I hope this week’s headlines and editorials don’t add to the blurriness of the public’s perception of cancer screening – that people might begin to think it’s a bad thing all around. The details matter….screening if it’s done right can save lives and dollars. That’s because for most tumor types, treating advanced, metastatic disease is costlier than treatment of early-stage, curable tumors.
A seemingly slight adjustment in a statistic, for teaching purposes, can significantly change a test’s calculated value….
The new findings have no bearing on whether or not cancer screening is cost-effective or life-saving. What the study does suggest is that med school math requirements should be upped and rigorous, counter to the trend
My take is that periodic colonoscopy has the potential to halve the number of deaths from colon cancer in the general population…As to how colonoscopy relates to fecal blood testing as a screening method at the population level, and the optimal start and frequency of either test, those remain uncertain.
The latest issue of the Annals of Internal Medicine contains 2 noteworthy papers on cervical cancer screening. The first, a systematic review of studies commissioned by the USPSTF, looked at 3 methods for evaluating abnormalities in women over 30 years: 1. Conventional cytology (as in a Pap smear; the cervix is scraped and cells splayed […]
Days ago, the USPSTF issued a new draft for its recommendations on routine PSA measurements in asymptomatic men. The panel’s report is published in the Annals of Internal Medicine. The main findings are two: first, the absence of evidence that routine PSA testing prolongs men’s lives, and second, that PSA evaluation may, on balance, cause […]
A question central to today’s discussion – which does at least acknowledge the decline in breast cancer mortality – is the extent to which mammography is responsible for this trend, as opposed to other factors such as increased awareness about cancer, better cancer treatments and other variables.
What the authors tried to do was analyze trends in breast cancer mortality in relation to mammography’s availability in distinct regions of Denmark over several decades. Using Poisson regression, a form of statistical analysis, they looked for a correlation and found none. They concluded that they couldn’t detect a benefit of screening mammograms among Danish women who might benefit (see below).
Here’s what I think are the two most serious flaws in this observational study:
Am I pro- or con- colonoscopy for routine screening, you might wonder. Well, that depends.
Am I pro- or con- famous singers and other celebrities extolling the benefits of particular medical interventions? Well, that depends, too.
But I’m sure I prefer “Puff the Magic Dragon.” Also “Leaving on a Jet Plane” fills me with imperfect memories of 6th grade.
After a while my oncologist stepped out into the waiting area and guided me to the hall by her office. “The cells are low,” she said. “We’ll have to wait another week, that’s all.”
I knew she was right. But a week seemed like a lifetime to me then….
Why bother, you might ask – wouldn’t it be easier to drop the subject?
“Make it go away,” sang Sheryl Crow on her radiation sessions.
I’ll answer as might a physician and board-certified oncologist who happens to be a BC survivor in her 40s: we need establish how often false positives lead, in current practice, to additional procedures and inappropriate treatment…These numbers matter. They’re essential to the claim that the risks of breast cancer screening outweigh the benefits.
The risks of radiation from CT scanning will almost certainly add to the current confusion and concerns about the risks of breast cancer screening.
Mammography differs from CT scanning in several important ways:
1. Mammograms involve much less radiation exposure than CT scans.
2. Mammography is well-regulated by the Food and Drug Administration (FDA) and other agencies. The Mammography Quality Standards Act (MQSA) requires…
3. Women who undergo screening mammograms can control when and where they get this procedure. Screening mammograms are elective by nature..
“Well, well” says the convenience store clerk. “Back for another test?”
“I think the first one was defective. The plus sign looks more like a division symbol, so I remain unconvinced,” states Juno the pregnant teenager.
“Third test today, mama-bear,” notes the clerk.
…”There it is. The little pink plus sign is so unholy,” Juno responds.
She’s pregnant, clearly, and she knows she is.
(see clip from Juno the movie*)
Think of how a statistician might consider Juno’s predicament…
Three key issues have escaped the headlines: 1. The expert panel carried out a careful analysis using data that are, necessarily, old; 2. The recommendations don’t apply to digital mammography; 3. Mammograms are not all the same.
We need to set the bar higher for mammography…
But consider – if the expert panel’s numbers are off just a bit, by as little as one or two more lives saved per 1904 women screened, the insurers could make a profit!
By my calculation, if one additional woman at a cost of, say, $1 million, is saved among the screening group, the provider might break even. And if three women in the group are saved by the procedure, the decision gets easier…
Now, imagine the technology has advanced, ever so slightly, that another four or five women are saved among the screening lot.
How could anyone, even with a profit motive, elect not to screen those 2000 women?
Smack in the midst of October-is-breast-cancer-awareness-month, the Journal of the American Medical Association published a provocative article with a low-key title: “Rethinking Screening for Breast Cancer and Prostate Cancer.” The authors examined trends in screening, diagnosis and deaths from cancer over two decades, applied theoretical models to the data and found a seemingly disappointing result.
It turns out that standard cancer screening is imperfect.
The subject matters, especially to me. I’m a medical oncologist and a breast cancer survivor, spared seven years ago from a small, infiltrating ductal carcinoma by one radiologist, an expert physician who noted an abnormality on my first screening mammogram…