Overall and Cancer-Specific Survival of Patients With Breast, Colon, Kidney, and Lung Cancers With and Without Chronic Lymphocytic Leukemia: A SEER Population-Based Study Benjamin M. Solomon, Kari G. Rabe, Susan L. Slager, Jerry D. Brewer, James R. Cerhan, and Tait D. Shanafelt Listen to podcast by Dr Travis at www.jco.org/podcasts All authors: Mayo Clinic, Rochester, MN. Published online ahead of print at www.jco.org on January 22, 2013. Authors’ disclosures of potential con- flicts of interest and author contribu- tions are found at the end of this article. Corresponding author: Tait D. Shanafelt, MD, Mayo Clinic, 200 First St SW, Rochester, MN 55905; e-mail: shanafelt.tait@mayo.edu. © 2013 by American Society of Clinical Oncology 0732-183X/13/3107-930/$20.00 DOI: 10.1200/JCO.2012.43.4449 A B S T R A C T Purpose Chronic lymphocytic leukemia (CLL) is associated with an increased risk of developing second cancers. However, it is unknown whether CLL alters the disease course of these cancers once they occur. Patients and Methods All patients with cancers of the breast (n = 579,164), colorectum (n = 412,366), prostate (n = 631,616), lung (n = 489,053), kidney (n = 95,795), pancreas (n = 82,116), and ovary (n = 61,937) reported to the SEER program from 1990 to 2007 were identified. Overall survival (OS; death resulting from any cause) and cancer-specific survival were examined, comparing patients with and without pre-existing CLL. Cancer-specific survival was evaluated for each tumor type in a site-specific manner (eg, death resulting from breast cancer in a patient with breast cancer). Results Patients with cancers of the breast (hazard ratio [HR], 1.70; P  .001), colorectum (HR, 1.65; P  .001), kidney (HR, 1.54; P  .001), prostate (HR, 1.92; P  .001), or lung (HR, 1.19; P  .001) had inferior OS if they had a pre-existing diagnosis of CLL after adjusting for age, sex, race, and disease stage. These results for OS remained significant for patients with cancers of the breast, colorectum, and prostate after excluding or censoring CLL-related deaths. Cancer-specific survival was also inferior for patients with cancers of the breast (HR, 1.41; P = .005) and colorectum (HR, 1.46; P  .001) who had pre-existing CLL after adjusting for age, sex, race, and disease stage. Conclusion Inferior OS and cancer-specific survival was observed for several common cancers in patients with pre-existing CLL. Additional studies are needed to determine the optimal management of these malignancies in patients with CLL and whether more aggressive screening or alternative approaches to adjuvant therapy are needed. J Clin Oncol 31:930-937. © 2013 by American Society of Clinical Oncology INTRODUCTION Chronic lymphocytic leukemia (CLL) is one of the most common hematologic malignancies, with ap- proximately 100,000 people living with this disease in the United States. 1 CLL behaves in an indolent fashion for many patients, and they often die as a result of unrelated causes. Numerous studies have suggested that CLL is associated with an increased risk of developing second cancers, including cancers of the lung, breast, colon, head and neck, kidney, bladder, prostate, thyroid, and skin (both melanomas and nonmelanomas) as well as both Hodgkin and non-Hodgkin lymphomas. 2-8 Although the in- creased risk of second cancers is well recognized, little is known about the disease course of second malignancies in patients with CLL compared with those without CLL. It is generally accepted that nonmelanoma skin cancers (eg, squamous and basal cell carcinomas of the skin) may behave more aggressively in the presence of CLL. 9-11 Re- cent population-based data also suggest that melanoma may behave more aggressively in indi- viduals with CLL, 12,13 raising the possibility that the presence of CLL not only influences the risk of developing solid tumors but may be associated with more aggressive behavior once they occur. If JOURNAL OF CLINICAL ONCOLOGY O R I G I N A L R E P O R T VOLUME 31  NUMBER 7  MARCH 1 2013 930 © 2013 by American Society of Clinical Oncology