3D mammography is on the upswing in the US, as experts argue about its value
BMJ 2019; 366 doi: https://doi.org/10.1136/bmj.l4506 (Published 17 July 2019) Cite this as: BMJ 2019;366:l4506All rapid responses
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Daniel Corcos’ comment concerning the article “3D mammography is on the upswing in the US, as experts argue about its value” makes several claims that are not supported by the facts.
1. His claim “The absence of benefit on breast cancer mortality in the long term, observed in epidemiological studies” is simply wrong.
Data from the Two County randomized controlled trial of screening has shown that the decline in breast cancer deaths persists and even increases through 30 years (Yen AM, Duffy SW, Chen TH, Chen LS, Chiu SY, Fann JC, Wu WY, Su CW, Smith RA, Tabár L. Long-term incidence of breast cancer by trial arm in one county of the Swedish Two-County Trial of mammographic screening. Cancer. 2012 Dec 1;118(23):5728-32. doi: 10.1002/cncr.27580. Epub 2012 May 17)
In the U.S. there has been a major decline of over 40% in breast cancer deaths since the onset of mammography screening (Hendrick RE, Baker JA, Helvie MA. Breast cancer deaths averted over 3 decades. Cancer. 2019 May 1;125(9):1482-1488.).
A huge study in Sweden shows that the incidence of breast cancer deaths is markedly reduced for women who participated in screening at 10 and 20 years compared to those who did not (Tabár L, Dean PB, Chen TH, Yen AM, Chen SL, Fann JC, Chiu SY, Ku MM, Wu WY, Hsu CY, Chen YC, Beckmann K, Smith RA, Duffy SW. The incidence of fatal breast cancer measures the increased effectiveness of therapy in women participating in mammography screening. Cancer. 2019 Feb 15;125(4):515-523.).
2. There are absolutely no data to support the claim that there are “mammography-induced” breast cancers. No one has ever seen a breast cancer caused by mammography. Radiation risk to the breast drops rapidly as women age. There is no measurable risk from mammography by the age of 40. Even the extrapolated risk is well below the smallest benefit (Mettler FA, Upton AC, Kelsey CA, Rosenberg RD, Linver MN. Benefits versus Risks from Mammography: A Critical Assessment. Cancer 1996;77:903-909.)
Some have been misled by the fact that the incidence of breast cancer in the U.S. was increasing steadily by 1-1.3% per year dating back to 1940 (Anderson WF, Jatoi I, Devesa SS. Assessing the impact of screening mammography: Breast cancer incidence and mortality rates in Connecticut (1943-2002). Breast Cancer Res Treat. 2006 Oct;99(3):333-40.). This was long before there was any mammography. The expected bump from prevalence cancers (first time screening) is superimposed. A failure to understand the fundamentals can lead to misinterpretation.
The lag time for a radiation induced breast cancer is approximately 8-10 years. Screening started in the U.S. in the mid 1980’s. Had screening been causing cancers there should have been a major spike at the end of the 1990’s. Instead, the incidence began to fall after the prolonged prevalence peak (expected as participation in screening plateaued). There are absolutely no data to suggest that mammography has caused any breast cancers.
Competing interests: No competing interests
TMIST IS A WASTE OF $100 MILLION!
The article about “3D Mammography” in the BMJ ([1]) contains important misunderstandings, but I am limited to 1000 words.
As its inventor ([2]), its name is “Digital Breast Tomosynthesis (DBT)”. “3D Mammography” (it is only quasi 3D) was coined to avoid my patent. The article implied that my comments were based on financial conflicts of interest. I have none. My patent has expired and I have no financial interest in the dissemination of DBT.
A 2D mammogram is like a book with clear pages. Hold it up to the light and you can see all the words, but they are superimposed and difficult to read. Cancers can be hidden on 2D mammograms by normal breast tissue. Like shadows on the wall, normal breast structures can also superimpose and create pseudo lesions. DBT allows us to “read each page” revealing cancers hidden by normal tissues on 2D mammography, while eliminating recalls for superimposed tissues.
The title is misleading. I know most of the “experts” in breast cancer screening. Few, if any, who use DBT for screening all women, “argue about its value”.
DBT is evolutionary. Xeroradiography replaced film mammography. Screen/Film mammography (SFM) replaced Xeroradiography. Full Field Digital Mammography (FFDM) replaced SFM. The study comparing FFDM and SFM (DMIST) involved fewer than 50,000 women ([3]) and showed little improvement in cancer detection. More than 7 times that number have participated in multiple studies of DBT ([4],[5],[6],[7],[8],[9],[10],[11]), consistently detecting more small invasive cancers than FFDM while reducing the number of recalls for additional evaluation.
