Fu Jianfei, Ruan Hang, Zheng Hongjuan, Cai Cheng, Zhou Shishi, Wang Qinghua, Chen Wenbin, Fu Wei, Du Jinlin
Department of Medical Oncology, Jinhua Hospital, Zhejiang University School of Medicine, Jinhua, Zhejiang, P.R. China.
Department of Colorectal Surgery, Jinhua Hospital, Zhejiang University School of Medicine, Jinhua, Zhejiang, P.R. China.
PeerJ. 2019 Feb 15;7:e6350. doi: 10.7717/peerj.6350. eCollection 2019.
This study was performed to identify a reasonable cutoff age for defining older patients with colorectal cancer (CRC) and to examine whether old age was related with increased colorectal cancer-specific death (CSD) and poor colorectal cancer-specific survival (CSS).
A total of 76,858 eligible patients from the surveillance, epidemiology, and end results (SEER) database were included in this study. The Cox proportional hazard regression model and the Chow test were used to determine a suitable cutoff age for defining the older group. Furthermore, a propensity score matching analysis was performed to adjust for heterogeneity between groups. A competing risk regression model was used to explore the impact of age on CSD and non-colorectal cancer-specific death (non-CSD). Kaplan-Meier survival curves were plotted to compare CSS between groups. Also, a Cox regression model was used to validate the results. External validation was performed on data from 1998 to 2003 retrieved from the SEER database.
Based on a cutoff age of 70 years, the examined cohort of patients was classified into a younger group ( = 51,915, <70 years of old) and an older group ( = 24,943, ≥70 years of old). Compared with younger patients, older patients were more likely to have fewer lymph nodes sampled and were less likely to receive chemotherapy and radiotherapy. When adjusted for other covariates, age-dependent differences of 5-year CSD and 5-year non-CSD were significant in the younger and older groups (15.84% and 22.42%, < 0.001; 5.21% and 14.21%, < 0.001). Also an age of ≥70 years remained associated with worse CSS comparing with younger group (subdistribution hazard ratio, 1.51 95% confidence interval (CI) [1.45-1.57], < 0.001). The Cox regression model as a sensitivity analysis had a similar result. External validation also supported an age of 70 years as a suitable cutoff, and this older group was associated with having reduced CSS and increased CSD.
A total of 70 is a suitable cutoff age to define those considered as having elderly CRC. Elderly CRC was associated with not only increased non-CSD but also with increased CSD. Further research is needed to provide evidence of whether cases of elderly CRC should receive stronger treatment if possible.
本研究旨在确定定义老年结直肠癌（CRC）患者的合理截止年龄，并探讨高龄是否与结直肠癌特异性死亡（CSD）增加及结直肠癌特异性生存（CSS）不佳相关。
本研究纳入了监测、流行病学和最终结果（SEER）数据库中的76858例符合条件的患者。采用Cox比例风险回归模型和Chow检验来确定定义老年组的合适截止年龄。此外，进行倾向评分匹配分析以调整组间异质性。使用竞争风险回归模型来探讨年龄对CSD和非结直肠癌特异性死亡（非CSD）的影响。绘制Kaplan-Meier生存曲线以比较组间CSS。同时，使用Cox回归模型验证结果。对从SEER数据库检索的1998年至2003年的数据进行外部验证。
基于70岁的截止年龄，将所研究的患者队列分为较年轻组（n = 51915，年龄<70岁）和较老年组（n = 24943，年龄≥70岁）。与较年轻患者相比，较老年患者更有可能采样的淋巴结较少，且接受化疗和放疗的可能性较小。在调整其他协变量后，较年轻组和较老年组的5年CSD和5年非CSD的年龄依赖性差异具有显著性（15.84%和22.42%，P < 0.001；5.21%和14.21%，P < 0.001）。与较年轻组相比，年龄≥70岁仍与较差的CSS相关（亚分布风险比，1.51；95%置信区间（CI）[1.45 - 1.57]，P < 0.001）。作为敏感性分析的Cox回归模型有类似结果。外部验证也支持70岁作为合适的截止年龄，且该较老年组与CSS降低和CSD增加相关。
70岁是定义老年CRC患者的合适截止年龄。老年CRC不仅与非CSD增加相关，还与CSD增加相关。需要进一步研究以提供证据，证明老年CRC患者是否应尽可能接受更积极的治疗。
