CLINICAL NEWS

Research from ASH ’ s online peer-reviewed journal , Blood Advances

A number of new treatments for patients with multiple myeloma ( MM ) have become available in recent years , enabling patients to live longer . Unfortunately , these patients are susceptible to developing another malignancy later in life , particularly if they were diagnosed with a malignancy prior to MM diagnosis .

In an analysis of data from the Swedish Cancer Registry , which collects information about all reported malignancy diagnoses since 1958 , Gudbjörg Jonsdottir , MD , from the University of Iceland in Reykjavik , and co-authors assessed susceptibility to subsequent cancers and survival in nearly 20,000 patients diagnosed with MM . Results were published in Blood Advances .

The study included 19,791 people who were diagnosed between January 1 , 1973 , and December 31 , 2010 ;

2,469 patients ( 12.5 %) had at least one prior malignancy diagnosis at the time of MM diagnosis , while the remaining 17,322 ( 87.5 %) did not . The most common types of prior malignancies were male reproductive cancer ( n = 427 ; 17.3 %), female reproductive cancer ( n = 401 ; 16.2 %), and breast cancer ( n = 329 ; 13.3 %).

Subsequent malignancies were developed by 216 ( 8.8 %) of the 2,469 patients with prior malignancies , and by 1,257 ( 7.3 %) if the 17,322 patients without prior malignancies .

“ A prior malignancy diagnosis in [ patients with ] MM was associated with a 40 percent increased risk of developing a subsequent malignancy , [ compared with patients without prior malignancy ],” the authors reported ( hazard ratio [ HR ] = 1.42 ; 95 % CI 1.23-1.65 ; p < 0.001 ). The risk was greater across all types of malignancies , including hematologic cancers , malignant melanoma , non-melanoma skin cancer , and malignancies of the respiratory tract ( see TABLE for all outcomes ).

“ These patients developed their subsequent malignancy almost a year sooner than those without a history of prior malignancy ,” the researchers added . The median time from first prior malignancy to MM diagnosis was 7.1 years ( range not provided ) in both those who did and did not develop a subsequent malignancy ( p = 0.732 ). These patients developed a first subsequent malignancy at a median of 2.3 years after diagnosis ( range = 0.02-21.5 years ), compared with 3.2 years ( range = 0.003-37.5 years ) among those who did not have a prior malignancy ( p = 0.003 ).

Risk of death was also increased among people diagnosed with a

TABLE . Risk of Developing Subsequent Malignancy in Patients With Multiple Myeloma With a Prior Malignancy Diagnosis , Compared With Those Without

Soft tissue and mediastinal ( n = 13 )

Unspecified tumors ( n = 39 )

* Two-sided p < 0.05 was considered statistically significant .

1.91 0.40-9.03 0.415

1.28 0.49-3.33 0.618 malignancy before MM ( HR = 1.21 ; 95 % CI 1.15-1.26 ; p < 0.001 ). In a “ dose-response ” analysis , the researchers observed that the risk appeared to increase with the number of prior malignancies : Patients with two or more prior malignancies had a 34 percent increased risk of death ( HR = 1.34 ; 95 % CI 1.19-1.52 ; p < 0.001 ), compared with those without prior diagnoses .

– GUDBJÖRG JONSDOTTIR , MD

These results “ might suggest inherent genetic susceptibility in these patients ,” the authors wrote . However , because genetic profiles were unavailable for all patients in this registry , the study was not able to examine that association . “ Other possible etiologies include immune dysfunction … or side effects from treatment ,” they noted , adding that further research is needed .

The study is limited by the reliance on a registry , which lacked clinical and treatment data , including cause of death and the pathologic stage of prior cancers , myeloma , and subsequent cancers . ●

The authors report no financial conflicts .

REFERENCE

Jonsdottir G , Lund SH , Björkholm M , et al . The impact of prior malignancies on second malignancies and survival in MM patients : a population-based study . Blood Advances . 2017 November 28 .

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