RESULTS
A total of 20,228 women diagnosed with endometrial cancers between
2009-2017 were identified (Figure 1). Demographic, clinical and surgical
data for patients stratified by a summary marginalization score are
presented in Table 1. The highest quintile (Q5) represents patients
living in the most marginalized neighborhoods.
Age distribution was slightly skewed, with more patients over seventy in
the highest marginalization quintile. Highly marginalized patients were
likely to be urban residents. Highly marginalized patients had more
comorbidities as reflected by higher Charlson scores (20% versus 27%
had a score of 0 in the most and least marginalized quintiles,
p<0.001), but severe obesity (BMI>40) was evenly
distributed across quintiles.
Of patients with known cancer stage (n=14318), 74% (10,508) were
diagnosed with stage I disease. 73% (14,810/20,228) of endometrial
cancers were of endometrioid histology. Patients in the most
marginalized neighborhoods were more likely to present at more advanced
stages: of patients with known stage, 70% (1506/2138) of patients in
quintile 5 presented with stage I disease, as compared to 76%
(2281/3023) of patients in quintile 1 (p<0.001). Highly
marginalized patients were also less likely to be treated surgically for
their disease: 11% (332/3111) of patients in the highest
marginalization quintile did not receive surgery, as compared to 7%
(299/4107) of patients in the lowest quintile (p<0.001).
Figure 2 shows Kaplan-Meier survival curves of patients from diagnosis
of endometrial cancer, by summary marginalization quintile. Marginalized
patients had significantly worse overall survival (log-rank test,
p<0.001). 5-year survival was 77% (95% CI, 75-79) among the
most highly marginalized patients (quintile 5) as compared to 83% (95%
CI, 81-84) among the least marginalized patients (quintile 1),
p<0.001.
Regression analyses of patient- and disease-dependent factors associated
with overall survival are shown in Table 2. On univariable analysis,
income quintile, as well as two of three marginalization domains
assessed (material deprivation and residential instability), were
significantly associated with the risk of death (p<0.001 for
all), as was the summary marginalization score. On multivariable
analysis, after adjustment for year of diagnosis, age, Charlson score,
obesity, prior cancer diagnosis, disease histology and stage,
marginalization remained a significant independent predictor of
survival, with a hazard ratio of 1.05 per quintile for death (95% CI,
1.03-1.08, p<0.001). This translates into a hazard ratio of
1.22 when comparing the highest and lowest marginalization quintiles.
Individual marginalization indices, including material deprivation (Q5
vs Q1: HR=1.32, 95% CI, 1.19-1.46) and residential instability (Q5 vs
Q1: HR=1.22, 95% CI, 1.10-1.35) were also significantly associated with
death after adjustment for year of diagnosis, age, Charlson score,
obesity, prior cancer diagnosis, disease histology and stage (Table 3).
The ethnic concentration index was not found to be prognostic for the
risk of death either on univariable analysis or on multivariable
analysis.