by The Department of Defense’s Breast Cancer Research Program issues a yearly report on the current state of breast cancer. This is a summary of the 2021 report, which you can read in its entirety HERE. All specific data references can be found at the end of the original report.
INCIDENCE and SCREENING:
In 2021, it is estimated that 281,550 women and 2,650 men will be diagnosed with INVASIVE breast cancer. An additional 49,290 women will receive a diagnosis of ductal carcinoma in situ (DCIS) – a pre-invasive, stage zero breast condition. (More about DCIS in a moment.)
As the number of women in higher-risk age groups continues to grow, the number of women being diagnosed continues to increase. From 2004-2017 the incidence rate grew about 0.5% per year, with the median age at diagnosis being 63 for White women and 60 for Black women. The reduction of women using hormone replacement therapy during menopause (after the 2003 Women’s Health Initiative trial showed an association with breast cancer risk) resulted in a decline in incidence for women over 50. It has more or less stabilized since that time.
Incidence of invasive breast cancer is low in females ages 15-39; however recent trends show a disturbing increase of 1.1% annually between 2010 and 2017.
The DoD reports that, compared to the general population, active duty females in the military have a 20-40% greater risk of developing breast cancer. As of 2008, approximately one in seven military active duty troops were women and over 90% of them are under 40 years old.
The obvious goal of screening programs is to find more breast cancers before they become deadly. The increase in breast cancer screening has also led to a dramatic increase in the diagnosis of DCIS. The survival rate for DCIS is nearly 100%. However, we still don’t know which cases of DCIS will progress to invasive cancers and which will never progress. The report states that “as a result, the overdiagnosis and overtreatment of DCIS remain persistent problems.”
MORTALITY:
In 2021, it is estimated that 684,996 people will die from breast cancer globally. In the United States, an estimated 43,600 women and 530 men will die from breast cancer. The report points out that if there are no major changes in the prevention or treatment of breast cancer by 2040, over one million women will die worldwide in that year.
Despite the widespread use of mammography since 1975, the rate at which women are initially diagnosed with metastatic breast cancer has changed very little.
Since the late 1990s, mortality rates have been decreasing slightly for all women. However there has been a deceleration in that decrease. From 2003-2007, breast cancer deaths decreased on average 2.3% per year. From 2014-2018, they only decreased by 1% per year. Decreases in mortality are generally attributed to earlier stage at diagnosis and better treatments that prolong life.
There remain persistent differences in the rate of breast cancer deaths by race and ethnicity. Non-Hispanic Black women have a 40% higher mortality rate than White women, despite have a lower incidence rate.
FIVE-YEAR SURVIVAL RATES:
Five-year survival rates are often used but are not a sole indicator of progress. For example, the National Cancer Institute reports a 99% five-year survival rate for women diagnosed with localized (early stage) breast cancer. This percentage does not account for the fact that many of those women would not have died within that time frame even if they had NOT been screened, nor for recurrence after five years. We don’t know how to prevent recurrence (and metastasis), and it is estimated that 20-30% of women will have a recurrence and may eventually die of breast cancer. Many women counted as alive at five years are still in treatment. And the rate is skewed by screening, since more women are being diagnosed early in their disease, which results in both a larger denominator of cases (women who will be counted as alive at five years) and a lead-time bias (the difference in time between when a woman is diagnosed by screening and when her condition would’ve become apparent and diagnosed without screening).
RECURRENCE AND METASTATIC DISEASE:
As noted, 20-30% of women with invasive breast cancer will have a recurrence. An estimated 90% of breast cancer deaths are due to metastatic spread of the original breast cancer, whether it was metastatic at diagnosis or whether metastasis developed later.
The risk of recurrence is greater within the first five years after diagnosis for ER-negative cancer. There is a consistent long-term risk of death for patients with ER-positive cancer, with a greater risk after seven years. Approximately 75% of breast cancers are ER-positive.
Approximately 155,000 women were living with metastatic (stage IV) breast cancer in the US in 2017. Of those women, 75% were initially diagnosed with stage I-III breast cancer. The report estimates that the projected number from 2020 data will be that 168,292 women will be living with stage IV breast cancer.
Scientists have identified treatments that sometimes slow the progression of the cancer, but they are most often temporary. It is important to remember that “treatments to permanently eradicate metastasis do not exist. There is no cure once metastatic disease has occurred.” Recent estimates on median survival with metastatic breast cancer indicate about three years, depending on many factors.
