Treating precancers reduces breast cancer deaths

Breast cancer deaths rose through the '70s and '80s, but declined in the '90s. For nearly the past 20 years, American women have had about a 2% annual drop in the breast cancer death rate.

Here is the mortality graph provided by the National Cancer Institutes SEER (Surveillance, Epidemiology and End Results) program.



Though nobody wants to take the blame for the rise in breast cancer deaths in the '70s and '80s, lots of people want credit for the fall of breast cancer deaths that began in the '90s. Was it due to a reduction to the exposure of carcinogens, or to better treatment, or to earlier diagnosis?

The fall in breast cancer deaths does not seem to be due to cancer prevention. While the deaths from breast cancer were falling, there was an apparent rise in the incidence of breast cancer cases. Here is the SEER graph for the incidence in breast cancer in the U.S.



Since the breast cancer incidence rose while the deaths from breast cancer dropped, it seemed as though the benefit must have come from better treatment or earlier detection.

A major study, attempting to resolve this issue, was published in the New England Journal of Medicine, in 2005:

Effect of screening and adjuvant therapy on mortality from breast cancer.
Berry DA, Cronin KA, Plevritis SK, Fryback DG, Clarke L, Zelen M, Mandelblatt JS, Yakovlev AY, Habbema JD, Feuer EJ; Cancer Intervention and Surveillance Modeling Network (CISNET) Collaborators. N Engl J Med 353:1784-1792, 2005.

They concluded that that 28 to 65 percent of the sharp decrease in breast cancer
deaths from 1990 to 2000 was due to mammograms. The remainder of the improvement was was attributed improved breast cancer treatment.

The study did not take into account the great contribution of precancer treatment to the reduction of breast cancer deaths.

Let's review this SEER data, this time taking into account the diagnosis of DCIS (ductal carcinoma in situ) a precancer that precedes the development of invasive breast cancer. Here is the SEER data for the incidence of all breast cancer and of DCIS (the precancer for breast cancer).



In the past few decades, there has been a huge rise in the number of diagnosed cases of breast precancers. This is due largely to the use of mammography, which can detect lesions that cannot be found by palpation. When a precancer is detected and removed, the patient does not develop invasive cancer.

The total number of breast cancer cases includes cases of DCIS. If we subtract the number of breast precancer cases (DCIS) from the total number of breast cancer cases, we get the incidence of invasive breast cancer cases. Here is the SEER data.



The middle bars in the graph represent the incidence of invasive breast cancers. The graph shows that incidence of invasive breast cancers has actually dropped since the early '90s, as the diagnosis and treatment of DCIS has risen.

Much of the decrease in breast cancer mortality can be accounted for by the diagnosis and treatment of breast precancers. In fact the drop in breast cancer deaths follows the same slope, and has about the same magnitude, as the drop in invasive breast cancers that follows the increase in breast precancer treatments.

- © 2010 Jules Berman

---

Science is not a collection of facts. Science is what facts teach us; what we can learn about our universe, and ourselves, by deductive thinking. From observations of the night sky, made without the aid of telescopes, we can deduce that the universe is expanding, that the universe is not infinitely old, and why black holes exist. Without resorting to experimentation or mathematical analysis, we can deduce that gravity is a curvature in space-time, that the particles that compose light have no mass, that there is a theoretical limit to the number of different elements in the universe, and that the earth is billions of years old. Likewise, simple observations on animals tell us much about the migration of continents, the evolutionary relationships among classes of animals, why the nuclei of cells contain our genetic material, why certain animals are long-lived, why the gestation period of humans is 9 months, and why some diseases are rare and other diseases are common. In “Armchair Science”, the reader is confronted with 129 scientific mysteries, in cosmology, particle physics, chemistry, biology, and medicine. Beginning with simple observations, step-by-step analyses guide the reader toward solutions that are sometimes startling, and always entertaining. “Armchair Science” is written for general readers who are curious about science, and who want to sharpen their deductive skills.

