BACKGROUND. Many studies found better cancer survival in patients with
a high socioeconomic status (SES) than in patients with a low SES. Co
morbidity at the time of diagnosis may be more frequent in patients of
lower SES, and negatively influences their survival. The authors stud
ied the association between SES and serious comorbidity at the time of
diagnosis among newly diagnosed cancer patients in the Netherlands. M
ETHODS, Included in the analyses were patients registered in 1993 in t
he population-based Eindhoven Cancer Registry (southeastern Netherland
s) with one of the most common carcinomas: breast (n = 457), lung (n =
442), colorectum (n = 384), prostate (n = 240), and stomach (n = 118)
. Information regarding comorbidity came from medical records. The SES
of the patients was derived from their postal code of residence and s
tratified into three categories. The risk of being diagnosed with at l
east one other chronic condition was calculated using logistic regress
ion analyses. RESULTS, The risk of being diagnosed with at least one o
ther chronic condition was higher among patients with a low or interme
diate SES than among those with a high SES for the five sites combined
as well as for carcinomas of the breast or lung. The gradient was les
s clear for patients with colorectal carcinoma, whereas no socioeconom
ic variation in comorbidity was found for patients with carcinomas of
the prostate or stomach. CONCLUSIONS, Socioeconomic variation in the p
revalence of serious comorbidity at the time of diagnosis does exist i
n some cancer sites, which may explain (partly) the socioeconomic grad
ient in survival observed in patients with tumors in these sites. (C)
1997 American Cancer Society.