What are the potential complications of lung cancer screening?
Current publications on lung cancer screening conclude that complications of screening are relatively minor and are outweighed by benefits.
Nevertheless, Medicare regulations require that those who want to be screened, must be provided with information on a long list of possible complications. Accordingly, a web page, like this one, that seeks to serve as a decision aid is obliged to provide specific information on potential complications.
Why? No other form of cancer screening requires decision aids.
By the early 1990s, critics of lung cancer screening had proposed a long list of possible complications that might arise from lung cancer screening.
License to smoke: The most common cause of lung cancer is cigarette smoking and it is very difficult for patients to quit smoking without counseling and assistance. Some critics of lung cancer screening suggested that screening would provide a “license to smoke”. That is, instead of quitting, the patient would consider CT screening as a good reason not to have to quit. Continued smoking would cause considerable harm.
Inconvenience: Individuals have to take time off from work and travel to be screened.
Expense: CT scans cost money. If the scan finds a nodule, further tests, and further expense can be incurred.
Discomfort: In cancer screening, patients often must undress, have an intravenous needle placed. Some exams like mammography can cause discomfort.
Anxiety: Many persons who are considering screening are worried about the future, because they have known family members or friends who have died of lung cancer. If a CT scan reports that a nodule has been detected, this finding might trigger an increase in anxiety.
False negative screening result: Screening tests can miss cancers, resulting in delay that might allow the undetected cancer to grow, progress and kill.
False positive screening result: CT scans detect not just lung cancers, but also other nodules caused by benign tumors, infections like tuberculosis or many other causes. Accordingly, the finding of a nodule on a CT scan – that is not cancer = may cause anxiety.
If the finding is not managed properly – according to guidelines – further complications may theoretically ensue.
Unnecessary diagnostic testing: If a benign nodule is detected, further testing may be performed, resulting in more expense, inconvenience and exposure to radiation.
Unnecessary surgery: In the past, many individuals who had lung nodules found on chest x-rays had surgery to diagnose or even remove non-cancer nodules. Such surgery provides no benefit, only risk of complications or even death.
Complications of unnecessary surgery: Such surgery provides no benefit, only risk of complications. Depending upon how much lung was removed, the patient may lose exercise ability.
Death after unnecessary surgery: Although uncommon, in earlier years, thoracotomy for lung resection had a mortality risk of approximately 1-2% for benign nodule resection.
Overdiagnosis of lung cancer: Some argued that high percentages (20-80%) of lung cancers diagnosed by CT screening were overdiagnosed. That is, these cancers would never cause any symptom or kill during normal expected life span.
Overtreatment of overdiagnosed lung cancer: If it were true that large numbers of lung cancers diagnosed by CT screening were overdiagnosed, then it would mean that large numbers of people would undergo unnecessary operations that would not help and would harm in a substantial number.
Radiation carcinogenesis: Some doctors maintain that even small doses of radiation are capable of causing cancer. Hence CT screening might cause more cancers than it cures.
Exploitation: Critics expressed concern that unscrupulous doctors would seek to get-rich-quick by starting low-quality CT screening programs.
Diversion of medical resources. Expenditure of large amounts of money on CT screening would take money away from other more important services. One prominent medical oncologist stated that “We cannot afford to screen for lung cancer; we need the money for treatment.”
Low cost-effectiveness; In any case, mathematical estimates suggested that it would cost large amounts of money to save a single life from lung cancer.
Town vs. Gown: It was predicted that, even if CT screening worked effectively in large medical centers, it might prove less effective and more risky, when performed in smaller community settings.
Conclusion:
CT screening critics insisted that population screening (outside of research projects) should not be approved until randomized control trial (RCT) research results proved a 20% reduction in lung cancer-specific mortality and, in addition, showed that the benefits outweighed the risks and complications of screening.
It has taken almost twenty years to obtain RCT proof that convinces skeptics that CT screening saves lives and has low risks and implement a national population screening program.
During that time period, approximately 3 million Americans died of lung cancer and very few Americans benefited from lung cancer screening.
To repeat, current publications on lung cancer screening conclude that complications of screening are relatively minor and are outweighed by benefits.
In the following sections, each of these potential risks is discussed in greater detail.
Potential Complications of Lung Cancer Screening: “License to Smoke”