Proposal for splenectomy-omitting radical distal pancreatectomy in well-selected left-sided pancreatic cancer: multicenter survey study

When distal pancreatectomy is carried out for left-sided pancreatic cancer, splenectomy is usually performed not only for margin-negative resection but also for effective clearance of the splenic hilar lymph nodes (LNs). However, the incidence of splenic hilar LN metastasis in these patients has not been definitively determined. From April 2010 to June 2011, in a pilot study, we analyzed the medical records of twelve patients who had undergone radical antegrade modular pancreatosplenectomy. Potential remnant soft tissue around the splenic hilum, which would be left following an extended Warshaw's procedure, was dissected and sent to a pathologist. Three Japanese medical centers conducted a retrospective survey of splenic hilar lymph node metastasis in left-sided pancreatic cancer to support our study. In the pilot study, all twelve patients had adenocarcinoma with a median tumor size of 2 cm. Six patients had LN metastasis and a median number of 4 splenic hilar LNs were evaluated; however, no splenic hilar LN metastasis was noted. In the Japanese multicenter survey (n = 85), only four patients had splenic LN metastasis. Small (< 3 cm) and proximal (neck/body) left-sided pancreatic cancer might not be associated with splenic hilar LN metastasis (P < 0.05). In well-selected left-sided pancreatic cancer, the incidence of splenic hilar LN metastasis is low enough that splenectomy-omitting radical distal pancreatectomy would be feasible. The rationale for routine splenectomy should be re-evaluated, and the oncologic effects of the preserved spleen need to be investigated further.