This is not the first time I’ve addressed the highly emotional topic of mammography, both in general and in women from 40-49 years of age.
I found it disappointing that, despite strong evidence suggesting that screening mammography actually led to greater harm, especially in the 40-49 year age group, the groups that had financial ties to mammography pretty much ignored the data and stated that they were going to continue business as usually. This included the Komen Foundation, the American Cancer Society and numerous radiological associations in the United States.
If these groups essentially admitted that mammography had questionable value, they would be going back on everything they stood for. This groups made it their major purpose to make sure every single woman had access to and received her annual mammogram. To now turn around and say, “Ummm…we MAY have been wrong about that whole getting a mammogram thing…” would devastate these organizations and their resultant credibility.
So they all came up with their reasons why some of the most recent and well designed studies were wrong. Never once was there a discussion that the data may actually have been accurate. And, without screening mammography as “prevention,” what exactly do these groups have to offer? These groups are very weak on prevention, and saying that early detection by mammography is worthless pretty much leaves true prevention via lifestyle as the only answer.
You can see the dilemma.
For all the reasons they gave that mammography still has value, this particular study makes this position even more tenuous. Here are the details of this study:
- The study was done on 89 835 women, aged 40-59 in Canada were randomly assigned to either annual mammography or no mammography.
- Women aged 40-49 in the mammography arm also had annual breast exams, but those in the control group only had a single exam followed by whatever normal care they would receive.
- All women aged 50-59 in both groups received annual physical breast examinations.
This group of women were then followed for the extended period of 25 years to see how many actually died as a result of breast cancer. Here’s what they found:
- During the initial 5 years of the study, 666 invasive breast cancers were diagnosed in the mammography group and 524 in the controls.
- In this same 5 years, 180 women in the mammography group and 171 women in the control group died of breast cancer.
- The risk of dying of breast cancer was almost identical.
- After the full 25 years, 3250 women in the mammography group and 3133 in the control group were diagnosed with breast cancer.
- Overall, in 25 years, 500 in the mammography group and 505 controls died of breast cancer.
From this study, which was able to successfully address the limitations found in other studies not showing a benefit, there was no difference in those who received a mammography versus those who did not.
Ok. So it’s all equal. Let everyone make their money and keep everything running as it is. Everyone’s happy.
Everyone, that is, except for the 106 women who were over-diagnosed with breast cancers that were never going to cause any problems but were treated anyway. The proverbial “won’t you don’t know won’t hurt you.” Worse, this study only looked at invasive breast cancers (the scarier type) and NOT ductal carcinoma in situ (DCIS). DCIS accounts for 25% of the cancers detected by mammography. Had this study included the numbers of overdiagnosis associated with DCIS found on mammography, this 106 number would go up greatly. Just looking at the invasive breast cancer, there was an overdiagnosis for every 424 women screened. And, as mentioned, if DCIS was included, this number is likely to be much higher.
The conclusion of the authors says it all: “Our data show that annual mammography does not result in a reduction in breast cancer specific mortality for women aged 40-59 beyond that of physical examination alone or usual care in the community. The data suggest that the value of mammography screening should be reassessed.”
For a procedure that serves as the cornerstone for mainstream medicines’ “prevention” of cancer, this is a big hit. Sadly, I don’t think we will see any real changes occur in our lifetimes. There is just WAY too much money to be lost.