News

Screen-detected breast cancers less likely to cause death


Evelyn Lewin


27/11/2018 11:43:48 AM

Breast cancers detected by screening mammography through BreastScreen Australia have better survival outcomes than those in women who have never screened.

The AIHW report found screen-detected breast cancers are less likely to cause death than never-screened breast cancers for all age groups.
The AIHW report found screen-detected breast cancers are less likely to cause death than never-screened breast cancers for all age groups.

A new report released by the Australian Institute of Health and Welfare (AIHW), Analysis of breast cancer outcomes and screening behaviour for BreastScreen Australia, found that screen-detected breast cancers are less likely to cause death than never-screened breast cancers for all age groups eligible for BreastScreen Australia.
 
For women aged 50–69, screen-detected breast cancers had a 69% lower risk of causing death than breast cancers diagnosed in women who had never screened.
 
Risk of death for screen-detected breast cancers was 55% lower for women aged 40–49, and 64% lower for women aged 70 and over.
 
Although it was not possible to know the stage of the breast cancers diagnosed in this study, tumour size (one of  three factors that determine stage, along with lymph node involvement and presence of distant metastases) was recorded for most breast cancers.
 
The study found that 55.3% of screen-detected breast cancers detected were small, compared with 27.6% of breast cancers diagnosed in women who had never screened.
 
Of the 73,440 breast cancers diagnosed in women aged 50–69 in 2002–12, 31,968 (44%) were screen-detected and 20,245 (28%) were diagnosed in women who had never screened.
 
The report noted these results indicate it is beneficial for a breast cancer to be detected through screening mammography, rather than due to breast cancer being symptomatic.
 
These findings align with the RACGP’s Guidelines for preventive activities in general practice (the Red Book), which states that, for asymptomatic, low-risk women, BreastScreen Australia recommends screening mammograms every two years for women aged 50–74.
 
While screening may save lives, the Red Book notes it is not without risks.
 
For every 2000 women invited for screening over 10 years, one will avoid dying of breast cancer and 10 healthy women, who would not have been diagnosed if there had not been screening, will be treated unnecessarily.
 
The AIHW report offered further analyses into screening behaviour.
 
It found that women who were regular participants in cervical screening were more likely to participate and become regular screeners in BreastScreen Australia.
 
The report also noted that participation in BreastScreen Australia is far lower for Aboriginal and Torres Strait Islander women, those who report speaking a language other than English at home, and in the most disadvantaged socioeconomic groups.
 
The report also highlighted its limitations. Of note, cancers in this project were restricted to invasive breast cancers, while inclusion of ductal carcinoma in-situ (DCIS) in future analyses would be of value.
 
Cancer outcomes and screening behaviour were also not explored for Aboriginal and Torres Strait Islander people, despite the fact that Aboriginal and Torres Strait Islander people have poorer outcomes and lower participation in BreastScreen Australia.
 
The new report is the second from an Australian-first project combining data from BreastScreen Australia, the National Cervical Screening Program and the National Bowel Cancer Screening Program, focusing on breast cancer outcomes and screening behaviour.



breast cancer breast screening BreastScreen australia



Login to comment