Mammography

[deleted4401]

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http://www.nejm.org/doi/full/10.1056/NEJMoa1206809

Does someone more articulate than me want to explain the results of this? Sounds like mammograms don't work all that well, but do work somewhat. Their should be a greater decrease in late stage cancers because of screenings, but that isn't what the data shows. In fact, many of the cancers being found/treated are indolent and unlikely to harm the woman.

-S

 

[Palex80]

I think, it's just another study, which shows the typical problems of screening for cancer.
You are increasing the incidence (because of overdiagnosis) and may prevent early stage disease to get diagnosed as late stage disease, but you don't have much of a shift in clinical endpoints for the patient.

A bit like the whole prostate PSA-screening story, if you ask me.

There is very little evidence for screening alltogether. Even colonoscopy (which is actually more than screening, since you can prevent cancer by removing non-cancer polyps, which may eventually transform into cancers) doesn't really work, if you take a critical view at the published evidence.

 

[Gfunk6]

Could it be that the majority of women who do NOT get screened (minority, live in underserved areas, lower income, poor access to healthcare) are actually the ones who present with late stage breast cancer?

That being the case, we may be screening low-risk women which has a low yield but missing the women who may need screening the most.

I don't have easy access to this PDF, but was wondering if the authors brought up that point.

 

[medgator]

Could it be that the majority of women who do NOT get screened (minority, live in underserved areas, lower income, poor access to healthcare) are actually the ones who present with late stage breast cancer?

That being the case, we may be screening low-risk women which has a low yield but missing the women who may need screening the most.

I don't have easy access to this PDF, but was wondering if the authors brought up that point.

Yup. Seems to be another assault on screening, but I question whether the mortality endpoint alone is enough to justify stopping/curtailing screening. Metastasis-free survival, breast conservation etc. are all nuances to this issue.that were not examined by this study.

Global health experts love to bash the US healthcare system based on its outcomes, but at least in cancer, we are doing pretty well compared to our European counterparts.

 

[deleted4401]

I don't know the study, but of course the US would have a greater survival rate for prostate cancer compared to countries that don't screen.

You catch a Gleason 6, PSA 4 prostate cancer and he lives 25 years after treatment, versus a guy in Barcelona that has his cancer found 17 years later and dies of it 8 years later. One has a survival rate of 25 years, the other 8 years, yet they live the same amount. Sure, the Spaniard has more morbidity and experienced prostate cancer mortality, but it goes to show that survival is not the optimal way to compare international oncologic outcomes. I think we can all agree on that.

S

 

[medgator]

I don't know the study, but of course the US would have a greater survival rate for prostate cancer compared to countries that don't screen.

You catch a Gleason 6, PSA 4 prostate cancer and he lives 25 years after treatment, versus a guy in Barcelona that has his cancer found 17 years later and dies of it 8 years later. One has a survival rate of 25 years, the other 8 years, yet they live the same amount. Sure, the Spaniard has more morbidity and experienced prostate cancer mortality, but it goes to show that survival is not the optimal way to compare international oncologic outcomes. I think we can all agree on that.

S

Absolutely.... the question is, what is the optimal way to compare them? There are so many potential benefits and risks to treatment outside of that ever important OS variable, yet that's what the literature seems to gravitate to at the end of the day.

 

[Palex80]

Absolutely.... the question is, what is the optimal way to compare them? There are so many potential benefits and risks to treatment outside of that ever important OS variable, yet that's what the literature seems to gravitate to at the end of the day.

You could use cancer specific survival, but that would cause other biases...

 

[medgator]

New salvo in mammogram controversy


Most Breast Cancer Deaths Occur in Younger, Unscreened Women: Study

Mammograms should begin at age 40, researcher says

New breast cancer research reveals a significant death rate among women under 50 who forgo regular mammograms and casts doubt on recent screening guidelines from a U.S. panel of experts.

The findings support the merit of regular mammograms, especially for younger women, said study researcher Dr. Blake Cady, professor emeritus of surgery at Harvard Medical School and Massachusetts General Hospital in Boston.

"I would propose that women start screening at age 40," Cady said. Younger women tend to have faster-growing, more aggressive tumors, experts say.

For the new study, published online Sept. 9 in the journal Cancer, researchers evaluated more than 600 breast cancer deaths, looking back at mammography records and other details.

Seventy-one percent of the deaths occurred among unscreened women, most of them younger, Cady found. Half of all the breast cancer deaths occurred in women under age 50, while only 13 percent of the women who died of breast cancer were 70 and older.

For the study, Cady and his colleagues tracked invasive breast cancer cases from their diagnoses, between 1990 and 1999, until 2007. Patients were treated at Partners HealthCare hospitals in Boston. The researchers had access to mammography use, surgery and pathology reports, and dates of death.

Cady's team used a technique called "failure analysis," in which scientists look back to see what might have gone wrong. "It's the converse of a randomized trial, which starts at point A and follows people until the end of the study," Cady said. "We follow people who have died and go backward to their original diagnosis and find out the details."

Women were described as unscreened if they had never had a mammogram or it had been more than two years since their last mammogram.