A study looking at the diagnosis and treatment of breast cancer in women aged 18 to 40 and women with inherited breast cancer (POSH)

Cancer type:

Breast cancer





This study looked at the treatment outcomes for women diagnosed with breast cancer under the age of 40. The study was for women who had inherited a gene that increases the risk of breast cancer. The full title is Prospective study of Outcomes in Sporadic versus Hereditary Breast Cancer. The study was supported by Cancer Research UK.

More about this trial

Breast cancer is most commonly diagnosed in post menopausal Open a glossary item women. But about 4% of all breast cancers treated in the UK are diagnosed in women under 40.

The aim of this study was to look at all the features of breast cancer diagnosed in younger women such as oestrogen receptor status and HER2 status. And then find out whether genetic background Open a glossary item affects the outcome of treatment.

In the future, the study will also look at women diagnosed with breast cancer who had a change to the BRCA1 or BRCA2 gene, to see whether such genetic changes affect treatment outcome.

Summary of results

The researchers found that overall more than 8 out of 10 women in the study (82%) lived for at least 5 years after being diagnosed with breast cancer.

The study recruited more than 3,000 women. By looking at their medical notes 6 and 12 months after diagnosis and then yearly, the researchers were able to analyse results for 2,956 women diagnosed with breast cancer up to the age of 40. The average age of the women was 36.

In 2013, the researchers published some results showing the effect of oestrogen receptor status. They looked at how many of the women lived for at least 5 years after diagnosis and found it was

  • 85% of women who had oestrogen receptor positive breast cancer
  • 76% of women who had oestrogen receptor negative breast cancer

But when they looked at the number of women who lived for at least 8 years, they found this was about the same for both groups at 68%.

Further analysis of the data gathered in the POSH study will provide important information about the longer term outcomes for women diagnosed with breast cancer at an early age. So far, about a quarter of the women in the study (26%) have had tests to see if they have change to the BRCA1 or BRCA2 gene. More women are now being tested and analysis of these results will show the influences that genetic changes have on response to treatment.

We have based this summary on information from the team who ran the study. The information they sent us has been reviewed by independent specialists (peer reviewed Open a glossary item) and published in a medical journal. The figures we quote above were provided by the study team. We have not analysed the data ourselves.

Recruitment start:

Recruitment end:

How to join a clinical trial

Please note: In order to join a trial you will need to discuss it with your doctor, unless otherwise specified.

Please note - unless we state otherwise in the summary, you need to talk to your doctor about joining a trial.

Chief Investigator

Professor Diana Eccles

Supported by

Cancer Research UK
NIHR Clinical Research Network: Cancer
Wessex Cancer Trust

Other information

This is Cancer Research UK trial number CRUK/07/079.

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Freephone 0808 800 4040

Last review date

CRUK internal database number:

Oracle 202

Please note - unless we state otherwise in the summary, you need to talk to your doctor about joining a trial.

Harriet wanted to try new treatments

Picture of Harriet

“I was keen to go on a clinical trial. I wanted to try new cancer treatments and hopefully help future generations.”

Last reviewed:

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