[1788] Clinicopathologic Comparison of Ampullary Versus Pancreatic Carcinoma: Preinvasive Component, Size of Invasion, Stage, Resectability and Histologic Phenotype Are the Factors for the Significantly Favorable Outcome of Ampullary Carcinoma

Burcu Saka, Takuma Tajiri, Nobuyuki Ohike, Pelin Bagci, Alyssa Krasinskas, Grace E Kim, Shishir K Maithel, Juan Sarmiento, David Kooby, Denizhan Ozdemir, Olca Basturk, Bassel El-Rayes, So Yeon Kong, Michael Goodman, Alton B Farris, Volkan Adsay. Emory University, Atlanta, GA; University of Pittsburgh, Pittsburgh, PA; UCSF, San Francisco, CA; Wayne State University, Detroit, MI

Background: The information on the clinical outcome differences of ampullary versus pancreatic carcinoma (AC vs PC) has been conflicting largely because of their poor definition and differential from each other, classified and analyzed together under the rubric of “periampullary cancers”.
Design: 292 stringently-defined ACs identified based on the refined criteria set forth recently (Am J Surg Pathol, 2012) were compared with 297 invasive PCs.
Results: Compared to PCs, ACs often presented with a significant mass-forming preinvasive component (tumoral intraepithelial neoplasm), smaller invasive carcinomas, less advance stage (lower incidence of lymph node metastasis), higher resectability, and less aggressive histologic phenotype (higher incidence of non-pancreatobiliary cases and less perineural invasion).

Comparison of Prognostic Parameters of AC vs PC
 Ampullary Cancer (n=292)Pancreas Cancer (n=297)p-value
Overall size (cm)2.6 (0.3-8.0)3.3 (0.7-11.0)<0.0001
Size of invasion (cm)1.9 (0.2-6.0)3.2 (0.7-11.0)<0.0001
Frequency of invasion size < 1.0 cm52 (17%)1 (0.4%)<0.0001
Frequency of LN mets119 (42%)177 (65%)<0.0001
Margin positivity rate13 (4%)91(34%)<0.0001
Histologic type as Pancreatobiliary139 (47%)286 (97%)<0.0001
Perineural invasion79 (27%)158 (86%)<0.0001
Vascular invasion187 (63%)84 (55%)0.105

Fig.1 Overall Survival Between Ampullary Cancer vs. Pancreatic Cancer

Conclusions: Ampullary carcinoma, defined by the refined criteria, have an incomparably better clinical outcome than pancreatic. Relative abundance of preinvasive component (leading to early diagnosis), smaller invasion size at the time of diagnosis, higher resectability (higher R0 rate, due to central location in the Whipple), less aggressive histologic phenotypes, lower incidence of lymph node metastasis (due to early diagnosis and less aggressive phenotypes) are the important factors in this favorable outcome.
Category: Pancreas

Tuesday, March 5, 2013 9:30 AM

Poster Session III # 213, Tuesday Morning


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