Pancreatic body and tail cancer and favorable metastatic lymph node behavior on the left edge of the aorta.

BACKGROUND: Lymph node (LN) metastasis in pancreatic body-tail cancer is a poor prognostic factor and the optimal LN dissection area for distal pancreatectomy (DP) remains unclear. Lymphatic flow from the tumors is thought to depend on the tumor sites. We examined LN metastasis frequency based on tumor site and recurrent patterns post-DP. METHODS: With a retrospective, single institutional study, we examined 100 patients who underwent DP as an upfront surgery for pancreatic cancer over 17 years. Tumor sites were classified as tumor confined to pancreatic body (and neck) (Pb(n)); and pancreatic tail (Pt). We compared metastatic LN and recurrence patterns based on tumor site. The median overall survival (OS) and disease-free survival (DFS) were analyzed. RESULTS: LN metastasis occurred in 59/100 (59.0%), with 23 and 25 tumors located in the Pb(n), and Pt, respectively. Those with the tumor in Pt had metastases to #10, #11d/p, and #18 LN mainly. However, the patients with the Pb(n) tumor had metastases to #8a/p, #11p, and #14p/d LN. There was no metastasis to #10 and #11d LN. The OS and DFS were 34 and 15 months, respectively. No significant difference was found in the OS, DFS, and recurrence patterns based on tumor sites. CONCLUSION: Differences in metastatic LN sites were observed in pancreatic body-tail cancer when tumors were confined to the left or right of the left aortic edge. Although it is necessary to validate this finding with a large-scale study, organ-preserving DP might be a treatment option for selected patients depending on the tumor sites.