Temozolomide non-responsiveness in aggressive prolactinomas and carcinomas: management and outcomes
Abstract Purpose Temozolomide is endorsed as the treatment of choice in aggressive or malignant pituitary adenomas. Herein we describe a case of an aggressive prolactinoma which was resistant to temozolomide and performed a literature review of similar non-responsive aggressive prolactinomas. Methods A 40-year-old female presented with a giant prolactinoma which required cabergoline, transsphenoidal surgery and radiotherapy to achieve near-normal prolactin and apparently no residual tumour. A year later, she presented with multiple cranial nerve involvement due to recurrent tumour extending to the infratemporal fossa. She underwent transfrontal surgery, second radiotherapy and was started on temozolomide. Despite 8 cycles of temozolomide (200mg/m 2, 5/28 day cycle), she had progressive disease and ultimately succumbed to the disease. Pubmed/MEDLINE, Google scholar and prior review articles were searched for manuscripts with aggressive prolactinomas who had been treated with temozolomide. Data on demography, duration of therapy and management outcomes were analysed in those with progressive disease. Literature review We identified 94 cases of aggressive/malignant prolactinomas in the literature who had received temozolomide. Progressive disease despite temozolomide was present in 36 cases (38%). There was a male preponderance (65%) and 40% had aggressive prolactinomas while the rest had carcinomas. Patients received a median of 8 cycles (IQR 3.5-11.5) of temozolomide. MGMT immunostaining was negative in 35%. Overall mortality at the time of publication was 40%, at a duration varying from 2 to 20 years from diagnosis. Conclusion Temozolomide resistance in aggressive/malignant prolactinomas is challenging. Progressive disease on optimal temozolomide treatment entails the use of newer agents.