Exploring the role of CA 19-9 dynamics in pancreatic cancer multidisciplinary treatment: Proposal of the PANC classification.

[BACKGROUND] Advancements in multiagent chemotherapy have transformed the management of pancreatic cancer as a systemic disease, with surgery playing a crucial role in determining prognosis. Serum carbohydrate antigen 19-9 remains the most critical biomarker for assessing treatment response and guiding clinical decisions. This study aimed to evaluate carbohydrate antigen 19-9 dynamics around chemotherapy and surgery to optimize treatment strategies and improve patient outcomes.

[METHOD] We retrospectively analyzed pancreatic cancer patients who received preoperative chemotherapy followed by radical resection. Based on carbohydrate antigen 19-9 response patterns before and after chemotherapy, as well as after surgery, we established the PANC classification and assessed its prognostic significance.

[RESULTS] Among 283 patients, the median overall survival was 56.3 months, and recurrence-free survival was 26.0 months. The PANC classification categorized patients as follows: type 1 (Preoperative normalization), 148 patients (52.3%), type 2 (After-surgery normalization), 103 patients (36.4%), type 3 (Non-normalized Decline), 12 patients (4.2%), and type 4 (Complex dynamics), 20 patients (7.1%). Type 1 and 2 responses were associated with favorable overall survival (61.1 and 57.8 months) and recurrence-free survival (35.0 and 25.6 months), whereas type 3 and 4 responses were associated with poorer outcomes. A multivariate Cox proportional hazard model identified types 1 and 2 (versus types 3 and 4) as independent prognostic factors (hazard ratio = 3.20; 95% confidence interval, 1.99-5.16; P < .001) along with other important factors.

[CONCLUSIONS] The PANC classification provides a practical framework for categorizing carbohydrate antigen 19-9 dynamics. It can be easily aligned with diverse treatment strategies across various institutions and regions, ultimately improving patient outcomes.