Abstract 1033: Adult B-cell lymphocytic leukemia associated with osteolysis but normocalcemia and normal hematologic parameters - rare case or influenced by mifepristone treatment

Abstract

Abstract Acute B-cell lymphoblastic leukemia (All) is much less common in adults than children and is much less common to present with bone pain. Extremely rare, but precedented, is the absence of hematologic abnormalities or lymphadenopathy. In some of the rare cases early diagnosis was achieved because hypercalcemia and bone pain were related to ectopic production of parathyroid-related peptide with consequent hypercalcemia and bone pain from hyperparathyroidism. However, there has been a case report in a 37-year-old male with B-cell lymphoblastic leukemia with osteolytic lesions, normal parathyroid hormone levels, and normal hematologic parameters despite >80% of the bone marrow replaced with blast cells. We present another case of a 55-year-old woman presenting with B cell ALL, bone pain and perfectly normal hematologic parameters despite 95% of the marrow replaced with blast cells. Her pain began 2 ½ months prior to the bone biopsy which was done because of the finding of osteolytic lesions on MRI. Her first bone marrow evaluation was performed 1 ½ months later. Related to further delays in even getting an appointment with the proper oncologist she was started on mifepristone 200mg daily to hopefully help delay a hematologic ALL crisis in view of 95% blast cells on biopsy. After 1 month of mifepristone therapy her CBC was still perfectly normal before standard chemotherapy was started. Mifepristone was started because of its effectiveness in improving length and quality of life in patients with a variety of advanced cancers without any more treatment options coupled with its beneficial effect in controlled studies with spontaneous leukemia in mice. Furthermore, the target for mifepristone, the immunomodulatory protein known as the progesterone induced blocking factor (PIBF), was found to be highly expressed by multiple human leukemia cell lines and was suppressed by mifepristone. The most common clinical state found in patients with advanced cancers following treatment with mifepristone is to stabilize the disease and inhibit further spread. The possibility exists that the failure to progress to typical pancytopenia after 95% of the bone marrow was replaced by blast cells was related to the mifepristone treatment. However, the possibility also exists that some unknown factor inhibiting this progression was operative as in some other very rare reported cases. With the possibility of a beneficial effect of treatment, mifepristone, an extremely well tolerated oral agent, could be considered for treating ALL when no other reasonable treatment options are available, e.g., a patient not likely to survive standard therapy or failure to respond to traditional chemotherapy. Even in this patient, if it takes more than 1 month to induce remission, her 40% 5-year survival will even be lower so one could consider maintenance therapy with mifepristone. Citation Format: Jerome H. Check. Adult B-cell lymphocytic leukemia associated with osteolysis but normocalcemia and normal hematologic parameters - rare case or influenced by mifepristone treatment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1033.