Cancer Mortality Rates Decline Suggesting Notable Gains in Common Cancer Types

Cancer mortality rates have steadily declined since 1991, resulting in an overall drop of 29% or approximately 2.9 million fewer cancer deaths if peak rates had persisted, according to a report published by the American Cancer Society.

This progress was driven by long-term declines in death rates for the 4 leading cancer types (lung, colorectal, breast, and prostate).

The authors indicated that this steady progression is largely due to reductions in smoking and subsequent declines in lung cancer mortality, which have accelerated in recent years. However, treatment breakthroughs have also contributed, such as those for hematopoietic and lymphoid malignancies in both children and adults, and more recently, checkpoint blockade immunotherapies and targeted therapies for metastatic melanoma.

“Continued advancements in more targeted therapeutics could move the needle further in the coming years,” Rebecca L. Siegel, MPH, scientific director of surveillance research at the American Cancer Society and an author on the report, said in an interview with CancerNetwork^®.

Most notably, declines accelerated for lung cancer, from 3% annually during 2008 through 2013 to 5% during 2013 through 207 in men and 2% to almost 4% in women, triggering the largest ever sing-year drop in cancer mortality of 2.2% from 2016 to 2017. However, lung cancer still remains the leading cause of cancer death, with mortality rates higher than breast, colorectal, and prostate cancers combined.

Among the other findings in leading cancer types:

• The breast cancer death rate dropped by 40% from 1989 to 2017.

• There was a 52% drop in the prostate cancer death rate from 1993 to 2017.

• Since 1980, there has been a 53% drop in the colorectal cancer death rate among men, and a 57% drop since 1969 among women.

Mortality declines were also impressive for melanoma following the FDA approval of new therapies for metastatic disease, such as ipilimumab (Yervoy) and vemurafenib (Zelboraf).

Melanoma mortality declines escalated to 7% annually during 2013 through 2017 from 1% during 2006 through 2010 in men and women aged 50 to 64 years and from 2% to 3% in those aged 20 to 49 years; however, even more strikingly were the annual declines of 5% to 6% in individuals aged 65 years and older, as rates in this age group were increasing prior to 2013.

“It’s clearly the influence of these drugs because improvements in survival in the past several years are limited to metastatic disease,” Siegel explained.

However, not all cancer types saw these improvements. For instance, over the past decade (2008-2017), reductions slowed for female breast and colorectal cancers, and ceased for prostate cancer. Cervical cancer also did not see any significant improvements, with 2017 alone reporting 10 women in their 20s and 30s dying every week in the US from the disease.

“Improved early detection is needed, especially for prostate cancer. Rapid declines in prostate mortality in previous years have halted, most likely because of rising incidence of metastatic disease diagnoses due to the discontinuation of PSA testing to screen for prostate cancer,” Siegel noted. “For many cancers, like pancreas and liver, there is no effective test for early detection. Research is also needed to shed light on causes for the rise in early-onset CRC and to develop effective treatment for certain cancers that do not respond to current therapies.”

Nevertheless, slowing momentum for some cancers amenable to early detection was juxtaposed with notable gains for other common cancers, according to the authors.

The study estimates that 1,806,590 new cancer cases and 606,520 cancer deaths will occur in 2020. The most common cancers expected to be diagnosed in men, accounting for 43% of all cases, are prostate, lung, and colorectal cancers. In women, the 3 the most common cancer types are predicted to be breast, lung, and colorectal, accounting for 50% of all new diagnoses; breast cancer alone is estimated to account for 30% of female cancers.

Reference:

Siegel RL, Miller KD, Jemal A, et al. Cancer Statistics, 2020. CA Cancer J Clin. doi:10.3322/caac.21590.