Most women diagnosed with early breast cancer ‘will survive long-term’, study finds

Reassurance for patients as death rate from breast cancer has fallen substantially since the 1990s

'Our study is good news for the great majority of women diagnosed with early breast cancer today because their prognosis has improved so much,' the authors of the study said.
'Our study is good news for the great majority of women diagnosed with early breast cancer today because their prognosis has improved so much,' the authors of the study said.

Most women diagnosed with early breast cancer can expect to become long-term cancer survivors, new research indicates.

The risk of death from breast cancer has fallen substantially since the 1990s, providing reassurance for patients and doctors, according to the large-scale study of English women with the disease.

The average risk of dying from breast cancer in the five years after a diagnosis has fallen from 14 per cent to 5 per cent since the 1990s, the study published in The BMJ shows. For those diagnosed during 2010-15, more than six in 10 women had a five-year risk of 3 per cent or less.

The researchers say their findings can help identify those for whom the risk of dying from breast cancer remains substantial.

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Worldwide, more than 2 million women receive a diagnosis of early breast cancer each year. While the risk of dying from breast cancer in these women has decreased over past decades, the extent of this decrease was previously unknown. Neither was it known whether this decrease applied to groups of women with certain characteristics or whether it applied to all groups.

To address this uncertainty, researchers used data from 512,447 women registered in England with early breast cancer (ie, cancer confined to the breast and possibly the axillary lymph nodes) as their first cancer between 1993 and 2015, and who were treated initially with surgery.

The results show that the annual breast cancer mortality rate was highest during the five years after diagnosis and then declined.

Considering just the 156,338 women with a diagnosis during 2010-15, cumulative five-year breast cancer mortality risk varied substantially between women with different characteristics. It varied according to patient age, whether the cancer was detected by screening, whether it had certain receptors, and according to cancer size, grade and the number of lymph nodes involved.

It was less than 3 per cent for 62.8 per cent of women but more than 20 per cent for 4.6 per cent of women.

As the study was observational, the findings can’t determine the specific causes of the reductions in mortality. Other limitations included a lack of data on cancer recurrence, and the fact that the study focused on women who were initially treated with surgery.

However, the study provides a detailed and accurate picture of breast cancer mortality in a complete population of women with early breast cancer for up to 20 years.

The authors say their analyses “provide patients with early breast cancer, and the clinicians who treat them, with estimates of their likely prognosis based on up-to-date data.”

They add: “Our study is good news for the great majority of women diagnosed with early breast cancer today because their prognosis has improved so much. Most of them can expect to become long-term cancer survivors.”

Paul Cullen

Paul Cullen

Paul Cullen is a former heath editor of The Irish Times.