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Mycosis fungoides increases risk for second cancers



– Patients with mycosis fungoides are at increased risk for developing other cancers and should be screened for second primary and hematologic malignancies, results of a cancer registry survey suggest.

A study of data on 6,196 patients included in 18 population-based cancer registries comprising the SEER-18 (Surveillance, Epidemiology, and End Results 18) database who were diagnosed and followed from 2000 to 2014 showed that 514 (8.3%) developed second cancers, compared with the 70.8 secondary malignancies that would be expected in the general population. This difference translated into a standardized incidence ratio (SIR) of 7.3, reported Amrita Goyal, MD, and Aleksandr Lazaryan, MD, PhD, of the University of Minnesota, Minneapolis.

Dr. Amrita Goyal of the University of Minnesota Neil Osterweil/Frontline Medical News

Dr. Amrita Goyal

“If you compare the rate of the development of these malignancies to a population of gender-matched controls, the rates of second malignancy are substantially higher in patients with MF [mycosis fungoides] than you would expect,” Dr. Goyal said in an interview at the annual T-cell Lymphoma Forum.

Patients with MF have a 500% greater risk for developing a second solid malignancy and a 2700% greater likelihood of developing a second hematologic malignancy, she said.

The investigators hypothesized that MF predisposes patients to second malignancies because of its immunocompromising effects.

Dr. Goyal said that, although the SEER data set does not include information on disease stage for all patients, when they looked at a separate cohort of 173 University of Minnesota patients with MF, they saw that patients with higher-stage MF were significantly more likely to develop secondary malignancies than patients with lower-stage disease.

The investigators looked at the actual and expected cancer incidence rates for the SEER-18 population sample, and used data on age, sex, race, and calendar year to generate incidence estimates for the general population.

They found that 514 patients in the SEER-18 population developed a total of 170 second primary hematologic malignancies, for a SIR of 27.4, compared with the general population. The most common hematologic cancers were Hodgkin lymphoma (SIR 69.8) and non-Hodgkin lymphoma (SIR 46.5), and other second hematologic malignancies included multiple myeloma (SIR 4.5), chronic lymphocytic leukemia (SIR 9.1). and acute leukemias (SIR 8.1).

The most frequently occurring second solid tumors included cancers of the nose, nasal cavity, and middle ear (SIR 30.4); thyroid (SIR 16.1); brain (SIR 15.1); and breast (SIR 8.0).

Other solid tumors with an approximately 400%-500% higher incidence included cancers of the prostate, bladder, colon, and kidneys.

Dr. Goyal and Dr. Lazaryan recommend development of targeted cancer screening strategies for patients with MF.

The study was funded in part by an American Society of Hematology HONORS grant. The researchers reported having no conflicts of interest. The T-Cell Lymphoma Forum is held by Jonathan Wood & Associates, which is owned by the same company as this news organization.

SOURCE: Goyal A et al. TCLF 2018 Abstract EP18_2.

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