Experts in breast cancer screening were prevented from serving on The U.S. Preventive Services Task Force (USPSTF) that gave DBT an “inconclusive” rating. No one on the USPSTF even provided care for women with breast cancer.
The claim that the evidence for DBT is “inconsistent” is false. When used for screening, DBT consistently finds more early cancers while reducing the recall rates compared to FFDM.
DBT does not increase the detection of DCIS. Dr. Baum disparaged finding "small invasive" cancers, yet this is when lives can be saved ([12]).
Storage is not a problem. Digital storage has exploded in capacity and plummeted in cost.
The claim that “traditional 2D units cost between $80,000 and $100,000” is based on obsolete S/F systems. Regardless, for every $100,000 that a system costs, if used fairly efficiently, this amounts to about $3 per patient.
Radiation risk to the breast falls rapidly with age with no direct data showing any risk for women ages 40 and over. The extrapolated risk is so small that it is outweighed by even the smallest benefit ([13]).
The death rate from breast cancer among women, unchanged for 50 years, has declined by more than 40% since 1990 ([14]) while it has not budged for men with breast cancer ([15]). Men are not screened.
The incidence of death from breast cancer is 40-60% lower among women who participate in screening compared to those who do not, despite everyone having access to modern therapy ([16]).
Early detection saves lives. TMIST is wasting $100 million to test a technology that is superior to FFDM. The money would be better spent on finding additional ways to detect more breast cancers at a time when cure is possible to further reduce deaths.
REFERENCES
[1] Lenzer J. 3D mammography is on the upswing in the US, as experts argue about its value. BMJ. 2019 Jul 17;366:l4506. doi: 10.1136/bmj
[2]. Kopans DB. Digital breast tomosynthesis from concept to clinical care. AJR Am J Roentgenol. 2014 Feb;202(2):299-308
[3] Pisano ED, Gatsonis C, Hendrick E, Yaffe M, Baum JK, Acharyya S, Conant EF, Fajardo LL, Bassett L, D'Orsi C, Jong R, Rebner M; Digital Mammographic Imaging Screening Trial (DMIST) Investigators Group. Diagnostic performance of digital versus film mammography for breast-cancer screening. N Engl J Med. 2005;353:1773-83.
[4] Skaane P, Gullien R, Bjørndal H et al. Digital breast tomosynthesis (DBT): initial
experience in a clinical setting. Acta Radiol. 2012 Jun 1;53(5):524-9.
[5] Skaane P, Bandos AI, Gullien R, et al. Comparison of digital mammography alone and digital mammography plus tomosynthesis in a population-based screening program. Radiology 2013; 267:47–56
[6] Ciatto S, Houssami N, Bernardi D, et al. Integration of 3D digital mammography with tomosynthesis for population breast-cancer screening (STORM): a prospective comparison study. Lancet Oncol 2013; 14:583–589
[7] Lång K, Andersson I, Rosso A, Tingberg A, Timberg P, Zackrisson S. Performance of one-view breast tomosynthesis as a stand-alone breast cancer screening modality: results from the Malmö Breast Tomosynthesis Screening Trial, a population-based study. Eur Radiol. 2015 May 1. [Epub ahead of print] PubMed PMID: 25929946
[8] Haas BM, Kalra V, Geisel J, Raghu M, Durand M, Philpotts LE. Comparison of
tomosynthesis plus digital mammography and digital mammography alone for breast
cancer screening. Radiology. 2013 Dec;269(3):694-700
[9] Rose SL, Tidwell AL, Bujnoch LJ, Kushwaha AC, Nordmann AS, Sexton R Jr. Implementation of breast tomosynthesis in a routine screening practice: an observational study. AJR Am J Roentgenol. 2013 Jun;200(6):1401-8
[10] Friedewald SM, Rafferty EA, Rose SL, Durand MA, Plecha DM, Greenberg JS, Hayes MK, Copit DS, Carlson KL, Cink TM, Barke LD, Greer LN, Miller DP, Conant EF. Breast cancer screening using tomosynthesis in combination with digital mammography. JAMA. 2014 Jun 25;311(24):2499-507. doi: 10.1001/jama.2014.6095
[11] Sharpe RE Jr, Venkataraman S, Phillips J, Dialani V, Fein-Zachary VJ, Prakash S, Slanetz PJ, Mehta TS. Increased Cancer Detection Rate and Variations in the Recall Rate Resulting from Implementation of 3D Digital Breast Tomosynthesis into a Population-based Screening Program. Radiology. 2015 Oct 9:142036. [Epub ahead of print]
[12] Saadatmand S, Bretveld R, Siesling S, Tilanus-Linthorst MM. Influence of tumour stage at breast cancer detection on survival in modern times: population based study in 173,797 patients. BMJ. 2015 Oct 6;351:h4901. doi:10.1136/bmj.h4901. PubMed PMID: 26442924
[13] Mettler FA, Upton AC, Kelsey CA, Rosenberg RD, Linver MN. Benefits versus Risks from Mammography: A Critical Assessment. Cancer 1996;77:903-909.
