Efficacy and safety of temozolomide in the treatment of aggressive pituitary neuroendocrine tumours in Spain

Successful Volume Control of Invasive Pituitary Adenoma Tumor With Pasireotide: A New Horizon for a Challenging Disease

A 62-year-old Sudanese female was diagnosed with a nonfunctioning pituitary adenoma in 2006. Despite undergoing 3 transsphenoidal surgeries and radiotherapy, her tumor persisted, causing debilitating symptoms, including headaches and visual defects. As a last resort, she was treated with pasireotide, a second-generation somatostatin analog with a broader receptor affinity than first-generation drugs. Over 6 months, the tumor mass was stabilized, and her symptoms, including headaches, disappeared. This case demonstrates a potential new therapeutic possibility for treating resistant pituitary adenoma with pasireotide, offering hope for patients when traditional treatments fail.

Temozolomide Treatment in Refractory Pituitary Adenomas and Pituitary Carcinomas

BACKGROUND

Temozolomide (TMZ), a nonclassical alkylating agent, possesses lipophilic properties that allow it to cross the blood-brain barrier, making it active within the central nervous system. Furthermore, the adverse reactions of the TMZ are relatively mild, which is why it is currently recommended as a first-line chemotherapy drug for refractory pituitary adenomas (RPAs) and pituitary carcinomas (PCs).

SUMMARY

Systematic evaluations indicate a radiological response rate of 41% and a hormonal response rate of 53%, underscoring TMZ clinical efficacy, particularly when combined with radiotherapy. Functional tumors demonstrate a higher response rate compared to nonfunctional tumors. While the optimal duration of TMZ treatment remains undetermined, studies suggest that longer therapy durations may lead to better prognoses. Additionally, prior to TMZ administration, it is advisable to conduct immunohistochemical analysis of O6-methylguanine-DNA methyltransferase, MSH2, MSH6, MLH1, PMS2, and N-methylpurine DNA glycosylase to assess the potential impact of repair mechanisms such as direct repair, mismatch repair pathway, and base excision repair on TMZ treatment. The efficacy of TMZ analogs, combined TMZ therapies, and TMZ with nanomaterials following TMZ treatment failure remains uncertain.

KEY MESSAGES

The involvement of experienced multidisciplinary pituitary teams in all management decisions for RPAs/PCs patients is essential.

Clinical features of pituitary carcinoma: analysis based on a case report and literature review

Introduction

Pituitary carcinoma (PC) is an extremely rare tumor of the adenohypophysis, which manifests as craniospinal dissemination and/or systemic metastasis. The diagnosis of PC is particularly difficult, as the clinical diagnosis only can be made after the metastasis is found. Owing to the complex diagnostic process and less effective treatments, the clinical prognosis of PC is usually very poor. Hence, it is of great significance to illustrate the diagnosis and treatment course of PC.

Methods

In this case report, we described a 48-year-old male patient who was diagnosed with pituitary adenoma (PA) initially and then was diagnosed with PC eventually after spinal cord metastasis was found, and we illustrated the treatment course as well. Furthermore, we summarized all the published case reports until now and provided a comprehensive review of the diagnosis, treatment, prediction, and clinical outcome of PC.

Results and Conclusions

We found that most PC patients had adrenocorticotropic hormone/prolactin (ACTH/PRL)-secreting tumors, Ki-67 ≥ 10%, and P53 positivity, which may have the potential to predict the transformation from PA to PC; surgery excision combined with temozolomide (TMZ) and radiotherapy is helpful to prolong the survival of PC patients.

Aggressive and Metastatic Pituitary Neuroendocrine Tumors: Therapeutic Management and Off-Label Drug Use

Pituitary neuroendocrine tumors (PitNETs) are the most common pituitary tumors and the second most common brain tumors. Although the vast majority (>90%) are benign, a small percentage (<2%) are aggressive. These aggressive PitNETs (AgPitNETs) are defined by the presence of radiological invasion, a high rate of cell proliferation, resistance to conventional treatments, and/or a high propensity for recurrence. Lastly, there are the rare pituitary carcinomas, also known as metastatic PitNETs (MetPitNETs), which account for only 0.2% of cases and are defined by the presence of craniospinal or distant metastases. At present, there are no definitive factors that allow us to predict with certainty the aggressive behavior of PitNETs, making the therapeutic management of AgPitNETs a real challenge. Surgery is considered the first-line treatment for AgPitNETs and MetPitNETs. Radiation therapy can be effective in controlling tumor growth and regulating hormone hypersecretion. Currently, there are no approved non-endocrine medical therapies for the management of AgPitNETs/MetPitNETs, mainly due to the lack of randomized controlled clinical trials. As a result, many of the medical therapies used are off-label drugs, and several are under investigation. Temozolomide (TMZ) is now recognized as the primary medical treatment following the failure of standard therapy (medical treatment, surgery, and radiotherapy) in AgPitNETs/MetPitNETs due to its ability to improve overall and progression-free survival rates in responding patients over 5 years. Other therapeutic options include pituitary-targeted therapies (dopamine agonists and somatostatin analogs), hormonal antisecretory drugs, non-hormonal targeted therapies, radionuclide treatments, and immunotherapy. However, the number of patients who have undergone these treatments is limited, and the results obtained to date have been inconsistent. As a result, it is imperative to expand the cohort of patients undergoing treatment to better determine the therapeutic efficacy and safety of these drugs for individuals with AgPitNETs/MetPitNETs.