The Prevalence of Second Malignancies and Autoimmune Diseases in Patients with Lymphoproliferative Disorders.

BACKGROUND: The incidence and prevalence of second malignancies and autoimmune diseases are high in patients with lymphoproliferative disorders (LPD). However, there is lack of specific data and the relative risks compared to general population are unknown.

METHODS: We performed retrospective chart analysis of 185 patients with LPD in a tertiary hospital from 2000 to 2006. The data was based on available chart reviews and interdepartmental charge codes. All second malignancies and autoimmune diseases were documented irrespective of time of onset.

FINDINGS: M:F ratio = 1.1: 1.0 (97M, 88F). Median age 56. Cases consisted of: CLL/SLL 52(28.1%), multiple myeloma 28(15.135%), unspecified Non-Hodgkin’s Lymphoma 40(21.62%), large cell 24(12.97%), follicular 16(8.64%), marginal zone 11(5.94%), mantle 4(2.16%), T-cell 1(0.54%), and Hodgkin’s 9(4.86%). 37 second malignancies were documented. The prevalence was as follows: prostate 14(7.56%), breast 7(3.783%), kidney 3(1.621%), skin 3(1.621%), colon 2(1.081%), lung 3(1.621%), CMML 1(0.54%), AML 1(0.54%), larynx 1(0.54%), vulva 1(0.54%), pituitary 1(0.54%). The US prevalence of cancers as of January 2003 (population 299,259,581) based on the SEER ( Surveillance, Epidemiology and End Results) data is as follows: all cancers 3.5073%, prostate 0.648%, breast 0.792%, colon 0.357%, kidney 0.077%, lung 0.119%, larynx 0.033%.

Relative risks for second malignancies in LPD patients were calculated (see table). 55 (29.7%) autoimmune diseases were also documented: hypothyroidism 34(18.378%), ITP 10(5.405%), rheumatoid arthritis (RA) 6 (3.243%), hemolytic anemia 3(1.621%), Sjogren’s 1(0.54%), cryoglobulinemia 1(0.54%). The prevalence of autoimmune diseases in the USA is 3.21%. The prevalence of specific autoimmune diseases except RA is unknown in the available literature. The relative risk of autoimmune disorders in LPD patients is 9.25 folds.

DISCUSSION: Our data shows that the prevalence of some second malignancies (renal, prostate, lung, laryngeal, breast, colon) and autoimmune disorders are very high in LPD patients. Due to lack of SEER data, we were unable to calculate the relative risks of other cancers and autoimmune diseases. The relative risk of a second malignancy is increased up to 5-fold (up to 21-fold with renal cancer) and autoimmune diseases up to 9.25-fold. This study has limitations in terms of the sample size and unavailability of some SEER data. However, the results are provoking and need to be validated in larger studies.