THYROID CANCER:
MORE THERAPEUTIC IATROGENESIS THAN TUMOR MORBIDITY AND MORTALITY
Thyroid cancer is the most common endocrine cancer, and thyroidectomy is the most frequently performed cervical surgery. In recent decades, the incidence of thyroid cancer has increased steadily, to the point that some writers have called it the cancer epidemic of the 21st century.
(1). This increase corresponds mainly to papillary carcinomas smaller than 1 cm; despite their detection and treatment at such early stages, there has been no significant change in mortality.
(2). Much has been discussed about the causes of this increase in incidence and the true magnitude of this “epidemic.” It is now clear that easy access to and indiscriminate use of ultrasound for the study of any cervical condition has led to this dramatic increase in the incidence of thyroid cancer.
(3). In a way, we have become victims of technology, which is used without regard for evidence-based recommendations. In addition to the problem of early detection of a condition for which treatment does not reduce mortality or recurrence, this “epidemic” has had a significant impact on the burden on the healthcare system and on patients' quality of life.
The number of asymptomatic cases of thyroid cancer has led to a concomitant increase in the number of surgeries, many of which are unnecessary; in the indication of complementary treatments such as radioactive iodine ablation, which has not been shown to modify outcomes that are important to the patient; in the corresponding appearance of treatment-related complications (laryngeal nerve injury, hypoparathyroidism, chronic sialadenitis), and in early dependence on levothyroxine. All of these complications impact healthcare costs, using resources that should be devoted to higher-priority conditions.
On the other hand, the effects on patients' quality of life as a result of diagnosis and labeling as “cancer patients” have produced a considerable number of patients who are not actually ill, but who suffer early in life from the emotional effects of having been diagnosed with cancer. This leads to growing anxiety about any symptoms, the need to undergo constant follow-up tests, and anxiety before each doctor's appointment. Despite the magnitude of this problem, there is little information available in the country about this disease and even less discussion in scientific journals.
In this issue of MEDICINA, three articles address the topic of thyroid cancer (4,5,6) and offer explanations for the current situation. It is specifically demonstrated that local and regional information on this subject is scarce, fragmented, heterogeneous, and often incomplete. Although it seems to reach the same conclusions as American and European studies, this particular situation in Latin American countries means that we continue to accept foreign explanations that may not correspond to our particular reality and that we continue to apply treatments that are probably not appropriate for our populations.
Concern about the condition of thyroid cancer requires doctors to take a critical look at the information that appears every day and to take bold action towards a more rational treatment adapted to our conditions. There is an urgent need for more local research on thyroid cancer and its real effect on people's lives, as well as the formation of multidisciplinary groups to treat the disease, similar to the group that publishes in this issue, which allows for more accurate and precise management of the disease. It is also necessary to assess the cost of thyroid cancer diagnosis and treatment in terms of quality of life and economic resources, specifically for those diagnosed incidentally, in order to offer local alternatives that respond to the specific needs of the country and its diverse regions.
Finally, as suggested in the articles mentioned above, it is extremely important to educate primary care physicians about the disease and the effects that an incorrect decision can have on people's futures. Only continuous and specific education in medical schools will be able to contain this diagnostic “epidemic” that greatly affects patients' futures.
REFERENCES
Ahn HS, Kim HJ, Welch HG. Korea’s thyroid-cancer «epidemic»–screening and overdiagnosis. N Engl J Med. 2014;371:1765-7.
Davies L, Welch HG. Current thyroid cancer trends in the United States. JAMA Otolaryngol Head Neck Surg. 2014; 140:317-22.
Zevallos JP, Hartman CM, Kramer JR, Sturgis EM, Chiao EY. Increased thyroid cancer incidence co- rresponds to increased use of thyroid ultrasound and fine-needle aspiration: a study of the Veterans Affairs health care system. Cancer. 2015; 121:741-6.
Vargas-Uricoechea H, Herrera-Chaparro J, Meza-Cabrera I, Agredo-Delgado V. Thyroid cancer, experience in South America and Colombia. Medicina (Bogotá) 2015; 37 (2): 139-162.
Vargas-Uricoechea H, Herrera-Chaparro J, Meza-Cabrera I, Agredo-Delgado V. Thyroid cancer and indications for thyroidectomy. Ten years of experience in the Department of Cauca, Colombia, 2004-2013. Medicina (Bogotá) 2015; 37 (2): 109-121.
Jácome Roca A. Differentiated thyroid cancer
Why is its frequency increasing? Medicina (Bogotá) 2015; 37(2): 184-195.
Article written by Dr. Álvaro Sanabria