Today’s Tosser: Dennis Byrne
ArchPundit
Or perhaps the Chicago Tribune Editorial Board for continuing to print this garbage.
There’s just one problem. According to an analysis in one of the most credible peer-reviewed journals in the country, the Mayo Clinic Proceedings, the risk is real. The study employed an often-used medical research technique called “meta-analysis” that allows researchers to combine data from other studies on the risk to get a larger picture. The result: Premenopausal women who used oral contraceptives prior to having their first child have a 44 percent higher chance of getting cancer than women who didn’t use the pill. If they used the pill for more than four years prior to their first full-term pregnancy, the risk increased 52 percent. Chris Kahlenborn, an internist at the Altoona (Pa.) Hospital and the study’s lead author, suggests one additional woman in 200 could get breast cancer. Extrapolated throughout the population, that could mean thousands more cases every year. I’d say that’s an important story.
I’m assuming Byrne didn’t understand the researcher because in the same issue of the Mayo Clinic Proceedings the editorial addressed the issue and it had something different to say:
Second, although OCs appear to be carcinogenic,7 the relative risk is small, and the absolute risk (excess breast cancers due to OC exposure) is very small. For example, the Oxford pooled analysis estimates that the excess number of cases of breast cancer expected to be diagnosed up to 10 years after discontinuation of OC use among 10,000 European or North American women is 0.5 cases for OC use from age 16 to 19 years, 1.5 cases for OC use from age 20 to 24 years, and 4.7 cases for OC use from 25 to 29 years. These cases are also likely to be clinically localized. Third, although a formal risk-benefit analysis is beyond the scope of this editorial, all risks and benefits of OC use must be considered, not just the risk of breast cancer. Other cancer risks may include cervical cancer and liver cancer in populations at low risk for hepatitis B viral infection. Additionally, IARC has determined that there is convincing evidence that OCs decrease the risk of ovarian and endometrial cancer, and there is accumulating evidence that they may lower the risk of colorectal cancer.7 Other major noncancer risks of OC use include ischemic stroke, venous thromboembolism, and myocardial infarction, but because these are rare events in women of childbearing age, the attributable risks are very small.8,16 Finally, there is a growing number of noncontraceptive health benefits associated with OCs, including relief from menstrual disorders; reduced risk of pelvic inflammatory disease, benign breast disease, uterine leiomyomas, and ovarian cysts; and improved bone mineral density
The essential problem is that a Meta-Analysis is only as good as the controls in the various case control studies. If the case control studies don’t match control and cases to relevant risk factors, then the outcomes are troublesome to say the least.
In this case, the relevant matching of cases determining the inclusion of the study only included age and general demographic information, while the studies vary upon health and behavioral risk factors such as smoking, general health, and even genetics.
IOW, correlation is not causation and while there is an interesting correlation, for meta-analysis to be useful in such a broad range of studies, the controls need to be similar.
The point is well made in a follow-up letter to the Mayo Clinic Proceedings. \
Confounding factors are a major issue in the interpretation of all case-control studies. For example, I previously noted that confounding is to be expected in case-control studies of the associations between conditions that are truly caused by high or low levels of steroid hormones and some forms of risky behavior (treated as risk factors).2 In the case of premenopausal breast cancer, the disease is thought to be partially caused by high levels of estrogenic (and perhaps androgenic) hormones. Moreover, the behavioral trait of sensation seeking is associated with high levels of both estrogenic and androgenic hormones.3 In contrast to age-matched controls, a higher proportion of young female sensation seekers would be expected to choose to engage in voluntary “risky” behavior, eg, smoking, OC use, and abortion. Thus, the association of OCs with breast cancer may simply be a reflection of the independent association of both these factors with high levels of estrogens and/or androgens. The point could be tested by assaying the hormones of control subjects and of young women at the time they first choose to use OCs. I hypothesize that, at the time of OC initiation, users have higher hormone levels than controls.
Byrne wants there to be a national scare over a finding that is interesting, but not definitive. That’s not science.
And it brings into question why the Tribune is promoting this clown and whatever junk science idea he has for the column. The Trib has very able science reporters who do a decent job sorting out evidence and reasonable interpretations of data. Why they choose to allow a completely ignorant fool to scare people from a fairly valuable piece of editorial real estate is the real mystery.