Radiation Oncology/NHL/CLL-SLL

Chronic Lymphocytic Leukemia and Small Lymphocytic Lymphoma (CLL/SLL) Overview CLL is the most common leukemia among adults in Western world It is characterized by accumulation of mature B-cells CLL molecular phenotype: CD5+, CD23+, surface Ig weak, CD79b weak/absent, FMC7 neg. Diagnosis: lymphocytosis (often >5 x 10^9 / L, but not an absolute cutoff) Risk factors are male sex, advanced age, white race, and family history of CLL or lymphoproliferative disorders Cause and pathogenesis are largely unknown Peripheral blood of some healthy adults shows circulating B-cell clones with surface phenotypes similar to CLL Monocloncal B-cell lymphomatosis (MBL) indicates presence of such B-cells in blood at <5000 per cubic millimeter Prevalence of MBL may be 3-5% in general population over 50 years of age It appears that these circulating B-cell clones may be present in blood of for years prior to development of CLL, and that the light chain re-arrangement is the same Thus, it may be reasonable to consider MBL a precursor state to CLL, in a similar fashion as MGUS is a precursor state to multiple myeloma CLL and SLL are histologically and immunophenotypically identical By definition, CLL has more marked peripheral blood involvement CLL: absolute lymphocyte count >=5 x109/L SLL: absolute lymphocyte count <5 x109/L Clinical course varies widely, but frequently characterized by indolent behavior Treatment commonly deferred while patients asymptomatic No consensus on best treatment, but nucleoside analogues and Rituxan have led to improved outcomes Staging Rai Staging Rai Stage Criteria Survival (yr)0 lymphocytosis only. no other abnormality > 13I lymphocytosis and lymph node enlargement. no other abnormality 8II lymphocytosis and spleen or liver enlargement (w/ or w/o lymph node enlargement). no other abnormality 5III lymphocytosis and anemia (Hgb < 11 g/dL); w/ or w/o spleen / liver / lymph node enlargement. no platelet abnormality 2IV lymphocytosis and thrombocytopenia (plts < 100,000 /µL) 1 Binet Staging Binet Stage Criteria Survival (yr)A <3 lymph node areas; no anemia or thrombocytopenia 12B 3 or more lymph node areas; no anemia or thrombocytopenia 5C Anemia (Hgb < 11) or thrombocytopenia (< 100,000 /µL) 2 Classification MD Anderson; 2007 (1985-2005) 17925562 -- "Assessment of chronic lymphocytic leukemia and small lymphocytic lymphoma by absolute lymphocyte counts in 2,126 patients: 20 years of experience at the University of Texas M.D. Anderson Cancer Center." (Tsimberidou AM, J Clin Oncol. 2007 Oct 10;25(29):4648-56.) Retrospective. 2126 consecutive CLL/SLL patients Outcome: rates of response, OS, and FFS not different among different groups Predictive factors: deletion of 17p or 6q, age >60, b2-microglobulin >2, albumin <3.5, creatinine >1.6 Conclusion: Patients with CLL or SLL can be treated similarly Richter's transformation Named for Maurice N. Richter who described it in 1928 Development of high grade NHL (typically diffuse large B-cell lymphoma) in the setting of CLL May be triggered by viral infections (e.g. EBV) or by genetic defects acquired by the malignant clone Occurs in ~4% of CLL patients Response rates to chemotherapy are low, up to ~40%; median OS is ~8 months 1993 7693038, 1993 — "Common clonal origin of chronic lymphocytic leukemia and high-grade lymphoma of Richter's syndrome." Cherepakhin V et al. Blood. 1993 Nov 15;82(10):3141-7. 1975 1096589, 1975 — "Richter's syndrome. A terminal complication of chronic lymphocytic leukemia with distinct clinicopathologic features." Long JC et al. Am J Clin Pathol. 1975 Jun;63(6):786-95. Original description; 1928 19969796, 1928 — "Generalized reticular cell sarcoma of lymph nodes associated with lymphatic leukemia." Richter MN et al. Am J Pathol. 1928; 4:285. Radiation Therapy Please see spleen irradiation Reviews 2006 16983131 -- "Narrative review: initial management of newly diagnosed, early-stage chronic lymphocytic leukemia." (Shanafelt TD, Ann Intern Med. 2006 Sep 19;145(6):435-47.) 2006 16901035 -- "Chronic lymphocytic leukemia: diagnosis and treatment." (Yee KW, Mayo Clin Proc. 2006 Aug;81(8):1105-29.)