Abstract
OBJECTIVE To study the clinicopathologic characteristics, changes in the nature and incidence of colorectal polyps in the Nanchang area, Jiangxi, Province.
METHODS We retrospectively investigated the patients with colorectal polyps who were diagnosed by colonoscopy and pathology in our hospital from 1990 to 2004. The analysis involved the incidence, average patient age, polyp location and pathological types. We recorded the changes of the polyp clinicopathologic features by comparing the clinicopathologic types of colorectal polyps over five-year periods.
RESULTS Of the 21,853 patients who received a colonoscopy, 2,889(13.2%) were diagnosed with colorectal polyps. Their average age was 46.6±16.5 years, with a male to female ratio of 1.8:1. The males were older than females (47.1±17.5 vs. 45.5±14.5, P<0.05). Location of the polyps: 41% in the rectum, 27.7% in the sigmoid colon, 35.8% in the left side verus 23.1% in the right side (P<0.05). Patients with polyps located in the transverse and ascending colon were older than those with polyps in the rectum and sigmoid colon (P<0.05). Adenomatous polyps comprised the most common type (67%) and the rectum was the most common site for each type, especially juvenile and retention polyps. Juvenile polyps were found in the youngest patients(12±4.8, P<0.05) and the adenomatous in the oldest (52±14, P<0.05). The ratio of patients with polyposis comprised 1.2%, and patients with polyps accompanied with colorectal cancer comprised 6.1%. Examination of the changes in the incidence, the average patient age, and adenomatous type showed that they had all increased, but the frequency of inflammatory and retention polyps decreased.
CONCLUSION Colorectal polyps are a common problem. The frequency is greater in males compared to females and the rectum and sigmoid colon had the highest incidence. Most juvenile and retention polyps were found in young patients, but most adenomatous occurred in adults. In recent years, the incidence of colorectal polyps, the average patient age, and the adenomatous type have increased in the Nanchang area, but inflammatory and retention types decreased.
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INTRODUCTION
The morbility from colorectal cancer has continued to increases with an advancement of the economy and improved living standards[1-3]. So for prevention and treatment of colorectal cancer it is important to investigate the clinicopathologic features of precancerous lesions and colorectal polyps. However, little information is known concerning the clinicopathologic aspects of colorectal polyps, especially from the Nanchang area of Jiangxi Province. Therefore we retrospectively investigated the polyps diagnosed by colonoscopy and pathology in Nanchang area patients. Our report is as follows.
MATERIALS AND METHODS
Patients and statistical index
Our retrospective analysis was conducted on 2,889 patients who were diagnosed with polyps by colonoscopy and pathology at the Endoscopic Center of the First Affiliated Hospital of Nanchang University (The Diagnosis and Treatment Center of Digestive Diseases of Jianxi). These patients were from a total of 21,853 who had undergone a colonoscopy over a 15-year period, from 1990 to 2004. Of the 21,853 patients who received a colonoscopy, 2,889 (13.2%) were diagnosed with colorectal polyps. The average age of patients with polyps was 46.6±16.5 years, ranging from 4 to 92 years, with a male to female ratio of 1.8:1 (1,875 to 1,014). The age period with the most patients was from 50 to 59 years and 60% of the patients ranged from 40 to 69 years. We assessed the incidence, age of onset, region of the polyps, and pathological type for five-year periods.
Diagnosis criterion and clinicopathological assessment
The polyps were classificated into the following pathological types: adenomatous, inflammatory polyp, falsification polyp, juvenile polyp, hyperplastic polyp, retention polyp, and polyposis. The locations of the polyps were classified into following regions: rectum, sigmoid colon, descending colon, splenic flexure, transverse colon, hepatic flexure, ascending colon, and ileocecal junction. The polyps were also classified into the rectum, left hemicolon (from the sigmoid colon to the splenic flexure ), and right hemicolon (from the transverse colon to the ileocecal junction).
Statistical analysis
Data are presented as the mean±SD, and the t-test was used to evaluate the differences. If the analysis of variance (ANOVA) revealed a significant difference among three or more groups, a paired t-test was used to evaluate the differences between any two groups. Chi-square analysis was also used to assess numerical data. The statistical analysis was done by using SPSS 10.0 software.
RESULTS
The patients’ symptoms included hematochezia (49%), abdominal pain (20%), constipation (12%), diarrhea (8%), abdominal distention (4%), anemia (4%), and others (3%).
The study of the 2,889 patients detected 3,625 polyps among which 25% had multiple polyps, 12% multiple polyps located in the same colon segment, and 13% multiple polyps located in a different colon segment. Female patients had more multiple polyps than male (P<0.05).
The location for the most (41%) polyps was the rectum, and then 27.7% in the sigmoid colon, 7.8% in the transverse colon, 7.2% in the ascending colon, 7% in the descending colon, 5.8% in the ileocecal junction, 2.3% in the hepatic flexure, 1.1% in the splenic flexure, 0.7% in the stoma. So the polyps located in the left hemicolon were significantly more than those found in the right hemicolon (35.8% vs. 23.1%, P<0.05).
