E238: A Novel Scoring System to Predict Neoadjuvant Treatment Efficacy in Pancreatic Adenocarcinoma

Introduction: While surgical resection is the only curative treatment for pancreatic adenocarcinoma (PDAC), neoadjuvant therapy may reduce margin positive resection, sterilize lymph nodes, and improve survival. However, the optimal duration of treatment has yet to be defined making the decision on when to proceed to surgery difficult. This study investigates a scoring system to track patient progress and aid in surgical decision making.

Methods: A retrospective chart review was performed on patients who received neoadjuvant chemotherapy for PDAC from 2019-2022 at a high volume center. Chemotherapy duration (gemcitabine plus nab-paclitaxel or FOLFIRINOX), radiographic response, and CA19-9 response were used to calculate a neoadjuvant score for each patient. Patients were assigned points based on the following algorithm: 1) Chemotherapy duration: 1 point for every month of treatment, 2) Ca 19-9 decrease: 50-74% - 1 point, 75-89% - 2 points, >90% - 3 points, and 3) Radiographic response: Partial – 1 point, Complete – 2 points. If CA19-9 levels were not a marker for a patient, the systemic immune-inflammation index (SII) was utilized. Resectability status, margins, histopathologic treatment effect on final pathology (graded by College of American Pathologists scoring of grade 1: marked, 2: partial, or 3: absent), and survival were evaluated.

Results:

All three score components were available for 34 of 41 patients (83%). Patients had resectable (50%), borderline resectable (44%), and locally advanced (6%) tumors. FOLFIRINOX was given to about 60% of patients. The median treatment duration was 2.5 months (range: 0.5 - 8). Neoadjuvant scores ranged from 0.5 to 10 with 56% having a score of 5 or greater. There was no difference in treatment duration or chemotherapy regimen between patients with a score greater than or less than 5. A score of 5 or greater prior to surgical resection was associated with a superior histopathologic treatment response. Of patients scoring 5 or higher, 25% had a marked response and 50% had a partial response as opposed to 0 and 40%, respectively, in patients scoring under 5 (p=0.045). Patients scoring 5 or higher had a significant increase in overall survival (p=0.04).  There was no significant difference in margin status or recurrence free survival based on neoadjuvant treatment score.


Conclusions:

This innovative scoring technique provides patient-specific guidance in pre-operative therapy duration to optimize timing of surgical intervention in PDAC. Prospective studies are needed to verify the utility of such a scoring algorithm.

Learning Objectives:

• List the benefits of neoadjuvant chemotherapy in the setting of pancreatic cancer.
• Demonstrate an understanding of the decision of timing of surgery.
• Describe the benefits of a neoadjuvant scoring system to personalized patient care.