To Revise or Not Revise? Isolated Margin Positivity in Localized Pancreatic Ductal Adenocarcinoma.

BACKGROUND: The study determined the proportion of patients with pancreatic adenocarcinoma (PDAC) who had margin-positive disease and no other adverse pathologic findings (APF) using institutional and administrative datasets. METHODS: Patients with clinical stage I or II PDAC in the National Cancer Database (NCDB 2010-2020) and those who underwent pancreatectomy at the authors' institution (2010-2021) were identified. Isolated margin positivity (IMP) was defined as a positive surgical margin with no APF (negative nodes, no lymphovascular/perineural invasion). RESULTS: The study included 225 patients from the authors' institution and 23,598 patients from the NCDB. The margin-positive rates were 21.8% and 20.3%, and the IMP rates were 0.4% and 0.5%, respectively. In the institutional cohort, 68.4% of the patients had recurrence, and most of the patients (65.6%) had distant recurrences. The median recurrence-free survival (RFS) was 63.3 months for no APF, not reached for IMP, 14.8 months for negative margins & 1 APF, 20.3 months for positive margins & 2 APFs, and 12.9 months with all APF positive. The patients in the NCDB with IMP had a lower median OS than the patients with no APF (20.5 vs 390 months), but a higher median OS than those with margin positivity plus 1 APF (20.5 vs 18.0 months) or all those with APF positivity (20.5 vs 15.4 months). Based on institutional rates of IMP, any margin positivity, neck margin positivity (NMP), and no APF, the fraction of patients who might benefit from neck margin revision was 1 in 100,000, and those likely to benefit from any margin revision was 1 in 18,500. In the NCDB, those estimated to derive potential benefit from margin revision was 1 in 25,000. CONCLUSIONS: Isolated margin positivity in resected PDAC is rare, and most patients experience distant recurrence. Revision of IMP appears unlikely to confer benefit to most patients.

Discordance Between Conventional and Detailed Lymph Node Analysis in Resected, Node-negative Pancreatic or Ampullary Adenocarcinomas and Association With Adverse Survival Outcomes: A Single-institution Analysis.

OBJECTIVE: To assess the frequency of occult metastases (OM) in patients with resected pancreatic ductal adenocarcinoma (PDAC) or ampullary adenocarcinoma (AA) discovered on detailed pathologic examination on lymph nodes (LNs) previously considered negative by conventional analysis and to examine the association between OM and overall survival (OS). BACKGROUND: Poor prognosis of patients with no pathologic evidence of LN metastases may be due to OM that is not detected on conventional LN analysis. METHODS: Patients with LN-negative resected PDAC or AA (2010-2020) were identified from our institutional database. Original hematoxylin and eosin ( H and E ) slides were reanalyzed. In addition, selected LN were analyzed by H and E (3 sections/LN) and pan-cytokeratin (AE1-AE3/PCK26) immunohistochemistry. RESULTS: A total of 598 LNs from 74 LN-negative patients were reexamined. Nineteen patients (25.7%) had OM; 9 (47.4%) were found with immunohistochemistry but not on H and E . The number of positive LNs ranged from 1 to 3. No clinicodemographic, pathologic, or treatment-related factors were associated with OM. On conventional LN analysis, 3/19 patients (15.8%) had stage IA, 9/34 (26.5%) had stage IB, and 7/19 (36.8%) had stage IIA. On detailed LN analysis, 11/19 patients (57.9%) were upstaged to IIB, whereas 8/19 (42.1%) had isolated tumor cells only (N0i+). OM was associated with shorter OS (median OS: 22.3 vs 50.5 months; hazard ratio=3.95, 95% CI: 1.58-9.86). CONCLUSIONS: There is a 26% discordance rate between conventional and detailed LN pathologic analysis in resected PDAC and AA. The presence of OM is associated with shorter OS.

Why the Treatment Sequence Matters: Interplay Between Chemotherapy Cycles Received, Cumulative Dose Intensity, and Survival in Resected Early-stage Pancreas Cancer.

