This article is more than 5 years old. Information may no longer be current.
Radiation may increase acute myeloid leukemia risk in lung cancer survivors
Click Here to Manage Email Alerts
CHICAGO — Younger age and radiation receipt increased the risk for acute myeloid leukemia among survivors of stage 2 and stage 3 lung cancer, according to study results presented at International Association for the Study of Lung Cancer Multidisciplinary Symposium in Thoracic Oncology.
Exposure to recreational, environmental and iatrogenic carcinogens may put lung cancer survivors at high risk for developing secondary malignancies.
“The incidence of such iatrogenic cancers and the relative contribution in lung cancer survivors are unknown. ... We explored the risk for subsequent hematologic malignances in survivors of lung cancer,” Sarit Appel, MD, radiation oncologist at Chaim Sheba Medical Center in Ramat Gan, Israel, said during a presentation. “We hypothesized that the radiation therapy may have a contributory role in the increased incidence of these malignancies.”
To determine this, researchers used the U.S.-based SEER 13 registry to compare the incidence of subsequent hematologic malignancies (observed risk) with the general population (expected risk) within the same time period. Researchers also used the chi square test to compare the incidence of hematologic malignancies among patients treated with and without radiation.
The analysis included patients diagnosed with stage 2 or stage 3 primary malignant lung or bronchus cancer between 1990 and 2013. In total, 716,805 patients did not receive radiation and 366,798 patients underwent external beam radiation therapy.
Compared with the general population, risk for nonlymphocytic leukemias increased in patients treated without radiation (HR = 1.3) and with radiation (HR = 2.1; P < .01 for both). AML comprised most of these cases among both those treated without (HR = 1.4) and with (HR = 2.5; P < .01 for both) radiation.
Chi-square statistics showed patients treated with radiation had increased incidence of AML (excess risk, 1.8 per 10,000) compared with patients who did not receive radiation (excess risk, 0.6 per 100,000; P < .01). Patients treated with radiation, however, did not have an increased risk for lymphoma, myeloma, chronic lymphocytic leukemia, acute lymphocytic leukemia or chronic myeloid leukemia.
The risk for AML appeared higher among patients — with or without radiation therapy — diagnosed when aged 33 to 40 years (HR = 16) than among those diagnosed when aged 45 to 59 years (HR = 4.4), 60 to 74 years (HR = 1.8; P < .01) and 75 years or older (HR = 1.2; P < .01).
The HR for patients aged 0 to 29 years could not be evaluated because this age group comprised 0.8% of the entire cohort.
Limitations of the study included the lack of data on the use of chemotherapy and growth factors; application of radiation therapy may be a surrogate marker for chemotherapy administration; and the inability to analyze the interplay of radiation and chemotherapy and granulocyte-colony stimulating factor, Appel said.
Still, younger patients and survivors who received radiation treatment — and even chemotherapy — are at increased risk, Appel said.
“Consider hematologic malignancies when patients present with abnormal CBCs on follow-up,” Appel said. – by Melinda Stevens
Reference:
Appel S and Lawrence YR. Abstract 3B.01. Presented at International Association for the Study of Lung Cancer Multidisciplinary Symposium in Thoracic Oncology; Sept. 14-16, 2017; Chicago.
Disclosure: Appel reports no relevant financial disclosures.