Prognostic to worse outcomes but the rates
Prognostic factorsA. At diagnosis: Rates of progression to overt myeloma are lowerfor patients with EMP compared to those with SBP but that has not been translatedto better overall survival in all studies.
A number of prognostic factors at thetime of diagnosis have been identified which have been used to develop prognosticscores but none of these is widely used 18. Three studies have identified associationof minimal bone marrow clonal disease with worse outcome. In the study byWarsame et al in patients with SBP only, plasmacytosis was assessed by immunofluorescenceand was associated with 15 months of progression-free interval (PFS) comparedto 42 months for patients with no BM involvement. 35 Two studies which used flow cytometry report a median timeto progression of 26 months in patients with clonal BM disease. Paiva et alshowed however that the prognostic adverse value does not hold for EMP 13-14. Abnormal sFLC ratio at diagnosis is alsoassociated with higher risk of progression to MM 36-37. A prognostic scoring method whichcombines PET/CT lesions and abnormal sFLC ratio at diagnosis was recentlydeveloped by Fouquet et al 27.
A prognostic model which includessFLC ratio and M-peak (?0.5 gr/dL vs >0.5 gr/dL) at diagnosis identifiedthree risk groups (low, medium, high with 5year progression rates of 13%, 26%and 62%) 19. The role of angiogenesis has alsobeen studied in older studies 38-39. Susnerwala et al have developed a prognostic scoring method based onhistological scoring for EMPs. 10 EMP outside the head and neck havebeen linked to increased risk of dissemination and worse outcome5.
B. Post-treatment: Several groups have demonstratedthat serum M-protein persistence post radiation therapy is a risk factor forprogression to MM in patients with SP 2, 5, 19-20,25, 40. For EMP lesions M-peak persistenceis not linked to worse outcomes but the rates of abnormal M-peak at diagnosisare too low to draw conclusions 5.