Distinct mutation spectrum, clinical outcome and therapeutic responses of typical complex/monosomy karyotype acute myeloid leukemia carrying TP53 mutations.

The present study aimed to define a subtype of complex/monosomal karyotype (CK/MK) acute myeloid leukemia (AML) by its distinct clinical features, p53 signaling and responses to p53 targeting agents. Ninety-eight young adults (range: 21-60 years; median: 49 years) with CK/MK AML were studied. They received standard induction, consolidation and allogeneic hematopoietic stem cell transplantation from siblings or matched unrelated donors if available. Chromosomal abnormalities most commonly affected chromosome 5 (30%), 7 (22%) and 17 (21%). Next generation sequencing of a 54-myeloid gene panel were available in 76 patients. Tumor protein 53 (TP53) mutations were most common (49%) and associated with the presence of -5/5q- (P < .001) and -17/17p- (P < .001), but not -7/7q- (P = .370). This "typical" CK/MK AML subtype was associated with significantly lower presenting white cell counts, higher number of karyotypic abnormalities, and inferior leukemia-free and overall survivals, compared with CK/MK AML without the typical features. Blood or bone marrow samples from typical CK/MK AML patients showed defective p53 signaling upon induction by etoposide. In vitro drug sensitivity analysis showed that they were sensitive to APR-246 that targeted mutant p53, but resistant to MDM2 antagonist MI-77301. Novel therapeutic strategies targeting TP53 mutations in CK/MK AML should be developed and tested in clinical trials.

Durable survival after chemotherapy in a HIV patient with Burkitt's lymphoma presenting with massive upper gastrointestinal bleeding.

Massive upper gastrointestinal bleeding is an uncommon presentation of Burkitt's lymphoma in a patient with HIV/AIDS, and is seldom reported in the literature. A 39-year-old man who has sex with men presented with abdominal pain and massive haematemesis and a rapid drop in haemoglobin level to 4.8 g/dL. Upper gastrointestinal endoscopy showed a large blood clot in the stomach, and an emergency laparotomy was performed because of unstable haemodynamics. This showed active bleeding from multiple tumours in the fundus and body of the stomach. The patient underwent gastrectomy and gastric biopsy confirmed Burkitt's lymphoma. Further tests showed lymphoma involvement in bone marrow and central nervous system. The patient tested positive for HIV, and had a CD4 count of 212 cells/mm(3) and viral load of 18,000 copies/mL at diagnosis. He was commenced on a chemotherapy regimen of CODOX-M/IVAC, and highly active antiretroviral therapy consisting of indinavir, stavudine and lamivudine. The major side effect was peripheral neuropathy. Infective complications during chemotherapy were controlled by broad-spectrum antibiotics and anti-fungal agents. Complete remission of the lymphoma was achieved after the chemotherapy and remission was maintained for more than 14 years.