Epidemiologia e fatores associados à recidiva do carcinoma diferenciado de tireoide em um hospital de referência no Estado da Paraíba

Abstract

Currently thyroid carcinoma (TC) has shown an increase in the incidence rate in most countries (about 1% per year). The annual incidence varies among populations, however it is between 2-3 cases / 100,000 men and 4-9 cases / 100,000 women. In the context of Paraíba, the National Cancer Institute's estimate for the biennium 2018-2019 is 5.88 / 100,000 for women and 2.08 / 100,000 for men. Objective: To verify the relationship between clinical and epidemiological factors of patients with differentiated thyroid carcinoma (DTC) treated at a reference hospital in the state of Paraíba, and risk of recurrence of the disease. Methods: The present paper presents a cross-sectional study, carried out through the collection of data obtained from the medical records of patients with DTC attended at Fundação Assistencial da Paraíba (FAP) from April 2011 to April 2018. It were considered risk factors as: history of occupational exposure to substances or ionizing radiation, smoking, presence of autoimmune thyroid disease (AITD), previous malignant neoplasm, and family history of thyroid cancer. It was used the Chi-square test for the association of qualitative variables and it were used logistic regression models with a significance level of 5% for analysis of possible associated factors. Results: 284 patients were selected, most of them female (86.6%), with an average age of 46.3 ± 14.4 years; about 40% of the individuals were farmers; 70.6% did not report occupational exposure; and 97.6% did not report radiation exposure. Forty-three (20%) reported a family history of TC and 75.7% did not present DTC. The classical variant papillary of DTC was the most prevalent (69.4%) and 32.7% of DTCs were multifocal. In the evaluation of risk of relapse, 98 (34.5%) presented intermediate risk and 43 (15.1%) high risk. The univariate analysis identified ¿age¿ (OR=1,05; IC=1,046-2,723; p=0,031), ""dwelling zone"" (OR=1,87; IC=1,10-3,17; p=0,02), ""pesticides exposure"" (OR=2,03; IC=1,135-3,618; p=0,016), ""AITD"" (OR=5,63; IC=1,204-26,351; p=0,045), ""histological subtypes of greate aggressiveness"" (OR=5,12; IC=1,037-25,28; p=0,001) and ""multifocal tumor"" (OR=2,56; IC=1,527-4,278; p=0,001) as risk factors for recurrence, nevertheless in the final multiple analysis, only more aggressive histological subtype, occupational and multifocal tumor were statistically significant. Discussion: Some results of this study are consistent with the data found in the literature such as age at diagnosis, higher prevalence of females and the classical variant papillary of DTC. In the multiple regression, multifocal tumors and variants considered more aggressive were also concordant. Regardeless of occupational exposure shows a statistically significant association with risk of recurrence, this study has a limitation concerning the design since exposure and disease are not contemporary conditions, the time of exposure was not measured, and also if there is presence of current or past contact with the substances. Conclusion: More aggressive histological variants and multifocal tumors are risk factors for recurrence of the disease. Occupational exposure to agrochemicals presents controversies regarding this risk, therefore new studies are needed to clarify this relationship.