Prognosis

Although novel treatment strategies have resulted in improved outcomes (including response rates and survival), MM remains an incurable disease. Patients with MM will inevitably relapse.

The major causes of death are infections, disease progression, and renal failure.

Surveillance, Epidemiology, and End Results (SEER) Program data report the following 5-year relative survival rates for patients diagnosed with myeloma (2014-2020 data):[219]

  • 80.3% (localized disease at diagnosis)

  • 60.4% (distant disease at diagnosis)

The International Staging System (ISS) criteria is a validated tool used to categorize patients with MM into one of the following three prognosis groups based on serum beta2-microglobulin and serum albumin levels:[61][63]

  • Stage I: beta2-microglobulin <3.5 mg/L and albumin ≥3.5 g/dL; these patients have a median survival of 62 months

  • Stage II: not stage I or III; these patients have a median survival of 44 months

  • Stage III: beta2-microglobulin ≥5.5 mg/L; these patients have a median survival of 29 months

Revised versions of the ISS (RISS and R2-ISS) incorporate chromosomal abnormalities and serum lactate dehydrogenase as additional parameters to improve risk stratification and prognostication.[62][63]​ See Criteria.

Treatment response criteria

The International Myeloma Working Group has developed uniform response criteria for treatment efficacy, which can also help with prognostic stratification. According to these criteria, complete response is defined by the absence of serum and urine monoclonal protein by immunofixation or electrophoresis, absence of any soft-tissue plasmacytomas, and less than 5% plasma cells in the bone marrow.[220]

Minimal residual disease (MRD)-negative status (i.e., absence of MRD) has been added to the criteria for complete response in order to further stratify the criteria due to the high frequency of recurrence among complete responders as previously defined, and with the availability of newer treatments with high response rates.[216] Two meta-analyses found that MRD-negative status after treatment for newly diagnosed MM is associated with prolonged overall survival.[221][222]

Sustained MRD, which is two consecutive MRD results of 10⁻⁵ 12 months apart, represents an additional MRD criterion.[216] The prognostic impact of sustained MRD is likely superior to that of a one-time MRD assessment and continues to be explored as part of clinical trials.[223]

MRD status can be evaluated by next-generation flow cytometry or next-generation DNA sequencing with varying levels of sensitivity. Although MRD status is emerging as a strong prognostic marker, further study is required to determine its role in clinical decision making.

Use of this content is subject to our disclaimer