Extrapulmonary small cell cancer: a Canadian province's experience.

BACKGROUND

The objective of this study was to determine variables that correlate with the survival of patients with extrapulmonary small cell carcinoma (EPSCC).

METHODS

Medical records of 101 eligible patients with EPSCC who were diagnosed in Saskatchewan from 1971 to 2002 were reviewed. Survival was calculated by using the Kaplan-Meier method. A logistic regression analysis with a backward elimination was carried out to determine prognostic variables that predicted mortality.

RESULTS

The median patient age was 72 years (range, 24-100 years), and the male-to-female ratio was 1.4:1. The primary disease sites were as follows: breast, 9%; gastrointestinal, 20%; genitourinary, 18%; gynecologic, 11%; head and neck, 10%; thymus, 2%; and unknown primary site, 31%. Fifty-one patients had limited disease (LD), and 50 patients had extensive disease (ED). Patients with LD had a median overall survival of 34 months (range, 0.2-276 months) compared with 2 months (range, 0.1-108 months) in patients with ED (P < .0001). Among different primary sites, patients with gynecologic small cell cancer (SCC) had a median survival of 54.4 months, whereas patients with SCC of an unknown primary site had a survival of 2.5 months. Among various variables that were examined with respect to their prognostic importance, an abnormal white blood cell count (odds ratio [OR], 6.9; 95% confidence interval [95% CI], 3.4-14.1), an Eastern Cooperative Oncology Group performance status >2 (OR, 4.5; 95% CI, 2.1-9.9), and ED (OR, 2.7; 95% CI, 1.4-5.0) were found to be correlated significantly with mortality.

CONCLUSIONS

The gastrointestinal and genitourinary tracts were the 2 major sites involved by EPSCC in the current series. Survival varied according to the primary sites, and patients with gynecologic tumors had the best prognosis. An abnormal white blood cell count, a poor performance status, and disease extent were important factors in predicting survival.