Update on familial pancreatic cancer

Genetic alterations in pancreatic cancer

The diagnosis of pancreatic cancer is devastating for patients and their relatives as the incidence rate is approximately the same as mortality rate. Only a small percentage, which ranges from 0.4% to 4% of patients who have been given this diagnosis, will be alive at five years. At the time of diagnosis, 80% of pancreatic cancer patients have unresectable or metastatic disease. Moreover, the therapeutic alternatives offered by chemotherapy or radiotherapy are few, if not zero. For all these reasons, there is an imperative need of analyzing and understanding the primitive lesions that lead to invasive pancreatic adenocarcinoma. Molecular pathology of these lesions is the key of our understanding of the mechanisms underlying the development of this cancer and will probably help us in earlier diagnosis and better therapeutic results. This review focuses on medical research on pancreatic cancer models and the underlying genetic alterations.

INK4/ARF germline alterations in pancreatic cancer patients

BACKGROUND

Roughly 40% of germinal mutations in melanoma families (MF) affect p16(INK4a) and p14(ARF). We investigated the association between INK4/ARF alterations and the occurrence of pancreatic cancer in MF and in sporadic pancreatic cancer (SPC) patients.

PATIENTS AND METHODS

Forty-nine MF, 66 SPC cases and 54 controls were enrolled. The INK4/ARF locus was screened.

RESULTS

As compared with the general population, the risk of pancreatic cancer (PC) was increased 9.4-fold [95% confidence interval (CI) 2.7-33.4] and 2.2-fold (95% CI 0.8-5.7) in G101W-positive and -negative MF, respectively, while mean ages at onset were 61 and 77 years, respectively. A 1.7 (95% CI 1.06-2.79) increased risk of cancer at any site was observed among first-degree relatives of SPC cases as compared with controls. The G101W founder mutation was detected in 4% of SPC cases but the rate increased to 13% when tumor clustering in either branch of families was taken into account. One G101W-positive PC patient with a melanoma in a first-degree relative harbored a germline deletion of the second allele, including exon 1B.

CONCLUSIONS

The presence of a deletion including exon 1B in two PC patients points to the involvement of p14(ARF) in the development of PC and may suggest that the increased risk of PC in MF is caused by impairment of both loci.