Patients with resected, histologically re-confirmed pancreatic ductal adenocarcinoma (PDAC) can achieve long-term survival despite T3 tumour or nodal involvement. The Finnish Register Study 2000-2013.

BACKGROUND: Long-term survival of patients with operated pancreatic ductal adenocarcinoma (PDAC) has been associated with resection status, disease stage and centralisation. However, no previous reports are available about long-term survivors of PDAC with confirmed histology covering an entire nation. Our aim was to analyze retrospectively confirmed long-term survivors of PDAC operated on in Finland 2000-2008.

METHOD: PDAC patients operated between 2000 and 2008 were selected from Finnish patient registers and archives. Histological slides of patients with over four-year survival were re-evaluated by an expert pancreatic pathologist. From the confirmed PDAC patients, demographic, oncologic and operative parameters were recorded. The cut-point of survival was 31.12.2013.

RESULTS: Out of the 598 patients operated on and originally diagnosed with PDAC, 52 of the long-term survivors (LTS) were confirmed as having had true PDAC. The four-year survival rate in high volume centres (HVC) was 13.0% and 6.7% elsewhere (p = 0.017). Five-year survival rate was 7.2%. After multivariate analysis only the size of the tumour persisted as prognostic factor for over four-year survival. Among LTSs, 50% of patients had stage IIB tumour and 40% had a R1 resection without difference with patients with shorter survival. The use of adjuvant therapy did not differ between the groups.

CONCLUSION: This is the largest single-nationwide cohort of long-term survivors with confirmed PDAC. Comprehensive pathological evaluation is mandatory for an adequate PDAC diagnosis and true survival analysis. Long-term survival can be achieved even in T3 patients with nodal involvement and may be explained by favorable tumour biology.