Outcome and prognostic factors for pituitary carcinomas: lessons from a systematic review

The purpose of this work was toinvestigate the clinicopathological characteristics at the initial diagnosis of the pituitary tumor and at pituitary carcinoma (PC) diagnosis, alongside with the management and outcomes of PCs, and identify potential prognostic factors and therapeutic strategies associated with the clinical outcome.

PubMed was searched in May 2021 for articles in English and French reporting PCs, the diagnosis of which was made on the presence of metastases. The cases without histological proof and with either another cancer present or an atypical history for a pituitary tumor were excluded.

One hundred and eighty-one articles reporting 207 cases were included, which included 38% corticotroph and 29% lactotroph carcinomas. An initial Ki67 index ≥10% was associated with shorter survival after the initial diagnosis (P = 0.01). Cases with early metastases were associated with both higher initial Ki67 index (P = 0.01) and shorter survival after PC diagnosis (P = 0.001). Interestingly, cases with short survival after PC diagnosis were associated with shorter time between the initial diagnosis and PC diagnosis (P = 0.0006) and had both higher initial Ki67 index (P = 0.003) and higher Ki67 index of the metastasis (P = 0.03). In addition, cases with long survival after PC diagnosis had received more frequently both systemic treatment after PC diagnosis (P = 0.0005) and local treatment for metastases (P < 0.0001).

An initial Ki67 index ≥10% is associated with worse outcome and appears as a promising early marker of future metastasis. Its presence should lead to an intensified surveillance and to a more timely management. Clinicians should not hesitate to use local treatment, independent of whether systemic treatment is used.