All-cause mortality in randomized trials of cancer screening

William C. Black, David Haggstrom, H. Gilbert Welch

Research output: Contribution to journalArticle

261 Citations (Scopus)

Abstract

Background: The most widely accepted end point in randomized cancer screening trials is disease-specific mortality. The validity of this end point, however, rests on the assumption that cause of death can be determined accurately. An alternative end point is all-cause mortality, which depends only on the accurate ascertainment of deaths and when they occur. We compared disease-specific and all-cause mortality in published randomized cancer-screening trials to indirectly assess the validity of the disease-specific mortality end point. Methods: We examined all 12 published randomized trials of cancer screening for which both end points were available (seven of mammography, three of fecal occult blood detection, and two of chest x-ray screening for lung cancer). For each randomized trial, we subtracted disease-specific mortality observed in the screened group from that observed in the control group and all-cause mortality in the screened group from that in the control group. We then compared the differences in these two mortality measures. Results: In five of the 12 trials, differences in the two mortality rates went in opposite directions, suggesting opposite effects of screening. In four of these five trials, disease-specific mortality was lower in the screened group than in the control group, whereas all-cause mortality was the same or higher. In two of the remaining seven trials, the mortality rate differences were in the same direction but their magnitudes were inconsistent; i.e., the difference in all-cause mortality exceeded the disease-specific mortality in the control group. Thus, results of seven of the 12 trials were inconsistent in their direction or magnitude. Conclusion: Major inconsistencies were identified in disease-specific and all-cause mortality end points in randomized cancer screening trials. Because all-cause mortality is not affected by bias in classifying the cause of death, it should be examined when interpreting the results of randomized cancer-screening trials.

Original languageEnglish (US)
Pages (from-to)167-173
Number of pages7
JournalJournal of the National Cancer Institute
Volume94
Issue number3
StatePublished - Feb 6 2002
Externally publishedYes

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Early Detection of Cancer
Mortality
Control Groups
Cause of Death
Occult Blood
Mammography
Lung Neoplasms
Thorax

ASJC Scopus subject areas

  • Cancer Research
  • Oncology

Cite this

All-cause mortality in randomized trials of cancer screening. / Black, William C.; Haggstrom, David; Welch, H. Gilbert.

In: Journal of the National Cancer Institute, Vol. 94, No. 3, 06.02.2002, p. 167-173.

Research output: Contribution to journalArticle

Black, William C. ; Haggstrom, David ; Welch, H. Gilbert. / All-cause mortality in randomized trials of cancer screening. In: Journal of the National Cancer Institute. 2002 ; Vol. 94, No. 3. pp. 167-173.
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