Chemotherapy Agents for Treatment of Acute Lymphoblastic Leukemia

The American Cancer Society (ACS), the Centers for Disease Control and Prevention (CDC), the National Cancer Institute (NCI), and the North American Association of Central Cancer Registries (NAACCR) collaborate annually to provide updated information regarding cancer occurrence and trends in the U.S. This year's report features a special section on cancer survival. Information concerning cancer cases was obtained from the NCI, CDC, and NAACCR and information concerning recorded cancer deaths was obtained from the CDC. The authors evaluated trends in age-adjusted cancer incidence and death rates by regression models and described and compared survival rates over time and across racial/ethnic populations. Incidence rates for all cancers combined decreased from 1991 through 2001, but stabilized from 1995 through 2001 when adjusted for delay in reporting. The incidence rates for female lung cancer decreased (although not statistically significant for delay adjusted) and mortality leveled off for the first time after increasing for many decades. Colorectal cancer incidence rates also decreased. Death rates decreased for all cancers combined (1.1% per year since 1993) and for many of the top 15 cancers occurring in men and women. The 5-year relative survival rates improved for all cancers combined and for most, but not all, cancers over 2 diagnostic periods (1975-1979 and 1995-2000). However, cancer-specific survival rates were lower and the risk of dying from cancer, once diagnosed, was higher in most minority populations compared with the white population. The relative risk of death from all cancers combined in each racial and ethnic population compared with non-Hispanic white men and women ranged from 1.16 in Hispanic white men to 1.69 in American Indian/Alaska Native men, with the exception of Asian/Pacific Islander women, whose risk of 1.01 was similar to that of non-Hispanic white women. The continued measurable declines for overall cancer death rates and for many of the top 15 cancers, along with improved survival rates, reflect progress in the prevention, early detection, and treatment of cancer. However, racial and ethnic disparities in survival and the risk of death from cancer, and geographic variation in stage distributions suggest that not all segments of the U.S. population have benefited equally from such advances. Published 2004 by the American Cancer Society.

Cardiotoxicity is a recognized complication of doxorubicin therapy, but the long-term effects of doxorubicin are not well documented. We therefore assessed the cardiac status of 115 children who had been treated for acute lymphoblastic leukemia with doxorubicin 1 to 15 years earlier in whom the disease was in continuous remission. Eighteen patients received one dose of doxorubicin (45 mg per square meter of body-surface area), and 97 received multiple doses totaling 228 to 550 mg per square meter (median, 360). The median interval between the end of treatment and the cardiac evaluation was 6.4 years. Our evaluation consisted of a history, 24-hour ambulatory electrocardiographic recording, exercise testing, and echocardiography. Fifty-seven percent of the patients had abnormalities of left ventricular afterload (measured as end-systolic wall stress) or contractility (measured as the stress-velocity index). The cumulative dose of doxorubicin was the most significant predictor of abnormal cardiac function (P less than 0.002). Seventeen percent of patients who received one dose of doxorubicin had slightly elevated age-adjusted afterload, and none had decreased contractility. In contrast, 65 percent of patients who received at least 228 mg of doxorubicin per square meter had increased afterload (59 percent of patients), decreased contractility (23 percent), or both. Increased afterload was due to reduced ventricular wall thickness, not to hypertension or ventricular dilatation. In multivariate analyses restricted to patients who received at least 228 mg of doxorubicin per square meter, the only significant predictive factors were a higher cumulative dose (P = 0.01), which predicted decreased contractility, and an age of less than four years at treatment (P = 0.003), which predicted increased afterload. Afterload increased progressively in 24 of 34 patients evaluated serially (71 percent). Reported symptoms correlated poorly with indexes of exercise tolerance or ventricular function. Eleven patients had congestive heart failure within one year of treatment with doxorubicin; five of them had recurrent heart failure 3.7 to 10.3 years after completing doxorubicin treatment, and two required heart transplantation. No patient had late heart failure as a new event. Doxorubicin therapy in childhood impairs myocardial growth in a dose-related fashion and results in a progressive increase in left ventricular afterload sometimes accompanied by reduced contractility. We hypothesize that the loss of myocytes during doxorubicin therapy in childhood might result in inadequate left ventricular mass and clinically important heart disease in later years.