TREATMENTS:
Standard treatment protocol for breast cancer has, for decades, included surgery, radiation, chemotherapy and/or hormonal therapy. Within the past 15 years, targeted antibody therapy has also been used.
It is important to note that despite newer forms of treatment and standards of care, mortality rates have only dropped marginally. There are subtypes of breast cancer that are distinguished by the presence or absence of key proteins – ER, PR and HER2. Most women within a subtype receive the same treatment. There are targeted therapies for some subtypes, however no targeted therapy has been approved for triple negative breast cancer (ER-, PR- and HER2-). TNBC is a particularly aggressive subtype that made up just under 11% of all diagnoses in 2010.
A recent meta-analysis of clinical studies on early stage breast cancer found a reduction in the risk of recurrence for all women who received chemotherapy as part of their treatment, but there was only a survival benefit for younger women. Studies showed an improvement of 7-11% in the 10-year survival of younger women, but only 2-3% for women ages 50-69, which is the age range when most breast cancer is diagnosed.
Standard adjuvant therapies (radiation, hormonal therapy and chemotherapy) show only a 5-10% impact on disease-specific survival. Currently, all individuals with breast cancer receive these therapies even though only a small number of them will benefit. This is because we still do not know how to predict which cancers will recur, and we don’t understand enough about how the differences within each tumor affect its response to therapy or recurrence.
Recently, more research has been focused on whether or not breast cancer can be treated with drugs that would “jump start” the body’s immune response to fight the cancer (cancer immunotherapy). The goal would be to get a patient’s immune system to attack the tumors. Researchers are also studying vaccines for treatment, and a number are in clinical trials, however they are not being tested in healthy populations yet.
All of these treatments carry a risk of morbidities (cardiac complications, neuropathy, lymphedema, etc.) and even mortality. It is estimated that over 30% of all breast cancers (invasive and DCIS) are considered to be overdiagnosed and overtreated. Overdiagnosed refers to diagnoses of cancers that would not have become apparent within the life of the patient – as may be the case with some DCIS. Overtreatment results from overdiagnosis – where no treatment is necessary – or the use of more aggressive therapies than are needed. It has recently been estimated that for every one breast cancer death avoided, three deaths occur from overtreatment.
Meanwhile, the cost of treating breast cancer continues to rise. In 2015 it was estimated that the national cost of cancer care overall is minimally projected to increase to about $246 billion by 2030 based just on the growth of the US population. It does NOT include costs for medical services or drugs, which are projected to grow by 34% and 40% respectively. In 2015, breast cancer care costs were $26 billion.
In 2020, it was reported that there were over 1,300 medicines and vaccines in clinical testing for the treatment of cancer, including at least 108 that were breast cancer specific. There are over 2,211 clinical trials currently underway evaluating drugs for breast cancer.
Significantly though, despite all these therapies and trials for new breast cancer treatments, the expected drop in mortality rates eludes us. The DoD report concludes by stating, “What remains unknown is whether the current approaches to developing drugs and conducting clinical trials can be redesigned to accelerate the rate of progress to end breast cancer.”
Indeed.
As an editorial postscript to this summary, I would like to highlight the importance of this research program. They are doing the hard, honest work of transparent research that will have a big impact on breast cancer mortality. Extending life and improving the quality of that life are important goals. However, the main goal should be SAVING lives from breast cancer – whether that is through understanding how to prevent it, or definitively being able to cure it. Therefore, BCRP selects applications for funding that address the following challenges:
- Prevent breast cancer (primary prevention)
- Identify determinants of breast cancer initiation, risk, or susceptibility
- Distinguish deadly from non-deadly breast cancers
- Conquer the problems of overdiagnosis and overtreatment
- Identify what drives breast cancer growth; determine how to stop it
- Identify why some breast cancers become metastatic
- Determine why/how breast cancer cells lie dormant for years and then re-emerge; determine how to prevent lethal recurrence
- Revolutionize treatment regimens by replacing them with ones that are more effective, less toxic, and impact survival
- Eliminate the mortality associated with metastatic breast cancer
The WBCC works collaboratively on the national level to secure and protect funding for breast cancer research totaling more than $4.4 billion since 1992 through the Department of Defense Breast Cancer Research Program (DoD-BCRP). More than $45 million of that funding has come back to Wisconsin institutions in the form of research grants. Please watch for alerts from us when we need you to call your Congressional representatives to protect the annual funding of this program. Alerts are sent by email, and are shared on our Facebook and Twitter accounts.