The number of people living with stage 4, metastatic breast cancer is unknown. A journalist or doctor might be surprised by this lack of information, as I was surprised a few years back. The NCI is working to fill this knowledge gap (see below). Yet there's not even a ballpark figure – give or take, say, 20,000 U.S. people – for the number of women and men who have this incurable condition.
Estimates exist. A range of 150,000 to 250,000, for instance, appears in connection with a recent educational campaign and photo-essay, Story Half Told, on metastatic breast cancer put forth by Pfizer, the pharmaceutical company. Pfizer includes this estimate in a related infographic, in a statement of need, and in a public document, The Value of Medicine in Metastatic Breast Cancer.
The source listed in these Pfizer documents is a page from the website AdvancedBC.org. From that post, of 2006, it's evident that Musa Meyer, an author and long-time advocate for people affected by advanced breast cancer, and Susan Grober, PhD, for Living Beyond Breast Cancer, were asking these questions ten years ago.
The Metastatic Breast Cancer Network, an all-volunteer advocacy group that promotes the needs of people affected by stage 4 breast cancer, offers an estimate of "over 155,555" – along with caveats about uncertainty – here on its website.
This lack of data is frustrating, if not infuriating, to women and men living with stage 4 disease. From a psychological standpoint, as with any group with unmet needs, it's damaging. Many affected say they want to be recognized, to "count," to be acknowledged – especially in the context of what some say is disproportionate attention given to early-stage breast cancer.
Recently I met Phyllis Groskin of Lexington, Massachusetts. At 63, she's been living with metastatic breast cancer since 2008. Her initial diagnosis was DCIS (stage 0) breast cancer, at age 43; for over a decade, until her recurrence, she thought she was disease-free.
"In this era, to not know how many people are living with metastatic disease is unconscionable," Groz said. On the day we spoke, in Washington DC, she'd met with staff of the two U.S. senators from her state, Elizabeth Warren and Edward Markey, to petition increased NIH funding of research for metastatic breast cancer. To explain the need for that research, we need numbers, she emphasized. "Having that data is crucial."
From a scientific perspective, these statistics matter because they influence research priorities and drug development. From a clinical viewpoint, they're needed to guide physicians about prognosis and treatment recommendations. As things stand, doctors can't say what proportion with early-stage disease will recur (a controversial statistic, to be considered separately). They don't know, on average, or based on the breast cancer subtype or otherwise, how long people are likely to live after a recurrent, stage 4 breast cancer diagnosis. Without such basic information, it's hard for doctors to give reasoned advice, or for patients to make informed choices.
Image courtesy of Joseph Gray: "I matter" on a woman's tee shirt, at the 9th annual Metastatic... [+]
"I don't think people should experience what it's like not to be counted," Shirley Mertz told me in a recent phone interview. She leads the Metastatic Breast Cancer Network (MBCN) and has been living with stage 4 disease for years. She is an educator and former high school principal who lives in the Chicago area. "Knowing the exact numbers says that we all matter, that what we are going through matters to our doctors, to scientists and to society," Mertz said.
Earlier this month, the MBCN held its 9th annual meeting. This year's educational symposium was the group's largest gathering yet: Approximately 330 individuals registered; 285 made it to this year's hosting institution, the Dana Farber Cancer Institute in Boston. For many conference-goers – women and men living with advanced breast cancer, their family and caregivers – traveling is not easy.
Nor, it turns out, is being counted.
"The number of people who are living with metastatic breast cancer is uncertain," confirmed Dr. Angela Mariotto, a statistician at the NCI's Surveillance Research Program.
The NCI estimates there are approximately 65,000 people who were initially found with metastatic breast cancer who are alive now, Mariotto said in a phone interview. This estimate comes from the group of approximately 6% of all U.S. breast cancer patients who have stage 4, metastatic disease at the time of diagnosis. But most cases – a greater number – of metastatic breast cancer arise in patients after a period of remission.
