MBC Statistics, Revisited

BY Dian "CJ" Corneliussen-James


There has been a great deal of discussion on social media about Metastatic Breast Cancer statistics. It is extremely difficult to discuss the origin of these statistics within the context of a Facebook post, due to limited space. But METAvivor felt the issue deserved more in-depth discussion, since about where the stats come from members of the MBC community.

The short answer re: where MBC stats come from is…there is no short answer. And the numbers and data can be very difficult to find and follow.

First, there is definitely a dearth of statistics about metastatic breast cancer. Despite this, we can glean information from reporting that does exist. An NIH report from 1998 put the number of deaths from metastatic breast cancer at 20% to 40% of people who are diagnosed with BC. A far more recent report by the National Cancer Institute stated that 30% of people diagnosed with breast cancer are initially or eventually diagnosed with MBC.

The calculations are incredibly complicated. One cannot compare the number dying in a given year against the number being diagnosed in the same year because very few are diagnosed and die in the same year. Moreover, while the average length of survival is 2-3 years, some patients live 20 and more years with a metastasis, while others are not diagnosed until 20 years after their primary cancer, and then go on to live anywhere from one to 20 or more years. Given this, what percentage of patients are really metastasizing and dying? This article from the Journal of the National Cancer Institute, while it does not strictly address the subject, does shed some light on the numerous complications that exist in trying to develop MBC statistics.

We have repeatedly heard that there are approximately 155,000 people living with metastatic disease. Where did this statistic come from? In 2006, Living Beyond Breast Cancer published a report called Silent Voices, which stated that “at any given time, a low estimate of 150,000, and a more reasonable estimate of 250,000 American, women are facing the ongoing challenges of living with metastatic disease.” (Read more about the report in our blog post.) For the next eight years or so, the 150,000 figure was used in the press and by breast cancer organizations. After repeated challenges by METAvivor as why people quoted the lower number instead of “more reasonable” high estimate of 250,000,” the number that was officially quoted crept up to 155,000. METAvivor has continued to argue in favor of using the higher estimate, but more importantly, we have disagreed with the logic that was used to come up with those numbers in the first place. If 40,000 – 41,000 Americans are dying annually, and 73,000 - 86,000 are being diagnosed with metastatic breast cancer every year (Silent Voices, page 8, paragraph 1), then we had a net annual gain of 33,000 to 45,000 MBC patients. So how, 11 years later, do we find ourselves numbering only 155,000 people living with MBC? We feel that this oft-quoted statistic may not be accurate, and needs to be revisited.

Finally, we want to discuss another important MBC statistic: the increase in the number of diagnoses among young women, aged 25 to 39. We are indeed meeting more and more young people with metastatic breast cancer. Our experience is substantiated by a report released in February 2013 in the Journal of Cancer Epidemiology, revealing the results of a study of younger women with MBC. Of more concern, it appears the recurrence is inversely proportional to the age at diagnosis, as indicated by this article in Oncology Nurse Advisor. So sadly, it the very youngest women who are being  hit hardest.

As an organization devoted to funding research for MBC patients, METAvivor is committed to finding statistics that accurately define the number of people living with MBC. Accurate statistics are essential so that we can gain a true understanding of the scale of the issue, educate people correctly about the disease, and advocate for increased funding for the critical research that will help extend and improve the quality of our lives.

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