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Risk of second primary colorectal cancer with particular reference to age at diagnosis
Author(s) -
O’Dwyer S. T.,
Renehan A. G.,
Zwahlen M.,
Egger M.
Publication year - 2006
Publication title -
colorectal disease
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.029
H-Index - 89
eISSN - 1463-1318
pISSN - 1462-8910
DOI - 10.1111/j.1463-1318.2006.01140_1.x
Subject(s) - medicine , colorectal cancer , colonoscopy , relative risk , population , epidemiology , cancer , absolute risk reduction , confidence interval , environmental health
Objective: Patients with a history of colorectal cancer are considered at increased risk of second metachronous colorectal cancer (SM‐CRC), for which they frequently receive intensive colonoscopic surveillance. In view of the ambiguous nature of the existing evidence and the growing interest in targeted surveillance, we sought to quantify long‐term risk with particular reference to age at diagnosis. Method: The Surveillance Epidemiology and End Results database was used to estimate risk of SM‐CRC after first incident colorectal cancer diagnosed between 1975 and 1999. We calculated time‐dependent rates using Kaplan–Meier estimates and relative risk compared with the US general population. Results: From 311 689 eligible patients, there were 6387 SM‐CRCs. At 15‐years following initial diagnosis, the SM‐CRC rate was 6.3% (95% CI, 6.1–6.5). For patients with synchronous primary cancers ( n = 9936, 3.2%), the 15‐year SM‐CRC rate increased to 10.5% (95% CI, 9.1–12.2). Younger age predicted for increased relative risks but absolute cumulative rates at 15 years were low (Table). Conclusion: The long‐term cumulative risk of SM‐CRCs after first colorectal cancer is low, even among younger age patients. These data do not support the routine use of high‐frequency colonoscopy surveillance in patients with a history of colorectal cancer.Age groups (years) 20–29 30–39 40–49 50–59 60–69 70–79 80+Relative risk – men 60.4 15.1 4.52 1.87 1.34 1.28 1.15 Relative risk – women 18.4 9.63 4.08 2.29 1.72 1.46 1.24 Absolute risk – both sexes 3.53 3.74 4.29 4.70 6.15 7.59 7.26