Curative Treatment for SPMs in Myeloma Patients

Despite a higher overall mortality related to myeloma, patients with the disease diagnosed with certain second primary malignancies (SPMs) had a similar cumulative incidence function (CIF) of cancer-related deaths as controls, according to a study published in Cancer.

“The results of the current study provide important guidance both for patients with myeloma who face the challenges of SPMs as well as for oncologists grappling with complex prognosis and treatment options in this population,” wrote Peter Barth, MD, of the Warren Alpert Medical School at Brown University, Rhode Island, and colleagues. “These findings support curative treatment approaches for incident SPMs diagnosed among patients with myeloma whenever possible, but treatment should be planned after a thorough consideration of the current status, history, and further treatment options for the plasma cell disorder.”

As patients with myeloma begin to live longer, concerns about SPM diagnoses have increased. In the study, Barth and colleagues used 2004–2015 data from the Surveillance, Epidemiology, and End Results (SEER) registry to identify patients with myeloma diagnosed with secondary cancers and to analyze overall and cause-specific survival, and CIF of cancer-related death.

Patients with myeloma diagnosed with breast (P = .003), prostate (P = .03), and lung cancer (P < .001) were significantly more often diagnosed at a localized stage compared with controls. The same was not true for melanoma, colorectal cancer, or bladder cancer.

Overall survival was significantly worse for patients with myeloma diagnosed with all of these cancers, with the exception of lung cancer. However, the same effect was not noted for cause-specific survival. There was no significant differences between patients with myeloma and controls for any cancer type except lung. In patients with myeloma and lung cancer, cause-specific survival was significantly better compared with controls.

“Outcomes in patients with lung cancer were unique, with a specific distribution of histologies and better cause-specific survival, which could not be explained by differences in stage of disease or the disparate use of surgery,” the researchers wrote.

The use of surgery in patients with nonmetastatic disease did not differ between patients with myeloma and controls, except for fewer prostatectomies noted in patients with myeloma (odds ratio [OR], 0.56; 95% CI, 0.42–0.74).

“Ongoing monitoring of myeloma during and after therapy for SPMs is paramount to intervene in the case of disease progression,” the researchers wrote. “The results of the current study provide observational evidence for the International Myeloma Working Group consensus recommendations, which emphasized the risk of myeloma-related death after diagnosis of an SPM.”