CML Patients With Prior Malignancies Have Excellent Outcomes

Patients with chronic myeloid leukemia (CML) with a history of prior malignancies generally fare as well as those without such a history, according to a new study. Concomitant therapy with tyrosine kinase inhibitors (TKIs) can be managed safely when required.

“With prolonged survival, questions arise regarding the effects of TKI treatment on prior medical conditions and the effect of such conditions on the management and outcomes of patients with CML,” wrote study authors led by Jorge E. Cortes, MD, of the University of Texas MD Anderson Cancer Center in Houston. Recent studies have suggested that there is an increased prevalence of other malignancies prior to CML diagnosis, compared with the general population, and the interaction of that prior malignancy with CML and its treatment have yet to be studied.

The new study included 630 patients with CML in the chronic phase treated with a TKI as initial therapy in clinical trials at MD Anderson Cancer Center; 626 of those had a known prior malignancy status. The results were published online ahead of print in Cancer.

A total of 62 patients (10%) had a history of 72 malignancies before CML diagnosis; these were divided into a group of 17 patients with nonmelanoma skin cancer (nMSC), and another group of 45 patients with primary malignancies other than nMSC, leaving 564 patients in the group with CML as the initial malignancy. Other common prior malignancies included breast cancer in 11 patients, melanoma in 7 patients, prostate cancer in 6 patients, and colorectal cancer in 5 patients.

The median time from diagnosis of the prior malignancy to the diagnosis of CML was 65 months in the primary malignancies group and 49 months in the nMSC group. Patients in the primary malignancies group were older than in the other two groups.

Most of the primary malignancies patients (93%) had no active disease and were not receiving treatment at the time of CML diagnosis; two were receiving tamoxifen for breast cancer, and one had undergone surgery for melanoma and was being treated with observation only.

CML-related outcomes were similar between all three groups. There were no differences with regard to 5-year event-free survival, failure-free survival, and transformation-free survival between the groups. There was, however, a decreased overall survival in the primary malignancies group; the 5-year overall survival rate in these patients was 79%, compared with 100% in the nMSC patients and 93% in the no prior malignancies group (P = .014).

A multivariate analysis showed that only older age and elevated creatinine level were associated with inferior survival. A history of prior malignancy was not associated with any decreased survival.

Four patients in the primary malignancies group experienced a recurrence of their initial malignancy. Three of those continued TKI therapy while receiving treatment for the other malignancy, and this was generally well tolerated, the authors noted.

“The results of the current study indicate that survivors of prior malignancies who develop CML as a second (or later) malignancy may have a similarly excellent outcome with TKI therapy as patients for whom CML is their first malignancy,” the authors concluded. “In fact, these data stress the importance of the control of other comorbid conditions after the diagnosis and treatment of CML.”