Tamoxifen: Praised As "Life Saving" But Still Causing Cancer

Tamoxifen: Causes Cancer But Praised As "Life Saving" Drug

Many of the drugs used to treat breast cancer today are probable or known cancer-causing agents. Tamoxifen, for instance, is classified by the World Health Organization as a "human carcinogen," but recent news headlines praised extended use of this drug for "saving lives." It is obvious that the mainstream media has swallowed the tamoxifen-flavored Kool-Aid ... will you?

Last week, mainstream media headlines lit up like Christmas lights with exuberant news that the chemotherapy drug tamoxifen, "Cuts Breast Cancer Deaths," "Saves Lives," "Dramatically Lowers Risk of Death," ad nauseam, when extended from 5 years of use to 10 in breast cancer patients.

These mostly uncritical pronouncements followed from a newly published study in Lancet, funded by a long list of contributors, including the US Army, EU-Biomed, UK Medical Research Council, and the UK division of AstraZeneca, the company that formed after the now defunct Imperial Chemical Industry, the drug's original patent holder and manufacturer, de-merged its pharmaceutical division Zeneca Group in 1993, merging with Astra AB in 1999 to assume its present incarnation as one of the world's most powerful pharmaceutical companies.

Most of these news stories made no mention of the fact that a major pharmaceutical industry funding source for the study would benefit directly and indirectly, perhaps in tens of millions of dollars, from its ostensibly positive findings.  Mind you, AstraZeneca is a founding (and still controlling) sponsor of Breast Cancer Awareness Month, the more than a quarter of a century old push to screen millions of asymptomatic women for so-called 'early-stage cancers' with x-ray mammography, a campaign which was recently shown to result in the overdiagnosis and unnecessary treatment of an astounding 1.3 million American women over the past 30 years. 

Therefore it is a sad reflection on the state of journalism today that more was not said about this glaring conflict of interest. Indeed, increasingly, mainstream medical news reports have transmogrified into thinly veiled infomercials for their major advertisers.

What Did The New Lancet Tamoxifen Study Actually Show?

According to the much lauded study, these are the actual differences observed between the 5 and 10 year treatment groups:   

Diagnosed breast cancer recurrence on tamoxifen was reduced from 25.1% in the 5 year group to 21.4% in the 10 year group – a 3.9% reduction.

Breast cancer deaths on tamoxifen were reduced from 15% in the 5 year group to 12.2% in the 10 year group – a 2.8% reduction.

Based on surface appearances, a 3.9% reduction in breast cancer recurrence, and especially a 2.8% reduction in breast cancer mortality, are benefits that can not be considered too small to be of consequence. After all, saving even one woman's life is no small thing.

Looking a bit deeper, however, these ostensibly positive numbers conceal a darker reality: many, if not most, of the initially diagnosed breast cancers in the studied populations, and which justified their follow-up treatment with tamoxifen in the first place, were probably misdiagnosed (which the medical establishment euphemistically calls "overdiagnosis"). And so too were many of the "recurring" cancers observed during the course of the 10-year study period. Therefore, the professed differences in morbidity and mortality in the extended tamoxifen treatment group, versus the 5-year group, may simply reflect the differing degrees to which these women were subjected to misdiagnosis and mistreatment (again, euphemistically known as "overtreatment"), and not any intrinsic therapeutic value to the drug itself.

In 2008 alone, it has been estimated that 70,000 U.S. women were overdiagnosed and overtreated for early-stage breast cancers that were not (and would not have become) malignant, and therefore were technically not cancerous at all, i.e. mammography detected lesions in women that were inherently benign, but were termed "pre-cancerous" and treated preemptively with the standard treatments, e.g. mastectomy, lumpectomy, radiation and chemotherapy. In fact, approximately 95% of early-stage breast cancers are overdiagnosed and overtreated, according to the latest meta-analysis on the topic that we covered in far greater depth in a recent article: 30 Years of Breast Screening: 1.3 Million Wrongly Treated.

So, taking this deeper context into account, what do the aforementioned Lancet study figures really indicate?   

Tamoxifen May Indirectly Reduce The Risk of Overdiagnosis and Overtreatment, While Doing Nothing To Fight Breast Cancer Itself

Due to the fact that tamoxifen is a powerful anti-estrogen, and that breast cells in their normal state have estrogen receptors susceptible to being "blocked" by it, it should be expected that this chemical would suppress the growth of estrogen-sensitive tissues, regardless of whether or not those tissues are benign or malignant.  Many things, in fact, suppress breast cell growth, even cancerous breast cells, by antagonizing these receptors (see Flaxseed Breast Cancer study). Longer tamoxifen treatment, therefore, would naturally result in a longer duration of estrogen-mediated growth suppression of cells within the breast, especially faster growing ones that are more likely to form a mammography-detectable lesion or benign tumor.  As a result, the observed 3.9% reduction in the recurrence of breast cancer observed in the 10 year study group (versus the 5 year group) may have resulted not from tamoxifen's ability to selectively target and kill breast cancer stem cells (which it is quite ineffective at doing, especially considering the emergence of tamoxifen-resistance), but rather, from reducing the likelihood of detection and the subsequent risk of over- or misdiagnosis

This would also explain how extended tamoxifen treatment resulted in a 2.8% reduction in breast cancer mortality. By reducing the number of mammography-detected "abnormal findings," and subsequent false cancer diagnoses, tamoxifen helped these women evade a battery of unnecessary diagnoses and treatments, which translated into a slightly lower overall breast cancer mortality. The "cause" of their lower mortality would therefore be from the avoidance of strictly iatrogenic (medicine-induced) psychological and physical trauma caused by what would have been for many of these women a second round of unnecessary and/or inappropriate treatments, and not the purported increased anti-cancer benefits of extended tamoxifen use.

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