Demographic and racial disparities in stomach cancer incidence and mortality

Stomach Cancer: A Descriptive Epidemiology

Personal Characteristics

Stomach cancer affects different demographics with a great deal of variation. In the period from 2002 to 2006, over two-thirds (64.3%) of all newly diagnosed stomach cancers occurred in patients over the age of 65 (ACS 2009; Horner et al. 2009). The age-adjusted incidence rate for the period was 7.9 new diagnoses per 100,000 men and women, with men experiencing incidence rates almost exactly twice that of women when all racial groups were combined, a trend that continued in mortality rates for the period (Horner et al. 2009). Overall mortality rates are projected at approximately half that of the incidence rate for the same period (ACS 2009). Overall prevalence stomach cancer was 64,122 as of 2006, and given rates of incidence and mortality in the interceding years, this number has remained relatively stable (Horner et al. 2009). Incidence, prevalence, and mortality have all dropped significantly in the past seventy-five years, however, sue to advances in health and care (NCI 2008).

Incidence and mortality is also highly influenced by race. The highest rate of incidence for stomach cancer in the United States was among the Asian/Pacific Islander demographic, with 18 out of every 100,000 men and 10 out of every 100,000 women being diagnosed during the most recent study (Horner et al. 2009; CDC 2009). The rate of mortality, however, is slightly higher in African-Americans, the demographic with the second-highest rate of incidence in both men and women (NCI 2009; Horner et al. 2009). The general downward trend in the rates of incidence and mortality in African-Americans has also been slightly shallower than in other demographics, though not as volatile as American Indians (NCI 2009).

Overall prevalence of stomach cancer is approximately .89% according to the data gathered by the most recent comprehensive study, meaning that one out of every one-hundred-and-thirteen men and women will be diagnosed with stomach cancer at some point in their lives, with the vast majority of these diagnoses coming after the age of sixty-five (Horner et al. 2009; NCI 2009). Religion and occupational differences do not appear to have been statistically significant factors in the rates of prevalence, incidence, or mortality of stomach cancers. race and gender, however, are both hugely influential, especially for rates on incidence and prevalence (Horner et al. 2009; ACS 2009). Both gender and race also have a definite and measurable effect on mortality rates, though this effect -- especially for gender -- is remarkably smaller in mortality rates than it is in the rates of prevalence and incidence (Horner et al. 2009).

Other personal characteristics that appear to contribute to the incidence and mortality rates of stomach cancer across all ages and races, though with heightened influence in demographics already identified as at-risk, include tobacco use and, interestingly, access to antibiotics (ACS 2009). This last, along with the advent of refrigeration for food storage -- which allowed fresh fruits and vegetables to be stored longer and consumed more regularly -- are both credited for reducing incidence, prevalence, and mortality of stomach cancer over the past seventy-five years, as the lack of access to antibiotics and fresh produce has been linked to higher rates in individuals and populations (ACS 2009). The overall five-year relative survival rate for stomach cancer is 25.7%, with women having a slightly higher survival rate overall than men (Horner et al. 2009).

Time Characteristics

Largely due to the overwhelming effect of age on the incidence rates of stomach cancer, time characteristics regarding the disease are difficult to ascertain and are largely inconsequential in practical terms. As nearly two thirds of all cases occur in patients over sixty five years of age, with the majority of these being diagnosed over the age of seventy, only a small number of individuals live to fully combat stomach cancer, though the cancer is not especially virulent or mortality inducing in younger ages. This can clearly be seen when a comparison of age-adjusted mortality rates due to stomach cancer in the United States are compared to the five-year survival rates for patients diagnosed with stomach cancer.

The overall mortality rate of stomach cancer in the United States from 2002 to 2006 was 3.95% (NCHS 2009). Comparatively, the relative survival rate five years after diagnosis with stomach cancer was 25.7% across the United States from the period of 1999-2005 (the closest five-year period to the period from which adjusted mortality rates were calculated for which information was available) (Horner et al. 2009). Despite nearly three-quarters of all stomach cancer patients dying within five years of their diagnosis with stomach cancer, the age-adjusted mortality rate of the disease is well under five percent. The disease does not have time to produce cyclical trends or other significant time characteristics, as it overwhelmingly affects elderly individuals and therefore has a low long-term survival rate.