Patient characteristics
The study cohort included 3011 patients with confirmed PDAC who underwent resection between 2014 and 2019. Of these, 2412 (80,1%) underwent Whipple’s procedure or PPPD, which was combined to a PD group. In contrast, 599 patients (19,9%) underwent DP. Patients were grouped according to their age in early-onset pancreatic cancer (EOPC; 18-49 years, n = 110 (3,7%) in total), middle-onset pancreatic cancer (MOPC, 50-70 years, n = 1399 (46,5%) in total) and late-onset pancreatic cancer (LOPC; > 70 years, n = 1502 (49,8%) in total).
In the PD group, EOPC consisted of 83 (3,4%), MOPC of 1123 (46,6%) and LOPC of 1206 (50,0%) patients. The DP group comprised 27 patients (4,5%) with EOPC, 276 (46,1%) with MOPC, and 296 (49,4%) with LOPC respectively. ASA scores differed in the PD (p < 0,05) and DP (p < 0,001) group across the different age groups. In the PD group, patients of the MOPC group tended to have a slightly elevated BMI (p < 0,05), whereas in the DP group BMI did not vary. In the PD group, with increasing age, DM was found with a significantly higher incidence preoperatively (p < 0,001); this was not the case for patients undergoing DP.
Preoperative bilirubin levels differed in the PD and DP group across the different ages. Tumor markers CEA and CA19-9 tended to be more elevated with increasing age, this difference was only significant for CA19-9 in the PD group. In the PD group, an enlarged pancreatic duct (PD) width was found with increasing age, while the opposite trend was seen in the DP group. There was no difference observed in pancreatic texture. Likewise, neither tumor size nor lymph node status diverged between age groups for both resection types. A summary of all the baseline characteristics can be seen under Table 1.
Perioperative outcomes
The majority of all operations was carried out as open operations (2838/3011; 94%). Only 54 (1,8%) of the total 3011 operations were performed laparoscopically while the rest was either laparoscopically assisted (45/3011; 1,5%) or secondarily converted to open surgery (73/3011, 2,4%); thus, comparisons between open and laparoscopic surgery was not feasible due to the small case numbers. For both PD and DP, the operating time was significantly shorter in EOPC compared to MOPC and to LOPC (p < 0,01 and p < 0,01; Table 2). In contrast, for both PD and DP, length of hospital stay was longer for patients with LOPC compared to MOPC and to EOPC (p < 0,01 and p < 0,05; Table 2). For patients receiving PD, length of stay on the ICU got significantly longer from EOPC to LOPC (p < 0,01) but did not differ for patients in the DP group (p = 0,07; Table 2). Resection (R) status did not differ and comparable rates of R0 resections were achieved and can be seen in Table 2.
We did not detect a difference in the occurrence of POPF, PPH or DGE between different age groups and resection techniques (Table 2, Figure 2). However, in patients undergoing PD, complications graded after Clavien-Dindo occurred more frequently in LOPC compared to MOPC and EOPC (p < 0,01; Table 2). Similarly, in patients undergoing PD, major complications (Clavien-Dindo ³ 3a) were observed more frequently in LOPC (370/1206, 30,7%) than in MOPC (294/1123, 26,2%) and EOPC (14/83, 16,9%%; p < 0,01; Table 2). In DP, there was a trend of increased mortality and FTR rates from EOPC to MOPC to LOPC, yet not statistically significant. In PD, mortality significantly increased from EOPC (2,4%) to MOPC (3,6%) to LOPC (6,6%, p < 0,01). Additionally, significantly higher FTR rates could also be observed (EOPC 14,3%, MOPC 13,6%; LOPC 21,6%; p < 0,05).
Risk predictors for major complications
To further analyze potential predictors regarding the risk of major complications (Clavien-Dindo ³ 3a) logistic regression was calculated separately for PD and DP.
In the PD group, increasing age (OR 1,24 [95% CI 1,13 - 1,36]; p = 0,001) and BMI (OR 1,02 [95% CI 1,00 - 1,04]; p = 0,013) as well as an ASA score of 3 or 4 (OR 1,44 [95% CI 1,21 - 1,73]; p = 0,001) was associated with a significantly increased risk of major complications. An enlarged pancreatic duct > 3mm (OR 0,75 [95% CI 0,60 - 0,92] p = 0,006) and hard pancreatic tissue (OR 0,69 [95% CI 0,56 - 0,84] p = 0,001) were associated with a significant reduction of major complications. Most important, hospitals certified as a pancreatic center by the DGAV (Deutsche Gesellschaft für Allgemein- und Viszeralchirurgie), showed a significant reduction for the occurrence of major complications (Table 3).
In multivariable regression analysis, age, ASA score and pancreatic texture were significantly associated with the risk of major complications.
In contrast to PD, no analyzed factor showed a significant association with the risk of major complications in DP (Table 3).