Clinical management of difficult to treat macroprolactinomas

ABSTRACT

Introduction: Prolactinomas represent the most common pituitary adenomas encountered in the clinic. While a majority of these tumors will be successfully treated by dopamine agonist (DA) such as cabergoline, their management becomes problematic since a resistance to DA can occur and/or if the tumor displays features of aggressiveness, two conditions that are closely related.

Areas covered: Epidemiology and medical treatment of prolactinomas; resistance to DA and molecular basis of DA-resistance; therapeutical alternatives in case of DA-resistant Prolactinomas and therapies in development; summarizing conclusions.

Expert opinion: The management of DA-resistant prolactinomas requires a multidisciplinary approach by an expert team. Along with discussions about surgery with or without gamma knife radiosurgery, genetic screening for multiple endocrine neoplasia type 1 (MEN1) syndrome is actively discussed in a case-by-case approach. In case of surgery, a careful analysis of the tumor sample can provide information about its aggressivity potential according to recent criteria. Ultimately, temozolomide can be indicated if the tumor is rapidly growing and/or threatening for the patient.

KEYWORDS:

• PRLoma
• dopamine agonist
• resistance
• surgery
• radiosurgery
• temozolomide

Article highlights

• Prolactin-secreting prolactinomas are resistant to dopamine agonists in about 10% of cases.

• Resistance to DA is defined by absence of either prolactin normalization or significant decrease of tumor volume under 2 mg/week of cabergoline.

• DA-resistant macroprolactinomas are primarily treated by surgery which provided relevant information on the tumor phenotype and behavior.

• Stereotactic radiotherapy is a third-line therapeutic option discussed in case of persistent secreting tumor residue.

• TMZ is a suitable option in case of aggressive prolactinoma uncontrolled by conventional therapies.

This box summarizes key points contained in the article.

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

This paper was not funded.