Differentiated Thyroid Cancer Clinical Trends in Quito, Ecuador

Research Article

Annals Thyroid Res. 2020; 6(2): 272-276.

Differentiated Thyroid Cancer Clinical Trends in Quito, Ecuador

Pacheco-Ojeda L¹*, Martínez-Jaramillo AL² and Romo-Castillo H³

¹Hospital Metropolitano, Ecuador

²Hospital de Especialidades Carlos Andrade Marín, Ecuador

³Facultad de Ciencias Médicas, Universidad Central, Ecuador

*Corresponding author: Pacheco-Ojeda Luis, Hospital Metropolitano, Sarmiento de Gamboa Oe 538, 170510, Quito, Ecuador

Received: September 03, 2020; Accepted: October 05, 2020; Published: October 12, 2020


Introduction: Thyroid cancer is the fifth most common cancer in women in Ecuador. This study aimed to assess the changes in clinical presentation and diagnosis of differentiated thyroid cancer at a third level hospital in Quito, Ecuador.

Methods and Materials: The study was a retrospective case series performed in three consecutive periods from 1990 to 2019 at a tertiary level hospital, Quito Ecuador, where the clinical records of 875 patients who had been diagnosed and surgically treated for differentiated thyroid cancer were retrospectively reviewed. Demographic, clinical, imaging, and pathological data were collected and analyzed.

Results: Significant trends toward older age, higher educational level, less palpable primary tumors, less palpable neck nodes, less DM, more ultrasound, CT and cytology exams, smaller primary tumors, more stage I patients, and more histological variant description, were found.

Conclusion: Thyroid cancer has not only steadily increased its incidence in recent years, but the clinical presentation, diagnostic and therapeutic approaches have significantly changed over the last three decades.

Keywords: Differentiated; Thyroid; Cancer; Clinical; Trends


DTC: Differentiated Thyroid Cancer; DM: Distant Metastases; SPMT: Second Primary Malignant Tumors; CT: Computed Tomography; MRI: Nuclear Magnetic Imaging; FDG-PET: Fluorodeoxyglucose Positron Emission Tomography; FNA: Fine Needle Aspiration; AJCC: American Joint Committee on Cancer; SEER: Surveillance Epidemiology and End Results; NICER: National Institute for Cancer Epidemiology and Registration


Thyroid cancer is one of the most common malignant neoplasms in many countries around the world as well as in Ecuador. It is the most common endocrine malignancy. A steady increasing incidence has been observed in developed as well as developing countries [1]. In the United States, in 2018, the incidence in men and women was 6.6 and 22.3 per 100.000 inhabitants, respectively. In Ecuador, the incidence is 6.6 and 35.0 for both sexes [2]. This incidence in Ecuadorian women is the fifth highest in the world. On the other hand, mortality in men and women has remained low: 0.35 and 0.47 per 100.000 inhabitants in the United States [1] and 0.3 and 1.8, respectively, in Ecuador [2]. Clinical presentation and evaluation changes, including new staging, have occurred during the last years. In the present study, we have analyzed the evolution of these facts in a selected population of Quito, Ecuador, South America.

Methods and Materials

We retrospectively reviewed the medical records and imaging studies of 957 thyroid cancer patients who were consecutively admitted and surgically treated at a tertiary level public hospital in Quito Ecuador in the years 1999-2019. Patients were classified into three consecutive periods: 1990-1999, 2000-2009, and 2010-2019. Demographic variables, clinical, imaging, and pathological findings were retrieved from the hospital database and evaluated, searching for trends between periods. Most patients underwent subtotal or total thyroidectomy. We performed the statistical analysis using RStudio software, version 1.3.959. Categorical variables were expressed as percentages and assessed using Χ2 test. Quantitative variables were represented by their means and standard deviations, after checking for normality assumption and evaluated by Analysis Of Variance (ANOVA). P values, two-tailed, less than 0.05 were considered statistically significant.


Out of 957 patients, 875 had a pathological diagnosis of Differentiated Thyroid Cancer (DTC): 836 (96%) were papillary, and 36 (4%) follicular. Eighty-two patients were excluded: 71 who had a different pathological diagnosis and 11 with DTC located in the thyroglossal tract or ectopic sites.

Seventeen parameters and their trends trough three decades were analyzed. Eighty-three percent of patients were women, and sex distribution remained the same throughout the three periods of time. Mean age increased significantly from 43 to 50 years between the first and the other two decades (Table 1). However, in the whole study population, 68% of patients were younger than 55 years of age. Regarding the level of education, there was a significant increase in patients with a university level of education, and regarding racial distribution, we observed a considerable rise in mestizo patients (Table 1). Ninety-two percent of patients were seen for a thyroid primary tumor, 7% for a locoregional recurrence, and 1% for persistent tumor. Data from these referred patients was incomplete in some of them. Patients seen with recurrence decreased significantly from 14% in the first decade to 4% in the last. The duration of symptoms also considerably reduced during the three periods of time (Table 1).