Looking Ahead on Breast Cancer Screening
My plan is to move on after this post – too much is happening in medicine to dwell on the mammography issue longer, or at least for the time being.
So I’ll close on the 2009 screening controversy with a few comments and considerations for the future.
Breast cancer, along with lymphoma and a few other tumors, is one of the few malignancies that oncologists can treat effectively in the majority of cases – well enough that most women with the disease now live for an essentially normal lifespan. About the risks and costs of breast cancer screening, I think they’re exaggerated and misrepresented in the recent news.
1. The Task Force analyzed data that are decades old;
2. The updated recommendations don’t apply to digital mammography (a fact rarely mentioned in the press coverage);
3. Radiologists vary in training and skill.
My conclusion is that rather than ditching a life-saving procedure that’s imperfect, we should make sure that all doctors and radiology facilities are up to snuff.
On the reputed risks of mammography, harms and costs stemming false positive test results –
The risks of mammography should be minimal if the FDA does its job regulating the procedure. Among women in their forties and fifties, the number of false positives in Category I (as outlined in my proposed classification) can be reduced by digital technology supplemented with sonograms, an inexpensive and safe procedure.
Clerical-type errors shouldn’t happen, as in all of healthcare. Put simply, the system needs be scrupulous.
False positives due to misunderstanding of results, as in Category 2, can be resolved by better education and more effective communication.
Regarding the costs of follow-up testing by sonograms, MRIs, and biopsies – the medical risks and financial costs can be minimized through more careful, besides current, evaluation of each method. Just this month, an article in the Annals of Internal Medicine described the value of core needle biopsy (by any of several methods) in evaluating breast lesions. This technology, in widespread use over the ten years, renders open biopsy – a procedure done in an operating room – obsolete; there’s no reason to consider operating room costs in assessing breast biopsies in 2010.
As for the risk of over-treatment, I think doctors and patients have a lot learn and discuss, carefully. My take on the news of the past season is that somehow there’s been a blurring of facts for different cancer types.
For decades, oncologists including me have recommended a “watchful waiting” approach for some elderly men who have prostate cancer. This sort of treatment, while often appropriate for a 75 or 85-year old man with a small prostate tumor, is irrelevant to the decisions facing a 45 year old woman with breast cancer, another disease entirely.
Going back to my definition of a false positive in mammography screening –
We need to distinguish between errors in the measurement (cancer or not) and errors in decisions that we – patients and doctors – make after upon detecting a premalignant or early-stage malignancy in a woman’s breast.
A finding of either DCIS or LCIS upon biopsy does not constitute a false positive result. Rather, it’s good medicine to identify these conditions, especially for a middle-aged woman who anticipates a meaningful half-life ahead. What goes wrong after the diagnosis, such as a rushed or ill-informed decision to treat only subtle pathology, is not a mistake from mammography.
Errors in over-treating small tumors, and all the physical and financial costs associated, should be attributed instead to a lack of knowledge regarding DCIS and LCIS. Our understanding of these conditions – the molecular and cellular pathology, the course over time if left untreated, and the effects of medication, surgery and other therapies – lags far behind what we know about most forms of breast cancer.
What I hope we can learn, through clinical trials over the next decade, is how best to treat low-grade conditions such as DCIS and LCIS. That way, the costs of over-treating those will not, come 2020, cloud what should be straightforward decisions on the diagnosis and treatment of breast cancer in relatively young women.