"In fact, the pattern of breast cancer risk with time in women in Denmark, is seen to move in striking parallel to the pattern of induced abortion exposure.

Figure 2 shows the close correlation of age-adjusted breast cancer risk and frequency of induced abortion, examining the data on all Danish women in 5-year (the standard interval used) birth cohort groupings.

3) Mischaracterization of their own findings and of other published research in the field.

a) Even on the paper’s face, the "Conclusions" section of the abstract of Melbye, et al., is noteworthy for its brevity: "Induced abortions have no overall effect on the risk of breast cancer." Yet even with the paper’s egregious flaws, it still evidenced a statistically significant trend of increased breast cancer risk with increasing gestational age at abortion. Thus, as their data table shows, they found a 12% risk elevation at 11-12 weeks (late first trimester) rising to an 89% risk increase for abortions later than 18 weeks.

This didn’t show up in their "overall" relative risk figure, because most abortions in Denmark (as in the US) are done somewhat earlier (7-10 weeks) in the first trimester, and their effect on breast cancer risk was statistically eliminated (see section 2 above).

b) Melbye et al. also make no mention in the abstract or the discussion of the fact that they found a 29% increased breast cancer risk among women who had an abortion as a teenager. The reason the authors were able to avoid mentioning this statistic is the fact that it was not statistically significant.

The reason it was not statistically significant is the small number of women in this category in their study, due to the recent inception (1973) of the computerized abortion registry they used.

c) The authors disparage and dismiss the findings of the worldwide literature compiled in our 1996 "Comprehensive review and meta-analysis"¹ with the blanket statement: "it is not unreasonable to assume that many of them (the 23 worldwide studies we compiled) were inherently biased, making the pooled conclusions biased as well." (See the "Brief guide to epidemiological study design and interpretation", page 7 of this issue.)

Two important points should be made here:

1) The potential problem of bias in case control control studies, is, as Melbye, et al., point out, that it would, if it exists, result in the "differential misclassification" of women who had abortions as not having had abortions.

The irony here is that the very study of Melbye, et al., takes the proverbial cake for misclassification by orders of magnitude, considering their misclassification of 60,000 women (see 1a above)! ii). The overall average 30% risk increase attributable to induced abortion which we reported in our meta-analysis, and which Melbye, et al., take exception to, is virtually the same statistic they obtained for women who had abortions as teenagers (see 3b above).

2) Melbye, et al., misrepresent their findings as essentially confirming the findings of other researchers who investigated the ABC link using prospective, computerized data: "This result is very much in line with the results of previous ... cohort studies".

To back this statement up, they cite four studies, three of which concern only (or mostly) spontaneous abortion (miscarriage), and are therefore entirely irrelevant. (See article in this issue for why miscarriages don’t usually increase breast cancer risk.) They also conveniently ignore the fact that one of the studies showing significantly increased risk (90%) also used prospective computerized data.

"It is of course outrageous that the Melbye study is being used to spread the claim that the ABC link does not exist. This is not good news for women, who are still actively being kept in the dark by the very agencies who should warn them about avoidable cancer risks.

"In this regard, Dr. Patricia Hartge, author of the NEJM editorial which accompanied the Melbye study, is only the most recent National Cancer Institute researcher disparaging the link. However I find it encouraging that the ABC debate is finally out in the open. I have already published a brief rebuttal in The Wall Street Journal, and coauthored another which is in press in the NEJM. The fact that Melbye et al. did such a bad job will only hasten the day when the ABC link will be common knowledge." -jb-


As anyone can plainly see, Dr. Brind thoroughly demolishes the Melbye-Danish study as being essentially invalid and drawing invalid conclusions. Notice how the report was critiqued by Dr. Brind and then compare this with the criticism of reports that show an abortion breast cancer link. One is thorough, factful and logical and the other is not; it's double-talk.

Other works of Dr. Brind:

Dr. Brind at the Subcommittee Hearings on "War on Cancer"
Dr.Brind's ABC Link at World Conference on Breast Cancer

Home