Mortality rates for women with early breast cancer have fallen over the last two decades, and most patients who are diagnosed promptly will survive for at least five years, according to findings published in The BMJ. The risk of death within five years of diagnosis has declined by 66% since the 1990s.

“Our study is good news for the overwhelming majority of women diagnosed with early breast cancer today because their prognosis has improved so much,” Carolyn Taylor, DPhil, of the University of Oxford, said in a press release. “Their risk of dying from their breast cancer in the first five years after diagnosis is now 5% on average.”

Taylor and colleagues conducted an observational study using data from the U.K.’s National Cancer Registration and Analysis Service to examine long-term breast cancer mortality based on when women were diagnosed. The analysis included all 512,447 women with early invasive breast cancer in England registered between January 1993 and December 2015. Early invasive breast cancer was defined as disease detected only in the breast or the breast and axillary (armpit) lymph nodes with no evidence of metastasis. The women received either mastectomy or breast-conserving surgery such as a lumpectomy. Follow-up continued until December 2020.

Across all time periods, cancer-related mortality was highest during the first five years after diagnosis, decreasing gradually over every five-year period. The risk of dying within five years of a breast cancer diagnosis was 14% between 1993 and 1999, falling to 5% between 2010 and 2015.

For women who were diagnosed between 2010 and 2015, the breast cancer mortality risk varied greatly based on their age, tumor size, the number of lymph nodes involved, whether the cancer was estrogen receptor positive or negative and HER2 status. For example, the estimated five-year mortality risk for a woman diagnosed at age 60 with an estrogen receptor–positive, HER2-negative tumor smaller than 20 millimeters and no lymph node involvement would be 0.2%, according to the researchers.

During this period, the five-year mortality risk was less than 3% for nearly two thirds of the women, less than 5% for three quarters of them and less than 10% for 88% of them. However, nearly 5% of the women still had a 20% or higher risk.

“The prognosis for women with early invasive breast cancer has improved substantially since the 1990s,” wrote the researchers. “Most can expect to become long-term cancer survivors, although for a few the risk remains appreciable.”

While this observational study could not determine the causes of the decline in mortality, they suggested more effective treatment likely plays a role. “In the future, further research may be able to reduce the risk of dying from breast cancer even more,” Taylor predicted.

In an accompanying opinion piece, Taylor and two breast cancer survivors stressed the need for clear communication about prognosis and the factors that influence it.

“When I was diagnosed 20 years ago, I was not given a prognosis other than the fact that this is serious and we need to treat you quickly,” said patient advocate Mairead MacKenzie. “But I think good, clear communication about prognosis can make a vast difference to a patient’s quality of life and how they can cope with things.”

Click here to read the study in The BMJ.

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