Other highlights in the July 21 JNCI

07/15/04

Study Verifies Reliability of SEER Cancer Database

A study that analyzed histologic lung cancer types reported to one of the cancer registries within the Surveillance, Epidemiology, and End Results (SEER) program has found that the database is reasonably reliable.

Since 1973, the SEER database has collected and published cancer incidence and mortality data from more than 10% of the U.S. population. The information in SEER on age, sex, date of diagnosis, and stage of disease is regarded as fairly precise, but the reliability of data on other variables, such as histologic tumor type, is largely unknown.

To assess the accuracy of histologic diagnosis data reported to SEER, R. William Field, Ph.D., of the University of Iowa in Iowa City, and colleagues compared histologic tumor types from 413 female lung cancer patients reported to the Iowa Cancer Registry, a SEER member, with those obtained through an independent review of pathology samples from the same patients. They found no difference in the distribution of histologic tumor types between the registry and the independent review.

In an editorial, Donald E. Henson, M.D., of the George Washington University Cancer Institute in Washington, D.C., and his colleague write, "As SEER matures, it becomes a valuable tool with far-reaching implications for the study of cancer. While some variation in individual diagnosis will occur, the regression of large numbers is taking effect, and the patterns of histologic tumor types are converging to their mean."

Contact: Dan McMillan, Office of Communications, University of Iowa, 319-335-6835, Daniel-mcmillan@uiowa.edu

False Positives Decrease Adherence in Cancer Screening Trial

People enrolled in a cancer screening trial who received a false-positive result from a screening test were less likely to adhere to the trial than participants who had normal test results, according to a new study.

The researchers suggested that additional education detailing the potential limitations of trial participation need to be provided so that participants are prepared for the likelihood of false positive results, and for the impact that false positive results can have on quality of life. Further, focusing additional attention and trial resources on nonadherent subgroups, including those who received false positive results, may improve overall adherence rates in a cost-efficient manner. Finally, future research needs to address the impact that repeated false positive screening results may have on long-term quality of life and trial adherence.

Kathryn L. Taylor, Ph.D., of Georgetown University in Washington, D.C., and colleagues surveyed people enrolled in the National Cancer Institute's Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial, a large cancer screening trial designed to assess whether annual screening for these cancers reduces mortality from these diseases.

Abnormal screening results were associated with short-term decreases in HRQL. In addition, these people were less likely to adhere to the trial--including having the required annual screening exams and completing an annual questionnaire--than those participants who had all normal results in the previous year's tests.

The researchers suggested that because peace of mind about cancer is often cited as a reason for undergoing cancer screening, participants in screening trials should be clearly informed that they may or may not achieve peace of mind from the trial because of the possibility of receiving abnormal test results.

"Future research needs to address the potential of such interventions as well as the impact of receiving repeated false-positive screening results on long-term HRQL and trial adherence," the authors write.

Contact: Lindsey A. Spindle, Media Relations, Georgetown University, 202-687-7707, las46@georgetown.edu

Breast-feeding Associated with Reduced Risk of Breast Cancer in BRCA1 Carriers
*NOTE: The embargo for this news item, and only this news item, has been lifted as of 11:00 a.m. on July 20, 2004. ALL OTHER TIP SHEET ITEMS ARE STILL UNDER THE EMBARGO LISTED ABOVE.

Breast-feeding for a cumulative total of more than 1 year is associated with a reduced risk of breast cancer in BRCA1 mutation carriers, according to a new study.

Studies of the general population have shown that the risk of breast cancer is reduced in women who breast-feed their children. In a case-control study, Steven A. Narod, M.D., of the Centre for Research in Women's Health in Toronto, and colleagues examined the association between breast cancer risk and breast-feeding among women with deleterious BRCA mutations. They found that, among women with BRCA1 mutations, the total duration of breast-feeding was associated with a reduced risk of breast cancer. Women with BRCA1 mutations who breast-fed for more than 1 year in total during their lifetime were less likely to have breast cancer than those who never breast-fed, although no such association was seen for women with BRCA2 mutations.

Contact: Steven A. Narod, Centre for Research in Women's Health, steven.narod@sw.ca

Study Investigates Possible Mechanism by which Tamoxifen Promotes Endometrial Cancer

Tamoxifen is used both to treat hormone-dependent breast cancer and to prevent the disease in women who have an elevated risk of breast cancer. Tamoxifen use has also been reported to increase a woman's risk of endometrial cancer, but the mechanism by which it may do this is not known. One suggested mechanism involves the formation of tamoxifen–DNA adducts in endometrial tissue, although the presence of these adducts in endometrial tissue is controversial.

Frederick A. Beland, Ph.D., of the National Center for Toxicological Research in Jefferson, Ark., and colleagues used a new method called electrospray ionization–tandem mass spectrometry in addition to established methods to look for tamoxifen-DNA adducts in endometrial tissue from women who had and had not taken tamoxifen. The researchers did not find any adducts and concluded that the formation of these adducts is not the mechanism by which tamoxifen causes endometrial cancer.

Contact: U.S. Food and Drug Administration Press Office, 301-827-3414, kathleen.quinn@fda.hhs.gov

Also in the July 20 JNCI:

  • Study Examines Effects of State-Mandated Reimbursement for Clinical Trials:
    http://www.eurekalert.org/emb_releases/2004-07/jotn-see071504.php
  • Common Therapy for HIV Associated with Cervical Abnormality Regression:
    http://www.eurekalert.org/emb_releases/2004-07/jotn-ctf071504.php
  • High-Dose Chemotherapy Not Superior to Conventional Chemotherapy in High-Risk Breast Cancer Patients:
    http://www.eurekalert.org/emb_releases/2004-07/jotn-hcn071504.php

    Source: Eurekalert & others

    Last reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
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