Systemic lupus erythematosus
The rate of SLE varies between countries, ethnicity, and sex, and changes over time. In the United States, one estimate of the rate of SLE is 53 per 100,000; other estimates range from 322,000 to over 1 million. In Northern Europe the rate is about 40 per 100,000 people. SLE occurs more frequently and with greater severity among those of non-European descent. That rate has been found to be as high as 159 per 100,000 among those of Afro-Caribbean descent. Childhood-onset systemic lupus erythematosus generally presents between the ages of 3 and 15 and is four times more common in girls.
Combined small-cell lung carcinoma
In a study of 408 consecutive patients with SCLC, Quoix and colleagues found that presentation as a solitary pulmonary nodule (SPN) is particularly indicative of a c-SCLC — about 2/3 of their SPN's were pathologically confirmed to be c-SCLC's containing a large cell carcinoma component.
In terms of case numbers, the estimated 8,800 to 13,200 c-SCLC cases occurring annually in the U.S. makes this disease roughly comparable in incidence to Hodgkin's Disease (8,500), testicular cancer (8,400), cervical cancer (11,300), and cancers of the larynx (12,300). However, these four "better-known" cancers all have exceptionally high (85%-95%) cure rates. In contrast, less than 10% of c-SCLC patients will be cured, and thus the number of annual cases of c-SCLC is a reasonable approximation of the annual number of deaths. Therefore, given the significant incidence and mortality attributable to this malignancy, (see "Prognosis and survival") it is arguably critical to better understand these aggressive lesions so specific strategies for their management can be rationally designed.