Colorectal cancer outcomes and treatment patterns in patients too young for average‐risk screening

Abstract

Background The proportion of cancer cases in younger patients is increasing though colorectal cancer (CRC) screening guidelines recommend starting at age 50. The national treatment patterns and outcomes of these patients are largely unknown. Methods This is a population-based retrospective cohort study of the nationally representative Surveillance, Epidemiology, and End Results registry for patients diagnosed with CRC from 1998-2011. Patients were categorized as being younger or older than the recommended screening age. Differences in stage at diagnosis, patterns of therapy, and disease-specific survival were compared between age groups using multinomial regression, multiple regression, cox-proportional hazards regression, and Weibull survival analysis. Results Of 258,024 CRC patients, 37,847 (15%) were younger than 50. Young patients were more likely to present with regional (Relative risk ratio [RRR]: 1.3, p<0.001) or distant (RRR: 1.5, p<0.001) disease. CRC patients with distant metastasis were more likely to receive surgical therapy for their primary tumor in the younger age group (adjusted probability: 72% vs. 63%; p<0.001), and radiation therapy was more likely in younger RC patients (adjusted probability: 53% vs. 48%; p<0.001). Patients younger than screening age had better overall disease-specific survival (Hazard ratio: 0.77; p<0.001), despite a larger proportion presenting with advanced disease. Conclusions Colorectal cancer patients diagnosed before age 50 are more likely to present with advanced stage disease. However, they receive more aggressive therapy and achieve longer disease-specific survival, despite the greater proportion with advanced-stage disease. These findings suggest the need for improved risk assessment and screening decisions for younger adults.

Trends in colorectal cancer incidence among younger adults—Disparities by age, sex, race, ethnicity, and subsite

“…We found that age‐adjusted invasive CRC incidence rates in younger adults (20‐49) have risen significantly since the mid‐1990s in NJ, similar to the increase in US younger adults 1, 2, 3, 4, 5, 6. This contrasts with older adults (≥50) in NJ and the US whose CRC incidence rates have declined significantly for several decades 1, 2, 3, 4, 5, 6.…”

“…This contrasts with older adults (≥50) in NJ and the US whose CRC incidence rates have declined significantly for several decades 1, 2, 3, 4, 5, 6. CRC incidence rates are increasing the fastest among the youngest adults ages 20‐39.…”

“…Careful studies of the risks and benefits of lowering the current screening age, perhaps specifically for low‐cost, low‐risk methods such as fecal immunochemical test kits or fecal DNA tests, should also be considered 2. Surveillance among survivors will then be key to understanding prevention and/or early detection of subsequent primaries.…”

“…Recent studies indicate colorectal cancer (CRC) has been rising in younger adults who are under the recommended screening age of 50 1, 2, 3, 4, 5, 6, 7. In New Jersey (NJ), an average of 435 younger adults (approximately 10% of all CRC cases) are diagnosed each year 8.…”

“…The latest research, using age‐period‐cohort modeling, found that US adults born around 1990 have double the risk of colon cancers and quadruple the risk of rectal cancer compared to adults born around 1950 1. Prior studies have analyzed race/ethnicity and sex,1, 2, 3, 4, 5, 6 but the authors are not aware of studies in NJ or the US which have examined trends by age, sex, race, ethnicity, and subsite in combination in younger adults with CRC. Right‐ and left‐sided colon cancers have markedly different underlying biological characteristics, and are distinct from rectal cancers.…”