A historic dispute over the cause of cancer
James Fleck: Anticancerweb Dec 1sth, 2018
On January 2nd, 2015 Science journal caused international scientific curiosity publishing an article on the cause of cancer. The article “Variation in cancer risk among tissues can be explained by the number of stem cell divisions”, was written by Cristian Tomasetti and Bert Vogelstein, both from Johns Hopkins University School of Medicine. The article states that 65% of the malignant tumors are due to a random DNA mutation in non-cancerous stem cells, which proliferation is responsible for keeping normal tissue homeostasis. The authors showed a strong statistical correlation (0.81) between the lifetime risk of different types of cancer and the number of normal stem cell divisions occurred in the respective target organs. The paper admitted that only one third (35%) of cell malignant transformation would be attributed to environmental or hereditary risk factors. This elegant data would be very well-received if an inappropriate conclusion comment did not happen. The authors proclaimed that “bad luck” would be the main cause for the malignant transformation.
On January 13th, 2015 the World Health Organization (WHO) published the International Agency for Research on Cancer (IARC) Press Release No. 231, strongly opposing the conclusion of the Johns Hopkins article. IARC conclusion was supported by a robust international epidemiological data. The director Christopher Wild correlated cancer mainly with environmental or behavior risk factors. He blamed the article for been based exclusively on American data. IARC emphasized that 50% of all cancer worldwide is preventable. The WHO agency based its claim on the incidence reduction of lung cancer associated with smoking cessation and the decreasing cases of liver cancer in vaccinated people against hepatitis B.
This is an interesting and historic battle with French IARC's “armes blanches”. The Johns Hopkins sophisticated lab data were well-methodologically supported, but lacking a population-base. IARC crude data were population-based, but with a low level of evidence, which is often seen in observational epidemiological studies.
The dialectic dispute only increased ambivalence. Meanwhile, cancer continues sliding between the two divergent views been the second cause of death in the world.
Cristian Tomasettiand Bert Vogelstein: Variation in cancer risk among tissues can be explained by the number of stem cell divisions, Science347: 78-81, 2015
* Illustration gently provided by Rosangela Dambros