From the Journals

Black/White gap gone: ‘The only cancer where this has happened’


The historically higher incidence rates of lung cancer among Black men, compared with White men, in the United States have all but been eliminated, at least among most men in the younger age groups, a new analysis from the American Cancer Society (ACS) indicates.

Among women, the trend is even more impressive, as the Black/White gap in lung cancer incidence rates has actually reversed in younger women. Black women in certain age groups are now less likely to develop lung cancer than White women, the same study indicates.

These trends reflect the steeper declines in smoking rates among Blacks in the US, compared with comparably-aged Whites, say the authors.

“This is the only cancer where this has happened,” lead author Ahmedin Jemal, DVM, PhD, senior vice president for Data Science at the American Cancer Society, told Medscape Medical News.

“If you look at cancers that are affected by access to screening and treatment, the disparity between the Blacks and the Whites has been increasing over the years because tests and treatment require access to insurance, so the Whites are getting more of them than the Blacks,” Jemal explained.

“But for smoking, all you have to do for prevention is just don’t smoke, so this is a success story that really should be highlighted,” he emphasized.

The study was published online Aug. 20 in JNCI Cancer: Spectrum.

Nationwide Incidence Data

For this study, Jemal and colleagues collected nationwide incidence data on individuals between ages 30 and 54 who had been diagnosed with lung cancer between 1997 and 2016.

“We categorized age at diagnosis by 5-year age intervals (from 30-34 to 50-54 years) and year of diagnosis by 5-year calendar period (from 1997-2001 to 2012-2016),” the investigators explain.

Analyses showed that lung cancer incidence rates generally decreased among both Black and White men during the study interval but the decline in incidence rates was steeper in Black men than in White men. As a consequence, the Black-to-White incidence rate ratios (IRRs) became similar in men born between 1967 and 1972 and reversed in women born since about 1967. For example, the Black-to-White IRRs in men between the ages of 40 and 44 who were born between 1957 and 1972 declined from 1.92 to 1.03.

Similarly, lung cancer incidence rates during the study interval declined among both Black and White women between the ages of 30 and 49 but, again, the decline was “considerably larger” among Black women. As a consequence, the Black-to-White IRR in women age 45 to 49 dropped from 1.25 during the period 1997-2001 down to 0.83 during the period 2012-2016.

This is in stark contrast to historical trends in lung cancer incidence rates, which were over 30% higher among similarly aged Black women born in the late 1950s. Now, lung cancer incidence rates are about 30% lower for similarly aged Black women born in 1972, compared with White women.

For Black and White women between age 50 and 54, lung cancer incidence rates either declined only slightly or remained stable during the study interval, the investigators reported.

The one exception to the diminishing gap in lung cancer incidence rates between Black and White men was an observed increase in IRRs in men born around the period 1977-1982

Among this group of men, who were between age 30 and 39 in the years 2012-2016, lung cancer incidence rates were higher in Black men than in White men.

As the authors point out, this increase in lung cancer rates among young Black men likely reflects a rapid rise in smoking seen among Black youth in the 1990s.

This trend coincided with an R.J. Reynolds tobacco ad campaign in which African Americans were targeted; between 1991 and 1997, the prevalence of smoking among Black high school students doubled from 14.1% to 28.2%, the investigators point out, citing a 2008 Centers for Disease Control and Prevention report on cigarette use among US high school students.


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