Treatment of aggressive pituitary tumours and carcinomas: results of a European Society of Endocrinology (ESE) survey 2016

Abstract

This survey confirms that TMZ is established as first-line chemotherapeutic treatment of APT/PC. Clinically functioning tumours, low MGMT and concurrent radiotherapy were associated with a better response. The limited long-term effect of TMZ and the poor efficacy of other drugs highlight the need to identify additional effective therapies.

Recent advances in understanding corticotroph pituitary tumor initiation and progression

“…Crooke’s cell adenomas, Nelson’s tumors, invasively growing corticotroph macroadenomas, and corticotroph carcinomas mostly have low MGMT expression 2, 97– 100 . This may explain the relatively good response of corticotroph carcinomas to temozolomide therapy in several cases 7, 94 . However, this also suggests that advanced aggressive corticotropinoma types may already be treated with temozolomide to prevent transformation into corticotroph carcinomas 101 .…”

“…Although the proportion of CAs within all pituitary tumor types is relatively small, they represent about 35% to 48% of all pituitary carcinomas 6, 7, 93 . This may be a consequence of the relative high proportion of aggressive tumor types (Crooke’s cell adenomas, Nelson’s tumors, and silent CAs) among the corticotroph tumors 2 .…”

“…This may be a consequence of the relative high proportion of aggressive tumor types (Crooke’s cell adenomas, Nelson’s tumors, and silent CAs) among the corticotroph tumors 2 . In most reports, several common features of corticotroph carcinomas are evident, such as repeated recurrence of the adenomas after incomplete surgical resection and transient response but finally resistance to different pharmacological therapies or to radiotherapy 6, 7, 66, 68, 73, 74, 94 . Usually, decades separate the first diagnosis of the CA and the full expression of the carcinoma phenotype.…”

“…Temozolomide, an alkylating chemotherapeutic drug, has been identified as an effective compound in the treatment of pituitary carcinomas 7, 94 . The effect of temozolomide is reduced in pituitary tumors with high expression of MGMT.…”

“…In the case of incomplete resection (for example, if the tumor is critically located in proximity to the optical nerves), the tumor might expand and become more aggressive over time, requiring repeated surgery, radiotherapy, pharmaceutical therapy, or adrenalectomy 1 . In rare cases, CAs finally transform to metastasizing corticotroph carcinomas for which temozolomide treatment has recently been established with some success in single cases 6, 7 .…”