Table 1: Characteristics of 6,862 patients diagnosed with stages II and III colorectal cancer, 1990–2010, by age at diagnosis.

⁢Age < 50 years
⁢ ()
⁢Age 50–69 years
⁢ ( = 3,018)
⁢Age ≥ 70 years
⁢ ( = 2,973)

Demographic characteristics
 White, non-Hispanic31761.4149071.5181081.0
 Black, non-Hispanic20013.363411.24496.7
 Medicare (only)1271.03519.168523.0
 Medicaid (any)1314.425410.63589.2
Clinicopathologic features
Tumor site
 Right colon17622.467931.995146.4
 Left colon11615.633215.137915.4
 Sigmoid colon13725.153622.248220.2
Stage at diagnosis
 Stage II36042.2143748.7153254.2
 Stage III51157.8158151.3144145.8
Histologic grade
 Well/moderately differentiated64078.7235282.2221673.4
Mucinous adenocarcinoma11011.12939.532111.5
Signet ring cell carcinoma120.8280.7291.2
MSI testing performed
Surgery type
 Local excision460.7160.5160.4
 Partial colectomy or proctectomy548056.4161950.5146641.1
 Subtotal colectomy24030.783938.4108050.6
 Total colectomy or proctectomy989.13466.52493.8
 Total proctocolectomy382.41633.41393.5
Lymph nodes examined
Socioeconomic indicators (census-tract-level)
SES index6
 Quintile 112215.837818.532217.2
 Quintile 211321.435020.327920.6
 Quintile 310919.532224.725917.5
 Quintile 411320.825116.027622.2
 Quintile 510422.627520.623822.6
Socioeconomic indicators (patient-level)
Hospital type
Teaching hospital
Total bed size
Clinical trial enrollment

Note. The table does not include patients who did not undergo cancer-directed surgery () or patients with incomplete staging information (); no variable had more than 10% missing data; missing observations range from 35 (tumor site) to 737 (clinical trial enrollment).
VA: Veterans Affairs; MSI: microsatellite instability; SES: socioeconomic status.
1Proportions weighted by sampling fraction.
2The term “rectal” includes both rectum and rectosigmoid junction.
3Microsatellite instability collected in 2010 only.
4Local excision includes excisional biopsy or polypectomy with or without photodynamic therapy, electrocautery, cryosurgery, laser ablation, laser excision, curette, and fulguration.
5Partial proctectomy includes low anterior resection and total mesorectal excision.
6Socioeconomic status based on composite census-tract-level indicators from Census 2000 and American Community Survey 2005–2009; limited to data collection years 2000, 2005, and 2010. Louisiana excluded due to Hurricanes Katrina and Rita’s impact on populations within Gulf Coast region in 2005.