With improved treatment, patients with multiple myeloma are surviving long enough to develop other cancers, Jorge J. Castillo, MD, and Adam J. Olszewski, MD, reported in a poster to be presented at the annual meeting of the American Society of Clinical Oncology.

The good news is that myeloma patients, when diagnosed with a subsequent solid tumor, are just as likely to respond to treatment and do just as well as patients without myeloma, according to Dr. Castillo of Dana-Farber Cancer Institute, Boston, and Dr. Olszewski of Alpert Medical School of Brown University, Providence, R.I.

When patients with myeloma develop a second cancer, they need to be treated in a way similar to the way that other cancer patients are treated, without assuming a poor prognosis, the researchers said.

They based their conclusion on Surveillance, Epidemiology, and End Results (SEER) data for patients diagnosed with six common cancers from 2004-2013.

“Among them, we identified [nearly 1,300] myeloma survivors, and we matched each to 50 randomly sampled controls with the same cancer by age, sex, race, and year of diagnosis. We then compared [cancer specific survival], cumulative incidence function (CIF) for death from the non-myeloma index cancer, and whether patients had surgery for non-metastastic, stage-matched tumors only,” the researchers wrote in their abstract.

They did analyses for breast, lung, prostate, colorectal, melanoma, and bladder cancers. The median time from diagnosis of myeloma to diagnosis of the second ranged from 35 months (bladder [133 myeloma patients] and lung [286 myeloma patients] cancers) to 50 months (melanoma [140 myeloma patients]). The median time after myeloma diagnosis was 40 months for those patients who developed breast, prostate, or colorectal cancers.

In the comparisons, myeloma survivors were significantly older (P less than .001) than patients initially diagnosed with the same respective cancers. In the case-control analysis, breast (P = .002) and lung cancers (P = .003) were more often diagnosed at an early stage among myeloma survivors.

The hazard ratio (HR) for cancer-specific survival for 189 myeloma patients diagnosed with breast cancer as compared to other breast cancer patients, for example, was 0.99, 95% confidence interval (CI) 0.61-1.61. The HR for the cumulative incidence function of cancer death was 0.82, 95% CI 0.50-1.35.

Myeloma patients were no less likely than were case-control subjects to have surgery for their cancers, with the exception of the 330 myeloma patients who developed prostate cancer (odds ratio, 0.59, 95% CI, 0.44-0.81).

Cancer-specific survival significantly differed (P less than .05) only for lung cancer, and was better among the 286 myeloma patients with lung cancer even when stratified by stage (HR 0.64, 95% CI 0.54-0.75). For cumulative incidence function of cancer death for lung cancer, the hazard ratio was 0.52 (95% CI 0.44-0.61). Better outcomes in lung cancer are not fully explained by earlier detection, suggesting a biological difference, the researchers reported.

Cumulative incidence function of cancer death was significantly lower for myeloma patients with lung and colorectal cancers.

Dr. Castillo disclosed honoraria from Celgene and Janssen; a consulting or advisory role with Biogen, Otsuka, and Pharmacyclics; and institutional research funding from Abbvie, Gilead Sciences, Millennium, and Pharmacyclics. Dr. Olszewski disclosed institutional research funding from Genentech, Incyte, and TG Therapeutics.

Citation: Outcomes of secondary cancers among myeloma survivors. 2017 ASCO annual meeting. Abstract No. 8043 .

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