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:
Whereas the cancer advocacy group, American Cancer Society announced it as
Same content, different emphasis.
Breast Screening: The debates rages.
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“In April, the National Cancer Centre Singapore (NCCS) published a study begun in 1994 that had followed 28,000 women aged 50 to 64 for a decade. It reported that women of all the three major races here with a close family history of breast cancer were twice more likely to get it than a Western female. But those with no such family history were at only half the risk of a Western female.
That is because mammography leads to “overdiagnosis” in the lower-risk group who thus “would benefit less from it”, the NCCS said. Those in the high-risk group, however, should consult their doctors on its need.”
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The Straits Times published an article by Andy Ho on the suitability of breast cancer treatment for women included under the current guidelines. Evidence suggests that there is a subset of women with sufficiently low risk of breast cancer (hence low likelihood of benefits) such that they are more likely to be harmed as a consequence of the screening process (such as from further invasive procedure that poses a small but finite risk).
Further more, he touched on the contentious issue of cancers (including pre-invasive cancers) that are of such low malignant potential that they may not cause problems for the women in whom they are detected in their natural life span.
These arguments broadly parallels the evolution of our understanding of the natural history of cancers such as prostate cancer. Until these issue is clarified with further studies, my recommendations are to stick with the current national guidelines, ESPECIALLY more so if there is a significant family history.
See HERE for his complete write up.
Breast cancer is the most common cancer among women in Singapore. Of all cancers diagnosed among women in Singapore, almost 30% are breast cancers. More than 1400 women are diagnosed with breast cancer each year and more than 300 die as a result of breast cancer each year1. The risk of developing breast cancer increases with age. Early detection through regular screening mammograms saves lives.
1 Singapore Cancer Registry Interim Report 2005-2009.
BreastScreen Singapore (BSS) is the national breast cancer screening programme which encourages women aged 50 years and older to go for screening mammograms (breast X-ray) once every 2 years. The aim of this Programme is to detect breast cancer early, allowing for more effective treatment and a reduction in the mortality rate.
Women aged 40 to 49 years old who wish to participate in this programme, are advised to talk to their doctor about the benefits and limitations of mammograms for women in this age group so that they can make an informed choice about going for screening. 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).
Am I eligible to participate in BreastScreen Singapore?
40 to 49 years old
50 years and older
|Singaporean or permanent resident||
|Have not gone for mammogram for the last 12 months||
|Have not gone for mammogram for the last 24 months||
|Have no breast symptoms such as breast lumps or blood-stained nipple discharge||
|Have not been breastfeeding for the past 6 months||
How often should I go for a screening mammogram?
- For 40 to 49 years old – once every year (should you decide to go for screening)
- For 50 years and older – once every two years
How much does it cost?
- The usual cost of screening mammography at polyclinics is $100. However, the test is offered at a subsidised rate of $50 for Singaporean citizens and $75 for permanent residents (PRs) under BSS at the polyclinics.
Can I use Medisave to pay for my screening mammogram?
- You may use your Medisave account or the account of an immediate family member (excluding siblings) for your screening mammogram at all Medisave approved screening centres. All BSS screening centres are approved centres for use of Medisave.
- Under the scheme, up to $300 per Medisave account per year can be used for screening mammograms.
- For a complete list of Medisave approved screening centres, please visit MOH website http://www.moh.gov.sg/mohcorp/hcfinancing.aspx?id=26368.
Which screening centres are participating in BSS and where are they?
BSS is available at the following X-ray centres (please click on the individual centres for more details):
National Healthcare Group Diagnostics (NHGD)
- X-ray centre (Level 4, HPB building)
How do I make an appointment?
Please call the following healthcare providers for an appointment. A doctor’s referral is not required to make an appointment, although you may wish to consult your doctor about the benefits and limitations of mammograms if you are 40 to 49 years old so that you can make an informed choice about going for screening:
- NHGD: 6275 6443 (6-ASK-NHGD)
- SingHealth: 6536 6000
- Radiologic Clinic: 6533 2721
For more information about BreastScreen Singapore and breast health, please call 1800 333 3030.
What do I need to do on the day of my appointment?
- Do not use any body lotion, deodorant, perfume, powder or ointment on your underarms or breasts
- Wear a comfortable two-piece outfit as you will need to undress from the waist up
- Remove any jewellery from your body
If you are pregnant or suspect that you may be pregnant, you should inform the clinic immediately (before your mammogram).
What happens on the day of my mammography?
Click here to view more Frequently Asked Questions about breast cancer screening.