Melanoma and the precancer time machine

In an earlier post, I explained the precancer time machine phenomenon. Basically, when you successfully treat precancers, you don't see an immediate drop in the incidence of invasive cancers; you see a drop in invasive cancers at some point in the future, corresponding to the time at which the treated precancers would have developed into invasive cancers.

In the earlier post, I demonstrated that the precancer time machine seemed to apply in the case of dcis and invasive breast cancer.

In today's post, I've used the latest SEER (The U.S. National Cancer Institute's Surveillance Epidemiology and End Results) cancer data to show that there seems to be the same phenomenon going on for melanoma precancers.

The topic of treating melanoma precancers has been somewhat controversial. It would seem to be a no-brainer that we can reduce the incidence of invasive melanomas by treating melanoma precancers (dysplastic nevi and in situ melanomas). Unfortunately, there is no epidemilogiic evidence to support this assertion. Basically, the incidence of invasive melanoma seems to be rising every year, despite our best efforts to stem the tide (through the use of sunscreens, avoiding exposure to strong sunlight, and treating precancers).

The latest SEER data (which covers cancer cases from 1973 to 2007) seems to offer some hope that conditions might be improving.

Here's the graph of invasive melanome incidence in the U.S. SEER population.



The tallest bars (blue) are the crude numbers of occurrences of invasive malignant melanoma. The middle bars (maroon) are the occurrences of invasive melanoma expressed as a proportion of the total number of SEER cases. The bottom bars (white), are the occurrences of melanoma expressed as a proprotion of the total population of the U.S. in the perspective years.

Here are the numbers:

       crude   of SEER  of U.S. Pop
1973   001062   001916   000501
1974   001305   001938   000610
1975   001559   002116   000721
1976   001601   002116   000734
1977   001791   002337   000813
1978   001829   002347   000821
1979   001973   002460   000876
1980   002190   002645   000963
1981   002298   002690   001001
1982   002352   002714   001015
1983   002350   002617   001005
1984   002462   002638   001043
1985   002795   002864   001174
1986   002947   002942   001227
1987   003050   002879   001258
1988   002948   002743   001205
1989   003194   002896   001294
1990   003272   002816   001311
1991   003518   002853   001395
1992   003569   002786   001399
1993   003611   002860   001400
1994   003904   003097   001499
1995   004189   003283   001594
1996   004438   003641   001673
1997   004627   003668   001728
1998   004739   003663   001753
1999   004893   003704   001794
2000   005105   003832   001814
2001   005380   003911   001886
2002   005377   003857   001867
2003   005514   003993   001898
2004   005859   004062   001998
2005   006451   004431   002180
2006   006431   004335   002152
2007   006325   004172   002097

In the last two years studied (2006, 2007), the incidence of invasive malignant melanoma has dropped. Is this just a fluke, or does it indicate a real trend? There's no way to be sure, but inspection of the graph would indicate that it's the first time since 1973 when incidence has dropped two years running.

What about the corresponding incidence of in situ melanoma (the non-invasive precursor for invasive melanoma)?

Here's the graph for in situ melanoma.


Here are the numbers.

       crude   of SEER  of U.S. Pop
1973   000035   000063   000016
1974   000059   000087   000027
1975   000081   000109   000037
1976   000096   000126   000044
1977   000155   000202   000070
1978   000177   000227   000079
1979   000177   000220   000078
1980   000263   000317   000115
1981   000276   000323   000120
1982   000326   000376   000140
1983   000384   000427   000164
1984   000466   000499   000197
1985   000638   000653   000268
1986   000723   000721   000301
1987   000782   000738   000322
1988   000824   000766   000337
1989   000976   000885   000395
1990   001127   000970   000451
1991   001192   000966   000472
1992   001373   001072   000538
1993   001375   001089   000533
1994   001599   001268   000614
1995   001920   001504   000730
1996   002091   001715   000788
1997   002258   001790   000843
1998   002533   001957   000937
1999   002765   002093   001013
2000   003202   002404   001137
2001   003508   002550   001230
2002   003656   002622   001269
2003   003429   002483   001180
2004   003604   002499   001229
2005   004060   002788   001372
2006   004048   002728   001354
2007   004291   002831   001422

The incidence of in situ melanoma keeps going up and up. That's as it should be. When we successfully cure more and more in situ melanomas, we reduce the incidence of invasive melanomas.

