Dr Nigel Jamieson and colleagues determined the prognostic influence of residual tumor at or within 1 mm of the mobilization margins compared with transection margins following pancreaticoduodenectomy for pancreatic ductal adenocarcinoma.
The prognostic strength of residual tumor status increases with frequency of margin positivity and is enhanced by protocol driven pathology reporting.
Currently, margins are treated uniformly with tumor at or close to any margin considered of equal prognostic significance.
The resection involved a mobilization phase freeing the posterior margin and anterior surface then a transection phase requiring lympho-vascular division forming the medial resection and pancreatic transection margin.
The comparative assessment of the relative importance of tumor involvement of these different margins has not previously been investigated.
Retrospective analysis of 148 consecutive resections for pancreatic ductal adenocarcinoma from 1996–2007 was performed.
The research team found that the individual margins were separately identified and analyzed by a senior pathologist.
An residual resection was defined as microscopic evidence of tumor 1 mm or less from a resection margin.
|Residual tumor status was confirmed in 74% patients|
|Annals of Surgery|
The researchers found that residual tumor at or within 1 mm of the mobilization margins tumor extension included both anterior and posterior cases.
Transection margins included pancreatic neck/body transection, medial and adjacent transection margins.
Residual tumor status was confirmed in 74% patients.
The team noted that the medial and posterior margins were most commonly involved.
Residual tumor status was found to an independent predictor of poor outcome.
Residual tumor at or within 1 mm of the mobilization margins involvement only was associated with a significantly longer median survival of 19 months versus 11 months for those with transection margin tumor involvement.
The research team found no significant difference in the survival of the residual tumor at or within 1 mm of the mobilization margins compared with R0 group.
Dr Jamieson's team concludes, "Following pancreaticoduodenectomy for pancreatic ductal adenocarcinoma, involvement of the transection margins in contrast to mobilization margins defines a group whose outcome is significantly worse."
"This may impact upon the allocation of adjuvant therapy within the setting of randomized controlled trials."