Positive predictive value of symptoms for early-onset colorectal cancer.
[BACKGROUND] Diagnosing colorectal cancer in people under age 50 relies largely on evaluation of symptoms, despite recent recommendations to initiate screening at age 45.
APA
Chubak J, Ichikawa L, et al. (2026). Positive predictive value of symptoms for early-onset colorectal cancer.. Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology. https://doi.org/10.1158/1055-9965.EPI-25-0697
MLA
Chubak J, et al.. "Positive predictive value of symptoms for early-onset colorectal cancer.." Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology, 2026.
PMID
41879678
Abstract
[BACKGROUND] Diagnosing colorectal cancer in people under age 50 relies largely on evaluation of symptoms, despite recent recommendations to initiate screening at age 45. There is limited information on the positive predictive value (PPV) of symptoms as indicators of early-onset colorectal cancer.
[MATERIALS AND METHODS] We identified patients ages 42-49 years in three community-based health systems between 2012-2020 whose first recorded colonoscopy had a diagnostic indication, with symptoms present in the two years before the colonoscopy. We computed the PPV for colorectal cancer by: each individual symptom, combinations of the three most common symptoms, and combinations of the three symptoms with highest PPVs and computed 95% confidence intervals (CI). We also evaluated PPV of recent symptoms stratified according to timing of onset and estimated the PPV of symptoms when followed by positive or negative fecal testing.
[RESULTS] The study included 28,198 patients. PPV for specific symptoms with or without other symptoms was 2.4% (95% CI: 2.2%, 2.7%) for blood loss and 4.5% (95% CI: 3.3%, 5.9%) for positive fecal testing. Pairwise and three-way combinations of blood loss, diarrhea, and abdominal mass had PPV point estimates for colorectal cancer above 3%.
[CONCLUSIONS] Our study suggests that specific symptoms and combinations may identify patients with ≥3% prevalence of colorectal cancer in patients aged 42-49, and that fecal testing results may further identify patients with a higher probability of colorectal cancer.
[IMPACT] Future research is needed to develop high PPV strategies for identifying early-onset colorectal cancer without compromising sensitivity.
[MATERIALS AND METHODS] We identified patients ages 42-49 years in three community-based health systems between 2012-2020 whose first recorded colonoscopy had a diagnostic indication, with symptoms present in the two years before the colonoscopy. We computed the PPV for colorectal cancer by: each individual symptom, combinations of the three most common symptoms, and combinations of the three symptoms with highest PPVs and computed 95% confidence intervals (CI). We also evaluated PPV of recent symptoms stratified according to timing of onset and estimated the PPV of symptoms when followed by positive or negative fecal testing.
[RESULTS] The study included 28,198 patients. PPV for specific symptoms with or without other symptoms was 2.4% (95% CI: 2.2%, 2.7%) for blood loss and 4.5% (95% CI: 3.3%, 5.9%) for positive fecal testing. Pairwise and three-way combinations of blood loss, diarrhea, and abdominal mass had PPV point estimates for colorectal cancer above 3%.
[CONCLUSIONS] Our study suggests that specific symptoms and combinations may identify patients with ≥3% prevalence of colorectal cancer in patients aged 42-49, and that fecal testing results may further identify patients with a higher probability of colorectal cancer.
[IMPACT] Future research is needed to develop high PPV strategies for identifying early-onset colorectal cancer without compromising sensitivity.