Giovanni Butturini

OBJECTIVE: The aim of this study was to compare oncological outcomes after minimally invasive distal pancreatectomy (MIDP) with open distal pancreatectomy (ODP) in patients with pancreatic ductal adenocarcinoma (PDAC). BACKGROUND: Cohort studies have suggested superior short-term outcomes of MIDP vs. ODP. Recent international surveys, however, revealed that surgeons have concerns about the oncological outcomes of MIDP for PDAC. METHODS: This is a pan-European propensity score matched study including patients who underwent MIDP (laparoscopic or robot-assisted) or ODP for PDAC between January 1, 2007 and July 1, 2015. MIDP patients were matched to ODP patients in a 1:1 ratio. Main outcomes were radical (R0) resection, lymph node retrieval, and survival. RESULTS: In total, 1212 patients were included from 34 centers in 11 countries. Of 356 (29%) MIDP patients, 340 could be matched. After matching, the MIDP conversion rate was 19% (n = 62). Median blood loss [200 mL (60-400) vs 300 mL (150-500), P = 0.001] and hospital stay [8 (6-12) vs 9 (7-14) days, P < 0.001] were lower after MIDP. Clavien-Dindo grade ≥3 complications (18% vs 21%, P = 0.431) and 90-day mortality (2% vs 3%, P > 0.99) were comparable for MIDP and ODP, respectively. R0 resection rate was higher (67% vs 58%, P = 0.019), whereas Gerota's fascia resection (31% vs 60%, P < 0.001) and lymph node retrieval [14 (8-22) vs 22 (14-31), P < 0.001] were lower after MIDP. Median overall survival was 28 [95% confidence interval (CI), 22-34] versus 31 (95% CI, 26-36) months (P = 0.929). CONCLUSIONS: Comparable survival was seen after MIDP and ODP for PDAC, but the opposing differences in R0 resection rate, resection of Gerota's fascia, and lymph node retrieval strengthen the need for a randomized trial to confirm the oncological safety of MIDP.

The importance of epigenetic modifications such as DNA methylation in tumorigenesis is increasingly being appreciated. To define the genome-wide pattern of DNA methylation in pancreatic ductal adenocarcinomas (PDAC), we captured the methylation profiles of 167 untreated resected PDACs and compared them to a panel of 29 adjacent nontransformed pancreata using high-density arrays. A total of 11,634 CpG sites associated with 3,522 genes were significantly differentially methylated (DM) in PDAC and were capable of segregating PDAC from non-malignant pancreas, regardless of tumor cellularity. As expected, PDAC hypermethylation was most prevalent in the 5' region of genes (including the proximal promoter, 5'UTR and CpG islands). Approximately 33% DM genes showed significant inverse correlation with mRNA expression levels. Pathway analysis revealed an enrichment of aberrantly methylated genes involved in key molecular mechanisms important to PDAC: TGF-β, WNT, integrin signaling, cell adhesion, stellate cell activation and axon guidance. Given the recent discovery that SLIT-ROBO mutations play a clinically important role in PDAC, the role of epigenetic perturbation of axon guidance was pursued in more detail. Bisulfite amplicon deep sequencing and qRT-PCR expression analyses confirmed recurrent perturbation of axon guidance pathway genes SLIT2, SLIT3, ROBO1, ROBO3, ITGA2 and MET and suggests epigenetic suppression of SLIT-ROBO signaling and up-regulation of MET and ITGA2 expression. Hypomethylation of MET and ITGA2 correlated with high gene expression, which was associated with poor survival. These data suggest that aberrant methylation plays an important role in pancreatic carcinogenesis affecting core signaling pathways with potential implications for the disease pathophysiology and therapy.

BACKGROUND: Pancreatic metastases from renal cell carcinoma are rare but highly resectable. The aim of this study was to review a series of patients with this condition. METHODS: The study involved 22 consecutive patients with histologically proven pancreatic metastases from renal cell cancer. RESULTS: Seventeen of the 22 patients had surgery. No patient died but eight of the 17 patients had a postoperative complication. Median follow-up was 33 (range 1-96) months. The 24- and 60-month survival probabilities were 0.84 and 0.53 respectively. Five patients who did not undergo surgery had 24- and 60-month survival probabilities of 0.53 and 0.26 respectively. The difference between the two groups was significant (P = 0.040). CONCLUSION: Despite the slow development of these secondaries and their well encapsulated morphology, the high rate of recurrence after limited resection suggests that radical resection should be recommended.