Japanese Journal of Clinical Oncology, 2015, 45(11) 1029–1035 doi: 10.1093/jjco/hyv137 Advance Access Publication Date: 18 September 2015 Original Article
Original Article
Young patients with colorectal cancer have increased risk of second primary cancers Yi-Hsin Liang1,2,3, Yu-Yun Shao2,3, Ho-Min Chen2,4, Chiu-Lin Lai4, Zhong-Zhe Lin2,5, Raymond Nien-Chen Kuo6, Ann-Lii Cheng2,3,5, Kun-Huei Yeh2,3,*, and Mei-Shu Lai4,7,8,* 1
Department of Oncology, National Taiwan University Hospital, Hsin-Chu Branch, Hsinchu City, 2Department of Oncology, National Taiwan University Hospital, Taipei City, 3Graduate Institute of Oncology, National Taiwan University, Taipei City, 4Center for Comparative Effectiveness Research, National Center of Excellence for Clinical Trial and Research, National Taiwan University Hospital, Taipei City, 5Department of Internal Medicine, College of Medicine, National Taiwan University, Taipei City, 6Institute of Health Policy and Management, College of Public Health, National Taiwan University, Taipei City, 7Taiwan Cancer Registry, Taipei City, and 8Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, Taipei City, Taiwan, ROC *For reprints and all correspondence: Mei-Shu Lai, Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, Room 518, No. 17, Xuzhou Rd., Taipei City 10055, Taiwan, ROC. E-mail:
[email protected]. edu.tw; Kun-Huei Yeh, Department of Oncology, National Taiwan University Hospital, No. 7, Chung-Shan South Rd., Taipei City 10002, Taiwan, ROC. E-mail:
[email protected] Received 12 June 2015; Accepted 14 August 2015
Abstract Objective: Because the number of long-term survivors of colorectal cancer has increased, second primary cancer has become an important issue. However, previous studies were heterogeneous in design, and few data for Asia-Pacific area were available. Methods: This was a retrospective population-based study conducted using the national database of the Taiwan Cancer Registry. Patients who have histology-proven primary colon cancer and rectal cancer from 1995 to 2005 were enrolled in this study. All second primary cancer events had to be histology proven. The standardized incidence ratio of second primary cancer was used as an indicator. Standardized incidence ratio was counted as the number of observed second primary cancer divided by the expected number of cancer cases in the general population. Results: A total of 65 648 eligible index patients were enrolled, and 3810 second primary cancer events were identified. The standardized incidence ratio for all of the patients was 1.03 (95% confidence interval: 0.99–1.06), which implied that the risk of second primary cancer was not significantly elevated in the index patients compared with that of the general population. The standardized incidence ratio for the patients aged 70 years was 2.52 (95% confidence interval: 2.28– 2.78), 1.18 (95% confidence interval: 1.12–1.23) and 0.80 (95% confidence interval: 0.76–0.84), respectively. In young patients (aged
