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Cancer Remains More Lethal to African Americans
"African Americans have the highest death rate and shortest survival of any racial and ethnic group in the U.S. for most cancers," reports the American Cancer Society in Cancer Facts & Figures for African Americans 2007-2008. The report cites a number of factors based in economic and social gaps that may contribute to the disparity, including access to insurance, health care, and health education.
The report comes in the context of the second consecutive year of declining cancer deaths, a trend for the overall U.S. population that also applies to the 13 percent who are African American. However, the inequity between whites and African Americans persists, with black men facing a 35-percent greater risk of death from cancer than white men, and black women 18 percent more likely to die of cancer than white women. More than 62,000 African Americans are expected to die of cancer in 2007.
The report also details statistics on risk factors and the use of screening tests, as well as the cancer sites that are most threatening. Lung cancer is the leading killer of both African Americans and whites, though it is more common among African American men and is increasing among African American women. Colorectal cancer strikes African Americans of both sexes more frequently than their white counterparts and is more lethal, as well. Black women are far less likely to have breast cancer than white women, yet far more likely to die from it.
Hematopoietic Drugs During Chemo May Raise Leukemia Risk
To address the diminished supply of white blood cells that results from chemotherapy, patients can receive granulocyte colony-stimulating factors (G-CSFs) or granulocyte-macrophage colony-stimulating factors (GM-CSFs) during treatment. A study led by researchers from Columbia University's Mailman School of Public Health, published February 7 in the Journal of the National Cancer Institute (JNCI), shows that these stimulating factors may be linked to an increased risk of subsequent acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS).
The cohort study included 5,501 women aged 65 or older who had received chemotherapy within 12 months of their breast cancer diagnosis. The researchers examined retrospective patient-chart data from the Surveillance, Epidemiology, and End Results program, as well as claims from the Centers for Medicare and Medicaid Services.
They found that women who received either G-CSFs or GM-CSFs were twice as likely to develop AML or MDS as women who did not receive the drugs. The overall incidence, however, was rare: 1.8 percent versus 0.7 percent within 48 months of the treatment.
The authors warn that it's not clear whether these factors caused the leukemia, or whether the higher doses of chemotherapy that often require G-CSFs or GM-CSFs for recovery are to blame, but they note that the risk should be considered for older patients and that more research is needed.
An accompanying editorial goes further: "Only when such studies are coupled to genome-wide single-nucleotide polymorphism analysis or comparable approaches to identify genes involved in leukemia predisposition will it be possible to predict whether G-CSF treatment of normal hematopoietic stem cell donors or cancer patients receiving adjuvant chemotherapy should be avoided in certain individuals."
Heart Attack Mortality Risk Increased After Hodgkin Disease Treatment
British researchers found that patients with Hodgkin disease who were treated with chemotherapy and radiotherapy regimens had an increased risk of death from myocardial infarction, according to study results published in the February 7 JNCI.
Dr. Anthony J. Swerdlow of the Institute for Cancer Research in Sutton, UK, and colleagues conducted a collaborative cohort study of 7,033 patients who were registered between November 1, 1967, and September 30, 2000, in the clinical databases of the British National Lymphoma Investigation, the Royal Marsden Hospital, St. Bartholomew's Hospital, and Christie Hospital.
The researchers examined the myocardial infarction mortality risk associated with four treatment regimens: chemotherapy with supradiaphragmatic radiotherapy, chemotherapy without supradiaphragmatic radiotherapy, chemotherapy without supradiaphragmatic radiotherapy or anthracyclines, and radiotherapy without anthracyclines.
Myocardial infarction accounted for 166 of 2,424 cohort deaths, which was more than expected. The mortality risk associated with myocardial infarction was 2.5 times that of the general population of England and Wales. Researchers also found that risks were increased significantly for patients who had been treated with supradiaphragmatic radiotherapy or with anthracyclines or vincristine. However, these results may not reflect the risks for patients currently being treated for Hodgkin disease, as several of the treatments analyzed in this study are no longer in use.
In an accompanying editorial, Dr. John D. Boice, Jr., of the International Epidemiology Institute in Rockville, MD, wrote, "One challenging aspect of the analyses, however, was that so many patients receive both radiotherapy and different combinations of chemotherapy that it is difficult to tease out the contribution of a single agent."
Many Advanced Cancer Patients in Phase I Trials Using CAM
More than one-third of advanced cancer patients enrolled in phase I clinical trials reported using "biologically based" complementary and alternative medicine (CAM) such as vitamins and supplements, a new study reports. The finding, the study's authors argue, suggests that CAM use could be compromising the results of phase I trials.
"We believe our results have potentially serious consequences with regard to the reliability of early phase trial results," wrote lead author Dr. Christopher K. Daugherty and colleagues from the University of Chicago Cancer Research Center.
To conduct the study, the researchers interviewed 212 patients with advanced cancer enrolled in phase I clinical trials at their institution - 80 percent of all patients participating in phase I studies there. Patients were interviewed about their use of biologically based CAM. Of the 72 patients who admitted to using such products, approximately half reported taking vitamins and minerals such as vitamins A, C, D, E, selenium, and zinc; the remainder took herbal preparations such as cat's claw, St. John's wort, and echinacea.
CAM users were younger than nonusers, they found, with a median age of 55 years for users compared to 62 for nonusers. In addition, patients with more pessimistic views of their prognosis were more likely to report CAM use.
Among the authors' chief concerns about CAM use by patients in phase I trials is their potential to "affect the reliability" of toxicity data. They pointed to the examples of St. John's wort and high-dose vitamin C, both of which "are known to have potentially significant interactions with chemotherapy."
They called for patients being considered for phase I trials to be closely questioned about CAM use. They also suggested excluding patients known to be taking CAM from phase I trials of experimental agents "because they create unknown risks to themselves and other potential trial participants, and lead to potentially unreliable clinical data."
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