Multiple myeloma survival in New South Wales, Australia, by treatment era to 2020.

Objective: Australia has relatively high multiple myeloma (MM) incidence and mortality rates. Advancements in MM treatment over recent decades have driven improvements in MM survival in high-income countries; however, reporting in Australia is limited. We investigated temporal trends in population-wide MM survival across 3 periods of treatment advancements in New South Wales (NSW), Australia.

Methods: Individuals with an MM diagnosis in the NSW Cancer Registry between 1985 and 2015 with vital follow-up to 2020, were categorized into 3 previously defined treatment eras according to their diagnosis date (1985-1995, chemotherapy only; 1996-2007, autologous stem cell transplantation; and 2008-2015, novel agents including proteasome inhibitors and immunomodulatory drugs). Both relative survival and cause-specific survival according to Fine and Gray's competing risks cumulative incidence function were calculated by treatment era and age at diagnosis.

Results: Overall, 11,591 individuals were included in the study, with a median age of 70 years at diagnosis. Five-year relative survival improved over the 36-year (1985-2020) study period (31.0% in 1985-1995; 41.9% in 1996-2007; and 56.1% in 2008-2015). For individuals diagnosed before 70 years of age, the 5-year relative survival nearly doubled, from 36.5% in 1985-1995 to 68.5% in 2008-2015. Improvements for those > 70 years of age were less pronounced between 1985-1995 and 1996-2007; however, significant improvements were observed for those diagnosed in 2008-2015. Similar overall and age-specific patterns were observed for cause-specific survival. After adjustment for gender and age at diagnosis, treatment era was strongly associated with both relative and cause-specific survival (P < 0.0001).

Conclusions: Survival of individuals with MM is improving in Australia with treatment advances. However, older age groups continue to experience poor survival outcomes with only modest improvements over time. Given the increasing prevalence of MM in Australia, the effects of MM treatment on quality of life, particularly in older age, warrant further attention.