Supplementary Material for: Retrospective Analysis of CA19-9 Decrease in Patients with Metastatic Pancreatic Carcinoma Treated with FOLFIRINOX or Gemcitabine in a Randomized Phase III Study (ACCORD11/PRODIGE4)

<b><i>Objectives:</i></b> Carbohydrate antigen 19-9 (CA19-9) is a sensitive and specific serum marker in pancreatic cancer. Our retrospective analysis aims to evaluate CA19-9 decrease in patients with metastatic pancreatic cancer treated in ACCORD11/PRODIGE4 (FOLFIRINOX vs. gemcitabine). <b><i>Methods:</i></b> A total of 342 patients were treated. CA19-9 was measured at 8 weeks (±2) in 160 patients from a total of 282 with abnormal CA19-9 values at baseline (gemcitabine arm, <i>n</i> = 75; FOLFIRINOX arm, <i>n</i> = 85). In the present study, 8-week CA19-9 decrease or greater CA19-9 decrease according to the 20 and 90% thresholds were analyzed. Progression-free survival (PFS) and overall survival (OS) were estimated in each subgroup. <b><i>Results:</i></b> In the FOLFIRINOX arm, patients with an 8-week CA19-9 decrease or greater CA19-9 decrease ≥20% showed improved median OS, PFS, and objective response rate. In the overall study population, median OS and PFS were significantly improved in patients with an 8-week CA19-9 decrease ≥20% (vs. &lt;20%). The 8-week CA19-9 decrease was predictive of PFS (interaction test significant according to treatment arm; <i>p</i> = 0.006). <b><i>Conclusion:</i></b> An 8-week CA19-9 decrease ≥20% is a prognostic factor for OS and PFS. The 8-week CA19-9 decrease (20% threshold) is predictive of PFS. It could help to evaluate the efficacy of FOLFIRINOX and gemcitabine regimens.

**研究目的**：糖类抗原19-9（Carbohydrate antigen 19-9, CA19-9）是胰腺癌的敏感且特异的血清标志物。本回顾性分析旨在评估接受ACCORD11/PRODIGE4试验（FOLFIRINOX方案对比吉西他滨）治疗的转移性胰腺癌患者的CA19-9下降情况。
**研究方法**：本研究共纳入342例患者。基线CA19-9水平异常的282例患者中，有160例在治疗第8周（±2周）时完成了CA19-9检测，其中吉西他滨组75例，FOLFIRINOX组85例。本研究分析了8周时的CA19-9下降幅度，以及以20%、90%为阈值的CA19-9下降情况，并对各亚组的无进展生存期（Progression-free survival, PFS）和总生存期（Overall survival, OS）进行估算。
**研究结果**：在FOLFIRINOX组中，8周时CA19-9下降幅度≥20%的患者，其中位总生存期、无进展生存期及客观缓解率均得到改善。在全部研究人群中，8周时CA19-9下降≥20%的患者，其中位总生存期和无进展生存期显著优于下降幅度<20%的患者。8周时CA19-9下降幅度可预测无进展生存期（按治疗组进行的交互检验具有统计学意义，*p*=0.006）。
**研究结论**：8周时CA19-9下降幅度≥20%是总生存期和无进展生存期的预后因素。以20%为阈值的8周CA19-9下降幅度可预测无进展生存期，该指标或可用于评估FOLFIRINOX方案与吉西他滨方案的治疗疗效。