Patterns in Cancer Incidence Among People Under 50 Years of Age

Cancer has traditionally been considered a disease of the elderly (defined as adults aged 50 years or older), but recent data suggest a marked increase in the incidence of cancer of various organs among patients younger than 50 years, known collectively as breast cancer. early appearance . These cancers affect a variety of organ systems, including the breast, colon and/or rectum, pancreas, head and neck, kidneys, and reproductive organs. The increase in early-onset cancers is likely associated with the increasing incidence of obesity , as well as changes in environmental exposures , such as smoke and gasoline, sleep patterns, physical activity, microbiota, and transient exposure to carcinogenic compounds.

Early-onset cancer is associated with substantial mortality and morbidity. Recent efforts have evaluated the incidence patterns of specific types of early-onset cancers. However, an updated overview of recent patterns of early-onset cancer in the US that is not limited to specific organ systems has not been reported. This study used population-based data from the National Cancer Institute’s Surveillance, Epidemiology, and End Results (SEER) program to characterize temporal patterns in the incidence of early-onset cancers in the US from 2010 to 2019.

The primary objective was to characterize the temporal patterns in early-onset cancer overall and by organ system. The secondary objective was to evaluate temporal patterns of early-onset cancer stratified by sex, age group, race, and ethnicity.

Importance  

Emerging data suggest that the incidence of early-onset cancers, defined as cancers diagnosed in people younger than 50 years, is increasing, but updated data is limited.

Aim  

To characterize patterns in the incidence of early-onset cancers in the US from 2010 to 2019 and provide granular data on the cancers with the fastest growing incidence rates.

Design, environment and participants  

This population-based cohort study analyzed data from 17 National Cancer Institute Surveillance, Epidemiology, and End Results registries from January 1, 2010 to December 31, 2019. Age-standardized incidence rates per 100,000 were extracted. people for early-onset cancers, with age-adjusted rates to the US standard population.

A total of 562,145 patients with early-onset cancer were identified and included between 2010 and 2019. Data were analyzed from October 16, 2022 to May 23, 2023.

Main results and measures  

The primary outcomes were incidence rates and descriptive epidemiological data for people younger than 50 years with cancer. The annual percentage change (APC) of the age-standardized incidence rate was estimated using the Joinpoint regression program .

Results  

Among 562,145 patients (324,138 [57.7%] aged 40 to 49 years; 351,120 [62.5%] women) with early-onset cancer, 4,565 (0.8%) were American Indian or Alaska Native, 54,876 (9.8%) were Asian or Pacific Islander, 61,048 (10.9%) were black, 118,099 (21.0%) were Hispanic, 314,610 (56.0%) were white, and 8,947 (1 .6%) were of unknown race and/or ethnicity.

From 2010 to 2019, the age-standardized incidence rate of early-onset cancers increased overall (APC, 0.28%; 95% CI, 0.09%-0.47%; P = 0.01) and in females (APC, 0.67%; 95% CI, 0.39%-0.94%; P = 0.001) but decreased in male individuals (APC, −0.37%; 95% CI, −0.51 % to −0.22%; P < .001).

In contrast, the age-standardized incidence rate of cancers in people aged 50 years or older decreased over the study period (APC, −0.87%; 95% CI, −1.06% to −0.67 %; P < 0.001).

In 2019, the largest number of incident cases of early-onset cancer occurred in the breast (n = 12,649). From 2010 to 2019, gastrointestinal cancers had the fastest growing incidence rates among all early-onset cancer groups (APC, 2.16%; 95% CI, 1.66%-2.67%; P < 0.001).

Among gastrointestinal cancers , those with the fastest growing incidence rates were those of the appendix (APC, 15.61%; 95% CI, 9.21%-22.38%; P < 0.001), intrahepatic bile duct ( APC, 8.12%; 95% CI, 4.94%-11.39%; P < 0.001) and pancreas (APC, 2.53%; 95% CI, 1.69%-3.38%; P < .001).

Figure: Incident cases of early-onset cancer in 2010 and 2019

Implications for clinical practice and future research

This nationwide study provides updated evidence that the incidence of early-onset cancers in the US is increasing and highlights several disparities. The increase in early-onset cancer occurred disproportionately among women, American Indians or Alaska Natives, Asians or Pacific Islanders, and people ages 30 to 39 .

More research is required to fully elucidate the reasons for these disparities. Healthcare professionals need to be informed about the increasing incidence of early-onset cancer, and investigations to detect possible tumors should be considered when clinically appropriate, even in patients younger than 50 years. These data will be useful to public health specialists and healthcare policy makers and will serve as a call to action for further research into the various environmental factors that may be associated with this concerning pattern.

Final message

This nationwide cohort study found that the incidence of early-onset cancers continued to increase in the US from 2010 to 2019. While breast cancer had the highest number of incident cases, gastrointestinal cancers had the highest rates of Fastest growing incidence among all early-onset cancers. . These data may have implications for the development of surveillance strategies and funding priorities.

Reference : Patterns in Cancer Incidence Among People Younger Than 50 Years in the US, 2010 to 2019 . Benjamin Koh; Darren Jun Hao Tan; Cheng Han Ng, MBBS; et al. JAMA Network Open. 2023;6(8):e2328171. doi:10.1001/jamanetworkopen.2023.28171