The lag between the rise in incidence of the in situ lesions and the drop in incidence of the invasive lesions is due to the precancer time machine phenomenon.

Can we be sure? Not yet. Hopefully, over the next five years or so, the data will become a little more convincing.

- © 2010 Jules Berman

key words: precancer, precancerous, skin cancer, dysplastic nevi, dysplastic nevus, dysplastic naevus, dysplastic naevi, cancer mortality, cancer prevention, carcinogenesis

---

In June, 2014, my book, entitled Rare Diseases and Orphan Drugs: Keys to Understanding and Treating the Common Diseases was published by Elsevier. The book builds the argument that our best chance of curing the common diseases will come from studying and curing the rare diseases.

I urge you to read more about my book. There's a generous preview of the book at the Google Books site. If you like the book, please request your librarian to purchase a copy of this book for your library or reading room.

Precancer time machine

In the previous post , we discussed breast precancer. We saw that as mammography picked up earlier and earlier lesions (precancers and early breast cancers), deaths from breast cancer dropped, along with the incidence of invasive breast cancer.


In this graph, which covers the years 1975 to 2007, the top line of bars (blue) represent the incidence of breast cancers (including invasive and non-invasice lesions). The next lower line of bars (maroon) is the incidence of the invasive breast cancers (the kind that account for breast cancer deaths), and the bottom line of bars represents the rate of precancers (ductal carcinoma in situ) collected by SEER.

As you recall from the previous blog , the big drop in cancer death rates did not occur until about 1990, well after there was a rise in the number of diagosed breast precancers.

Why didn't the precancers diagnosed in the 1980s produce an immediate drop in the rate of breast cancer deaths or in the incidence of invasive cancers?

Precancer treatment works like a time machine. When you cure a precancer today, you don't see a reduction in the number of cancers that would arise that same day. You see a reduction in the number of cancers that will arise in some future date (if the precancer had been allowed to develop into a cancer, over time).

If a precancer would ordinarily require 5 years to develop invasive features (i.e., become a cancer), and you diagnose and treat the precancer in 2010, then you will eliminate a cancer that would have occurred in 2015. This explains the delay in the decrease in cancer mortality that you can always expect to see with successful precancer treatment initiatives.

- © 2010 Jules Berman

key words: precancer, precancerous, dcis, ductal carcinoma in situ, breast cancer, breast cancer mortality, cancer prevention, carcinogenesis

---

About my book, Precancer: The Beginning and the End of Cancer. Nearly every type of cancer passes through a precancer phase, during which it cannot metastasize or invade other tissues. While medicine is not always successful in treating or curing advanced stages of cancers, recent advances in our understanding of carcinogenesis have helped us to develop strategies to prevent, diagnose, and treat many cancers at the precancer stage. Research in this field is escalating rapidly as the evidence increasingly shows that the number of annual cancer deaths could be drastically reduced through the effective treatment and cure of precancer lesions. This book begins by explaining why it has been so difficult to cure cancers, followed by a review of precancer biology, with descriptions of the most common precancer lesions. The final chapters provide practical socio-political and medical goals for precancer treatment, including discussions of the economics and politics of treating precancers.

I urge you to read more about this important topic. Google Books has provided a generous preview of this book.

Treating breast precancers saves lives

Breast cancer deaths rose through the '70s and '80s, but declined in the '90s. For nearly the past 20 years, American women have had about a 2% annual drop in the breast cancer death rate.

