Other highlights in the May 4 JNCI
Failure to Screen, Pap Test Failure Most Common Reasons for Cervical Cancer Diagnosis
Increasing Pap screening adherence and improving the accuracy of Pap screening could reduce the incidence of invasive cervical cancer among women with access to screening and could afford earlier detection of cervical cancer, a new study concludes.
Cervical cancer is highly preventable and treatable. Therefore, the occurrence of an invasive cervical cancer represents a failure in the screening process. To elucidate factors associated with screening failure, Wendy A. Leyden, of Kaiser Permanente in Oakland, Calif., and colleagues examined the medical records of 833 women enrolled in one of seven comprehensive health care plans who were diagnosed with cervical cancer despite having access to cancer screening and treatment services.
They found that 56% of cases were in women who had not had a Pap test during the period 4 to 36 months prior to diagnosis, whereas 32% of cases were attributed to Pap test detection failure and 13% of cases to failure to follow up an abnormal test result. Most (81%) of the women with no Pap screening had had at least one unrelated outpatient visit 4 to 36 months prior to their cancer diagnosis.
"Despite the many exciting new technologies that may improve our ability to predict or detect cervical neoplasia, we must not lose sight of the need to increase screening adherence," the authors write. "Even the most perfect screening method will not detect disease in a woman who has not participated in the prevention process."
Contact: Laura H. Marshall, Kaiser Permanente, [email protected], 510-271-5826
Survival Not Improved With Dose-Dense Chemotherapy for Small-Cell Lung Cancer
A randomized trial has found that a dose-dense regimen of chemotherapy with blood progenitor cell support did not improve survival compared with standard-dose chemotherapy in patients with small-cell lung cancer (SCLC). However, patients who received the dose-dense regimen had fewer infections and fewer days of treatment than patients who received standard chemotherapy.
Long-term survival in patients with SCLC is poor. Studies that have tested different dose intensities of various chemotherapy regimens for SCLC have yielded conflicting results. Paul Lorigan, M.D., of Christie Hospital Manchester in England, and colleagues conducted a phase III randomized trial to determine whether doubling the dose density of ifosfamide, carboplatin, and etoposide (ICE) chemotherapy with blood-progenitor-cell support improved survival compared with standard ICE chemotherapy in patients with SCLC who had a relatively good prognosis. A total of 318 patients were randomly assigned to receive ICE chemotherapy every 4 weeks (standard arm) or every 2 weeks (dose-dense arm).
Overall survival and 2-year survival were similar in the two arms. The treatment duration was shorter in the dose-dense arm than in the standard arm, but this difference was not statistically significant.
Contact: Alicia Custis, Communications Manager, Christie Hospital, [email protected], 44-0161-446-3706
Hormone Decreases Ability of Breast Cancer to Spread, Animal Study Finds
A hormone used in the contraceptive Depo-Provera increased expression of a metastasis suppressor gene and decreased the ability of breast cancer cells to spread in both laboratory experiments and an animal model.
Medroxyprogesterone acetate (MPA) is a progestin that is used in Depo-Provera and has been tested as a treatment for advanced breast cancer. An earlier study found that MPA increases the expression of a metastasis suppressor gene called Nm23-H1 in estrogen and progesterone receptor-negative breast cancer cells via the glucocorticoid receptor. Patricia S. Steeg, Ph.D., of the National Cancer Institute, and colleagues tested whether treating hormone receptor–negative breast cancer cells with MPA could decrease the ability of the cancer cells to metastasize.
In cell line studies, the authors found that MPA treatment reduced the colony-forming ability of human breast cancer cells and that it did so via its effect on Nm23-H1. In animal studies, mice with breast cancer micrometastases were randomly assigned to injection with MPA or a control substance. Mice injected with MPA developed fewer and smaller lung metastases than mice injected with the control.
In an editorial, V. Craig Jordan, Ph.D., D.Sc., of Fox Chase Cancer Center in Philadelphia, suggests that the novel mechanism targeted in this study may be exploited in the future treatment of estrogen receptor–negative breast cancer patients. He also notes the clinical challenge of preventing metastasis in a disease that is typically diagnosed after metastatic spread has already occurred.
Article: NCI Press office, [email protected]; 301-496-6641 Editorial: Karen Carter Mallet, Fox Chase Cancer Center, [email protected], 215-728-2700
Plasma Levels and Intake of B Vitamin May Be Associated With Decreased Risk of Colorectal Cancer and Adenoma
Vitamin B6 intake may be associated with lower future risk of colorectal tumors in women, according to a new study.
Several nutrients, including vitamin B6, play important roles in biochemical pathways related to DNA synthesis and DNA methylation, which are involved in carcinogenesis. Esther K. Wei, Sc.D., from Brigham and Women's Hospital and Harvard Medical School in Boston, and colleagues studied whether vitamin B6 measured as dietary intake and as the main active circulating form, known as pyridoxal 5'-phosphate, or PLP, is associated with the risk of colorectal cancer and colorectal adenoma in women by performing a nested case–control study of 32,826 women in the Nurses' Health Study who provided blood specimens between 1989 and 1990.
During the study period, 194 colorectal cancer cases and 410 colorectal adenoma cases were identified. The authors observed that women in the highest quartile of plasma PLP concentration, compared with women in the lowest quartile, had a reduced future risk of colorectal cancer and colon cancer, after adjusting for important risk factors associated with colorectal cancer as well as dietary folate and methionine intake, and multivitamin use. Total vitamin B6 intake was also inversely associated with future risk of colorectal tumors among these women. "Additional animal, epidemiologic, and intervention studies are required to clarify the association between dietary and plasma vitamin B6 and colorectal neoplasia," the authors write.
Contact: Melanie Franco, Brigham & Women's Hospital, [email protected], 617-534-1605
Also in the May 4 JNCI:
Constitutively Active K-cyclin/cdk6 Kinase in Kaposi Sarcoma–Associated Herpesvirus–Infected Cells, Lead author: Rukiyah Van Dross, Ph.D., University of Kansas Medical Center. Study Examines Influence of Celebrity Endorsements of Cancer Screening: http://www.eurekalert.org/emb_releases/2005-05/jotn-sei042805.php Study Identifies Possible Marker for Efficacy of Gefitinib in Lung Cancer Patients: http://www.eurekalert.org/emb_releases/2005-05/jotn-sip042805.php
Source: Eurekalert & othersLast reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
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