Abstract
Following clinic observations of patients with the diagnosis of oligodendroglioma and a systemic cancer, a chart review was done to understand the possible complications that a systemic cancer might bring to the treatment of the patient. Inclusion criteria was histological diagnosis of diffuse or anaplastic oligodendroglioma and another non-skin systemic cancer. Exclusion criteria was the diagnosis of genetic syndrome that predispose tumorigenesis. A total of 12 patients and 13 cancers were identified. 1p19q co-delection information was available for all patients except for 2. The most common systemic cancers were breast (46%) and gynecological cancers (16%). Different from CBTRUS data, men were underrepresented, being 31% of the patients, but difference did not reach statistical significance (p =0.08). Regarding age, patients were older than expected (53 + 12 years old, p< 0.0001). Systemic cancer was diagnosed after the oligodendroglioma diagnosis in 54% of the cases. Age at the diagnosis of systemic cancer was 54 + 10 years old. All patients are alive, except for two. Thromboembolism was seen in 25% of the patients (p=0.2 when comparing with literature for oligodendroglioma), and occurred always after the oligodendroglioma diagnosis. Thrombocytopenia was not associated to prior chemotherapy. No deviation of glioma treatment was seen. This chart review of patients with Oligodendroglioma and a systemic cancer identifies that this population is older than expected and thromboembolism rates are similar to the literature. The overrepresentation of women in this cohort represents the profile of systemic cancer that accompanied oligodendrogliomas. It is unclear why breast and other gynecological cancers were the most common. Further studies, likely multicentric due to the rarity of this diagnosis, as further research in large repository data should be performed to confirm this finding.