Study: two thirds of cancer types due to ‘bad luck’

Of 31 types of cancer, researchers at the Johns Hopkins University School of Medicine found only nine with links to lifestyle and genetic faults

Published: Updated:

Two thirds of cancers can be attributed to random mistakes in cell division and not genetics or lifestyles according to U.S. scientists, The Telegraph reported on Friday.

Of 31 types of cancer, researchers at the Johns Hopkins University School of Medicine found only nine with links to lifestyle and genetic faults.

The remaining 22 were due to random mistakes in cell division which cannot be controlled.

“If two-thirds of cancer incidence across tissues is explained by random DNA mutations that occur when stem cells divide, then changing our lifestyle and habits will be a huge help in preventing certain cancers, but may not be as effective for a variety of others,” Cristian Tomasetti told The Telegraph.

“We should focus more resources on finding ways to detect such cancers at early, curable stages,” he added.

While pivotal for body renewal and damage repair, an error in cell division, where one chemical letter in the DNA is incorrectly traded for another, exasperates the production of cancerous cells.

The study found that the frequency of these errors was linked to a higher rate of cancer, leading to the assumption that these mutations were what drove cancerous tumors and not external environmental forces as widely perceived.

“Our study shows, in general, that a change in the number of stem cell divisions in a tissue type is highly correlated with a change in the incidence of cancer in that same tissue,” lead researcher Bert Vogelstein said.

Pancreatic cancer is more common than pelvic cancer because cells in the pancreas regenerate quicker than those in our pelvis.

However, lung and skin cancer were more common that what their mutations would stipulate, which according to scientists suggests that genetics and lifestyle did indeed increase the risk.

“We found that the types of cancer that had higher risk than predicted by the number of stem cell divisions were precisely the ones you'd expect, including lung cancer, which is linked to smoking; skin cancer, linked to sun exposure; and forms of cancers associated with hereditary syndromes,” Vogelstein was quoted as saying.

“While some genetic mistakes are due to bad luck, we know that our cancer risk depends on a combination of our genes, our environment and other aspects of our lives, many of which we can control,” Emma Smith, senior science information officer at Cancer Research UK told The Telegraph.

“Making these changes is not a guarantee against cancer, but it stacks the odds in our favor,” she said.

The research heightens awareness on the importance of early prediction, Hans Clevers, a stem cell and cancer biologist at the Hubrecht Institute in Utrecht said.

“The average cancer patient is just unlucky,” he added, explaining that the study will help patients realize that the disease was not their fault.