, the American Cancer Society says.
Dr. Jacques P. Fontaine
Lung cancer death rates, which were falling by 3% in men and 2% in women annually in 2008 through 2013, dropped by 5% in men and nearly 4% per year in women annually from 2013 to 2017, according to the society’s 2020 statistical report.
Those accelerating reductions in death rates helped fuel the biggest-ever single year decline in overall cancer mortality, of 2.2%, from 2016 to 2017, their report shows.
According to the investigators, the decline in melanoma death rates escalated to 6.9% per year among 20- to 49-year-olds over 2013-2017, compared with a decline of just 2.9% per year during 2006-2010. Likewise, the melanoma death rate decline was 7.2% annually for the more recent time period, compared with just 1.3% annually in the earlier time period. The finding was even more remarkable for those 65 years of age and older, according to investigators, since the declines in melanoma death rates reached 6.2% annually, compared with a 0.9% annual increase in the years before immunotherapy.
Smoking cessation has been the main driver of progress in cutting lung cancer death rates, according to the report, while in melanoma, death rates have dropped after the introduction of immune checkpoint inhibitors and targeted therapies.
By contrast, reductions in death rates have slowed for colorectal cancers and female breast cancers, and have stabilized for prostate cancer, Ms. Siegel and coauthors stated, adding that racial and geographic disparities persist in preventable cancers, including those of the lung and cervix.
“Increased investment in both the equitable application of existing cancer control interventions and basic and clinical research to further advance treatment options would undoubtedly accelerate progress against cancer,” said the investigators. The report appears in CA: A Cancer Journal for Clinicians.
While the decline in lung cancer death rates is good news, the disease remains a major killer, responsible for more deaths than breast, colorectal, and ovarian cancer combined, said Jacques P. Fontaine, MD, a thoracic surgeon at Moffitt Cancer Center in Tampa, Fla.
“Five-year survival rates are still around the 18%-20% range, which is much lower than breast and prostate cancer,” Dr. Fontaine said in an interview. “Nonetheless, we’ve made a little dent in that, and we’re improving.”
Two other factors that have helped spur that improvement, according to Dr. Fontaine, are the reduced incidence of squamous cell carcinomas, which are linked to smoking, and the increased use of lung cancer screening with low-dose computed tomography.
Squamous cell carcinomas tend to be a central rather than peripheral, which makes the tumors harder to resect: “Surgery is sometimes not an option, and even to this day in 2020, the single most effective treatment for lung cancer remains surgical resection,” said Dr. Fontaine.
Likewise, centrally located tumors may preclude giving high-dose radiation and may result in more “collateral damage” to healthy tissue, he added.
Landmark studies show that low-dose CT scans reduce lung cancer deaths by 20% or more; however, screening can have false-positive results that lead to unnecessary biopsies and other harms, suggesting that the procedures should be done in centers of excellence that provide high-quality, responsible screening for early lung cancer, Dr. Fontaine said.
While the drop in melanoma death rates is encouraging and, not surprising in light of new cutting-edge therapies, an ongoing unmet treatment need still exists, according to Vishal Anil Patel, MD, director of cutaneous oncology at the George Washington Cancer Center in Washington.
“We still have a lot to learn, and a way to go, because we’ve really just made the first breakthrough,” Dr. Patel said in an interview.
Dr. Vishal Patel
Mortality data for melanoma can be challenging to interpret, according to Dr. Patel, given that more widespread screening may increase the number of documented melanoma cases with a lower risk of mortality.
Nevertheless, it’s not surprising that advanced melanoma death rates have declined precipitously, said Dr. Patel, since the diseases carries a high tumor mutational burden, which may explain the improved efficacy of immune checkpoint inhibitors.
“Without a doubt, the reason that people are living longer and doing better with this disease is because of these cutting-edge treatments that provide patients options that previously had no options at all, or a tailored option personalized to their tumor and focusing on what the patient really needs,” Dr. Patel said.
That said, response rates remain lower from other cancers, sparking interest in combining current immunotherapies with costimulatory molecules that may further improve survival rates, according to Dr. Patel.
In 2020, 606,000 cancer deaths are projected, according to the American Cancer Society statistical report. Of those deaths, nearly 136,000 are attributable to cancers of the lung and bronchus, while melanoma of the skin accounts for nearly 7,000 deaths.
The report notes that variation in cancer incidence reflects geographical differences in medical detection practices and the prevalence of risk factors, such as smoking, obesity, and other health behaviors. “For example, lung cancer incidence and mortality rates in Kentucky, where smoking prevalence was historically highest, are 3 to 4 times higher than those in Utah, where it was lowest. Even in 2018, 1 in 4 residents of Kentucky, Arkansas, and West Virginia were current smokers compared with 1 in 10 in Utah and California,” the investigators wrote.
Cancer mortality rates have fallen 29% since 1991, translating into 2.9 million fewer cancer deaths, the report says.
Dr. Siegel and coauthors are employed by the American Cancer Society, which receives grants from private and corporate foundations, and their salaries are solely funded through the American Cancer Society, according to the report.
SOURCE: Siegel RL et al. CA Cancer J Clin. 2020;70(1):7-30. doi: 10.3322/caac.21590.