Young‐onset colorectal cancer in New South Wales: a population‐based study

• Published in: Medical journal of Australia Vol. 205; no. 10; pp. 465 - 470
• Main Authors: Boyce, Stephen, Nassar, Natasha, Lee, Cathy Yuen Yi, Suen, Michael KL, Al Zahrani, Saleh, Gladman, Marc A
• Format: Journal Article
• Language: English
• Published: Australia 21-11-2016
• Subjects: Adult; Age of Onset; Aged; Aged, 80 and over; Cohort Studies; Colorectal Neoplasms - mortality; Colorectal Neoplasms - pathology; Digestive system diseases; Environment and public health; Female; Humans; Incidence; Kaplan-Meier Estimate; Male; Mass Screening; Middle Aged; Multivariate Analysis; Neoplasms; New South Wales - epidemiology; Proportional Hazards Models; Registries; Survival Rate
• ISSN: 0025-729X; 1326-5377
• DOI: 10.5694/mja16.00237

Objective: Australia has the highest incidence of colorectal cancer (CRC) in the world. The incidence of young‐onset CRC (yCRC) is increasing in developed nations. Our aim was to determine the incidence of yCRC in New South Wales, the demographic and clinico‐pathological characteristics of these patients, and their survival.
Design, setting, participants: A population‐based cohort study of all cases of CRC diagnosed in NSW during 2001–2008. Data on newly diagnosed cases of CRC were obtained from the NSW Central Cancer Registry; mortality data were obtained from the NSW Registry of Births Deaths and Marriages (to 2012). The characteristics and tumour‐related factors of patients under 50 years of age (yCRC) were compared with those for patients aged 50 years or more.
Main outcome measures: Current incidence of yCRC and trends in incidence; 5‐year cancer‐specific survival rates and risks of death compared with older patients.
Results: 32 178 patients were diagnosed with CRC, including 2001 (6.2%) with yCRC. The incidence of yCRC was unchanged across the study period (2001, 13.7 cases per 100 000 population; 2008, 11.8 per 100 000; P = 0.26). Rectal cancer was more frequent in yCRC than in older patients (34.4% v 26.0%), as was distant disease (21.2% v 15.3%). However, 5‐year cancer‐specific survival was greater for patients with yCRC (68.8%; 95% CI, 66.2–71.2%) than for older patients (66.3%; 95% CI, 65.6–67.0%; P < 0.001).
Conclusions: The incidence of yCRC did not increase in NSW during 2001–2008. Despite more advanced disease at presentation, cancer‐specific survival was better than for older patients with CRC.