CT-Based Risk Scoring System Outperforms AJCC TNM Staging for Predicting Recurrence of Pancreatic Ductal Adenocarcinoma

For patients who undergo radical resection for pancreatic ductal adenocarcinoma (PDAC), a new computed tomography (CT)-based early recurrence scoring (ERS) system may provide significantly enhanced prediction of post-op recurrence in comparison to traditional staging with the American Joint Committee on Cancer (AJCC) Tumor, Node, Metastasis (TNM) system.

In a new multicenter retrospective study, recently published in European Radiology, researchers developed and compared the ERS system versus AJCC TNM staging in a total cohort of 333 patients who had radical resection for resectable PDAC. In addition to the CA 19-9 blood test, the ERS system incorporated CT assessments for perineural invasion, tumor necrosis and lymph node metastasis that demonstrated 1.83, 3.20 and 1.84 hazard ratios (HRs), respectively for PDAC recurrence at < one year post-op, according to the study.

In a testing cohort of 92 patients (mean age of 60), the study authors found a 22.1 percent higher AUC than the AJCC TNM system for predicting early PDAC recurrence (85.1 percent vs. 63 percent) and a 36.7 percent higher AUC in the 31-patient external validation cohort (90.1 percent vs. 53.4 percent).

“ … We developed an easily usable and reproducible ERS score to predict ER after radical resection of PDAC, which was internally and externally validated and outperformed the widely adopted AJCC TNM staging system,” wrote lead study author Yan Deng, M.D., who is affiliated with the Department of Radiology at the West China Hospital and Sichuan University in Chengdu, China, and colleagues, and colleagues.

The researchers pointed out that patients with high-risk ERS scores ( > 17) had greater than 50 percent higher post-op PDAC recurrence rates than those with low-risk ERS scores (< 17) in the testing cohort (81.4 percent vs. 22.5 percent) and the external validation cohort (81.2 percent vs. 26.7 percent).

Patients at high-risk of early PDAC recurrence had a 15.6 percent higher incidence of lymphovascular invasion (LVI), a 17.1 percent higher prevalence of 3/4 grade tumor differentiation and an 18.4 percent higher rate of lymph node positivity, according to the study authors.

“This scoring system has certain clinical application value in predicting ER after radical resection and selecting optimal patients for radical resection. Neoadjuvant therapy may be a more reasonable choice for patients with a high risk of ER (ERS ≥ 17),” noted Deng and colleagues. “Specifically, in the present study, high-risk patients predicted by ERS were more likely to have poor differentiation, lymph node metastasis, LVI, and worse (recurrence-free survival).”

(Editor’s note: For related content, see “Predicting Diabetes on CT Scans: What New Research Reveals with Pancreatic Imaging Biomarkers,” “FDA Grants Breakthrough Device Designation for Emerging High-Intensity Focused Ultrasound Treatment of Pancreatic Cancer” and “New Study Identifies Key Computed Tomography Findings for Post-Op Recurrence of Pancreatic Cancer.”)

In regard to study limitations, the authors acknowledged the potential for bias with the retrospective study design, the small cohort for external validation, poor consistency with lymph node metastasis assessment on CT and a lack of uniform treatment regimens for patients receiving adjuvant therapy.