A Case of Therapy-Related Acute Myeloid Leukemia Associated with Adjuvant Temozolomide Chemotherapy for Anaplastic Astrocytoma

Temozolomide duration and secondary hematological neoplasms: A literature review and implications for patients with neuroendocrine neoplasms

Evidence-based recommendations for the optimal duration and sequencing of temozolomide-based treatments in advanced neuroendocrine neoplasms are lacking. Here, we conducted a systematic review of the literature for a descriptive analysis of temozolomide-associated myelodysplasias and leukemias to guide treatment planning. A database search of PubMed and Embase was conducted to identify case reports and/or case series reporting secondary myelodysplasias or leukemias in the setting of temozolomide therapy. Key data items extracted from the studies were the temozolomide dose and duration, latency to hematological disorder, type of secondary malignancy and cytogenetics. Reported cases were summarized graphically. A total of 16 studies with 27 patient cases of therapy-related hematologic neoplasms were identified, all of which were case reports or case series. The median treatment duration and cumulative dose were 19 months and 18,000 mg/m² , respectively. Most patients (21/27) were diagnosed on, or after, 12 months, while only one patient was diagnosed before 6 months of treatment. Most of the patients were diagnosed, while still on treatment with temozolomide. Graphically, cases clustered around a cumulative dose of 10,000 to 30,000 mg/m² and a latency period of 10 to 40 months which translates to an approximate treatment duration of 12.5 to 37.5 months. Taken together, most reported treatment-related hematological neoplasms appear to develop on or beyond the 12-month mark, while patients are still on treatment with temozolomide. For patients with neuroendocrine neoplasms, where sequencing of multiple therapies is important, we suggest an approach to optimizing treatment duration by establishing disease response at 6 months before continuing further treatment and restricting treatment to or establishing closer vigilance beyond 12 months.

Successful reduction of ACTH secretion in a case of intractable Cushing's disease with pituitary Crooke's cell adenoma by combined modality therapy including temozolomide

Crooke's cell adenoma (CCA) is an aggressive subtype of corticotroph adenoma; however, CCA is associated with a high incidence of low expression of methyl guanine methyl transferase (MGMT), suggesting that temozolomide (TMZ) treatment might be effective for this tumor type. The case of a 56-year-old woman with Cushing's disease caused by a pituitary CCA is presented. At the age of 38 years, the patient presented to our hospital with polyuria and a visual field defect. MRI and laboratory studies showed a 4.5-cm-diameter pituitary tumor with plasma adrenocorticotropic hormone (ACTH) and serum cortisol levels of more than 500 pg/mL and 40 μg/dL, respectively. At 39 years of age, the patient underwent a craniotomy, and her plasma ACTH and cortisol levels decreased to less than 200 pg/mL and 10 μg/dL, respectively; however, these hormone levels increased gradually to 3,940 pg/mL and 70 μg/dL, respectively, by the time the patient was 56 years old. Histopathological re-examination of the previously resected specimen showed that the pituitary tumor was MGMT-negative CCA. TMZ treatment after the second operation decreased the plasma ACTH levels from 600-800 pg/mL to 70-300 pg/mL. No signs of recurrence were observed in the seven years following these treatments with added prophylactic radiation therapy. These clinical findings suggest that TMZ treatment to patients with CCA accompanied with elevated ACTH may be good indication to induce lowering ACTH levels and tumor shrinkage.