Here is the mortality graph provided by the U.S. National Cancer Institutes SEER (Surveillance, Epidemiology and End Results) program.



Though nobody wants to take the blame for the rise in breast cancer deaths in the '70s and '80s, lots of people want credit for the fall of breast cancer deaths that began in the '90s. Was it due to a reduction to the exposure of carcinogens, or to better treatment, or to earlier diagnosis?

The fall in breast cancer deaths does not seem to be due to cancer prevention. While the deaths from breast cancer were falling, there was an apparent rise in the incidence of breast cancer cases. Here is the SEER graph for the incidence in breast cancer in the U.S.



Since the breast cancer incidence rose while the deaths from breast cancer dropped, it seemed as though the benefit must have come from better treatment or earlier detection.

A major study, attempting to resolve this issue, was published in the New England Journal of Medicine, in 2005:

Berry DA, Cronin KA, Plevritis SK, Fryback DG, Clarke L, Zelen M, Mandelblatt JS, Yakovlev AY, Habbema JD, Feuer EJ. Effect of screening and adjuvant therapy on mortality from breast cancer. Cancer Intervention and Surveillance Modeling Network (CISNET) Collaborators. N Engl J Med 353:1784-1792, 2005.

They concluded that that 28 to 65 percent of the sharp decrease in breast cancer deaths from 1990 to 2000 was due to mammograms. The remainder of the improvement was was attributed improved breast cancer treatment.

The study did not take into account the great contribution of precancer treatment to the reduction of breast cancer deaths.

Let's review this SEER data, this time taking into account the diagnosis of DCIS (ductal carcinoma in situ) a precancer that precedes the development of invasive breast cancer. Here is the SEER data for the incidence of all breast cancer and of DCIS (the precancer for breast cancer).



In the past few decades, there has been a huge rise in the number of diagnosed cases of breast precancers. This is due largely to the use of mammography, which can detect lesions that cannot be found by palpation. When a precancer is detected and removed, the patient does not develop invasive cancer.

The total number of breast cancer cases includes cases of DCIS. If we subtract the number of breast precancer cases (DCIS) from the total number of breast cancer cases, we get the incidence of invasive breast cancer cases. Here is the SEER data.



In this graph, which covers the years 1975 to 2007, the top line of bars (blue) represent the incidence of breast cancers (including invasive and non-invasice lesions). The next lower line of bars (maroon) is the incidence of the invasive breast cancers (the kind that account for breast cancer deaths), and the bottom line of bars represents the rate of DCIS.

Look carefully at the middle bars (maroon), representing the incidence of invasive breast cancers. The graph shows that incidence of invasive breast cancers has actually dropped since the early '90s, as the diagnosis and treatment of DCIS has risen.

Much of the decrease in breast cancer mortality can be accounted for by the diagnosis and treatment of breast precancers. In fact the drop in breast cancer deaths follows the same slope, and has about the same magnitude, as the drop in invasive breast cancers that follows the increase in breast precancer treatments.

- © 2010 Jules Berman tags: cancer prevention, cancer treatment, early treatment, precancer, precancer treatment, preneoplasia, preneoplastic

---

About my book, Precancer: The Beginning and the End of Cancer. Nearly every type of cancer passes through a precancer phase, during which it cannot metastasize or invade other tissues. While medicine is not always successful in treating or curing advanced stages of cancers, recent advances in our understanding of carcinogenesis have helped us to develop strategies to prevent, diagnose, and treat many cancers at the precancer stage. Research in this field is escalating rapidly as the evidence increasingly shows that the number of annual cancer deaths could be drastically reduced through the effective treatment and cure of precancer lesions. This book begins by explaining why it has been so difficult to cure cancers, followed by a review of precancer biology, with descriptions of the most common precancer lesions. The final chapters provide practical socio-political and medical goals for precancer treatment, including discussions of the economics and politics of treating precancers.

I urge you to read more about this important topic. Google Books has provided a generous preview of this book.