The role of Ca 19-9 in progression, recurrence and survival of borderline resectable pancreatic cancer

Pancreatic cancer (PC) is one of the most fatal types of cancer. Based on imagiologic findings, around 15% are considered borderline resectable (BRPC). There is evidence that neoadjuvant chemotherapy (NACT) improves overall survival (OS) compared with upfront surgery in these patients. Ca19-9 is the most commonly used and best validated serum tumor marker for PC. Elevated baseline levels have been associated with reduced OS, nodal involvement and margin status positivity after surgery, both in resectable and BRPC.

Retrospective analysis of patients from a tertiary care hospital with BRPA who received NACT. Serum Ca19-9 before NACT was analyzed as a predictor of disease progression, recurrence and survival. Kaplan-Meier survival curves assessed progression free survival (PFS) and OS and univariate and multivariate analyses identified prognostic variables.

Our sample consisted of 54 patients diagnosed between January 2013 and November 2022. The median age at diagnosis was 63 years (min. 35, max. 80), 53,7% (n=29) were male and 88,9% (n=48) had ECOG-PS 0-1. After NACT, 42,6% (n=23) had disease progression, 20,4% (n=11) stability and 37% (n=20) partial response. Concerning the chosen chemotherapy regimen, 55,6% (n=30) did mFOLFIRINOX and 40,7% (n=22) Gemcitabine. Only 35,2% proceeded to surgery, being that half of these had unsuccessful surgery due to irresectability of the lesion. In these 10 years of follow-up 70,4% had documented disease progression and 87% died. The median OS of the sample was 11 months - 10 months in the high Ca19-9 group (95%CI 7,58-12,41) and 19 months in the low Ca19-9 group (95%CI 12,38-25,61), p=0,002. Having surgery (HR 0,29; 95%CI 0,13-0,64; p=0,002) and a lower Ca19-9 (HR 0,34; 95%CI 0,15-0,80; p=0,014) were independent markers for better OS on multivariate analysis. Out of the 9 patients who had successful pancreaticoduodenectomy, 66,6% had lower Ca19-9 (p=0,432). The PFS was 6,5 months - 6 months in the high Ca19-9 and 7 months in the low group (p=0,831). There were no significant associations regarding PFS.

In this sample, patients with baseline elevated Ca19-9 levels had a statistically significant worse OS. There are some confounding factors to take into account that could increase Ca19-9, such as cholangitis or jaundice. This tumor marker could eventually become a predictor of response to treatment and further prospective multicenter studies are needed to better define its role in BRPC management.

The authors.

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All authors have declared no conflicts of interest.