A pioneering study correlates genetic alterations and environmental factors in liver cancer

IDIBAPS researchers have participated in a pioneering study in hepatocellular carcinoma, the most common liver cancer, in which all the genetic alterations that occur in this type of tumor have been characterized. In an article published in the journal Nature Genetics scientists provide a complete overview of the disease and these genetic alterations associated with the etiology and clinical characteristics, the proposed treatments for patients approved for other cancers, which could be applied in each case. Dr. Josep Maria Llovet, ICREA professor at the IDIBAPS Hepatic Oncology Group and director of the Liver Cancer Program at the Icahn School of Medicine at Mount Sinai (New York), and Dr. Roser Pinyol, researcher at the same group, have participated in this article led by Dr. Jessica Zucman-Rossi, from the INSERM-Paris.

Hepatocellular carcinoma (HCC) is a type of liver cancer that constitutes about 80% of malignant liver tumors. It represents the fifth leading cause of cancer in the world (750,000 new cases / year) and the second leading cause of cancer death after lung cancer. Despite improvements in the early diagnosis techniques, surgery and ablative and pharmacological treatments, this cancer has still a very high mortality and, only one molecular therapy, sorafenib, has demonstrated its effectiveness in the case of tumors in advanced stages.

In the study published in Nature Genetics researchers have analyzed samples from 243 patients with HCC using a genetic analysis technique called Whole-Exome Sequencing. This has enabled them to draw, for the first time, a map of all the genetic alterations that occur in this type of cancer. When crossing these alterations with the patients’ clinical characteristics they have been able to establish the risk factors, such as infection by the hepatitis B or C, alcohol or tobacco, associated with each type of alteration. Moreover, the researchers have also determined how mutations increase as the cancer progresses and have proposed treatments that are approved for other type of tumors, which could be used in at least 28% of cases.

This study, a part of the HEPTROMIC project, an European initiative for the study of HCC led by Dr. Josep M. Llovet, identifies relationships between environmental factors and patterns of mutations in HCC, and provides a map of the genes and pathways altered in different clinical stages of the disease. The article highlights the importance of including genetic parameters, in addition to the clinical ones, in establishing a diagnosis, and allows determining which patients with this type of tumor can benefit from specific treatment in future clinical trials.

Article reference:

Exome sequencing of hepatocellular carcinomas identifies new mutational signatures and potential therapeutic targets

Kornelius Schulze, Sandrine Imbeaud, Eric Letouzé, Ludmil B Alexandrov, Julien Calderaro, Sandra Rebouissou, Gabrielle Couchy, Clément Meiller, Jayendra Shinde, Frederic Soysouvanh, Anna-Line Calatayud, Roser Pinyol, Laura Pelletier, Charles Balabaud, Alexis Laurent, Jean-Frederic Blanc, Vincenzo Mazzaferro, Fabien Calvo, Augusto Villanueva, Jean-Charles Nault, Paulette Bioulac-Sage, Michael R Stratton, Josep M Llovet & Jessica Zucman-Rossi

Nature Genetics (2015) doi:10.1038/ng.3252