Endocrine Abstracts

Background: Growth hormone directly stimulates tumour growth, angiogenesis and metastasis through autocrine and paracrine effects on cancer cells, while through IGF1 inhibits apoptosis and promotes epithelial proliferation. Although disputed, some studies have shown an increased cancer incidence in acromegaly patients, especially in uncontrolled subjects, while others have not.

Aim: To assess prevalence of cancer in a cohort of patients with long term treated acromegaly.

Methods: Retrospective study by analyzing the files of 162 inpatients with acromegaly (105F/57M, mean age at diagnosis 43.7 ± 12.8 years), hospitalized in a tertiary endocrine center between 2019 and 2022. Median follow-up period was 9 years. IGF1 was measured by chemiluminescence. For cancer screening, thyroid ultrasound in palpable nodules, fine needle aspiration, cytology exam in suspected nodules and pathology exam in operated patients, colonoscopy, PAP and mammography were performed according to the guidelines. Four patients were excluded because of long distance (>5 years) between cancer and acromegaly diagnosis.

Results: 96 patients (59.2%) had normal IGF1 levels at their last follow-up; 16 patients (9.9%) with cancer were identified: 7 differentiated thyroid carcinomas (DTC), 4 colorectal carcinomas, 2 cervical cancers, 1 endometrial cancer, 1 malignant melanoma, 1 non-Hodgkin lymphoma B-cell. Thyroid nodules prevalence was 66.7% (n=108). Fine needle aspiration biopsy was performed in 22 patients (Bethesda I:1, Bethesda II:13, Bethesda III:5, Bethesda IV, V, VI:3 patients). Colonoscopy was performed in 52 patients (32%), 27 colonoscopies were normal, 25 revealed polyps (48%); out of 25 polyps, 4 were malignant. Cancer patients showed similar acromegaly duration (median 9 years) compared to non-cancer patients (median 8.5 years, P=ns). 6/10 cancer patients previously underwent pituitary radiation while 50/96non-cancer patients had not (P=0.02, chi-square).

Conclusion: DTC and colon polyps’ prevalence in our series of acromegaly patients was higher compared to non-acromegaly population, however larger prospective studies might clarify this relationship.