US sees largest-ever one year drop in cancer death rates thanks to advancement in lung cancer treatment
Fewer people are dying from cancer in the US, which has seen the largest single-year drop in death rates ever reported. This progress is primarily driven by the recent rapid decline in lung cancer deaths.
The cancer death rate declined by 29% from 1991 to 2017, including a 2.2% drop from 2016 to 2017, the largest-ever one-year decline, according to the latest edition of the American Cancer Society's annual report.
The cancer death rate rose during most of the 20th century, largely because of a rapid increase in lung cancer deaths among men as a consequence of the tobacco epidemic. However, a decline in smoking, as well as improvements in early detection and treatment, have resulted in a continuous fall in the cancer death rate since its peak of 215.1 deaths (per 100,000 population) in 1991, says the research team.
The overall drop of 29% as of 2017 (152.4 per 100,000 population) translates into an estimated 2,902,200 fewer cancer deaths (1,983,000 in men and 919,200 in women) than what would have occurred if mortality rates had remained at their peak. The number of averted deaths is larger for men than for women because the death rate in men peaked higher and declined faster.
“The continuous decline in the cancer mortality rate since 1991 has resulted in an overall drop of 29%, translating into approximately 2.9 million fewer cancer deaths. This steady progress is largely due to reductions in smoking and subsequent decline in lung cancer mortality, which have accelerated in recent years,” says the study published in CA: A Cancer Journal for Clinicians.
It says: “The pace of mortality reductions for lung cancer - the leading cause of cancer death - accelerated in recent years (from 2% per year to 4% overall) spurring the record one-year drop in overall cancer mortality.”
Cancer is a major public health problem worldwide and is the second leading cause of death in the US. A total of 2,820,034 deaths were recorded in the US in 2017, 21% of which were from cancer.
During the most recent decade of data (2008-2017), the death rate declined by 1.5% per year for cancer while remaining stable for all other causes of death combined, reflecting a slowing decline for heart disease, stabilizing rates for cerebrovascular disease, and an increasing trend for accidents (unintentional injuries; 2.6% per year) and Alzheimer's disease (3.2% per year).
The progress against cancer reflects a large drop in deaths for the four major cancers -- lung, breast, prostate, and colorectum.
“As of 2017, the death rate has dropped from its peak for lung cancer by 51% among males (since 1990) and by 26% among females (since 2002). The death rate for female breast cancer dropped by 40% (since 1989); and for prostate cancer, it dropped by 52% (since 1993). For colorectal cancers, the death rate declined by 53% among males (since 1980) and by 57% among females (since 1969),” says the study.
“Declines in lung cancer mortality have accelerated, from approximately 3% annually during 2008 through 2013 to 5% during 2013 through 2017 in men and from 2% to almost 4% in women. However, lung cancer still accounts for almost one-quarter of all cancer deaths, more than breast, prostate, and colorectal cancers combined,” says the study. Further, cervical cancer, which is almost completely preventable, caused 10 premature deaths per week in women ages 20-39 in 2017.
According to the team, the most rapid declines in death occurred for melanoma of the skin, on the heels of breakthrough treatments approved in 2011 that pushed one-year survival for patients diagnosed with metastatic disease from 42% (2008-2010) to 55% (2013-2015).
“In 2011, the US Food and Drug Administration (FDA) approved ipilimumab, the first immune checkpoint inhibitor approved for cancer therapy,63 and vemurafenib, a BRAF inhibitor, for the treatment of advanced melanoma. Subsequently, the 1-year relative survival rate for metastatic melanoma escalated from 42% for patients diagnosed during 2008 through 2010 to 55% for those diagnosed from 2013 through 2015,” says the study.
The progress is likewise reflected in the overall melanoma death rate, which dropped by 7% annually from 2013 through 2017 in men and women aged 20 to 64 years. This is as compared with the decline from 2006 through 2010 of approximately 1% annually among individuals aged 50 to 64 years and 2% to 3% among those aged 20 to 49 years. The impact was even more striking for individuals aged 65 years and older, among whom rates were increasing before 2013 but are now declining by 5% to 6% per year.
"The accelerated drops in lung cancer mortality as well as in melanoma that we're seeing are likely due at least in part to advances in cancer treatment over the past decade, such as immunotherapy. They are a profound reminder of how rapidly this area of research is expanding, and now leading to real hope for cancer patients,” says Dr. William G. Cance, chief medical and scientific officer for the American Cancer Society.
The overall cancer incidence rate in children (aged birth to 14 years) and adolescents (aged 15-19 years) has been increasing slightly (by 0.7% per year) since 1975 for reasons that remain unclear. In contrast, death rates have declined continuously for decades, from 6.3 (per 100,000 population) in children and 7.1 in adolescents in 1970 to 2.0 and 2.7, respectively, in 2017, for overall cancer mortality reductions of 68% in children and 63% in adolescents.
“Much of this progress reflects the dramatic decline in leukemia mortality of 83% in children and 68% in adolescents,” say experts.
Projections for 2020
In total, there will be approximately 1,806,590 cancer cases diagnosed, which is the equivalent of approximately 4,950 new cases each day.
The study also estimates the most common cancers expected to be diagnosed in men and women in 2020.
Prostate, lung, and bronchus (referred to as lung hereafter), and colorectal cancers will account for 43% of all cases in men, with prostate cancer alone accounting for more than 1 in 5 new diagnoses, shows the analysis. For women, the three most common cancers will be breast, lung, and colorectal, accounting for 50% of all new diagnoses; breast cancer alone accounts for 30% of female cancers.
The lifetime probability of being diagnosed with an invasive cancer is slightly higher for men (40.1%) than for women (38.7%) in 2020. “The reasons for the excess risk in men are not fully understood, but probably largely reflect differences in environmental exposures and endogenous hormones, as well as complex interactions between these influences. Recent research suggests that sex differences in immune function and response may also play a role,” say experts.
The researchers estimate that 606,520 Americans will die from cancer in 2020, corresponding to more than 1,600 deaths per day.
“The greatest number of deaths will be from cancers of the lung, prostate, and colorectum in men and the lung, breast, and colorectum in women. Almost one-quarter of all cancer deaths will be due to lung cancer,” according to 2020 estimates.
Cancer is the second most common cause of death among children aged 1 to 14 years in the US, surpassed only by accidents. According to the analysis, an estimated 11,050 children and 5,800 adolescents will be diagnosed with cancer in 2020, and 1,190 and 540, respectively, will die from the disease, says the study.