Li Zheng, Zhang Xiaojie, Guo Chunguang, Sun Chongyuan, Li Zefeng, Fei He, Chen Yingtai, Zhao Dongbing
Department of Pancreatic and Gastric Surgical Oncology, National Cancer Center/National Clinical Research for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College Beijing 100021, China.
Am J Cancer Res. 2023 May 15;13(5):1938-1951. eCollection 2023.
There has been a long-standing controversy regarding the number of lymph nodes (LNs) examined intraoperatively for accurate lymphatic staging and significantly better survival of patients with pancreatic ductal adenocarcinoma (PDAC), and no consensus has been reached for the elderly with the age of over 75 years. Given these, the present study aims to investigate the appropriate number of examined lymph nodes (ELNs) for elderly patients mentioned above. In this study, population-based data on 20,125 patients in 2000 to 2019 from the Surveillance, Epidemiology, and End Results database were reviewed retrospectively. The eighth edition staging system of the American Joint Committee on Cancer (AJCC) was applied. Propensity score matching (PSM) was performed to reduce the effects of multiple biases. By using binomial probability law and maximally selected rank statistics, the minimum number of ELN (MNELN) for accurate nodal involvement assessment and optimal ELN number for significantly better survival were calculated, respectively. In addition, Kaplan-Meier curves and Cox proportional hazard regression models were constructed for further survival analysis. As a result, 6623 patients were enrolled in total in the study. Elderly patients had fewer lymph node metastases and a smaller lymph node ratio (LNR) (all <0.05). However, poorer overall survival (OS) and cancer-specific survival (CSS) of elderly patients were observed in each pN stage (all <0.05), except for CSS in N2. The proportions of N2 and N0 stages increased and decreased respectively with increasing number of ELN significantly. MNELN for accurate nodal assessment was 19 according to binomial probability law, and the optimal ELN number for significantly better survival was 17. Additionally, the number of ELN (<17 or ≥17) was also considered a strong prognostic predictor for elderly PDAC patients (≥75 years) in the Cox proportional hazard regression model (Overall survival: hazard ratio [HR]=0.74, 95% confidence interval [CI]: 0.65-0.83, <0.001; Cancer-specific survival: HR=0.75, 95% CI: 0.66-0.85, <0.001). In conclusion, extended lymphadenectomy is suitable for elderly PDAC patients undergoing curative-intent surgery owing to an accurate assessment of nodal status and improved long-term prognosis. However, a random, prospective clinical trial is warranted before the recommendation of extended lymphadenectomy for the elderly.
关于术中检查的淋巴结数量对于准确进行淋巴分期以及显著提高胰腺导管腺癌（PDAC）患者生存率的问题，长期以来一直存在争议，对于75岁以上的老年患者尚未达成共识。鉴于此，本研究旨在调查上述老年患者合适的检查淋巴结数量（ELNs）。在本研究中，回顾性分析了监测、流行病学和最终结果数据库中2000年至2019年20125例患者的基于人群的数据。应用了美国癌症联合委员会（AJCC）第八版分期系统。进行倾向评分匹配（PSM）以减少多种偏倚的影响。分别使用二项式概率定律和最大选择秩统计量计算准确评估淋巴结受累情况所需的最小检查淋巴结数量（MNELN）以及显著提高生存率所需的最佳ELN数量。此外，构建了Kaplan-Meier曲线和Cox比例风险回归模型进行进一步的生存分析。结果，本研究共纳入6623例患者。老年患者的淋巴结转移较少且淋巴结比率（LNR）较小（均<0.05）。然而，除N2期的癌症特异性生存率外，各pN分期中老年患者的总生存期（OS）和癌症特异性生存期（CSS）均较差（均<0.05）。随着ELN数量增加，N2期和N0期的比例分别显著增加和降低。根据二项式概率定律，准确进行淋巴结评估所需的MNELN为19，显著提高生存率所需的最佳ELN数量为17。此外，在Cox比例风险回归模型中，ELN数量（<17或≥17）也被认为是老年PDAC患者（≥75岁）的一个强有力的预后预测因素（总生存期：风险比[HR]=0.74，95%置信区间[CI]：0.65 - 0.83，<0.001；癌症特异性生存期：HR=0.75，95% CI：0.66 - 0.85，<0.001）。总之，由于能够准确评估淋巴结状态并改善长期预后，扩大淋巴结清扫术适用于接受根治性手术的老年PDAC患者。然而，在推荐对老年患者进行扩大淋巴结清扫术之前，有必要进行一项随机、前瞻性临床试验。