[14] Hendrick RE, Baker JA, Helvie MA. Breast cancer deaths averted over 3 decades.
Cancer. 2019 May 1;125(9):1482-1488.
[15]. http://seer.cancer.gov/csr/1975_2010/results_merged/sect_04_breast.pdf Last accessed 7/27/2019 Table 4.6
[16] Tabár L, Dean PB, Chen TH, Yen AM, Chen SL, Fann JC, Chiu SY, Ku MM, Wu WY, Hsu CY, Chen YC, Beckmann K, Smith RA, Duffy SW. The incidence of fatal breast cancer measures the increased effectiveness of therapy in women participating in mammography screening. Cancer. 2019 Feb 15;125(4):515-523.
Competing interests: No competing interests
A careful look at mammography screening trials indicates that mammography saves women’s lives when it detects a cancer. Overdiagnosis is a minor problem. The absence of benefit on breast cancer mortality in the long term, observed in epidemiological studies, is caused by mammography-induced breast cancers. Mammography-induced cancers can be seen in every country after screening implementation as an increase in breast cancer incidence and deaths from breast cancers occurring in old women. This question, as well as the cancer risk of medical X-rays, seems not to be discussed.
Competing interests: No competing interests
Response to Daniel Kopans' comment
Daniel Kopans claims that mammography-induced cancers are not supported by facts, on the basis of his denial of the current epidemiological evidence. The absence of clear benefit from mammography screening in large scale epidemiological studies has been largely documented by Welch, Jorgensen, Gotzsche, Autier and others (1-5), and Daniel Kopans himself has explained the observations by a concomitant increase in breast cancer incidence (6), which we have shown not to be a coincidence, but directly related to the previous mammograms (7 and Corcos and Bleyer, unpublished data).
The major decline in cancer mortality observed in all developed countries after 1990 can entirely be explained by therapeutic improvement, as it is observed also in women under the age of screening, and independently of the period of screening (4,8,9). The absence of clear benefit from a method which catches the cancer early can only be explained by the simultaneous occurrence of cancers.
I agree with Daniel Kopans that the mean lag time for a radiation induced cancer is 8-10 years, but this is precisely what occurs in all countries, after excluding prevalent screening. In the USA, for instance, instead of decreasing after the end of screening implementation (high prevalent screening) in 1990, invasive breast cancer incidence in the 1990s was still 30% to 40% higher than the prescreening levels in women aged over 65 years, rather than decreasing, as would have been expected by catching the cancer early.
In the UK, where the period of implementation has been shorter (from 1988 to 1993) it has been possible to determine more precisely the time lag (7). Cancers occur at a frequency of approximately 4 per thousand mammography sessions in women in their 50s, with a mean lag time of 8-10 years, but some cancers occur after only 6 years.
The denial of the cancer risk of medical X-rays has several sources. Medical X-rays were routinely used before the question of cancer risk was considered, and everything was attempted to minimize the risk. The term of « low dose » was used even though the amount of radiation absorbed in one second is more than one million times the amount a human cell gets in the same time from natural background. The dose-response relationship is still considered to be linear, although there is no evidence that this is true, and although most dose-response relationship are hyperbolas.
Finally, the only appropriate way to address the question is to collect the published epidemiological data on the risk related to imaging. Using this method in the 90s, John Gofman, a prominent expert in the radiation risk, claimed that 75% of breast cancers in the USA were caused by medical X-rays (10). Although there was no valid rebuttal of his conclusion, he could not publish it in medical journals. I have had a similar experience and can testify that, although, as Kopans says, «there are absolutely no (published) data to suggest that mammography has caused any breast cancers », everybody can see in the cancer registries of every country a strong increase in breast cancer incidence in old women after mammography screening implementation. The only question is why this information is absent from medical journals.
References
1) https://www.ncbi.nlm.nih.gov/pubmed/26147578
2) https://www.ncbi.nlm.nih.gov/pubmed/26510017
3) https://www.ncbi.nlm.nih.gov/pubmed/22240405
4 )https://www.ncbi.nlm.nih.gov/pubmed/21798968
5) https://www.ncbi.nlm.nih.gov/pubmed/29208760
6) https://www.ncbi.nlm.nih.gov/pubmed/28210564
7) https://www.biorxiv.org/content/10.1101/238527v1
8) https://www.ncbi.nlm.nih.gov/pubmed/26562826
9) https://www.ncbi.nlm.nih.gov/pubmed/21846758
10) https://ratical.org/radiation/CNR/PBC/index.html
Competing interests: No competing interests