Clinical significance of the genetic landscape of pancreatic cancer and implications for identification of potential long-term survivors.

Abstract

PURPOSE:

Genetic alterations of KRAS, CDKN2A, TP53, and SMAD4 are the most frequent events in pancreatic cancer. We determined the extent to which these 4 alterations are coexistent in the same carcinoma, and their impact on patient outcome.

EXPERIMENTAL DESIGN:

Pancreatic cancer patients who underwent an autopsy were studied (n = 79). Matched primary and metastasis tissues were evaluated for intragenic mutations in KRAS, CDKN2A, and TP53 and immunolabeled for CDKN2A, TP53, and SMAD4 protein products. The number of altered driver genes in each carcinoma was correlated to clinicopathologic features. Kaplan-Meier estimates were used to determine median disease free and overall survival, and a Cox proportional hazards model used to compare risk factors.

RESULTS:

The number of genetically altered driver genes in a carcinoma was variable, with only 29 patients (37%) having an alteration in all 4 genes analyzed. The number of altered driver genes was significantly correlated with disease free survival (P = 0.008), overall survival (P = 0.041), and metastatic burden at autopsy (P = 0.002). On multivariate analysis, the number of driver gene alterations in a pancreatic carcinoma remained independently associated with overall survival (P = 0.046). Carcinomas with only 1 to 2 driver alterations were enriched for those patients with the longest survival (median 23 months, range 1 to 53).

CONCLUSIONS:

Determinations of the status of the 4 major driver genes in pancreatic cancer, and specifically the extent to which they are coexistent in an individual patients cancer, provides distinct information regarding disease progression and survival that is independent of clinical stage and treatment status.

• Authors: Shinichi Yachida, Catherine M White, Yoshiki Naito, Yi Zhong, Jacqueline A Brosnan, Anne M Macgregor-Das, Richard A Morgan, Tyler Saunders, Daniel A Laheru, Joseph M Herman, Ralph H Hruban, Alison P Klein, Siân Jones, Victor Velculescu, Christopher L Wolfgang, Christine A Iacobuzio-Donahue
• Journal: Clinical cancer research : an official journal of the American Association for Cancer Research (Clin Cancer Res) Vol. 18 Issue 22 Pg. 6339-47 (Nov 15 2012) ISSN: 1557-3265 [Electronic] United States
• PMID: 22991414 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)
• Copyright: ©2012 AACR.

Chemical References

• Cyclin-Dependent Kinase Inhibitor p16
• KRAS protein, human
• Proto-Oncogene Proteins
• SMAD4 protein, human
• Smad4 Protein
• TP53 protein, human
• Tumor Suppressor Protein p53
• Proto-Oncogene Proteins p21(ras)
• ras Proteins

Topics

• Aged
• Carcinoma, Pancreatic Ductal (genetics, mortality, secondary)
• Cyclin-Dependent Kinase Inhibitor p16 (genetics, metabolism)
• DNA Mutational Analysis
• Disease-Free Survival
• Female
• Humans
• Kaplan-Meier Estimate
• Male
• Middle Aged
• Pancreatic Neoplasms (genetics, mortality, pathology)
• Proportional Hazards Models
• Proto-Oncogene Proteins (genetics)
• Proto-Oncogene Proteins p21(ras)
• Risk Factors
• Smad4 Protein (genetics, metabolism)
• Survivors
• Tumor Burden (genetics)
• Tumor Suppressor Protein p53 (genetics, metabolism)
• ras Proteins (genetics)