What is the biology of a disease?
Understanding the biology of disease is considered the foundation of the practice of medicine. Knowing what is normal versus abnormal and the evolution of conditions believed to be pathologic is the underpinning of whether any therapeutic intervention is warranted. For example understanding which infections pose a risk and whether treatment is effective determines whether therapy is needed. If you get an infection, which is self limited there is no reason to take an antibiotic which has its own risks as well as expense. The biology of disease for cancer is
- Does this type cancer grow and if yes how quickly?
- Does the cancer spread?
- Does this cancer ever cause symptoms?
- What percent of patients who died of other causes have this type of cancer?
- What is the death rate attributable to this type of cancer?
An article in the New England Journal of Medicine on thyroid cancer, http://bit.ly/2bDmh5Y, describes the massive over diagnosis and treatment of thyroid disease. Patients often undergo unnecessary screening studies which identify abnormalities that are then biopsied revealing “pathology” reported as “cancer”. These incidental areas of abnormality pose much less risk to the patient than the surgical treatment recommended to remove them. The study once again highlights the profound lack of understanding of the “biology of disease” and sadly many patients are subjected to unnecessary and dangerous surgery/radiation where the risks of any therapeutic intervention dramatically outweigh the benefits.
Over a third of the population have tiny cancers in their thyroid, but only one in a hundred thousand people die from thyroid cancer. These so called cancers are misnamed with virtually no life threatening character or significant risk to the patient.
Atul Gawande, in a New Yorker article from May 11th of 2015, describes a classic case of over diagnosis of thyroid cancer in which he was the treating surgeon. A woman in her fifties was referred to him for thyroid removal for a 5mm area of “cancer” incidentally identified while removing an adjacent benign lump.
The patient was advised by Dr Gawande, that she didn’t need any surgery and that the surgery posed a greater risk of causing harm than the identified abnormality. He advised her to be followed up with ultrasound examinations.
The patient, in spite of being given excellent medical advice, still requested surgery which, for some reason, Dr Gawande agreed to do. Unfortunately the patient had a bleeding complication post operatively and required yet another surgery. She recovered after the second surgery but what would our opinion be if she had died or ended up with a permanent disability due to these unnecessary surgeries?
Physicians continue to practice medicine and recommending invasive dangerous therapies without explaining to patients that we do not understand the fundamental biology of disease of many conditions. 20 to 30 percent of cancers diagnosed by looking at the tumor under the microscope by pathologists, our current gold standard, are not biologically significant (the misnomered cancers will not cause harm to the patient).
Women treated for breast cancer, especially ductal carcinoma in situ (DCIS) face the same dilemma. The same “cancer” misappellation has been described for DCIS identified in breast biopsies. Women often have surgery, radiation and some even choose prophylactic mastectomy for this questionable indication. There is a movement to treat patients with DCIS less aggressively.
It is estimated that 20 to 25% of lung cancers identified by screening are not biologically significant and pose no long term risk to the patient. Many of these patients are subjected to deforming surgery and toxic chemotherapy/ radiation therapy without knowing if the tumor represents a risk to their health. The lack of understanding of disease processes extends to the identification of likely incidental tiny clots in the lungs (pulmonary embolism) which are almost certainly unrelated to the clinical symptoms of the patient but which often generate aggressive therapy. Many other pathologies are identified on imaging which generate unnecessary intervention.
Patients should seek detailed information about any recommended intervention especially surgery. They should understand risk benefits and alternatives especially the risks of doing nothing or just following findings reported as abnormal. I always recommend patients seek second opinions any time a significant intervention is recommended.
Physicians need to practice evidence based medicine and provide complete informed consent to patients. It is very important that they refuse to recommend unnecessary procedures and refuse to perform risky surgery even if requested by frightened patients. It is a physician’s ethical obligation to educate and inform patients requesting unnecessary surgery and refuse to perform the procedure.
Frequently, patients needlessly suffer terrible complications and even death based on medicines' lack of understanding of the biology of diseases. Without transparency to patients explaining the lack of fundamental knowledge, harm continues to occur.
Nicolas Argy, MD, JD
Copyright © 2016 Nicolas Argy