US Cancer Deaths continue to decline, and are particularly Lung Cancer
In the United States, the risk of death from cancer overall has been continuously dropping since 1991, notes the American Cancer Society (ACS) in its latest report.
There has been an overall decline of 32% in cancer deaths as of 2019, or approximately 3.5 million cancer deaths averted, the report notes.
“This success is largely because of reductions in smoking that resulted in downstream declines in lung and other smoking-related cancers,” lead author Rebecca Siegel, MPH, from the ACS, and colleagues report in the latest edition of the society’s annual report on cancer rates and trends.
The paper was published online January 12 in CA: A Cancer Journal for Clinicians.
In particular, there has been a fall in both the incidence of and mortality from lung cancer, largely due to successful efforts to get people to quit smoking, but also from earlier diagnosis at a stage when the disease is far more amenable to treatment, note the authors.
For example, the incidence of lung cancer declined by almost 3% per year in men between the years 2009 and 2018 and by 1% a year in women. Currently, the historically large gender gap in lung cancer incidence is disappearing such that in 2018, lung cancer rates were only 24% higher in men than they were in women, and rates in women were actually higher in some younger age groups than they were in men.
Moreover, 28% of lung cancers detected in 2018 were found at a localized stage of disease compared with only 17% in 2004.
Patients diagnosed with lung cancer are also living longer, with almost one third of lung cancer patients still alive 3 years after their diagnosis compared with only 21% a decade ago.
However, lung cancer is still the biggest contributor to cancer-related mortality overall, at a death toll of 350 per day — more than breast, prostate, and pancreatic cancer combined, the authors comment.
This is also 2.5 times higher than the death rate from colorectal cancer (CRC), the second leading cause of cancer death in the US, they note.
Nevertheless, the decrease in lung cancer mortality accelerated from 3.1% per year between 2010 to 2014 to 5.4% per year during 2015 to 2019 in men and from 1.8% to 4.3% in women. “Overall, the lung cancer death rate has dropped by 56% from 1990 to 2019 in men and by 32% from 2002 to 2019 in women,” Siegel and colleagues emphasize.
Overall, the ACS projects there will be over 1.9 million new cancer cases and over 600,000 cancer deaths across the US in the year 2022.
Patterns Are Changing
With prostate cancer now accounting for some 27% of all cancer diagnoses in men, recent trends in the incidence of prostate cancer are somewhat worrisome, the authors comment. While the incidence for local-stage disease remained stable from 2014 through to 2018, the incidence of advanced-stage disease has increased by 6% a year since 2011. “Consequently, the proportion of distant-stage diagnoses has more than doubled,” the authors note, “from a low of 3.9% in 2007 to 8.2% in 2018,” they report.
The incidence of breast cancer among women has also been slowly increasing by 0.5% per year since about the mid-2000s. This increase is due at least in part to declines in fertility and increases in body weight among women, the authors suggest. Declines in breast cancer mortality have also slowed in recent years, dropping from 1% a year from 2013 to 2019 from 2% to 3% per year seen during the 1990s and the 2000s.
As for CRC, incidence patterns are similar by sex but differ by age. For example, incidence rates of CRC declined by about 2% per year between 2014 and 2018 in individuals 50 years and older, but they increased by 1.5% per year in adults under the age of 50. Overall, however, mortality from CRC decreased by about 2% a year between 2010 and 2019, although this trend again masks increasing mortality from CRC among younger adults, where death rates rose by 1.2% per year from 2005 through 2019 in patients under the age of 50.
The third leading cause of death in men and women combined is pancreatic cancer. Here again, mortality rates slowly increased in men between 2000 and 2013 but have remained relatively stable in women.
Between 2010 and 2019, cancers of the tongue, tonsils, and oropharynx caused by human papilloma virus (HPV) increased by about 2% a year in men and by 1% a year in women.
Death from cervical cancer — despite being one of the most preventable cancers overall — is still the second leading cause of cancer death in women between 20 and 39 years of age. “Most of these women have never been screened so this is low-hanging fruit easily addressed by increasing access to screening and [HPV] vaccination among underserved women,” Siegel said in a statement.
On the other hand, mortality from liver cancer — having increased rapidly over the past number of decades — appears to have stabilized in more recent years.
Survival at 5 Years
For all cancers combined, survival at 5 years between the mid-1970s and 2011 through 2017 increased from 50% to 68% for White patients and by 39% to 63% for Black patients. “For all stages combined, survival is highest for prostate cancer (98%), melanoma of the skin (93%) and female breast cancer (90%),” the authors point out.
In contrast, survival at 5 years is lowest, at 11% for pancreatic cancer, 20% for cancers of the liver and esophagus, and 22% for lung cancer.
Indeed, for most of the common cancers, cancer survival has improved since the mid-1970s with the exception or uterine and cervical cancer, the latter because there have been few advancements in treatment.
Even among the more rare blood and lymphoid malignancies, improvements in treatment strategies, including the use of targeted therapies, have resulted in major survival gains from around 20% in the mid-1970s for chronic myeloid leukemia (CML) patients to over 70% for CML patients diagnosed between 2011 and 2017.
Similarly, the discovery and use of immunotherapy has doubled 5-year survival rates to 30% for patients with metastatic melanoma from 15% in 2004. On the other hand, racial disparities in survival odds continue to persist. For every cancer type except for cancer of the pancreas and kidney, survival rates were lower for Black patients than for White patients, as researchers point out.
“Black individuals also have lower stage-specific survival for most cancer types,” the report authors note. Indeed, after adjusting for sex, age, and stage at diagnosis, the risk of death is 33% higher in Black patients than White patients and 51% higher in American Indian/Alaska Natives again compared to White patients.
That said, the overall incidence of cancer is still highest among White individuals, in part because of high rates of breast cancer in White women, which may in part reflect overdiagnosis of breast cancer in this patient population, as the authors suggest.
“However, Black women have the highest cancer mortality rates — 12% higher than White women,” they observe. Even more striking, Black women have a 4% lower incidence of breast cancer than White women but a 41% higher mortality risk from it.
As for pediatric and adolescent cancers, incidence rates may be increasing slightly among both age groups, but dramatic reductions in death by 71% among children and by 61% among adolescents from the mid-70s up until now continue as a singular success story in the treatment of cancer overall.
All the authors are employed by the ACS.
CA Cancer J Clin. Published online January 12, 2022.
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