Colorectal cancer in Guangdong Province of China: A demographic and anatomic survey

Table 1 Basic demography of study population (n = 8172)

Gender
Male:female	4841:3331
Mean age (yr)	56
Area
Pear River Triangle area	4327
East area	1583
West area	1480
North area	782

Table 2 Anatomic distribution of CRC (n = 8172)

	n	%
Rectum	4434	54.3
Sigmoid	1505	18.4
Descending	292	3.6
Splenic flexure	113	1.4
Transverse	485	5.9
Hepatic flexure	365	4.5
Ascending	703	8.6
Caecum	275	3.4
Total	8172	100

CRC: Colorectal cancer.

Table 3 Age group and location of CRC n (%)

Age group (yr)	Rectum	Left sided	Right sided	Total
≤ 30	301 (60.3)	102 (20.4)	96 (19.3)	499 (100.0)
31-40	496 (57.0)	194 (22.3)	179 (20.6)	869 (100.0)
41-50	786 (57.8)	297 (21.8)	278 (20.4)	1361 (100.0)
51-60	1067 (54.0)	499 (25.2)	411 (20.8)	1977 (100.0)
61-70	1201 (52.9)	534 (23.5)	536 (23.6)	2271 (100.0)
> 71	583 (48.8)	304 (25.4)	308 (25.8)	1195 (100.0)
Total	4434 (54.3)	1930 (23.6)	1808 (22.1)	8172 (100.0)

Significance was determined using Chi-squared tests (χ² = 39.223, P = 0.000).

Table 4 Mean age and year group in different areas

Yr	n	mean age (yr)	≤30 yr	31-40 yr	41-50 yr	51-60 yr	61-70 yr	≥71 yr	Male:female
1986-1988	462	52	37	62	101	153	82	47	1.7:1
1989-1991	532	55	41	69	104	159	125	34	1.7:1
1992-1994	866	56	56	116	158	251	208	77	1.6:1
1995-1997	1103	58	68	133	183	270	341	108	1.3:1
1998-2000	1523	59	85	138	267	358	447	228	1.5:1
2001-2003	1793	60	99	174	275	379	520	346	1.4:1
2004-2006	1893	60	113	177	273	407	548	375	1.5:1
	3.11	82	2.11	2.91	1.71	1.71	5.71	7.01	3

¹Increasing fold;

²Increasing years of mean age;

³χ² = 12.703, P = 0.013, the difference was significant.

Table 5 Anatomic distribution, histology type, differentiation degree of CRC in different areas n (%)

Areas	Rectum	Left sided	Right sided	Total	Tubular adenocarcinoma	Papillary adenocarci-noma	Other adenocarci-noma	Total	Well-and moderately-differentiated	Poorly-differentiated	Total
Pearl Triangle area	2349 (54.3)	1039 (24.0)	939 (21.7)	4327 (100.0)	3436 (79.4)	363 (8.4)	528 (1.4)	4327 (100.0)	2914 (81.6)	627 (18.4)	3571 (100.0)
East area	901 (56.9)	363 (22.9)	319 (20.2)	1583 (100.0)	1165 (73.6)	271 (17.1)	147 (1.6)	1583 (100.0)	878 (77.1)	261 (22.9)	1139 (100.0)
North area	415 (53.1)	173 (22.1)	194 (24.8)	782 (100.0)	484 (61.9)	124 (15.9)	174 (0.9)	782 (100.0)	299 (47.8)	326 (52.2)	625 (100.0)
West area	769 (52.0)	355 (24.0)	356 (24.0)	1480 (100.0)	1097 (74.1)	15 (10.1)	368 (4.7)	1480 (100.0)	829 (63.6)	474 (36.4)	1303 (100.0)
Total	4434 (54.3)	1930 (23.6)	1808 (22.1)	8172 (100.0)1	6182 (75.6)	773 (9.5)	1217 (2.0)	8172 (100.0)2	4920 (74.8)	1718 (25.2)	6638 (100.0)3

¹χ² = 13.307, P = 0.038;

²χ² = 459.561, P = 0.000;

³χ² = 409.296, P = 0.000.