By David Liu

A new study in the Dec 2011 issue of Cancer Epidemiology, Biomarkers & Prevention suggests that mammograpgy screening of women may reduce the risk of death from breast cancer.

The study led by Suzie J. Otto and colleagues from University Medical Center in Rotterdam, The Netherlands found only 5.3 percent of women who were screened were diagnosed with stage IV breast cancer while among women who did not receive mammogram screenings, the rate was 29.5 percent.

Compared to those who did not have mammogram screenings, women who did in three age groups, 50 to 69, 50 to 75 and 70 to 75  were 39%, 48% and 84% less likely to die from breast cancer, respectively.

The researchers concluded "The study provides evidence for a beneficial effect of early detection by mammography screening in reducing the risk of breast cancer death among women invited to and who attended the screening."

This is not the first study to demonstrate that "mammography screening increases the rate of breast cancer survival".

However, a health observer reminds readers that the apparent benefits are derived not necessarily from mammography screenings nor treatments.  He says studies of this sort did not consider one important factor - that is, timing of diagnosis.  The benefits may not be really benefits, but some confusion from the calculation of the 5-year survival rates.

He gives an assumptious example to explain why.

Assume that a woman is destined to have a clinically significant breast tumor or breast cancer at age 45.  Without mammogram screenings, the tumor can only be diagnosed after symptoms of the tumor promote doctors to examine the woman for breast cancer.  Diagnosed at this time, the tumor is often more likely to be more advanced.  We further assume that she subjects herself to the standard breast cancer treatments after diagnosis and she lives 3 years postdiagnosis.  That is, she dies at 48 years old.  In this case, she is not a survivor.

Mammogram screenings allow breast cancer tumors to be diagnosed in very early stages.   It is likely that this woman if subjecting herself to the mammogram screening at age 40 may be diagnosed with breast cancer at 40.   Doctors often immediately give patients standard breast cancer treatments.  Assume the woman dies at 48.  In this case, she lives 8 years postdiagnosis.  Doctors would say that mammogram screenings save her life because she lives more than 5 years postdiagnosis.

Readers need to know that in the latter case, even if there is no treatment used for the woman, she is a survivor already because her cancer found by mammogram screening at age 40 is supposed to become clinically significant at age 45 at which age her condition can be diagnosed by measures other than screenings. So even if she dies at the time of diagnosis in this case without receiving any treatment, she is a survivor.

The example suggests that the increased survival rates of breast cancer can be a function of the timing of diagnosis and it can have nothing to do with treatments.

Doctors often say early diagnosis leads to early treatment, which in turn leads to an extended survival.  But the fact is that the "increased survival rates" may not have anything to do with treatments.  It's all about the timing of diagnosis!

Often times, studies of mammogram screenings do not consider the consequences of the screening.  Few studies tell readers what happen to the breast cancer survivors after 5 years of survival.  Mammogram screenings per se can increase the risk of breast cancer, which is a fact.

Doctors consider mammogram screenings a measure to prevent breast cancer.  Statements of that sort are misleading.  Mammogram screenings do not prevent breast cancer.  It can only help find breast cancer in its very early stages.  

Breast cancer in many cases are preventable simply by modifying many environmental risk factors.  Some things that help reduce the risk include maintaining a healthy level of vitamin D, avoiding night shifts, reducing intake of meat, high fat, omega-6 fatty acids, alcohol and sugar, fried foods, and increasing intake of fruit and vegetables, omega-3 fatty acids, grain products, and drinking green tea among other things.