By now, we’ve all heard about the importance of cancer screening. But for those with a detected cancer, a new article highlights that the removal of the malignancy might not be where you should stop in your health journey.
James DeGregori, PhD, deputy director of the CU Cancer Center and professor in the Department of Biochemistry and Molecular Genetics is one of the researchers behind the commentary in Cancer Cells that was published this week.
For this article, DeGregori partnered with three researchers from London, Paul Pharoah, MD/PhD, Peter Sasieni, PhD, and Charles Swanton, MD/PhD. Swanton brought the group together in order to explore theoretical underpinnings of results from cancer screenings.
The article notes that while screening trials lead to meaningful reductions in deaths from respective cancers there is not always a visible reduction in all-cause mortality. All-cause mortality is a term used to refer to death from any cause.
“For example, if you screened 10,000 people for a specific type of cancer, you generally do not actually see more people surviving longer than a group of 10,000 who were not screened,” explained DeGregori.
This commentary addresses why cancer screening trials often do not have evident benefits for all-cause mortality, despite earlier detection of many cancers. One area that they discuss that has previously been mentioned is that if a particular cancer only affects a small percentage of the population, even with those 10,000 participants the number of cancer cases would be relatively low, and thus the benefit for all-cause mortality is “below the radar”.
According to the American Cancer Society, it is estimated that there will be an estimated 1.8 million new cancer cases diagnosed this year. That is about 0.5% of the U.S. population.
The group proposed some statistical methods to better evaluate whether there is a strong likelihood that there is a benefit in all-cause mortality due to cancer screening. In which case they show that even trials that reduced cancer incidence but without significant all-cause mortality benefit actually demonstrated a reasonable probability of such a benefit.
Overall decline of the body
The aspect of the commentary that DeGregori was more involved in was the proposal that the detection of a malignancy, including cancers, is a marker of an overall decline in the body.
“In other words, once we get old, the human body starts to decline and that decline increases the probability of getting cancer, but it also increases the chances of dying from heart disease, kidney disease and many other diseases,” says DeGregori. “So, what we are actually arguing is that when you detect a cancer and can treat that cancer, we have to consider that that person now still may be at a greater risk for some other malady.”
This is due to the overall physiological decline that the person is experiencing either from their age or from the fact that they smoke or have an unhealthy lifestyle.
“When we take that into account, we may need to start to recognize that when we detect an early-stage cancer in someone, that we can’t just remove that cancer and pat ourselves on the back.”
While it is helpful to remove those cancerous cells, it should be thought of as a warning sign and that patients should be carefully monitored and examined for other possible health conditions such as heart disease.
“We are suggesting that we could perhaps improve all-cause mortality if we recognize these early cancers or any cancer is a marker of other disease risks as well,” says DeGregori. “It is sort of like a canary in the coal mine. We need to look at a positive cancer test as indicating a strong likelihood that there is something else wrong in the human body.”
Aged tissues with these different markers increase the risk of cancers, but also the risk of many other diseases.
Therefore, detection of lung cancer with CT screening (for example) should elicit enhanced monitoring
and interventions for the other conditions.
You have a red flag, now what
DeGregori suggests that the medical community takes this information and develop interventions that will reduce additional risks.
“The next step depends on the individual, but it would be good to start with a good diagnostic workup.”
The recommendations after the full workup to check for other health conditions could range from exercising more and improving your diet to dealing with a significant health concern.
“We cannot make a general recommendation, but we would encourage doctors to do more than just remove the offending malignancy that was detected by the screening,”
Still important to keep up with your cancer screenings
It is important to point out that failure to demonstrate all-cause mortality benefits in screening trials should not diminish the importance of cancer screening for reducing deaths from cancers. The goal of screenings for cancer is to detect cancers at an earlier stage when they are much easier to treat and often can be removed by surgery.
“This is most evident for example with skin cancer,” says DeGregori. “If you catch melanoma early it can be removed in a 15-minute, out-patient surgery. Now the survival probability is close to 100%. If that same tumor went to the point that is started invading into the skin or beyond, with each increasing stage of malignancy your odds of survival drop dramatically. Before the advent of immunotherapies, it would go to essentially zero.”
There are many screening options available. Some of the most common screenings include a colonoscopy for colon cancer, mammograms for breast cancer, pap smear for cervical cancer and a newer screening, and CT for lung cancer.
COVID-19’s impact on screening
COVID-19 is having a large impact on people going in to receive their annual screening. This is leading to an unplanned experiment that will give researchers data on decreased screenings and the impact it will have on late-stage diagnoses.
“This is, unfortunately, going to be an experiment that we did not want to do but that might show a very clear signal that did not require an actual trial. We expect to see a bump in many of these cancers in the coming years,” says DeGregori.