A total of 37, 776 cases of invasive cervical cancer in the SEER registry dataset were diagnosed between 1973 and 2007. The overall incidence of invasive cervical cancer was highest in the 45–49-year age group. However, peak age group varied by histologic types. Squamous cell incidence peaked in the 45–49-year age groups. The peak ages for adenocarcinoma and adenosquamous carcinoma were both in the 35–39-year age group ().
Age distribution of invasive cervical cancer histologic subtypes, 1973–2007.
Over the 35-year period, age-adjusted incidence rates for all invasive cervical cancer decreased by 54% from 13.07/100,000 women in 1973–1975 to 6.01/100,000 women in 2006–2007. Join-point analysis showed that, on an annual basis, invasive cervical cancer declined by 6.4% between 1973 and 2007. This rate of change was not constant over the 35-year study period, with a 9.9% decrease between 1973 and 1983. The decline stabilized between 1983 and 1992; since then, the incidence rate decreased by a rate of 7.7% annually.
Of note, the age-adjusted incidence rates for all invasive cervical cancers for black women declined by 72.2% from 22.79/100,000 women in 1973–1975 to 6.8/100,000 women in 2006–2007. A decline of 54% was experienced among whites, from an annual incidence rate of 13.07/100,000 women in 1973–1975 to 6.01/100,000 women in 2006–2007 (). Between 1973 and 2007, join-point analysis showed an overall decrease in the incidence of invasive cervical cancer among whites by 5.9%. Among blacks, however, there was an even greater (10.4%) decrease over the same period. shows the decrease in incidence among blacks and whites between 1974 and 1983. Incidence decreased at a statistically significant rate of 10% among white women per year between 1974 and 1983. Among black women, the decrease was greater (14.1% annually) when compared to white women.
Invasive cervical cancer incidence rates by race, 1973–2007.
Trend Analysis of Invasive Cervical Cancer by Race, 1973–2007
By histologic type
shows a decline in the age-adjusted incidence rates of squamous cell carcinomas of 61.1%, from 10.28/100,000 women in 1973–1975 to 3.97/100,000 women in 2006–2007. Age-adjusted incidence rates for adenosquamous carcinoma declined by 16%, from 0.27/100,000 women in 1973–1975 to 0.23/100,000 women in 2006–2007. However, the age-adjusted incidence rates for adenocarcinomas increased by 32.2%, from 1.09/100,000 women in 1973–1975 to 1.44/100,000 women in 2006–2007.
Invasive Cervical Cancers by Histologic Subtype, 1973–2007
The trend in incidence by histologic type varied over the 35 years. The overall incidence of squamous cell cancer decreased annually between 1973 and 2007 by 8%, and the incidence of adenocarcinoma increased by an average of 2.9% per year over the same period. The trend analysis indicates that the incidence of squamous and adenosquamous carcinoma decreased between 1973 and 1983 by 10.4% and 4.6% per year, respectively, but there was a subtle increase in squamous cell carcinomas between 1983 and 1992 of 5.4% annually. Between 1992 and 2001, there was an 8.9% annual decrease in squamous cell carcinoma incidence and a 9.2% annual decrease between 2001 and 2007 ().
Trend Analysis of Invasive Cervical Cancer Histologic Subtypes, 1973–2007
By race and histologic type
Between 1973 and 2007, the age-adjusted incidence rates of squamous cell cancer among white women declined by 60.6%, from 9.49/100,000 women in 1973–1975 to 3.74/100,000 women in 2006–2007(). Among black women, there was a 72.2% decline, from 18.90/100,000 women to 5.25/100,000 women during the same period. shows that the age-adjusted incidence rates of adenocarcinomas among white women increased by 41.8%, from 1.1/100,000 women in 1973–1975 to 1.56/100,000 women in 2006–2007. This increase was not reflected among black women, where we observed a 15.2% decline from 0.92/100,000 women in 1973–1975 to 0.78/100,000 women in 2006–2007. The age-adjusted incidence rates of invasive adenosquamous cervical cancer for whites was relatively stable (0.25/100,000 women) over the study period. However, among blacks, there was a 59.4% decline from 0.69/100,000 women in 1973–1975 to 0.28/100,000 women in 2006–2007.
FIG. 3. (A)
Squamous cell carcinoma histology incidence rate by race, 1973–2007. (B) Adenocacinoma and adenosquamous histology incidence rates by race, 1973–2007.
shows the incidence trend for cell types by race. Among whites, squamous cell incidence decreased 7.7% per year, whereas for blacks, there was a greater decrease (10.9%) per year; both declines were statistically significant. Among whites, adenocarcinoma incidence increased by 3.6% per year, and for blacks, the opposite (a decrease of 2.1% annually) occurred. Similar results were seen in the incidence trends of adenosquamous cell types, with the incidence for white women increasing by 1.3% annually, and that for black women decreasing by 6.1% per year.
Trend Analysis of Cell Types by Race, 1973–2007
Approximately, 56.45% of all invasive cervical cancers were diagnosed at the localized stage, regional stage cancer accounted for 34.36%, and the remaining 9.29% of total invasive cervical cancer cases were diagnosed at the distant stage. There was an overall decline in the age-adjusted rates among those with squamous cell histology irrespective of stage of diagnosis. A similar decline was seen among the two racial groups. For adenocarcinoma, however, white women had increased rates irrespective of stage of diagnosis, and a corresponding decline was reported in the overall and black age-adjusted incidence rates irrespective of stage of diagnosis. Finally, incidence rates for adenosquamous cancers for white women increased for regional stage, with an overall decline in other stages.