Breast Screening


Breast Screening: More Fuel for the debates.

Every few months see the publication of yet another article questioning if  doctors involved in breast cancer care are telling their patients the full picture with regards to the benefits, and the hazards of breast screening. While there is no doubt that breast screening saves SOME women’s lives, it is increasingly clear that these lives so saved comes at a price of over-diagnosis and over treatment of cancers that may not been and never would have been a danger to the women’s life.

However, there is currently no way to tell which patients diagnosed with breast cancer could safely forgo treatment, breast-cancer specialists say. “When you can tell me which cancers need to be treated and which don’t, then I will consider this argument” about overdiagnosis, says Clifford Hudis, chief of the Breast Cancer Medicine Service at Memorial Sloan-Kettering Cancer Center in New York City.

In 2009, the US. Preventive Services Task Force, a government-backed advisory panel, issued new guidelines that suggested women should start routine mammograms at age 50 rather than 40, in part because the tests have such high false positive rates and the benefits in lives saved did not outweigh the worry and anguish caused by the false positive results.

In the latest salvo from the “Responsible, Full-discolsure, Evidence-based Mammographic screening camp” (My term, quite a mouthful but saying Anti-mammographic screening would have been plain wrong), researchers from the United States examined the Effect of Three Decades of Screening Mammography on Breast-Cancer Incidence and concluded that:

“ …screening mammography has only marginally reduced the rate at which women present with advanced cancer. Although it is not certain which women have been affected, the imbalance suggests that there is substantial overdiagnosis, accounting for nearly a third of all newly diagnosed breast cancers, and that screening is having, at best, only a small effect on the rate of death from breast cancer.”

In Britain, an expert panel concluded that while mammography screening saves lives, “that screening comes with a cost: The review found that for every life saved, roughly three other women were over-diagnosed, meaning they were unnecessarily treated for a cancer that would never have threatened their lives.”

The expert panel was commissioned by Cancer Research UK and Britain’s department of health and analyzed evidence from 11 trials in Canada, Sweden, the UK and the US.

“It’s clear that screening saves lives,” said Harpal Kumar, chief executive of Cancer Research UK. “But some cancers will be treated that would never have caused any harm and unfortunately, we can’t yet tell which cancers are harmful and which are not.”

“Cancer charities and public health authorities have been misleading women for the past two decades by giving too rosy a picture of the benefits,” said Karsten Jorgensen, a researcher at the Nordic Cochrane Centre in Copenhagen who has previously published papers on overdiagnosis.

“It’s important they have at least acknowledged screening causes substantial harms,” he said, adding that countries should now re-evaluate their own breast cancer programs.

I recognize that the controversy in breast cancer screening would always be an emotive issue for women everywhere. In Singapore, screening continued under the Health Promotion Board’s BreastScreen Singapore programme which recommends:

“ If you are 40-49 and decide to get screened, you should go for a screening mammogram once a year until you are 50 (after which screening mammograms are recommended every 2 years).”

 More efforts need to be made to inform patients and doctors about the benefits AND risks of screening.

IMHO, what we need is a better tool for predicting which women have substantial risks of life-limiting breast cancer and target screening to this enriched group of high-risks patients. This will go some way towards limiting the main detractors of over-diagnosis and over-screening.

Illustrating the schism between the opponents and proponents of breast screening, the popular press exemplified by Reuters announced the British expert group findings as:

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