He thyroid cancer registers sustained increases in several regions of the world. Rates have increased faster than other types of cancer.
In the United States, where the incidence tripled between 1980 and 2016 according to the SEER database, the phenomenon has led researchers and doctors to examine what factors explain this trend: diagnostic improvements, metabolic changes, increased exposure to medical radiation or environmental alterations.
Explode – Shutterstock
Some recent studies, according to ‘BBC News’, show that overdiagnosis alone does not explain everything. Reviewed research indicates increases in both small tumors and advanced and metastatic tumors. A study in California analyzed more than 69,000 patients between 2000 and 2017 and found that cases and deaths increased regardless of tumor size.
Another work showed increases in metastatic papillary cancers and an annual growth of 1.1% in mortality.
In addition, Sanziana Roman, an endocrine surgeon at UCSF, told the British media that the increase is observed even in regions without robust screening programs.
More large and advanced tumors are also detected, suggesting a real increase in incidence.
The relationship between ionizing radiation in childhood and thyroid cancer is well documented. After the 1986 Chernobyl accident, rates skyrocketed among children in Belarus, Ukraine and Russia.
In addition, a study that attributes about 36% of cases in Japanese atomic bomb survivors since 1958 to childhood exposure.
Besides, The global increase in obesity has been linked to the risk of thyroid cancer. The analyzed cohorts indicate that people with high BMI have more than a 50% additional probability of developing the disease.
The report notes that the mechanisms remain unclear, but researchers are studying chronic inflammation, insulin resistance and hormonal alterations, such as changes in TSH levels, as possible pathways.
Unsplash
Research on endocrine disruptors present in everyday products, such as PFOA and PFOS, linked to kitchen utensils, food packaging, cosmetics, carpets and firefighting foam. These substances can alter hormonal functioning.
The evidence of its direct relationship with thyroid cancer is contradictory, so the hypothesis is still being studied, according to the media.
Some island countries have high rates of thyroid cancer. Certain trace elements present in volcanic areas, such as zinc, cadmium or vanadium, could play a role.
However, there is no study at the moment that supports the hypotheses raised by specialists.
By José Guerrero
