Your cancer is not a just matter of “bad luck”

15 Jan 2015

The International Agency for Research on Cancer strongly disagrees with the conclusion of a scientific report on the causes of human cancer, which argues that bad luck is the main cause of cancer - more than hereditary or external environmental factors.

The study, which has received widespread media coverage, compares the number of lifetime stem cell divisions across a wide range of tissues with lifetime cancer risk and suggests that random mutations (or "bad luck") are "the major contributors to cancer overall, often more important than either hereditary or external environmental factors."

CareAcross-staring-at-sea

Serious contradiction and methodological limitations of the study

IARC experts point to a serious contradiction with the extensive body of epidemiological evidence as well as a number of methodological limitations and biases in the analysis presented in the report. If misinterpreted, this position could have serious negative consequences from both cancer research and public health perspectives. "We already knew that for an individual to develop a certain cancer, there is an element of chance, yet this has little to say about the level of cancer risk in a population," explains IARC Director Dr Christopher Wild. "Concluding that 'bad luck' is the major cause of cancer would be misleading and may detract from efforts to identify the causes of the disease and effectively prevent it."

Furthermore, IARC experts identify several limitations in the report itself. These include:

  • the emphasis on very rare cancers that together make only a small contribution to the total cancer burden.
  • Due to the lack of data, the report excludes common cancers for which incidence differs substantially between populations and over time. The latter category includes some of the most frequent cancers worldwide.
  • Moreover, the study focuses exclusively on the United States population as a measure of lifetime risk. The comparison of different populations would have yielded different results.

Cancer etiology goes beyond 'bad luck'

As supported by scientific evidence, the most common cancers occurring worldwide are strongly related to environmental and lifestyle exposures, meaning that in principle, these cancers are preventable. "The remaining knowledge gaps on cancer etiology should not be simply ascribed to 'bad luck'," says Dr Wild. "The search for causes must continue while also investing in prevention measures for those cancers where risk factors are known. This is particularly important in the most deprived areas of the world, which face a growing burden of cancer with limited health service resources." 

 

Source: Medical News Today
No Comment