Table 2.
Characteristics of Medicare Beneficiaries Undergoing Resection for Stage II/III Colon Cancer
| Characteristic | Stage II With No Poor Prognostic Features (n = 6,234) |
Stage II With Any Poor Prognostic Features (n = 18,613) |
Stage III (n = 18,185) |
||||||
|---|---|---|---|---|---|---|---|---|---|
| No Chemo (n = 5,057) | Chemo (n = 1,177) | P | No Chemo (n = 14,779) | Chemo (n = 3,834) | P | No Chemo (n = 7,817) | Chemo (n = 10,368) | P | |
| Patient characteristics | |||||||||
| Age, years, % | < .001 | < .001 | < .001 | ||||||
| 65-69 | 10.2 | 25.4 | 7.7 | 21.6 | 5.0 | 19.4 | |||
| 70-74 | 18.5 | 30.1 | 15.9 | 31.5 | 11.2 | 29.6 | |||
| 75-79 | 24.7 | 28.8 | 23.1 | 28.0 | 20.2 | 29.0 | |||
| 80-84 | 25.7 | 11.7 | 25.7 | 13.7 | 28.5 | 16.7 | |||
| 85+ | 20.9 | 4.0 | 27.7 | 5.2 | 35.0 | 5.3 | |||
| Male sex, % | 41.6 | 49.5 | < .001 | 38.3 | 47.0 | < .001 | 36.3 | 45.2 | < .001 |
| Race/ethnicity, % | .005 | .09 | < .001 | ||||||
| White | 86.8 | 86.2 | 87.0 | 86.7 | 83.9 | 84.8 | |||
| Black | 5.8 | 4.1 | 6.2 | 5.4 | 8.0 | 6.3 | |||
| Asian or Pacific Islander | 3.9 | 5.8 | 3.3 | 3.7 | 4.4 | 5.0 | |||
| Hispanic or other | 3.5 | 4.0 | 3.6 | 4.2 | 3.7 | 4.0 | |||
| SEER registry, % | < .001 | < .001 | .02 | ||||||
| California | 27.2 | 29.1 | 29.1 | 27.6 | 28.0 | 26.9 | |||
| Connecticut | 12.1 | 6.9 | 10.5 | 8.3 | 10.3 | 9.8 | |||
| Detroit | 8.6 | 10.8 | 10.3 | 12.7 | 10.6 | 11.1 | |||
| Hawaii | 2.4 | 2.6 | 1.2 | 1.0 | 1.9 | 2.0 | |||
| Iowa | 12.6 | 13.0 | 14.7 | 13.6 | 13.0 | 12.2 | |||
| New Mexico | 2.7 | 2.5 | 2.3 | 2.3 | 2.8 | 2.7 | |||
| Seattle | 7.4 | 6.7 | 7.6 | 6.8 | 7.2 | 6.8 | |||
| Utah | 3.4 | 3.1 | 2.7 | 2.4 | 3.4 | 3.4 | |||
| Atlanta and rural Georgia | 4.0 | 4.8 | 3.8 | 4.1 | 3.9 | 3.9 | |||
| Kentucky | 5.4 | 5.4 | 4.2 | 5.4 | 5.0 | 5.0 | |||
| Louisiana | 4.0 | 4.3 | 4.1 | 5.0 | 3.9 | 4.6 | |||
| New Jersey | 10.3 | 10.9 | 9.6 | 11.0 | 10.1 | 11.6 | |||
| Marital status, % | < .001 | < .001 | < .001 | ||||||
| Married | 50.1 | 64.9 | 44.1 | 59.7 | 39.2 | 59.4 | |||
| Widowed | 35.3 | 21.7 | 40.8 | 25.7 | 45.1 | 25.9 | |||
| Single, separated, or divorced | 11.4 | 10.9 | 12.0 | 11.5 | 12.5 | 11.9 | |||
| Unknown | 3.2 | 2.6 | 3.1 | 3.1 | 3.1 | 2.8 | |||
| Residence location, % | .06 | .005 | .28 | ||||||
| Major metropolitan | 53.9 | 57.8 | 54.7 | 57.3 | 56.6 | 55.8 | |||
| Metropolitan or urban | 35.5 | 32.2 | 34.6 | 31.9 | 32.7 | 33.8 | |||
| Less urban or rural | 10.6 | 10.0 | 10.6 | 10.8 | 10.7 | 10.4 | |||
| Median household income (census tract), $ in thousands* | .07 | .01 | < .001 | ||||||
| Mean | 46.7 | 48.1 | 44.0 | 45.1 | 43.4 | 46.1 | |||
| SD | 23.3 | 23.9 | 21.7 | 22.1 | 21.0 | 22.5 | |||
| Less than 12-year education (census tract), %† | .97 | .61 | < .001 | ||||||
| Mean | 18.1 | 18.2 | 19.3 | 19.4 | 19.8 | 18.8 | |||
| SD | 12.1 | 12.3 | 12.5 | 12.9 | 12.9 | 12.5 | |||
| HCC comorbidity score | < .001 | < .001 | < .001 | ||||||
