Relapse rate and relapse patterns in patients undergoing curative resection for Pancreatic Ductal Adenocarcinoma (PDAC): Identifying high risk patients
Session type: Poster / e-Poster / Silent Theatre session
PDAC has a 5-year relapse rate >80% following curative resection. Identifying patients at higher risk of relapse and factors related with specific patterns of disease spread may inform selection of candidates for closer follow-up.
The outcome of patients with PDAC (Jan’05-Sep’17) who underwent curative resection, and with available follow-up and relapse status data, was analysed retrospectively. The aim was to identify factors associated with higher relapse risk and specific relapse patterns. Kaplan Meier, Log-rank, Chi squared and T-tests were used for analysis.
Of 228 patients, 182 were eligible. Patient characteristics: 55.5% male, median age 65.7 years (95%CI 64.2-67.2), T3 (81.9%), lymph node (N)1 (71.4%), involved resection margin (R)1 (61.5%). Adjuvant chemotherapy was given to 113 patients (62.1%) [5-fluorouracil (5-FU)(38.9%), Gemcitabine (G) (31.9%), G+5-FU (29.2%)-based]. Median overall survival (OS) was 21.6 months (95%CI 17.9-28.9). After a median follow-up of 17.9 months, 143 patients relapsed [relapse rate 78.6%, median time-to-relapse 8.9 months (95%CI 7.7-10.1)]. Median OS was shorter (log-rank p-value <0.001) in the “relapse” group (17.5 months (95%CI 15.9-20.9) vs. “non-relapse” (not reached).
Patients with “relapse” had higher rate of N1 disease (76.2% vs 53.8%; p-value 0.0161). No other factors related with increased relapse rate were identified. Local relapse (59.4%): resection bed (54.6%) +/- regional N (16.8%). Distant relapse (69.9%): median number of organs affected was 1; liver 41.3%, lung 20.9%, peritoneum 11.9%, distant N 4.9%, bone 2.8%, others 2.1%. Three relapse patterns were identified: regional only (30.1%), distant only (40.6%) and combined (regional + distant) (29.3%). Adjuvant chemotherapy reduced the risk of combined relapse (p=0.04).
Relapse rate following curative resection for PDAC remains high, with predominance for distant recurrence. Patients with N1 disease have the highest risk of relapse and may benefit from closer follow-up.