Clinical significance of CA19-9 normalization during neoadjuvant chemoradiation therapy for resectable pancreatic cancer

Abstract

Anatomical tumor extension as well as the biological behavior of pancreatic cancer (PC) are emphasized for designing an appropriate treatment strategy in patients with PC. In this context, a highly elevated CA19-9 level was incorporated with borderline resectability as one of the biological factors, and even in anatomically resectable cases, patients with a very elevated CA19-9 level are classified as borderline resectable (biological borderline: biological BR). The appropriate assessment of the biological BR factor is important to optimize the treatment strategy in each individual patient with PC. In neoadjuvant chemoradiation therapy (CRT) for resectable (R) and BR pancreatic cancer, oncologic outcomes of biological BRPC (BR-biol) were significantly unfavorable compared with those with resectable PC and comparable with those of anatomical BRPC (BR-anat). Outcomes of BR-biol cases with normalization of serum CA19-9 levels (<37U/ml) after neoadjuvant CRT (post-CA19-9) (nBR-biol) were significantly favorable compared with those of BR-biol with a failure to normalize post-CA19-9 (eBR-biol) and comparable with those with resectable disease with normalized post-CA19-9. These observations suggest that post-CA19-9 normalization indicates biological downstaging in biological BRPC in the neoadjuvant CRT strategy for patients with PC.