PURPOSE: To describe the epidemiology of racial and gender differences of lung carcinoid tumor, a well-differentiated neuro-endocrine carcinoma, in comparison with small cell carcinoma, a poorly differentiated neuro-endocrine carcinoma of the lung.
METHODS: Data were obtained from the NCI's Surveillance, Epidemiology, and End Results (SEER) Program, Registry 9, for the years 1973–2004. During this time, 433,411 cases of lung cancer were reported and 5,679 cases of carcinoid tumors (5,110 cases in Whites, 424 in Blacks). Incidence rates are expressed as cases per 100,000 Whites or Blacks. Statistical analysis tests were used for comparisons of significance.
RESULTS: Carcinoid tumors represented 1.3% of all lung neoplasms (1973–2004) and have a higher incidence in Whites (0.88 per 100K) relative to Blacks (0.74 per 100K), and a higher incidence in women (0.89 per 100K) relative to men (0.77 per 100K). White women have the highest rate (0.95 per 100K) while the lowest rates are found in Black men (0.71 per 100K). The incidence of carcinoid tumors has been increasing for the last 31 years in all groups. The 65–69 age strata are the most common ages at diagnosis in both races and genders and the upper lobe is the most common. In contrast, the rates for small cell carcinoma of the lung (SCLC), a poorly differentiated neuro-endocrine carcinoma, were higher in men (8.73 per 100K) than women and higher in Black men (9.98 per 100K) than White men. SCLC is also most common in the upper lobe for both races and genders. Unlike carcinoid tumors, the incidence of SCLC has been decreasing.
CONCLUSION: Carcinoid tumors and small cell carcinomas of the lung show neuro-endocrine differentiation but demonstrate different racial and gender epidemiologic parameters and differences in progressive incidence rates.
CLINICAL IMPLICATIONS: Epidemiologic data support the distinct carcinogenic pathways to these two neuro-endocrine carcinomas despite their presumed identical cell of origin and neuro-endocrine differentiation.
DISCLOSURE: Arnold Schwartz, No Financial Disclosure Information; No Product/Research Disclosure Information