lung cancer among women, acquired immunodeficiency syndrome h as led to increases in non Hodgkin's lymphoma and Kaposi's sarcoma amo ng young and middle-aged men, and sunlight exposure patterns have affe cted the trends in melanoma. Some trends remain unexplained, however, and may reflect changing exposures to carcinogens yet to be identified and clarified.