OBJECTIVE: To define the optimal threshold of perioperative chemotherapy completion and relative dose intensity (RDI) for patients with resected pancreatic ductal adenocarcinoma (PDAC). BACKGROUND: Many patients who undergo pancreatectomy for PDAC fail to initiate or complete recommended perioperative chemotherapy. The association between the amount of perioperative chemotherapy received and overall survival (OS) is not well-defined. METHODS: Single-institution analysis of 225 patients who underwent pancreatectomy for stage I/II PDAC (2010-2021). Associations between OS, chemotherapy cycles completed, and RDI were analyzed. RESULTS: Regardless of treatment sequence, completion of ≥67% of recommended cycles was associated with improved OS compared with no chemotherapy [median OS: 34.5 vs 18.1 months; hazard ratio (HR): 0.43; 95% CI: 0.25-0.74] and <67% of cycles (median OS: 17.9 months; HR: 0.39; 95% CI: 0.24-0.64). A near-linear relationship existed between cycles completed and the RDI received (ß = 0.82). A median RDI of 56% corresponded to the completion of 67% of cycles. Receipt of ≥56% RDI was associated with improved OS compared with no chemotherapy (median OS: 35.5 vs 18.1 months; HR: 0.44; 95% CI: 0.23-0.84) and <56% RDI (median OS: 27.2 months; HR: 0.44; 95% CI: 0.20-0.96). Neoadjuvant chemotherapy is associated with increased odds of receiving ≥67% of recommended cycles (odds ratio: 2.94; 95% CI: 1.45-6.26) and ≥56% RDI (odds ratio: 4.47; 95% CI: 1.72-12.50). CONCLUSIONS: Patients with PDAC who received ≥67% of recommended chemotherapy cycles or ≥56% cumulative RDI had improved OS. Neoadjuvant therapy was associated with increased odds of receiving ≥67% of cycles and ≥56% cumulative RDI and should be considered in all patients with resectable PDAC.

Assessing the use of Extended Venous Thromboembolism Prophylaxis on the Rates of Venous Thromboembolism and Postpancreatectomy Hemorrhage Following Pancreatectomy for Malignancy.

OBJECTIVE: To compare rates of venous thromboembolism (VTE) and postpancreatectomy hemorrhage (PPH) in patients with pancreatic or periampullary malignancy preimplementation and postimplementation of routine extended VTE prophylaxis. BACKGROUND: Guidelines recommend up to 28 days of VTE prophylaxis following major abdominal cancer operations. There is a paucity of data examining rates of VTE and PPH in patients who receive extended VTE prophylaxis following pancreatectomy. METHODS: Single-institution analysis of patients who underwent pancreatectomy for malignancy (2004-2021). VTE and PPH rates within 90 days of discharge were compared based on receipt of extended VTE prophylaxis with enoxaparin. RESULTS: A total of 478 patients were included. Twenty-two (4.6%) patients developed a postoperative VTE, 12 (2.5%) of which occurred postdischarge. Twenty-five (5.2%) patients experienced PPH, 13 (2.7%) of which occurred postdischarge. There was no associated difference in the development of postdischarge VTE between patients who received extended VTE prophylaxis and those who did not (2.3% vs 2.8%, P =0.99). There was no associated difference in the rate of postdischarge PPH between patients who received extended VTE prophylaxis and those who did not (3.4% vs 1.9%, P =0.43). In the subset of patients on antiplatelet agents, the addition of enoxaparin did not appear to be associated with higher VTE (3.9 vs. 0%, P =0.31) or PPH (3.0 vs. 4.5%, P =0.64) rates. CONCLUSIONS: Extended VTE prophylaxis following pancreatectomy for malignancy was not associated with differences in postdischarge VTE and PPH rates. These data suggest extended VTE prophylaxis is safe but may not be necessary for all patients following pancreatectomy.