Whether breast cancer is detected during screening mammograms or detected in other ways may help define a woman's prognosis, according to a new study.
Screening mammography detects breast cancers at an earlier stage of development than breast cancers detected symptomatically--the so-called stage shift--and so mammographically detected breast cancers tend to have better prognoses. This stage shift is subject to various biases, so that earlier detection may not translate into lower mortality. In addition, screen-detected cancers tend to grow more slowly than cancers detected in other ways, which may also affect survival.
To examine the prognostic value of the method of breast cancer detection on survival, Donald A. Berry, Ph.D., of the University of Texas M. D. Anderson Cancer Center in Houston, and colleagues used data from three large North American randomized controlled trials of breast cancer screening. In all three trials, the authors found that after adjusting for tumor size, lymph node status, and disease stage, clinically detected cancers were associated with a 53% greater hazard of death from breast cancer compared with screen-detected cancers.
In an editorial, Ian F. Tannock, M.D., Ph.D., and Monika K. Krzyzanowska, M.D., of Princess Margaret Hospital in Toronto, discuss these results and those of another recent study, both of which reported better survival associated with screen-detected cancers. They conclude, however, that knowing the method of detection might add only limited prognostic value beyond that of well-established prognostic factors.
Some Cancer Patients Treated With Cetuximab May Require Magnesium Supplementation
Some cancer patients being treated with cetuximab (Erbitux) may develop abnormally low blood levels of magnesium (hypomagnesemia) and require supplementation, according to a new study.
Cetuximab--a monoclonal antibody against the epidermal growth factor receptor (EGFR)--is used to treat patients with metastatic colorectal cancer and is being evaluated for the treatment of several other solid tumors. After treating a 34-year-old male colorectal cancer patient who developed profound fatigue and hypomagnesemia while on cetuximab therapy, Deborah Schrag, M.D., of Memorial Sloan-Kettering Cancer Center in New York, and colleagues reviewed the incidence of electrolyte abnormalities among a consecutive case series of 154 patients treated with cetuximab at their institution.
Of the 34 patients who had their magnesium levels measured at least once during cetuximab treatment, six had grade 3 hypomagnesemia and two had grade 4. The authors hypothesize that because EGFR is strongly expressed in the kidney--particularly where most of the magnesium is reabsorbed into the organ--blocking EGFR with cetuximab may interfere with magnesium transport. They suggest that if cetuximab-treated patients have symptoms of hypomagnesemia--fatigue, paresthesias (itching, burning, or tingling skin sensations), and low levels of calcium in the blood--then they should have their magnesium levels checked and, if low, receive magnesium supplementation.
Contact: Joanne Nicholas, Memorial Sloan-Kettering Cancer Center, 212-639-3573, email@example.com
Men With Extra X Chromosome May Have Higher Risk of Some Cancers
A new study has found that men with Klinefelter syndrome--having one or more extra X chromosomes--may have an elevated risk of non-Hodgkin lymphoma and breast and lung cancers.
Men with Klinefelter syndrome may have hypogonadism or other hormonal, physical, or developmental abnormalities. Case reports have suggested that these men may have an increased risk of several cancers, but information about the long-term cancer risks in these men is limited by the lack of large cohort studies.
To examine the cancer risks among men with Klinefelter syndrome, Anthony J. Swerdlow, D.Sc., of the Institute of Cancer Research in Sutton, England, and colleagues conducted a cohort study, following 3,518 men who had been diagnosed with the syndrome in Britain between 1959 and 2002. They compared cancer incidence and mortality among these men with that of men in the British population.
Compared with the general population, men with Klinefelter syndrome had higher mortality from lung cancer, breast cancer, and non-Hodgkin lymphoma and lower mortality from prostate cancer. Mortality from breast cancer among men with 47,XXY mosaicism and mortality from non-Hodgkin lymphoma among men with a 48,XXYY constitution were particularly high. The authors conclude that these results support a hormonal etiology for breast cancer in men and for prostate cancer.
Contact: Nadia Ramsey, Science Press Officer, Institute of Cancer Research, 44-207-153-5359, firstname.lastname@example.org
Study Examines Racial Disparities in Colon Cancer Treatment
Elderly black and white colon cancer patients are equally likely to consult with medical oncologists, but they do not receive recommended adjuvant treatment at the same rates after this consultation, according to a new study.
Studies have shown that black patients are less likely than white patients to receive screening and diagnostic tests and some treatments. A 2001 study, published in the Journal of the National Cancer Institute, reported that black patients were less likely than white patients to receive recommended chemotherapy for stage III colon cancer. To determine whether health care system factors, including those related to the hospitals in which patients are treated and the doctors who treat them, may help explain this disparity, Laura-Mae Baldwin, M.D., M.P.H., of the University of Washington in Seattle, and colleagues used data from several sources to examine receipt of chemotherapy after stage III colon cancer resection in 5,294 elderly black and white Medicare-insured patients. Nearly 80% of both black and white patients consulted with a medical oncologist. Among those who received a consultation, 70.4% of white patients but only 59.3% of black patients received chemotherapy. The disparity was highest among patients ages 66 to 70, and approximately half of this disparity was attributable to patient, physician, hospital, and environmental factors, 27% to surgical length of stay and neighborhood socioeconomic status, and only 12% to health systems. The authors conclude that more qualitative research is needed to understand the factors that contribute to the lower receipt of chemotherapy by black patients.
Contact: Clare Hagerty, University of Washington, 206-543-3620
Working Group Makes Recommendations for Reporting Tumor Marker Studies
Despite efforts to define cancer tumor markers, few markers have proven to be clinically useful. In 2000, the National Cancer Institute-European Organisation for Research and Treatment of Cancer First International Meeting on Cancer Diagnostics recommended the development of guidelines for reporting tumor marker studies.
In a commentary, Lisa M. McShane, Ph.D., of the National Cancer Institute, and colleagues set out guidelines for the reporting of tumor marker studies. The guidelines indicate relevant information about the study design, pre-planned hypotheses, patient and specimen characteristics, assay methods, and statistical methods that should be included in reports of marker studies. The goal of the guidelines is to facilitate assessment of study quality and generalizability of study results, and ultimately to improve the design, analysis, and reporting of tumor marker studies.
Contact: National Cancer Institute Press Office, 301-496-6641, NCIPressOfficers@mail.nih.gov
Also in the August 17 JNCI:
Note: The Journal of the National Cancer Institute is published by Oxford University Press and is not affiliated with the National Cancer Institute. Attribution to the Journal of the National Cancer Institute is requested in all news coverage. Visit the Journal online at http://jncicancerspectrum.