Patterns in lung cancer incidence rates and trends by histologic type in the United States, 2004-2009

Abstract

Objective: The examination of lung cancer by histology type is important for monitoring population trends that have implications for etiology and prevention, screening and clinical diagnosis, prognosis and treatment. We provide a comprehensive description of recent histologic lung cancer incidence rates and trends in the USA using combined population-based registry data for the entire nation.

Materials and methods: Histologic lung cancer incidence data was analyzed from CDC's National Program of Cancer Registries (NPCR) and the National Cancer Institute's Surveillance, Epidemiology and End Results (SEER) Program. Standardized rates and trends were calculated for men and women by age, race/ethnicity, and U.S. Census region. Rate ratios were examined for differences in rates between men and women, and annual percent change was calculated to quantify changes in incidence rates over time.

Results: Trend analysis demonstrate that overall rates have decreased, but incidence has remained stable for women aged 50 or older. Adenocarcinoma and squamous cell carcinoma were the two most common histologic subtypes. Adenocarcinoma rates continued to increase in men and women, and squamous cell rates increased in women only. All histologic subtype rates for white women exceeded rates for black women. Histologic rates for black men exceeded those for white men, except for small cell carcinoma. The incidence rate for Hispanics was nearly half the rate for blacks and whites.

Conclusion: The continuing rise in incidence of lung adenocarcinoma, the rise of squamous cell cancer in women, and differences by age, race, ethnicity and region points to the need to better understand factors acting in addition to, or in synergy with, cigarette smoking that may be contributing to observed differences in lung cancer histology.

Keywords: Histologic type; Incidence; Lung cancer; Surveillance; Time trend; Tumor registry.

Figure 1

Lung Cancer Incidence Trends by Sex and Age—United States, 2004–2009^a Data are from population-based registries that participate in the National Program of Cancer Registries and/or the Surveillance, Epidemiology, and End Results and meet high-quality data criteria. These registries cover approximately 98% of the U.S. population. a Rates are per 100,000 and age-adjusted to the 2000 U.S. Std Population (19 age groups—Census P25-1130) standard * Annual percent change (APC) is significantly different from zero (p<0.05)

Figure 2

Lung Cancer Incidence Trends by Sex: Small Cell vs. Non-Small Cell Lung Cancer Subtypes—United States, 2004–2009^a Data are from population-based registries that participate in the National Program of Cancer Registries and/or the Surveillance, Epidemiology, and End Results and meet high-quality data criteria. These registries cover approximately 98% of the U.S. population. Lung cancer histology groups were defined using International Classification of Diseases for Oncology version 3 (ICD-0-3): non-small cell carcinoma (8010-8015, 8020-8022, 8030-8040, 8046, 8050-8052, 8070-8084, 8090-8110, 8120-8131, 8140-8156, 8160-8162, 8170-8175, 8180, 8190-8221, 8230-8231, 8240-8263, 8270-8280, 8290-8337, 8340-8347, 8350-8390, 8400-8562, 8570-8576, 8580-8671, 8940-8941), small cell carcinoma (8041-8045). Non-small cell carcinomas were further categorized as squamous cell (8051-8052, 8070-8084, 8120-8131), adenocarcinoma (8050, 8140-8149, 8160-8162, 8190-8221, 8250-8263, 8270-8280, 8290-8337, 8350-8390, 8400-8560, 8570-8576, 8940-8941), large cell carcinoma (8011-8015), and Other non-small cell carcinoma (8010, 8020-8022, 8030-8040, 8046, 8090-8110, 8150-8156, 8170-8175, 8180, 8230-8231, 8240-8249, 8340-8347, 8561-8562, 8580-8671). a Rates are per 100,000 and age-adjusted to the 2000 U.S. Std Population (19 age groups—Census P25-1130) standard * Annual percent change (APC) is significantly different from zero (p<0.05)