Alyssa Mellott
Systemic disease Diagnosed based on type of white blood cell affected & speed at which it progresses Acute vs. Chronic Myelogenous vs. Lymphocytic
Forms in bone marrow B & T lymphocytes: a mature form of lymphoblasts that are critical to the immune system 3 subtypes 1. Precursor B cell Adults 2. Mature B cell Genetic changes 3. Precursor T cell* Pediatric* Invades blood & spreads to lymph nodes & lymphoid organs
Most common subtype of leukemia Most common cancer diagnosed in children More prominent in: 2-10 year olds White people Males
Family history Chromosome instability disorders Ex. Down’s Syndrome Viral infections Ex. Epstein Barr Radiation exposure Previous radiation or prenatal x-rays Environmental factors
Neutropenia Fever Malaise Petechiae Lymphadenopathy Hemorrhage Fatigue Bone/joint pain Pallor Enlarged spleen
Bone marrow produces lymphocytes ALL: too many lymphocytes & they don’t function properly Can’t fight infection & overcrowding = less RBC’s & platelets This causes Bleeding (lack of platelets) Fatigue (lack of RBC’s) Build up of WBC’s in spleen, lymph nodes, & liver = swelling & discomfort
Both can develop from lymphocytes ALL starts in the bone marrow & can spread to other parts of the body Lymphoma starts in lymph nodes & other organs & can spread to the bone marrow
Radiation, chemotherapy, & bone marrow transplant Combination or alone Chemo alone is most common
Chemo alone 3 steps 1. Induction: intense 2-3 weeks, goal is remission Agents: doxorubicin, methotrexate, vincristine, ect. 2. Consolidation: goal to kill remaining cells Agents: same + cytarbine & etoposide 3. Maintenance: goal to reduce risk of leukemia coming back Agents: mercaptopurine & methotrexate tablets + vincristine injection
TBI Conditioning for bone marrow transplant 1200 cGy 6 fractions German Helmet cGy Cranial Spinal + German helmet Helmet to 2400 cGy Spine to 1500 cGy Treatment of testis cGy Relapse due to methotrexate Can be prophylactic
For patients in fair health Can do lower dose TBI for weaker patients Chemotherapy can severely damage normal bone marrow cells Restore bone marrows ability to make blood Autogeneic vs. Autologous Severe side effects
7 year old male Presented with lymphadenopathy & petechiae in 2011 ALL Relapse in 2014 Had chemotherapy & prophylactic cranial radiation to 1200 cGy in 2011 CNS = sanctuary site Remission Orchiectomy in June 2014 due to relapsed testicular disease Testes = sanctuary site Methotrexate Started 3 cycles of chemo again Reinduction Vincristine Steroids Doxorubicin Asparaginase TBI and testicular boost at MXE in September to prepare for BMT
TBI 1200 cGy total 6 fractions/BID 6 mV Boost to testes 1200 cGy total 6 fractions/BID 12 meV
Antibody therapy A form of targeted therapy Radiation and chemotherapy side effects can limit quality of life Focus on pediatric relapse cases Usually a poor prognosis (~30% in 5 years)
1. Monoclonal antibodies In phase III trial for pediatric ALL Leukemic blasts express antigens on their surface that can be selectively targeted by monoclonal antibodies This allows directed delivery of highly potent drugs Advantages over chemo: Longer circulating half-lives Greater accumulation in tumor cells Fewer systemic side effects
2. Antibody-Drug Conjugates (ADC’s) Next generation of antibodies Being tested for ALL & AML A highly potent cytotoxic agent is bound to an antibody by a linker, resulting in selective targeting of leukemia cells 3. Bispecific T-Cell Engager (BiTE) Each antibody contains two binding sites One designed to engage the patient’s own immune system and the other to target malignant cells
Less severe side effects More “targeted” Minimal changes over last 50 years in drugs to induce & maintain remission in pediatric leukemia Could change routine management of this disease Cannot not penetrate blood-brain barrier Still a challenge to get these drugs to sanctuary sites CNS & testes Still in trials
Busulfan (BU) Alkylating agent One of most potent anti-leukemia drugs Very toxic to normal bone marrow cells but not immunosuppressive Need fludarabine to get new stem cells to engraft Limited toxicity to organs Most common alternative to TBI Study: childhood leukemia survivors Best conditioning treatment for BMT? TBI 174 patients vs. Busulfan 66 patients Health status & quality of life? Median follow up = 10.1 years
Patients that developed more than three late complications 59.2% of TBI patients 44% of BU patients
Side EffectsBUTBI Height growth failure 27.3%49.4% Overweight*22.7%13.8% Hypothyroidism15.2%28.2% Secondary Tumors4.5%11.5% Gonadal Dysfunction 48.1%53.9% Alopecia*25.8%2.9% Cataract4.5%51.7%
Seems to be equally effective BU replace TBI? Children & TBI More damaging to physical and mental development (lower IQ) Higher risk for secondary cancers Patients considered were all long-term survivors TBI seems to have more serious side effects in children
Antibody therapy vs. common chemotherapy agents Side effects Relapse/ALL Better prognosis? BU vs. TBI as conditioning for BMT Side effects Long term quality of life Pediatric development
Bernard F, Auquier P, Michel G, et al. Health status of childhood leukemia survivors who received hematopoietic cell transplantation after BU or TBI: an LEA study. Bone Marrow Transplantation [serial online]. May 2014;49(5): Available from: Academic Search Complete, Ipswich, MA. Accessed October 23, “Childhood Lymphoblastic Leukemia Treatment.” Cancer.gov. National Cancer Institute, n.d. Web. 30 Oct Hackworth, Ruth. "Pediatric Tumors." Applied Technical Oncology. Lecture "Intravenous Busulfan Before Stem Cell Transplant." MD Anderson Cancer Center. University of Anderson Texas MD Anderson, n.d. Web. 30 Oct "Stem cell transplant for acute lymphocytic leukemia." American Cancer Society. American Cancer Society, n.d. Web. 30 Oct Vedi A, Ziegler D. Antibody therapy for pediatric leukemia. Frontiers In Oncology [serial online]. April 2014;4:1-10. Available from: Academic Search Complete, Ipswich, MA. Accessed October 27, 2014.