Magaji Bello Arkilla, Moy Foong Ming, Roslani April Camilla, Law Chee Wei
Julius Centre University of Malaya, Department of Social & Preventive Medicine, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia.
University of Malaya Cancer Research Institute (UMCRI), Kuala Lumpur, Malaysia.
BMC Cancer. 2017 May 18;17(1):339. doi: 10.1186/s12885-017-3336-z.
Colorectal cancer is the third most commonly diagnosed malignancy and the fourth leading cause of cancer-related death globally. It is the second most common cancer among both males and females in Malaysia. The economic burden of colorectal cancer is likely to increase over time owing to its current trend and aging population. Cancer survival analysis is an essential indicator for early detection and improvement in cancer treatment. However, there was a scarcity of studies concerning survival of colorectal cancer patients as well as its predictors. Therefore, we aimed to determine the 1-, 3- and 5-year survival rates, compare survival rates among ethnic groups and determine the predictors of survival among colorectal cancer patients.
This was an ambidirectional cohort study conducted at the University Malaya Medical Centre (UMMC) in Kuala Lumpur, Malaysia. All Malaysian citizens or permanent residents with histologically confirmed diagnosis of colorectal cancer seen at UMMC from 1 January 2001 to 31 December 2010 were included in the study. Demographic and clinical characteristics were extracted from the medical records. Patients were followed-up until death or censored at the end of the study (31st December 2010). Censored patients' vital status (whether alive or dead) were cross checked with the National Registration Department. Survival analyses at 1-, 3- and 5-year intervals were performed using the Kaplan-Meier method. Log-rank test was used to compare the survival rates, while Cox proportional hazard regression analysis was carried out to determine the predictors of 5-year colorectal cancer survival.
Among 1212 patients, the median survival for colorectal, colon and rectal cancers were 42.0, 42.0 and 41.0 months respectively; while the 1-, 3-, and 5-year relative survival rates ranged from 73.8 to 76.0%, 52.1 to 53.7% and 40.4 to 45.4% respectively. The Chinese patients had the lowest 5-year survival compared to Malay and Indian patients. Based on the 814 patients with data on their Duke's staging, independent predictors of poor colorectal cancer (5-year) survival were male sex (Hazard Ratio [HR]: 1.41; 95% CI: 1.12, 1.76), Chinese ethnicity (HR: 1.41; 95% CI: 1.07,1.85), elevated (≥ 5.1 ng/ml) pre-operative carcino-embryonic antigen (CEA) level (HR: 2.13; 95% CI: 1.60, 2.83), Duke's stage C (HR: 1.68; 95% CI: 1.28, 2.21), Duke's stage D (HR: 4.61; 95% CI: 3.39, 6.28) and emergency surgery (HR: 1.52; 95% CI: 1.07, 2.15).
The survival rates of colorectal cancer among our patients were comparable with those of some Asian countries but lower than those found in more developed countries. Males and patients from the Chinese ethnic group had lower survival rates compared to their counterparts. More advanced staging and late presentation were important predictors of colorectal cancer survival. Health education programs targeting high risk groups and emphasizing the importance of screening and early diagnosis, as well as the recognition of symptoms and risk factors should be implemented. A nationwide colorectal cancer screening program should be designed and implemented to increase early detection and improve survival outcomes.
结直肠癌是全球第三大常见诊断恶性肿瘤及第四大癌症相关死亡原因。在马来西亚，它是男性和女性中第二常见的癌症。由于目前的趋势和人口老龄化，结直肠癌的经济负担可能会随着时间的推移而增加。癌症生存分析是癌症早期检测和治疗改善的重要指标。然而，关于结直肠癌患者生存情况及其预测因素的研究较少。因此，我们旨在确定1年、3年和5年生存率，比较不同种族群体的生存率，并确定结直肠癌患者生存的预测因素。
这是一项在马来西亚吉隆坡马来亚大学医学中心（UMMC）进行的双向队列研究。纳入2001年1月1日至2010年12月31日在UMMC就诊且经组织学确诊为结直肠癌的所有马来西亚公民或永久居民。从病历中提取人口统计学和临床特征。对患者进行随访直至死亡或在研究结束时（2010年12月31日）进行截尾。截尾患者的生命状态（是否存活）与国家登记部门进行交叉核对。使用Kaplan-Meier方法进行1年、3年和5年间隔的生存分析。使用对数秩检验比较生存率，同时进行Cox比例风险回归分析以确定5年结直肠癌生存的预测因素。
在1212例患者中，结直肠癌、结肠癌和直肠癌的中位生存期分别为42.0个月、42.0个月和41.0个月；而1年、3年和5年相对生存率分别为73.8%至76.0%、52.1%至53.7%和40.4%至45.4%。与马来族和印度族患者相比，华裔患者的5年生存率最低。基于814例有杜克分期数据的患者，结直肠癌（5年）生存不良的独立预测因素为男性（风险比[HR]：1.41；95%置信区间：1.12，1.76）、华裔（HR：1.41；95%置信区间：1.07，1.85）、术前癌胚抗原（CEA）水平升高（≥5.1 ng/ml）（HR：2.13；95%置信区间：1.60，2.83）、杜克分期C（HR：1.68；95%置信区间：1.28，2.21）、杜克分期D（HR：4.61；95%置信区间：3.39，6.28）和急诊手术（HR：1.52；95%置信区间：1.07，2.15）。
我们患者的结直肠癌生存率与一些亚洲国家相当，但低于更发达国家。男性和华裔患者的生存率低于其他人群。分期越晚和就诊越迟是结直肠癌生存的重要预测因素。应实施针对高危人群的健康教育项目，强调筛查和早期诊断的重要性，以及症状和风险因素的识别。应设计并实施全国性的结直肠癌筛查项目，以提高早期检测率并改善生存结果。
