Background
Breast cancer is the most common invasive cancer diagnosed in females in Australia and is the leading cause of cancer death in this group
Mammography has been demonstrated to reduce morbidity and mortality from breast cancer
BreastScreen Australia is the national breast cancer screening program offering free mammography screening to asymptomatic women since 1991. A clear upper age limit has not been set for breast cancer screening in Australia; however, recruitment strategies are specifically targeted at women aged 50 – 69 years who are reminded to have a mammogram every two years via written invitations
Methods
An examination of recent national cancer data was undertaken to assess age specific breast cancer mortality rates and a literature and policy review was conducted to assess the legitimacy of rationale used to limit invitations for breast cancer screening to women younger than 70 years of age.
Results
There has been a slow decline in the number of women older than 69 years participating in the national BreastScreen program over the past decade, with only 11% of women in this age group participating in 2004–5
A comparison of death rates from female breast cancer in 2005 with BreastScreen participation rates in 2004–5
A comparison of death rates from female breast cancer in 2005 with BreastScreen participation rates in 2004–5. Data source: Ref
One reason given for targeting women 50–69 years for screening is that early detection in this age group offers women "a better chance of successful treatment and recovery" presumably, because of a higher likelihood of comorbid conditions, reduced treatment tolerance and shorter life expectancy in women above 69 years
Effectiveness
In the past, elderly women have been significantly underrepresented in the evidence base used to determine the effectiveness of mammography. Researchers used age limits in recruitment as cut off points to minimise potential problems caused by comorbid health conditions and the risk of loss to follow up from unexpected early death
A recent study with over 860,000 participants aged between 70–75 years has shown that breast cancer screening using mammography reduces deaths from the disease in women in this age group. This study also found that screening did not cause significant harm by exposing the older women to over-diagnosis and over-treatment
Life expectancy
The size of the older population in Australia is growing, with females representing an increasing proportion of the population. At age 70, the average life expectancy of a woman living in Australia is over 15 years
Comorbidity
The existence of comorbid conditions has been used as rationale to exclude women over 69 years in breast cancer screening invitations. The findings of the most recent Australian Bureau of Statistics
Research
Treatment
The ability of elderly women to endure cancer treatment has been raised in the breast screening debate. Yet, less invasive surgical procedures and better targeting of breast cancer treatments strengthen support for the involvement of older women in breast cancer screening programs
Cost
Resource limitation has also been given as a possible underlying reason for not encouraging routine screening older women. However, cost-effectiveness analyses suggest that breast cancer screening after the age of 65 years reduces mortality at reasonable costs in women who are without significant comorbidities and that it is likely to be worthwhile until a woman has an estimated life expectancy of between five and 10 years
Community views
In 1997, Glasziou highlighted the importance of involving target groups in screening decisions in order to develop "rational and acceptable policy" around breast cancer screening
The Australian community as a whole benefits from elderly members who are in good health and are given the opportunity to reach an average life expectancy at a minimum. Their contribution to childcare and other unpaid caring duties; financial, practical and emotional assistance to family members and friends, and voluntary work has been reported to add up to around 7% of the gross domestic product
Overseas not-for-profit community support organisations also advocate for organised breast cancer screening for the elderly. The American Cancer Society advises women to continue breast cancer screening as long as they are in good health and are suitable candidates for cancer treatment
Discussion
Detection of early stage breast cancers offers the potential for longer survival and enhanced quality of life for many women irrespective of age. There is a pressing need to assemble all relevant evidence, including community needs, with regard to breast cancer screening in the elderly and translate it into a cohesive policy.
We acknowledge that at policy level, making decisions around screening age is a complex process, but age alone should not be a criterion for discontinuing invitations to attend regular breast screening. Screening may not be suitable for all, as some women may have other health problems that would reduce the long-term benefit of screening or may choose not to screen for other reasons. For others, screening may provide some additional life years, that might otherwise be lost. Regardless of which position women take, the opportunity to weigh up the potential benefits and risks of mammography needs to be available to all if they so choose.
Decision-making aids, in conjunction with opportunities to discuss these decisions with their healthcare providers can assist women define their individual position around whether they wish to attend repeat screening. This information can be fed back to BreastScreen through an opt-off process, closing the loop on consumer involvement and improving public communication. Continuing the recall system, while providing realistic opportunities for women to examine benefit-harm tradeoffs would ensure that breast cancer screening remains equitable in all age groups and that beneficiaries can avail themselves of this service, fully informed of the consequences of their decisions.
Conclusion
With the growing number of older women in Australia, breast cancer will become an increasingly significant health concern, yet there is suboptimal surveillance of breast cancer in those aged over 69 years. Prompts to continue breast cancer screening are currently provided on the basis of chronological age alone. Continuing reminders after aged sixty nine and adopting a patient centred approach (which takes the form of an informed, shared, decision-making process between a woman and her medical practitioner) for individual decisions about screening is proposed.
Competing interests
The authors declare that they have no competing interests.
Authors' contributions
CS undertook the data analysis and literature and policy review, and was the main author of this paper; MR supervised the analysis and review and contributed to the development, drafting and editing of the paper; SC provided input and important comments on drafts of the manuscript.