Malignant neoplasms in people with hypothyroidism in Spain: A population-based analysis

Abstract

Purpose The objective of this study was to determine the association between hypothyroidism and overall and site-specific cancer in Spanish population. Methods A cross-sectional study was performed using the population-based database BDCAP (Base de Datos Clínicos de Atención Primaria, primary care clinical database) to analyze the relative risk of cancer in Spanish population with hypothyroidism. Results In a total of 2,414,165 patients diagnosed with hypothyroidism in BDCAP in 2019, the relative risk (OR) of cancer, compared to the non-hypothyroid population, was 1.73 (1.72–1.74) (P<0.0001). The higher risk was observed in both men (OR 2.15 [2.13–2.17]; P<0.0001) and women (OR 1.67 [1.636–1.68]; P<0.0001). However, hypothyroid persons aged 65 years or older had a reduced risk of cancer (OR 0.98 [0.97–0.98]; P<0.0001). In addition, hypothyroid patients aged 65 or over showed a decreased risk of cancers of the bladder, colorectal, gastric, pancreatic and prostate. Socioeconomic characteristics such as income level, municipality size, country of birth and employment situation had limited influence on the association between hypothyroidism and cancer. However, hypothyroid patients receiving replacement therapy exhibited higher cancer risk compared with patients without treatment (OR 1.30 [1.28–1.31]; P<0.0001). Conclusion Spanish hypothyroid patients of both genders have a risk of overall cancer higher than that found in non-hypothyroid population. However, people over 65 years have a reduced risk of various malignancies. This peculiarity of hypothyroidism should be considered by the health authorities.

Causal Associations of Hypothyroidism with Prostate Cancer, Colorectal Cancer and Lung Cancer: A Mendelian Randomization Study

“…And another study from Ben Boursi showed that untreated hypothyroidism was associated with increased risk of CRC [11] . This result conflicted with an observatory study in Spain by Juan J. Diez, which indicated that hypothyroid patients aged 65 or over had a decreased risk of colorectal cancer [12] .…”

“…In this MR analysis, we didn't observe significant associations of genetic predisposition to hypothyroidism with bladder cancer, stomach cancer and pancreas cancer with P > 0.05. According to an observational study in Spain, hypothyroidism increased risk of all the specific neoplasms studied, except for bladder cancer but the conclusion was totally different in the hypothyroid patients aged 65 or over [12] . And another study in Danish indicated that there was no causal association between hypothyroidism and long-term risk of gastrointestinal cancer [35] .…”

Thyroid dysfunction and risk of cutaneous malignant melanoma: a bidirectional two-sample Mendelian randomization study

“…The International Agency for Research on Cancer (IARC) predicts that there will be 18.1 million new cancer cases worldwide in 2020 ( 29 ). In addition, the American Cancer Society predicts that 1.95 million new cancer cases and 600,000 cancer deaths are expected in the United States in 2023 ( 30 ). Current research on the connection between thyroid health and cancer is contradictory.…”