Changes in the Demographic and Clinicopathological Characteristics of Thyroid Cancer: A Population-Based Investigation in Algeria, 1993-2013

Abstract

Over the last three decades, the incidence of thyroid cancer has increased worldwide. The reasons for this increase remain controversial. In Algeria, however, to date, information on thyroid cancer has been limited to a hospital-based case series. We analyzed data from a population-based cohort study in Oran District, Algeria, to describe demographic and clinicopathological characteristics of patients diagnosed with thyroid cancer between 1993 and 2013. Medical records and pathology reports of thyroid cancer patients who had surgery were reviewed. Changes in demographic and clinicopathological features over the 21-year period are described. During the study period, thyroid cancer was diagnosed in 1248 women (86.5%, mean age 43.7±15.2 years) and 195 men (23.4%, mean age 48.1±15.9 years). Most cases (83.1% for women and 69.8% for men) sought a diagnosis following a self-neck check. The most common histologic types were papillary (58.3%), follicular (29.7%), anaplastic (4.1%), and medullary (0.8%) carcinomas. The incidence of papillary carcinomas significantly increased (p<0.001) while the incidence of other histologic types significantly decreased over time. Tumor size overall significantly decreased (p<0.001) while the frequency of small (≤20 mm) and larger (>20 mm) carcinomas significantly increased (p<0.05). The frequency of thyroid cancers with capsular effractions and angioinvasions also decreased over time. Thyroid cancer incidence in Algeria has increased substantially in line with international trends with changes in clinical practice being a possible contributing factor. However, the increasing papillary-to-follicular cancer ratio may be due to changes in iodine nutrition status in Algeria. Further research, including exploration of biological and molecular features of thyroid cancer, will enable a better understanding of risk factors and etiopathogenetic mechanisms.

Epidemiology, Clinic-histopathological features and Surgical treatment of Papillary Thyroid Cancer: A Retrospective Descriptive Study in Northwestern Algeria

“…Dysthyroidism in 19.4%, 13.6% fortuitously, during a consultation for another health issue, 4.9 % with dysphagia, and 3.9 % with dysphonia. The majority of PTC was diagnosed by self-neck checks, and most initially appeared as cervical swelling or thyroid nodules (Bendouida et al, 2015;Boukheris et al, 2020b). This is consistent with our results.…”

“…It was first implemented in 1967 in areas with a high prevalence of endemic goiter and then nationwide since 1990 (Guidoum et al, 2015). The results of a population-based investigation in Algeria (1993Algeria ( -2013 by (Boukheris et al, 2020b) suggest a shift from an iodine deficiency state to sufficient to excessive iodine supplementation.…”

Thyroid cancer incidence and trends by demographic and tumor characteristics in Oran, Algeria: 1993–2013, a population-based analysis

“…We failed to retrieve all pathology reports of thyroid cancer patients diagnosed in the early period of the study, and information on tumor size was not complete. However, it is unlikely that these limitations have invalidated our study because the observed trends are consistent with a context that includes a history of iodine deficiency and a high prevalence of thyroid cold nodules and goiter in the cohort (Boukheris et al, 2020).…”

“…The increased incidence among women compared with men is consistent with the fact that women in Oran tend to take up medical care more readily than men. In a previous investigation, we found that a self-neck check was the most frequent circumstance that led to thyroid cancer diagnosis in 83.1% of women and 69.8% of men (Boukheris et al , 2020). We hypothesize that a detection effect may have caused, at least in part the observed increase in thyroid cancer incidence during this time period.…”

“…A few factors can explain this trend: the evolution of medical practices with the introduction of thyroid ultrasound in 1990 and fine needle aspiration in 1998, and the dramatic expansion of the private medical sector since the early 1990s. In a previous investigation, we found that 96% of patients have undergone thyroid surgery in public hospitals, whereas 92% of them have had their thyroid specimens examined in private pathology laboratories (Boukheris et al , 2020). Furthermore, we suspect that the gradual return to greater social stability and security in the early 2000s nationwide may have encouraged the general population to seek actively medical care, in particular women.…”