Virtually all patients with MM will relapse after responding to initial treatment. Access to the best available therapies, including clinical trials and treatment with a multidisciplinary team, are crucial to achieving the best outcomes for relapsed disease.

Signs and symptoms will depend on if there is end-organ damage as a result of clinical relapse. Patients may be asymptomatic when there is progressive disease without end-organ damage.

Indicators of progression or relapse may include:

• new or increased size of plasmacytomas or bone lesions
• new or worsening end-organ damage (e.g. anaemia, hypercalcaemia, renal impairment)
• progressive rise in paraprotein, serum free light chain or urinary Bence Jones

For specific criteria of clinical relapse and progressive disease, see the MSAG Clinical practice guideline: multiple myeloma (Quach & Prince 2019).