TEMOZOLOMIDE THERAPY IN AGGRESSIVE PITUITARY TUMORS

Program: Abstracts - Orals, Featured Poster Presentations, and Posters
Session: MON 167-198-Hypothalamus-Pituitary Development & Biology
Basic/Clinical
Monday, June 17, 2013: 1:45 PM-3:45 PM
Expo Halls ABC (Moscone Center)

Poster Board MON-178
Lea Juárez-Allen*1, Oscar Domingo Bruno2, Silvia Christiansen3, Maria Pallotta3, Carlos Vigovich4, Marcos Manavela5, Karina Danilowicz6 and Reynaldo Manuel Gomez7
1Hospital de Clínicas, Buenos Aires, Argentina, 2Estudios Metabólicos y Endocrino, Buenos Aires, Argentina, 3Hospital Italiano, Buenos Aires, Argentina, 4Hospital de Clinicas de Buenos Aires, Ciudad Autonoma de Buenos Aires, Argentina, 5Hospital de Clínicas, Argentina, 6Hospital de Clinicas, Buenos Aires, Argentina, 7Hosp de Clinicas, Buenos Aires, Argentina
Aggressive pituitary tumors are invasive macroadenomas refractory to surgical and medical treatment, showing tendency to continuous growth and implicating a bad vital prognosis. Until some years ago, no drug therapies were efficacious in that kind of tumors. First publications using the alkylating agent Temozolomide (TMZ) appeared in 2006 with variable responses reported in a limited number of cases. We present here our experience with the use of Temozolomide in a small series of 6 patients, 5 women and 1 man, aged 34-78 years, with different variants of aggressive pituitary tumors. They had been operated on between 1 to 5 times, 3 of them had radiotherapy and in 4 diverse drug treatments were used without success neither on hormonal dysfunction nor on tumor volume reduction. Patients were treated with TMZ 150-200 mg/m2 for 5 days every 28 days.  Patient 1 (76 year-old man) with a prolactin secreting pituitary carcinoma, died due to progression of his disease after the 2nd cycle. Severe neutropenia was observed in patient 2 (47 year-old woman) bearing a clinically non-functioning pituitary adenoma after the 1st cycle, so TMZ was withdrawn. In patient Nº 3 (acromegalic 34 year-old woman) and 4 (39 year-old woman with Nelson’s syndrome) no response was observed after 4 and 6 months, respectively, and the treatment was stopped. Conversely, Cushing´s disease patients 5 and 6 (52 and 42-year old women) had clinical, endocrine and radiological remission after TMZ with total or nearly total disappearance of the macroadenoma in both cases.  Patient 5, previously reported in part (1) completed 29 cycles and 12 months after TMZ withdrawal, MRI failed to show any sign of tumor relapse and she needs hydrocortisone supplements.  In patient 6 TMZ was indicated because of massive tumor growth eleven months after pituitary surgery, being presently at her 13th cycle of therapy.  MGMT enzyme determinations were negative in both cases. We conclude that TMZ therapy for aggressive pituitary tumors may be very useful especially in patients harboring corticotrophic tumors. International cooperative work on greater number of cases of aggressive pituitary tumors should be crucial to establish the indications, optimal doses and duration of Temozolomide administration.

1) Oscar D Bruno, Maria G Pallotta. Remission of Hypercortisolism and disappearance of an Aggressive Corticotropinoma after Temozolomide Therapy.ENDO2012 (Sun723).

Nothing to Disclose: LJ, ODB, SC, MP, CV, MM, KD, RMG

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