The most pathological type was adenomatous (67%), and then 20.1% inflammatory, 8.6% retention, 2% juvenile, 0.4% hyperplastic, and 0.2% falsification polyps. There were 36 patients with polyposis (1.2%) (Fig.1).
Polyposis
The ratio of male to female patients did not change among the age groups (<20 years old, 10-year periods from 20 to 69, >70 years old). Males were older than females (47.1±17.5 vs. 45.5±14.5, P<0.05). The average age of patients with polyps in the transverse and ascending colons was significantly greater than those with polyps in the rectum and sigmoid colon. There was a significant difference in the ages of patients among the different pathological types. The average ages of patients were as follows: juvenile polyps, 12±4.8 years; retention polyps, 27±13.7; polyposis, 33.9±14.2; falsication polyps, 35±28.3; hyperplastic polyps, 41.7±10.5; inflammatory polyps, 43±13.8; adenomatous, 52±14. So juvenile polyps were common in juveniles, and adenomatous in middle and older people.
The male to female ratio was not significantly different among different pathological types (P>0.05), or among different lesion regions (P>0.05).
Different pathological types were most common in the rectum, especially retention and juvenile polyps. More polyps were found in the left than in the right hemicolon for each pathological type, with exception of inflammatory polyps (P<0.05).
Of the total 21,853 patients who received colonoscopy, 1,561 patients were diagnosed with colorectal cancer, 177 patients with polyps were associated with colorectal cancer, and 67 patients were diagnosed with malignant change (canceration) from polyps (Figs.2~4).
Protruding type polyp canceration
Protruding type polyp canceration
Flat type polyp canceration
When comparing the clinicopathologic features among each five-year period, the incidence of colorectal polyps in recent years has significantly increased (from 1.25% to 14.6%, P<0.01), the average patients age has also increased (from 44.5± 16 to 48.4±16, P<0.05), as well as adenomatous type, but retention and inflammatory polyps have declined. However, there was no significant alternation in the sex ratio and lesion region over the 15-year period.
Clinicopathological features of polyps in each five-year period.
DISCUSSION
Our results showed that 13.2% of the patients who received a colonoscopy in the Nanchang area had colorectal polyps with a male to female ratio of 1.8:1. The main symptoms of patients with polyps were hematochezia, abdominal pain, constipation, and diarrhea. The average patient age was 46.6±16.5, ranging from 4 to 92 years, with highest age period in 50 to 59 years. The average age of males was older than females, but that of females with multiple polyps were older than males. The average age of patients with transverse or ascending polyps was older than those with rectum or sigmoid polyps.
Most polyps were found in the rectum, then sigmoid colon, ascending and descending colon, ileocecal junction, hepatic flexure, and splenic flexure. Polyps in the left were more than in the right hemicolon among different pathological types, but opposite to inflammatory polyps. Adenomatous polyps were the most common pathological type, then inflammatory polyps, and retention polyps. Juvenile polyps and retention polyps were usually found in juveniles, but adenomatous, inflammatory polyps, and hyperplastical polyps were often found in middle age and older people. There were 177 patients (6.1%) with polyps associated with colorectal cancer, and 67 patients with polyps were diagnosed with canceration from polyps.
Among the studies reported from China, the number of patients with polyps in some studies were less than 1,000[4-8], and the incidence of colorectal polyps ranged from 10.06% to 13%, the male to female ratio ranged from 1.39:1 to 3.0:1, the average age ranged from 42.2 to 58 years, and the incidence of rectal polyps ranged from 21.8% to 67%[8-11]. Our results are similar to those studies in the incidence, the male to female ratio, symptoms, average patients age, and polyp location. However, the number of patients researched in our study was the largest among all reported studies, adenomatous polyps were more compared to other reports, and the patients with canceration from polyps were less. These results suggest that there is a difference in clinicopathologic features of polyps in different areas, and that the incidence of canceration from polyps is relatively low in the Nanchang area[12,13], which may indicate that people’s living standards in the Nanchang area are lower than in other cities.
Our results suggest that the incidence of colorectal polyps has significantly increased in recent years, the average age of patients with polyps has increased, the adenomatous type has enhanced, but retention polyps and inflammatory polyps have declined. However, there was no significant change in the sex ratio and lesion region over the 15-year period. The increase of average age may be related to population aging, because more patients were found in the age period from 50 to 69 years, which may also be one of reason why the incidence of polyps increases.
In conclusion, colorectal polyps are a common problem. The frequency is greater in males compared to females and the rectum and sigmoid colon had the highest incidence. Most juvenile and retention polyps were found in young patients, but most adenomatous occurred in adults. In recent years, the incidence of colorectal polyps, the average patient age, and the adenomatous type have increased in the Nanchang area, but inflammatory and retention types decreased.
- Received January 10, 2007.
- Accepted February 11, 2007.
- Copyright © 2007 by Tianjin Medical University Cancer Institute & Hospital and Springer
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