Autologous stem cell transplant poses slight second malignancy risk to MM patients

Autologous stem cell transplant (aHSCT) seems to increase the risk of haematologic second primary malignancy (SPM) among multiple myeloma (MM) patients, though the absolute estimates were small, a recent has found.

According to the researchers, the risks were “outweighed by the potential benefits to both overall and progression-free survival conferred by aHSCT use. As MM patients continue to live longer, robust data on SPM risks associated with various treatment strategies are necessary for high quality, informed shared decision making.”

The study included 16,331 MM patients (median age, 66 years; 54 percent male) diagnosed between 1991 and 2013. AHSCT was used in 19.6 percent of all newly diagnosed patients, though more commonly employed in male and younger patients, as well as in those with fewer comorbidities.

A total of 933 SPMs were detected, arising after a median of 3.8 years after MM diagnosis. Multivariable analysis showed that aHSCT did not increase the risk of SPM development (hazard ratio [HR], 1.13, 95 percent confidence interval [CI], 0.94–1.14; p=0.19), but did so with haematologic, as opposed to solid tumour, SPMs (HR, 1.51, 95 percent CI, 1.01–2.27; p=0.046).

Nevertheless, the cumulative SPM incidence rates 5 and 10 years were 4.0 percent and 6.6 percent, respectively. At the same time points, death rates attributable to SPM were similarly low, at 1.9 percent and 3.0 percent, respectively.

In comparison, MM-related death rate reached 59.1 percent by 10 years, while noncancer death was at 18.1 percent.