The main limitation – to collecting this information – is that recurrent breast cancer is not a reportable condition; most U.S. registries just count new cases and cancer deaths. If and when a breast cancer patient has a recurrence, sometime after initial treatment, there is no national registry to which doctors must submit that information. Apart from individual healthcare systems or clinical trials – in which few early-stage patients participate – there's no organized tracking of all cases between diagnosis and death. This results in most cases of metastatic breast cancer going untallied, and survival of those affected being unmeasured.
"These are difficult questions," Mariotto considered. In recent years, the NCI has been overhauling its SEER program to collect more detailed information on pathology at the time of diagnosis. Since 2010 it has been collecting Her2 status and OncotypeDx results, for instance.
"Now the NCI is looking at recurrences prospectively," she said. "But the challenge is getting the follow-up." The agency is using a variety of strategies to learn of recurrences, including examining procedure and diagnostic codes in insurance databases, and drawing on information gleaned from pathology and imaging reports.
"From our data, it seems that survival has been improving for women who are initially diagnosed with metastatic breast cancer," Mariotto told me. "It will be a few more years until there is sufficient information to discern survival patterns based on molecular pathology." She referred me to SEER data demonstrating this trend.
In recent years, the median, relative survival at 5-years is only 33% for those with metastatic disease at diagnosis, as compared to others in the same population without breast cancer:
This chart, based on SEER data provided by Dr. Mariotto, reveals trends in 5-year survival in women... [+]
For survival with metastatic breast cancer after recurrence, information is limited. What data are available suggests that survival with metastatic disease after recurrence is shorter, in general, than after presentation with stage 4 disease. Mariotto is currently using mathematical models to estimate the number of women living with metastatic breast cancer in the United States.
Mariotto referred to a 2010 study comparing survival after a de novo (initial) metastatic breast cancer diagnosis, as opposed to survival after recurrence with metastatic disease. In that analysis of over 3,500 women diagnosed between 1992 and 2007, the median survival was 39.2 months among those with de novo stage IV disease, and 27.2 months with relapsed disease. Caution is due in interpreting these results today, however, as there were fewer hormonal and other, targeted drugs available for most of that retrospective study period.
Dr. Julia Perkins is a senior medical director at Pfizer Oncology who spoke at a Story Half Told presentation and panel discussion I attended in New York City on September 30. Through a Pfizer representative, I asked her about the statement: "It is estimated that 150,000-250,000 women and men in the U.S. are living with metastatic breast cancer," as was included in that display and other Pfizer documents.
Dr. Perkins responded by email. She indicated that Pfizer's initiative "aims to extend the breast cancer dialogue to be inclusive of women with metastatic breast cancer." For the Story Half Told program, "Pfizer recruited a multi-disciplinary steering committee comprised of leading breast cancer advocates and oncologists to review program statistics and materials and help ensure we considered the insights and concerns of the patient community." In regard to the above estimate, she wrote:
The source of this statement is a 2006 analysis entitled 'Silent Voices' published in The Breast, commissioned by the non-profit organization, Living Beyond Breast Cancer. In this analysis, renowned breast cancer advocate Musa Mayer derived these numbers from the following calculation:
"Between one-half and two-thirds of women diagnosed at Stage II and III (regional disease) will ultimately develop metastatic disease. In combination with the women who initially present at Stage IV (distant disease), this would mean that every year between 73,000 and 86,000 American women discover they have metastatic breast cancer. We can therefore estimate 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."
... this 150,000-250,000 prevalence statistic is widely adopted by breast cancer advocates and institutions, as well as industry. It too was vetted by the A Story Half Told Steering Committee.
Metastatic breast cancer has not been widely studied and quantified, which makes statistics challenging to obtain. Because the metastatic breast cancer patient community has long been overshadowed by those with early stage disease, the Story Half Told initiative has attempted to foster research and analysis that builds understanding and support for the metastatic breast cancer patient community.
We agree more research and data collection is needed on a large scale to better understand the scope of the metastatic breast cancer community, and we support efforts to do so, including those being led by the Metastatic Breast Cancer Alliance, of which Pfizer is a founding member.
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