The epidemiology of aggressive pituitary tumors (and its challenges)

Abstract

Pituitary tumors are not rare if prevalence rates from autopsy or radiological series are considered; approximately 0.5% of all pituitary adenomas will come to medical attention. Less than 0.1% of these pituitary adenomas will become malignant, and probably around 0.5% of all detected adenomas will display an aggressive course. However, the exact incidence of both aggressive pituitary adenomas and pituitary carcinomas is unknown, as most data come from series with selected patients, such as surgically treated patients, which is likely not a reflection of all patients with a pituitary adenoma. An aggressive pituitary adenoma is not well-defined; even though an overarching definition, capturing both immunohistochemical and clinical characteristics is probably not waterproof, adoption of a widely accepted definition will be very helpful to harmonize research and establish more reliable epidemiological data.

Cushing’s disease and aggressive pituitary tumours : Aspects on epidemiology, treatment, and long-term follow-up

“…Although grading of symptoms was not possible in our study, the results imply persisting mental health issues despite achieved biochemical remission. The findings in study IV support two previous cross-sectional studies in which increased prevalence of psychopathology and cognitive impairment was found after remission for 11 (range 1-32), and 13 (5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19) years, respectively (90,91).…”

“…In a study by Dorn et al (89), including 33 patients with Cushing's syndrome, significant psychopathology was present in two thirds at diagnosis, and decreased to 24% 12 months after remission. However, compared to controls, cross-sectional studies have shown increased psychopathology and cognitive impairment after longterm remission for 11 (range 1-32), and 13 (5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19) years respectively (90,91).…”

“…a radiologically invasive tumour with unusually rapid growth, or continued tumour growth despite optimal standard therapies including surgery, radiotherapy and medical treatments (17). This definition leaves room for arbitrary judgement and hampers accurate estimations of incidence and prevalence (18). It should be noted that invasiveness is not equal to aggressiveness, although indicating a higher risk of recurrence (19).…”

“…The true rate of aggressive tumours is unknown. Dekkers et al recently reviewed the epidemiology of aggressive pituitary adenomas/carcinomas and suggested that of all detected pituitary tumours it is likely that less than 0.1% will turn malignant and less than 0.5% will exhibit true aggressive behaviour, although emphasizing the difficulties in estimating the true rates (18). Functioning tumours are overrepresented in carcinomas and aggressive adenomas.…”

Pituitary Neoplasm Nomenclature Workshop: Does Adenoma Stand the Test of Time?

“…The 2017 WHO classification recognizes pituitary tumors as having a low or high probability of recurrence [ 1 ]. Of pituitary tumors requiring surgical treatment, 15% are “aggressive” [ 37 ] but only 0.1% to 0.2% of these progress to become true carcinomas, as defined by evidence of cerebrospinal and/or systemic metastases [ 45-49 ]. Histopathological and molecular markers are unable to identify the very rare tumors that exhibit aggressive growth or very rarely malignancy.…”