SMAD4 gene mutations are associated with poor prognosis in pancreatic cancer

Abstract

Purpose: Recently, the majority of protein coding genes were sequenced in a collection of pancreatic cancers, providing an unprecedented opportunity to identify genetic markers of prognosis for patients with adenocarcinoma of the pancreas.

Experimental design: We previously sequenced more than 750 million base pairs of DNA from 23,219 transcripts in a series of 24 adenocarcinomas of the pancreas. In addition, 39 genes that were mutated in more than one of these 24 cancers were sequenced in a separate panel of 90 well-characterized adenocarcinomas of the pancreas. Of these 114 patients, 89 underwent pancreaticoduodenectomy, and the somatic mutations in these cancers were correlated with patient outcome.

Results: When adjusted for age, lymph node status, margin status, and tumor size, SMAD4 gene inactivation was significantly associated with shorter overall survival (hazard ratio, 1.92; 95% confidence interval, 1.20-3.05; P = 0.006). Patients with SMAD4 gene inactivation survived a median of 11.5 months, compared with 14.2 months for patients without SMAD4 inactivation. By contrast, mutations in CDKN2A or TP53 or the presence of multiple (> or =4) mutations or homozygous deletions among the 39 most frequently mutated genes were not associated with survival.

Conclusions: SMAD4 gene inactivation is associated with poorer prognosis in patients with surgically resected adenocarcinoma of the pancreas.

Figure 1

Kaplan Meier curves of survival probability by patients with and without mutation or deletion in the SMAD4 gene.

Figure 2

Kaplan Meier curves of survival probability by patients with and without mutation or deletion in the TGFβR2 gene.

Figure 3

Kaplan Meier curves of survival probability by patients with and without mutation or deletion in the TP53 gene.

Figure 4

Kaplan Meier curves of survival probability by patients with < 4 mutations or homozygous deletions and with ≥4 mutations or homozygous deletions.