Thyroid Cancer and its Relationship with pre-existing Thyroid Disease and Nodule Size: A retrospective study from a Tertiary Care Centre in Pakistan

Abstract

Objective: To determine the prevalence of thyroid cancer in patients with pre-existing thyroid diseases (particularly autoimmune thyroid disorders such as Graves’ disease) and to explore the association between nodule size and malignancy type among patients treated at a tertiary care centre in Pakistan.

Methodology: A retrospective descriptive analysis of 62 patients diagnosed with thyroid cancer between January 2015 and August 2024 was conducted. Variables included were cancer type, pre-existing thyroid condition, confirmatory diagnostic method, nodule size, recurrence, metastasis, and surgical intervention. Percentages and frequencies were calculated to identify associations and trends.

Results: Out of 62 patients, 59 (95.2%) had valid data on thyroid cancer type. Papillary thyroid carcinoma (PTC) was the most common (76.3%) followed by anaplastic carcinoma (11.9%) medullary carcinoma (6.8%) and follicular carcinoma (5.1%). Thyroid cancer was only identified in 8.1% of patients with thyroid disorder (hypothyroidism or hyperthyroidism), while 91.9% had no prior thyroid condition. Nodules between 1–3 cm accounted for nearly half of all malignancies. Recurrence and metastasis occurred in 4.8% and 19.4% patients respectively. Surgery was performed in 71% of patients.

Conclusion: This study did not find any strong association between thyroid cancer and pre-existing thyroid disease. Most malignant nodules were between 1–3 cm, highlighting the need for early and thorough evaluation of all thyroid nodules irrespective of thyroid disease history or nodule size.