| Mean | 1.8 | 1.5 | 2.1 | 1.9 | 2.9 | 2.3 | |||
| SD | 1.2 | 1.1 | 1.4 | 1.2 | 1.6 | 1.3 | |||
| Tumor characteristics | |||||||||
| Year of diagnosis, % | < .001 | < .001 | < .001 | ||||||
| 1992-1995 | 18.5 | 16.9 | 23.2 | 21.3 | 22.6 | 18.2 | |||
| 1996-1999 | 18.6 | 19.7 | 21.5 | 22.5 | 19.8 | 20.1 | |||
| 2000-2002† | 28.2 | 35.3 | 28.9 | 32.0 | 27.4 | 31.2 | |||
| 2003-2005† | 34.7 | 28.0 | 26.4 | 24.2 | 30.1 | 30.5 | |||
| Tumor location, % | .002 | < .001 | < .001 | ||||||
| Right colon | 64.2 | 60.0 | 54.3 | 50.2 | 58.2 | 56.6 | |||
| Transverse colon | 10.1 | 8.6 | 11.8 | 10.8 | 10.9 | 9.1 | |||
| Left colon | 8.1 | 9.8 | 10.1 | 11.0 | 9.2 | 9.2 | |||
| Sigmoid colon | 16.0 | 20.0 | 22.4 | 26.4 | 20.0 | 23.5 | |||
| Unknown | 1.6 | 1.7 | 1.5 | 1.6 | 1.7 | 1.6 | |||
| Comorbidity and treatment measures, % | |||||||||
| Any hospitalization in the previous year | 28.1 | 19.0 | < .001 | 29.1 | 21.0 | < .001 | 32.7 | 22.0 | < .001 |
| Rehospitalization within 30 days of discharge | 11.0 | 8.4 | .009 | 12.8 | 9.2 | < 0.001 | 16.1 | 8.8 | < .001 |
| Any in-hospital surgical complication | 2.9 | 2.1 | .14 | 4.1 | 4.1 | .91 | 4.8 | 2.9 | < .001 |
| Oncologist visit within 30 days of surgery | 21.9 | 54.7 | < .001 | 23.3 | 54.6 | < .001 | 28.1 | 58.3 | < .001 |
| Poor prognostic features, % | |||||||||
| Emergent admission | 0.0 | 0.0 | 26.4 | 22.3 | < .001 | 26.6 | 16.9 | < .001 | |
| Intestinal obstruction on admission | 0.0 | 0.0 | 6.1 | 6.9 | .08 | 6.0 | 4.6 | < .001 | |
| Intestinal perforation on admission | 0.0 | 0.0 | 2.4 | 4.4 | < .001 | 2.7 | 1.6 | < .001 | |
| T stage | < .001 | < .001 | |||||||
| Tis, T0, T1, or T2 | 0.0 | 0.0 | 0.0 | 0.0 | 9.4 | 11.7 | |||
| T3 | 100.0 | 100.0 | 82.8 | 73.9 | 70.4 | 70.2 | |||
| T4 | 0.0 | 0.0 | 17.2 | 26.1 | 20.2 | 18.1 | |||
| No. of nodes resected, % | < .001 | < .001 | |||||||
| 0-11 | 0.0 | 0.0 | 72.5 | 69.5 | 50.7 | 47.8 | |||
| ≥ 12 | 100.0 | 100.0 | 27.5 | 30.5 | 49.3 | 52.2 | |||
| Tumor grade, % | .66 | .001 | .02 | ||||||
| Well differentiated | 8.5 | 8.1 | 7.4 | 6.9 | 4.8 | 5.0 | |||
| Moderately differentiated | 91.5 | 91.9 | 66.4 | 64.1 | 62.5 | 64.3 | |||
| Poorly or undifferentiated | 0.0 | 0.0 | 26.1 | 29.0 | 32.7 | 30.7 | |||
| No. of poor prognostic features, % | < .001 | < .001 | |||||||
| 0 | 100.0 | 100.0 | 0.0 | 0.0 | 19.4 | 24.0 | |||
| 1 | 0.0 | 0.0 | 60.5 | 56.5 | 39.0 | 43.2 | |||
| 2 | 0.0 | 0.0 | 30.1 | 31.0 | 28.1 | 23.7 | |||
| 3 | 0.0 | 0.0 | 7.9 | 10.7 | 10.9 | 7.6 | |||
| 4, 5, or 6 | 0.0 | 0.0 | 1.6 | 1.9 | 2.7 | 1.6 | |||
NOTE. Percentages may not sum to 100% due to rounding.
Abbreviations: Chemo, chemotherapy; SEER, Surveillance, Epidemiology, and End Results; SD, standard deviation; HCC, Hierarchical Condition Categories.
*
A total of 2,243 individuals with missing data are not included in these means.
†
Three SEER registries (Kentucky, Louisiana, New Jersey) were added in 2000.