Endocrine Abstracts

Abstract: Pituitary adenomas (PA) may occur in association with malignancies. Although an increased risk of cancer has been reported in acromegalics, this has been poorly studied in patients with other phenotypes. We wished to evaluate the prevalence of recognized malignancies in PA.

Material and Methods: A series of 422 consecutive PA patients followed at the Neuromed Institute between 2006 and 2012 was retrospectively reviewed and analysed. Data were compared with the Italian registry of tumours.

Results: Patients (289 F, 133 M) were affected by PRL-(223), GH-(52), ACTH- (19) and non-functioning (128) PA. Malignancies were recorded in 25 patients (5.9%, 13F, 12M) with a significant difference according to the PA phenotype (P=0.015): the highest prevalence was observed in patients affected by NFPA (14/128, 10.9%), followed by GH and PRL-secreting PA (4/52, 7.7% and 7/211, 3.1%,respectively). The overall prevalence of cancer was not significantly higher than in the Italian population (4.6%, Pns), except for patients with NFPA (Chi-2=9.05, P=0.003). Fourteen different types of malignancies were recorded, including four papillary thyroid cancer, four bronchial cancer, four prostate cancer (three NFPA patients and one acromegalic for each type). Only two breast and two colon cancers were observed (one NFPA and one prolactinoma for each type). Cancer patients were older than other patients (53.0±15.1 vs 38.5±16.1 years-old, P<0.001), and among them men tended to be older than women (57.4±17.0 vs 49.3±12.9 years, P=0.109). Two patients developed more than one malignancy.

Conclusion: Patients with NFPA may be at higher risk of cancer than previously reported, and this should be taken in mind during the follow-up of such patients. The absence of colon cancer in this series of acromegalics suggests that improvements in disease control and resection of colonic polyps are efficiently reducing the risk in these patients.