Pancreatic cancer develops for years

Pancreatic cancer: First cells mutate as early as 20 years before the onset of cancer.

(28.10.2010) Before pancreatic cancer breaks out, it often lurks for years in the body. Scientist of the „Howard Hughes Medical Institute“ and Johns Hopkins University have their research findings in the current issue of the journal „Nature“ published, which assume that the pancreatic cancer in a large number of cases, early on recognizable and treatable.

Pancreatic cancer is mostly deadly
Pancreatic cancer (pancreatic cancer) causes death in about 95 percent of those affected. One of the causes is that only 10 to 15% of pancreatic carcinomas are still surgically treatable at the time of diagnosis. In addition, according to recent studies, the five-year survival rate is only between three and 25 percent after surgery. For inoperable tumors the chances of survival are correspondingly worse.

Genetic analysis shows: Tumors develop over years
In the genetic analysis of the pancreatic cancer tumors, the scientists came to the conclusion that the first cell mutations often take place already 20 years before the actual occurrence of pancreatic carcinomas. Thus, it is not surprising, according to the researchers, that the survival rate of pancreatic cancer is e.g. In the UK, according to the BBC, it has not improved over the past 40 years as the disease is often aggressive at the time of diagnosis and does not respond to treatment. As part of the genetic analysis, the researchers have extensively studied tissue samples derived from primary tumors in the pancreas and other areas of the body (metastases). Thus, the DNA of each gene of the tumors was sequenced and looked for signs of mutations. The researchers found that the metastatic tumors had an average of 61 cancer-related mutations, with two thirds of the mutations could be detected directly in the tumor of the pancreas.

Molecular clock to determine the duration of development
Since the genetic mutations proceed at a relatively uniform rate, the number of mutations provides an indication of how long the pancreatic carcinomas have already developed in each stage of the disease. Taking into account this so-called molecular clock, the scientists came to the conclusion that the tumor cells on average not until 11.7 years after a single genetic mutation has taken place in a cell of the pancreas, are formed. Subsequently, it would take an average of another 6.8 years to get metastases. After metastasis formation, however, patients only had less than three years left to die in the cases. According to the scientists, it is therefore to be assumed that on average, pancreatic carcinomas developed in the body for more than 20 years before the deadly cancer broke out.

Earlier diagnosis could help
So far, there were two theories, according to the scientist Bert Vogelstein, why tumors of the pancreas ended fatally in about 95 percent of cases. Thus, some experts believe that the tumors of pancreatic cancer are very aggressive from the beginning, the other part was the assumption that the disease at the time of diagnosis is already very advanced and treatment is therefore impossible or rather hopeless. The now in „Nature“ published results make it clear that the second theory seems to apply to at least a majority of the tumors. However, this also means hope for those affected, because with a corresponding early diagnosis, could be completely new treatment options and the most fatal course of pancreatic cancer can be avoided. Every year, around 12,800 people in Germany contract pancreatic carcinoma, with men being on average 68 years of age and 75 years of age. (Fp)

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Picture credits: tokamuwi