• 3/3/2002
  • Palm Desert
  • American Head and Neck Society

A new research study asserts that even though the overall incidence of head and neck cancers has remained stable, young Americans are being diagnosed with higher rates of oral and tongue cancer.

The goal of the research was to update and confirm the changes in incidence of young adult oral tongue cancer, as well as other head and neck cancers, using a large cancer surveillance database in the United States. A unique feature of the analysis was to describe incidence trends by use of a new statistical methodology, joinpoint regression, and to establish the statistical significance of changes in disease rate.

Methodology: Data for the analysis were obtained from the Surveillance, Epidemiology, and End Results Program Public-Use CD-ROM (1973-1997), National Cancer Institute, DCCPS, Cancer Surveillance Research Program, Cancer Statistics Branch, released April 2000. Information was obtained on all cancers occurring in residents from nine population-based registries, i.e., five states (Connecticut, Hawaii, Iowa, New Mexico, and Utah) and four standard metropolitan statistical areas (Atlanta, Detroit, San Francisco-Oakland, and Seattle-Puget Sound). The studied cities encompass 10 percent of the U.S. population.

The SEER Program used the International Classification of Diseases for Oncology to code site, histology, and behavior for all cancers. The study only included invasive tongue cancer cases Incidence rates were tabulated as per 100,000 population and age-adjusted by the direct method to the 1970 U.S. standard population. Rates for three age groups (<40 years, 40-64 years, and >=65 years) age-adjusted within these groups, according to every single calendar year from 1973 to 1997. To better describe tongue cancer data, calculations were made for race- and gender-specific age-adjusted incidence rates with five-year intervals of time beginning in 1973-1977 and extending to 1993-1997.

Results: The SEER program registered 63,409 head and neck cancer (oral and pharynx) patients from 1973 to 1997. Of these, 3,339 patients were less than 40 years old. Between 1973-1984 and 1985-1997 periods, the overall incidence of head and neck cancer was stable.

In regard to the number of cases and observed incidence rates, researchers noted a slight decrease in 1985-1997 in both age groups of 40-64 and >=65 years. In contrast, however, the number of patients with head and neck cancer increased among young Americans less than 40 years. The increase seemed to be mainly caused by tongue cancer. Tongue cancer among young Americans ranked second to salivary gland cancers in all head and neck cancers and increased 62 percent when comparing 1985-1997 to 1973-1984. Laryngeal cancer showed no significant change in incidence during the two time periods.

Using joinpoint regression analysis, the significant increase in tongue cancer among young adults occurred during the 1973-1984 period, the estimated annual percent change (EAPC) being 6.7 (95 percent). After 1985, the incidence rates stopped rising but remained steadily high. An absolute increase of 5-year survival from tongue cancer occurred over the last 25 years and ranged from 11.7 percent (<40 years) to 6.6 percent (40-64 years) with the most significant improvement occurring in young Americans with regional and distant disease (27 percent and 21 percent, respectively).

Conclusions: The increase in tongue cancer in individuals born after 1938 and its association with improved survival suggest the emergence of a distinct disease process independent of tobacco and alcohol use. This disease process is apparent in white, but not black, populations and is of uncertain cause.

Many reports suggest that head and neck cancer, particularly oral tongue cancer, is increasing among young adults internationally. Within the United States, one study reported an increase in tongue cancer mortality among young adults under the age of 30. The increase was cited as beginning in the mid-1970s. A recent clinical report indicated that the percentage of young adults with oral tongue cancer as a percentage of the total tongue cancer population seen at the M.D. Anderson Cancer Center increased from four percent in 1971 to 18 percent in 1993.

Because incidence rates for overall head and neck cancer have remained stable, the increase of young adult patients is highly concerning. Factors that may account for oral cancer in the young adults remain unknown. Suspected causes include smokeless tobacco, various forms of drug abuse, virus, as well as host susceptibility factors. However no clear evidence exists to support the significance of any single determinant including the role of tobacco.

The authors of Head and Neck Cancer Incidence Trends in Young Americans, 1973-1997, With a Special Analysis for Tongue Cancer, are Stimson P. Schantz, MD, and Guo-Pei Yu, MD, both from the The New York Eye and Ear Infirmary, New York, NY. Their findings were presented before the spring meeting of the American Head and Neck Society in Palm Desert, CA.