Study: Survival and mutation status in breast cancer patients under age 40

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This study is about: 

Whether having a BRCA mutation affects survival outcomes for breast cancer patients under age 40.

Why is this study important?

Only 5% of breast cancers occur in women under age 40, yet a significant number of deaths occur in this age group. Women diagnosed under age 40 or also more likely to test positive for a BRCA mutation compared to women who develop breast cancer later in life. Previous studies have reported conflicting outcomes regarding the survival of young breast cancer patients with a BRCA mutation compared to those who test negative for a mutation. This study is important because it shows no difference in survival between the two groups. It is also important because its scope and size underscore the accuracy of its findings.

Study findings: 

POSH (Prospective Outcomes in Sporadic versus Hereditary) breast cancer is an ongoing study in the United Kingdom. It is the largest prospective study on outcomes in young breast cancer patients with and without a BRCA mutation. Researchers evaluated the outcomes (survival) of 2,733 younger women diagnosed with breast cancer; 338 (12%) were BRCA-positive. Patients were identified within the first 12 months of diagnosis and followed-up at 6 months, 12 months, and then yearly.  The study found that having a BRCA mutation did not impact young breast cancer patients’ survival, and that young BRCA-positive patients who develop triple-negative breast cancer had a survival advantage during the first few years after diagnosis compared to non-carriers. Lead researcher Diana M. Eccles, MD, of the University of Southampton and University Hospital Southampton NHS Foundation Trust, stated, “…our findings suggest that younger women with breast cancer who have a BRCA mutation have similar survival to women who do not carry a mutation after receiving treatment.”

What does this mean for me?

If you are a young woman with a BRCA mutation who develops breast cancer, this study confirms that your survival outcome is similar to young breast cancer patients without BRCA mutations. Interestingly, this study also showed that if you are a BRCA mutation carrier with triple-negative breast cancer, you have a survival advantage during the first 2 years after diagnosis compared to patients who are non-carriers.  

This article is relevant for:

Young breast cancer patients

This article is also relevant for:

Triple negative breast cancer


People with a genetic mutation linked to cancer risk

Breast cancer survivors

Women under 45

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Questions to Ask Your Doctor

  • What are my treatment options if I have an inherited mutation?
  • Are there any treatment clinical trials enrolling people with an inherited mutation? 
  • Should I have genetic testing? 


Study background:

POSH (Prospective Outcomes in Sporadic versus Hereditary) breast cancer is a large, prospective study that recruited female patients in 127 hospitals in the United Kingdom from 2000 to 2008. Patients were ages 18 to 40 when first diagnosed with invasive breast cancer. Long-term follow up is ongoing.

Nearly 90% of patients received chemotherapy. Half had breast-conserving surgery and half had a mastectomy. The researchers examined detailed clinical follow-up information, including date and site of disease recurrence, at 6 months, 12 months, and then annually.  

Researchers of this study wanted to know:

What was the overall survival, from initial diagnosis to death from any cause, in young, BRCA-positive women compared to young, BRCA-negative women. It also assessed distant disease-free survival or the time from initial diagnosis to first distant disease.

Population(s) looked at in the study:

Among the 2,733 patients in the POSH study:

  • 338 (12%) carried a BRCA1 or BRCA2 mutation
  • 558 women (20%) had triple-negative breast cancer (TNBC)
    • BRCA mutations were identified in 136 (24%) of TNBC patients

Study findings: 

At an average follow-up of 8.2 years, 678 (25%) of the patients had died. Among these patients, 651 (96%) of 678 deaths were due to breast cancer. Statistical analysis showed no significant difference throughout the study in overall survival (OS) among patients with BRCA-positive breast cancer compared with those with BRCA-negative disease. The 2-year OS rate was 97.0% vs 96.6%, the 5-year OS rate was 83.8% vs 85.0%, and the 10-year OS rate was 73.4% vs 70.1%, respectively.

Researchers also analyzed a specific subgroup: women with BRCA mutations who had triple-negative breast cancer. This group had an improved 2-year OS rate of 95% compared to 91% for BRCA-negative patients; however, this survival advantage was not observed at the 5-year or 10-year follow-up.


Since study participation was restricted to women age 40 or younger, these results may not translate to BRCA mutation carriers who are older when diagnosed. It’s also important to note that during the study recruitment period (between 2000 and 2008), BRCA testing and risk-reducing surgery were not routine for early-stage breast cancer. In addition, breast cancer treatment recommendations in the U.K. have also changed over the course of recruitment, which may have affected the survival rates. The study was conducted prior to availability of panel testing, so the number of participants with mutations outside of BRCA1 and BRCA2 is unknown. 

Media Coverage

After this study was published in Lancet Oncology last month, a number of related media articles began with sensationalized headlines, including “A Gene That ‘Causes Cancer’ Probably Doesn’t Increase Your Chances of Dying from Cancer” and “The ‘Deadly Breast Cancer Gene’ Is a Myth, Lancet Study Confirms.” Understandably, these headlines created quite a social media stir. FORCE covered the uproar in two recent Headline Hype blog posts


Understanding survival outcomes in young BRCA carriers with breast cancer is important because these patients have increased risk of also developing ovarian cancer, contralateral (in the other breast) breast cancer, or a new primary cancer in the same breast. These risks determine treatment, and knowing that young BRCA1 or BRCA2 mutation carriers do not have different survival outcomes than non-carriers can help with patient decisions on treatment and risk reduction.

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Posted 02/15/18

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