Treatment and long-term outcomes in pituitary carcinoma: a cohort study.

Background: Pituitary carcinoma (PC) is an aggressive neuroendocrine tumor diagnosed when a pituitary adenoma (PA) becomes metastatic. PCs are typically resistant to therapy and develop multiple recurrences despite surgery, radiotherapy and chemotherapy. Recently, treatment with temozolomide (TMZ) has shown promising results, although the lack of prospective trials limits assessment of benefit.

Methods: We describe a single-center multidisciplinary experience in managing PC patients over a 22-year period and review previously published PC series.

Results: Seventeen patients were identified. Median age at PC diagnosis was 44 years (range 16-82 years), and the median time from PA to PC transformation was 5 years (range 1-29 years). Median follow-up time was 28 months. Most PCs were hormone-positive (n = 12): ACTH (n = 5), PRL (n = 4), LH/FSH (n = 2) and GH (n = 1). All patients underwent at least one resection and at least one course of radiation after PC diagnosis. Immunohistochemistry showed high Ki-67 labeling index (>3%) in 10/15 cases. Eight patients (47%) had only central nervous system (CNS) metastases; six (35%) had combined CNS and systemic metastases. The most commonly used chemotherapy was TMZ, and TMZ-based therapy was associated with the longest PFS in 12 (71%) cases, as well as the longest period from PC diagnosis to first progression (median 30 months). The 2, 3 and 5-year survival rate of the entire cohort was 71, 59 and 35%, respectively. All patients surviving >5 years had been treated with TMZ-based therapy.

Conclusions: PC management benefits from multidisciplinary care and multimodality therapy. TMZ-based regimens were associated with high survival rates and long disease control.