Patterns of Sociodemographic and Clinicopathologic Characteristics of Stages II and III Colorectal Cancer Patients by Age: Examining Potential Mechanisms of Young-Onset Disease

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)
		Weighted^1%		Weighted^1%		Weighted^1%
Demographic characteristics
Sex
Male	472	54.0	1685	56.0	1377	44.3
Female	399	46.0	1333	44.0	1596	55.7
Race/ethnicity
White, non-Hispanic	317	61.4	1490	71.5	1810	81.0
Black, non-Hispanic	200	13.3	634	11.2	449	6.7
Hispanic	189	14.7	495	9.7	386	6.7
Other	165	10.5	399	7.6	328	5.6
Insurance
Private/HMO/VA/other	637	78.9	2214	76.8	1848	67.2
Medicare (only)	127	1.0	351	9.1	685	23.0
Medicaid (any)	13	14.4	254	10.6	358	9.2
None	75	5.8	128	3.6	21	0.6
Clinicopathologic features
Tumor site
Right colon	176	22.4	679	31.9	951	46.4
Left colon	116	15.6	332	15.1	379	15.4
Sigmoid colon	137	25.1	536	22.2	482	20.2
Rectum^2	433	36.9	1456	30.8	1140	18.0
Stage at diagnosis
Stage II	360	42.2	1437	48.7	1532	54.2
Stage III	511	57.8	1581	51.3	1441	45.8
Histologic grade
Well/moderately differentiated	640	78.7	2352	82.2	2216	73.4
Poorly/undifferentiated	186	21.3	526	17.8	641	26.6
Mucinous adenocarcinoma	110	11.1	293	9.5	321	11.5
Signet ring cell carcinoma	12	0.8	28	0.7	29	1.2
MSI testing performed
Yes	68	27.3	83	9.7	44	7.1
No	140	72.7	540	90.3	423	92.9
Unknown	23		29		15
Treatment
Surgery type
Local excision^4	6	0.7	16	0.5	16	0.4
Partial colectomy or proctectomy^5	480	56.4	1619	50.5	1466	41.1
Subtotal colectomy	240	30.7	839	38.4	1080	50.6
Total colectomy or proctectomy	98	9.1	346	6.5	249	3.8
Total proctocolectomy	38	2.4	163	3.4	139	3.5
Other	9	0.7	35	0.7	23	0.6
Lymph nodes examined
0	24	1.8	89	2.0	73	1.7
1–11	258	25.8	1302	37.8	1499	45.0
≥12	560	72.4	1537	60.2	1297	53.3
Socioeconomic indicators (census-tract-level)
SES index^6
Quintile 1	122	15.8	378	18.5	322	17.2
Quintile 2	113	21.4	350	20.3	279	20.6
Quintile 3	109	19.5	322	24.7	259	17.5
Quintile 4	113	20.8	251	16.0	276	22.2
Quintile 5	104	22.6	275	20.6	238	22.6
Socioeconomic indicators (patient-level)
Hospital type
Private	67	11.9	238	7.2	247	10.1
Government	182	16.1	540	17.4	387	13.5
Nonprofit	621	72.0	2212	75.4	2313	76.4
Teaching hospital
No	370	45.2	1397	51.9	1564	53.9
Yes	498	54.8	1585	48.1	1374	46.1
Total bed size
<200	194	26.1	676	25.1	710	27.2
200–400	336	39.3	1330	43.2	1335	43.6
≥400	339	34.6	982	31.6	895	29.2
Clinical trial enrollment
No	728	91.7	2494	94.4	2583	98.2
Yes	67	8.3	179	5.6	74	1.8

.
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.