Of more than 18 million Americans who have a history of cancer, two thirds were aged 65 or older as of January 1 of this year, according to a joint report by the American Cancer Society (ACS) and the National Cancer Institute (NCI).
This number has increased by more than 1 million since 2019 and will continue to rise. It is predicted that almost 270,000 new cases of prostate cancer will be diagnosed in 2022.
The growing population of cancer survivors largely reflects "the combined effects of a growing and aging population" as well as "advances in early detection and treatment," lead author Kimberly Miller, MPH, of the ACS, Atlanta, Georgia, and colleagues write.
As this population continues to grow, health professionals, caregivers, and patients will need more guidance "on how to manage late and long-term effects of cancer and its treatment" and more resources "to ensure equitable access to survivorship care," Miller added in a statement.
The study was published online June 23 in CA: A Cancer Journal for Clinicians.
To understand the evolution of cancer survivorship, the ACS and NCI collaborate every 3 years to estimate the prevalence of cancer in the US. To estimate the number of cancer survivors as of January 1, 2022, the team used incidence and survival data from the Surveillance, Epidemiology and End Results cancer registries, vital statistics from the Centers for Disease Control and Prevention's National Center for Health Statistics, and population projections from the US Census Bureau. The authors also compared cancer incidence rates from 1975 to 1999 and from 2000 to 2018.
In their latest review, Miller and colleagues found that 8.3 million men and 9.7 million women who had a history of cancer were alive at the beginning of this year. Among survivors, more than half (53%) were diagnosed in the past 10 years.
The three most prevalent cancers among men were prostate cancer, affecting more than 3.5 million men, melanoma (n = 760,640), and colorectal cancer (CRC) (n = 726,450). For women, the top three most prevalent cancers were breast cancer, affecting more than 4 million women, along with cancers of the uterus (n = 891,560) and thyroid (n = 823,800).
The 5-year relative survival rates for individual cancer types continue to improve, but some have seen greater gains than others.
Among women with a history of invasive breast cancer, the 5-year relative survival rate increased from 75% for patients diagnosed in the mid-1970s to 90% for those diagnosed between 2011 and 2017 — largely because of advances in hormonal treatments and earlier detection with mammography, the investigators note.
For patients diagnosed with stage I disease, the 5-year relative survival rate approached 100%. This rate declined to 28% for those diagnosed with stage IV breast cancer.
Survival rates for other cancers included in the analysis demonstrate a similar trend.
For CRC, for instance, the 5-year relative survival rate increased from 50% during the mid-1970s to 65% for patients diagnosed between 2011 and 2017 — again reflecting earlier diagnosis and advances in surgical techniques as well as novel systemic therapies. For those diagnosed with stage I CRC, the 5-year survival rate topped 90% but declined sharply to about 15% for patients diagnosed with stage IV disease.
For melanoma, the 5-year relative survival rates have remained high and have increased — from 82% in the mid-1970s to 93% between 2011 and 2017. More than 70% of these patients are diagnosed at stage I, which has a 5-year relative survival rate approaching 100%.
For lung cancer, although the 5-year relative survival rates remain low, they have nearly doubled since the early 1990s — from 13% for patients diagnosed between 1989 and 1991 to 22% for those diagnosed between 2011 and 2017. Fewer than one third of these patients are diagnosed with stage I disease, for which the 5-year survival rate is 65%. The rate declines to 5% for those diagnosed with stage IV disease.
Uterine cancer is one of the few cancers for which survival has not substantially improved since the mid-1970s because there have been few advances in treatment. Most cases, however, are caught early. The 5-year survival rate is 95% for stage I disease. For all stages combined, it is 81%.
Notable disparities emerge when comparing survival rates among Black and White women, which range from 84% for White women to 63% for Black women.
This disparity can be explained, in part, because "Black women have a higher burden of aggressive tumor subtypes and are substantially less likely to be diagnosed with stage I disease," the authors note. "However, survival in Black women is lower regardless of histology or stage, pointing to pervasive disparities in access to treatment."
Blood malignancies are much less common than most solid tumors, and survival rates often vary by age. For instance, the 5-year relative survival rate for children and adolescents with acute myeloid leukemia — one of the most common types of leukemia — is 69%. That rate declines to 58% for patients aged 20 to 49, 35% for those 50 to 64, and 9% for those 65 and older.
For all childhood and adolescent cancers combined, the 5-year relative survival rate has increased substantially from the mid-1970s to 2011–2017: 58% to 85% among children and 68% to 86% among adolescents.
The authors point out that, given the time frame of the analysis, the findings do not reflect the potential impact of COVID-19 on cancer survival. Miller and colleagues acknowledge that the pandemic has "exacerbated existing challenges in access to care across the cancer spectrum."
CA Cancer J Clin. Published online June 25, 2022. Full text
The authors have disclosed no relevant financial relationships.
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