Introduction
Multiple myeloma (MM) is a malignant disease with abnormal proliferation of clonal plasma cells, and is the second most common malignancy of the hematological system. The diagnosis and treatment of MM have been improved and perfected with the introduction of new drugs and improved detection methods, so the biennial update of the Chinese MM diagnosis and treatment guidelines is important to improve the diagnosis and treatment of MM in China.
1.Clinical manifestations
Common symptoms of MM include myeloma-related organ damage, i.e. “CRAB” symptoms (increased blood calcium, renal impairment, anemia, bone disease, as detailed in the diagnostic criteria), and target organ damage related manifestations such as amyloidosis.
2.Diagnostic criteria, typing and staging
(1) Testing items (Table 1)
For patients with clinical suspicion of MM, the necessary tests should be completed for MM disease, and those who are in a position to do so can be tested for items that are important for diagnosing the disease and determining the prognosis.
(2) Diagnostic criteria
With reference to the guidelines of WHO, National Comprehensive Cancer Network (NCCN) and International Myeloma Working Group (IMWG), the criteria for diagnosing symptomatic myeloma (active myeloma) and asymptomatic myeloma (smoldering myeloma) are shown in Tables 2 and 3.
(3) Staging
The types of immunoglobulins that proliferate abnormally are classified as follows: IgG, IgA, IgD, IgM, IgE, light chain, biclonal, and nonsecretory. Each of these can be further divided into κ and λ types according to the light chain type.
(4) Staging
Staging according to the traditional Durie-Salmon (DS) staging system and the International Staging System (ISS) (Table 4, Table 5)
3.Differential diagnosis
MM needs to be differentiated from the following diseases that can present with M proteins: monoclonal gammopathy of undetermined significance (MGUS), Walden’s macroglobulinemia (WM), smoldering WM and IgM MGUS, AL amyloidosis, isolated plasmacytoma (bone or extraosseous), POMES syndrome, reactive plasmacytosis (RP), osteolytic lesions of metastatic carcinoma, plasmacytoblastoma lymphoma (PBL), etc.
4.Prognosis of MM
MM is biologically and clinically heterogeneous, which makes its efficacy and prognosis very different. Prognostic factors can be categorized into two major groups: host factors and tumor characteristics. A single factor is usually not sufficient to determine prognosis, and multiple factors need to be combined to stage and risk stratify patients.
Among the prognostic staging systems for MM, Durie-Salmon staging mainly reflects tumor load; ISS is mainly used to determine prognosis; R-ISS is a newly revised staging system for prognosis determination, in which cytogenetics and lactate dehydrogenase are prognostic factors independent of ISS, so R-ISS has better prognostic determination ability and more clear prognostic differentiation for MM patients. effective. In addition, the Mayo Stratification of Myeloma And Risk-adapted Therapy (mSMART) stratification system is also more widely used, which was originally proposed by the Mayo Clinic in 2007 and is based on cytogenetic testing in the hope of facilitating treatment selection, and has now been updated to the 2013 version (Table 6). 2014 IMWG consensus on the combined application of ISS and fluorescence in situ hybridization (FISH) results for risk stratification of patients (Table 7).
There is still no definitive evidence that treatment can be adjusted based on risk stratification, except in some specific cases. As treatment options increase, the situation will become more complex in the future, and the application of a standardized and uniform staging stratification system in clinical practice and research, and its further optimization, will allow for eventual individualization of treatment.