Radiation Oncology/NHL/CLL-SLL
From Wikibooks, the open-content textbooks collection
|
Front Page: Radiation Oncology | RTOG Trials | Randomized Trials |
|
|
Non-Hodgkin lymphoma: Main Page | Randomized |
|
Chronic Lymphocytic Leukemia and Small Lymphocytic Lymphoma (CLL/SLL)
Contents |
[edit] Overview
- CLL is the most common leukemia among adults in Western world
- It is characterized by accumulation of mature B-cells
- Risk factors are male sec, 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 simlar 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 >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 lead to improved outcomes
[edit] Classification
- MD Anderson; 2007 (1985-2005) PMID 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
[edit] 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 PMID 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 PMID 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 No PMID, 1928 — "Generalized reticular cell sarcoma of lymph nodes associated with lymphatic leukemia." Richter MN et al. Am J Pathol. 1928; 4:285.
[edit] Radiation Therapy
- Please see spleen irradiation