Colorectal carcinoma over 30 years at one hospital: no evidence for a shift to the right

Reevaluation of a rightward shift in colorectal cancer: A single-center retrospective study in Tianjin

OBJECTIVES

Some Western reports have shown a proximal shift in colorectal cancer (CRC), but there are few studies in China. This study aimed to provide more information for the management and screening of CRC by investigating trends in the anatomic distribution of CRC among the Chinese population in recent years.

METHODS

A retrospective study was conducted on patients with CRC admitted to the Digestive Endoscopy Center of Tianjin Medical University General Hospital between January 2000 and December 2017. Patients were divided into a left-sided colorectal cancer (LSCRC) group and a right-sided colon cancer (RSCC) group. The detection rates of LSCRC and RSCC based on patients' age and sex, and on the time periods were analyzed.

RESULTS

A total of 2319 cases were diagnosed with CRC among 75 183 consecutive patients. The prevalence of CRC showed a significant reduction from 2000-2008 to 2009-2017 (3.8% vs 2.7%, P < .001). The proportion of RSCC presented a downtrend from 2000-2008 to 2009-2017 (40.6% vs 37.7%, P > .05). There were slightly more RSCCs in female patients than in male patients, with no significant difference (40.9% vs 36.5%, P > .05). The proportion of RSCC in patients aged ≥50 years was similar to that in younger patients. The alarming symptoms between LSCRC and RSCC showed a significant difference (P < .05).

CONCLUSIONS

In the present study, the prevalence of CRC declined significantly with time. However, there did not appear to be a rightward shift in CRC among the patients in Tianjin over the past 18 years.

Trends in colorectal incidence by anatomic subsite from 1985 to 2005: a population-based study

BACKGROUND

Conflicting results on the shift of right-left ratio in colon cancer incidence have been reported. We examine incidence trends by subsite in a population-based study.

MATERIALS AND METHODS

Colorectal cancer cases diagnosed in the 1985-2005 period were identified through the Tuscany Cancer Registry. Colon subsite was defined as proximal and distal; gender, age at diagnosis, histology, and stage were analyzed. Average annual incidence and age-specific rates according to subsite were calculated.

RESULTS

A total of 21,160 colorectal cancer cases were extracted; in 18,311 cases, the subsite was identified: 6,916 rectal, 5,239 proximal, and 6,156 distal. A larger proportion of distal colon cancers presented as early stage when compared with proximal. Incidence of rectal and distal colon cancer remained stable, while proximal colon cancer incidence increased.

CONCLUSIONS

Proximal colon cancer incidence rate increased through the period. Temporal variations in the incidence rate by subsite could suggest different carcinogenic pathways of right- and left-sided colon cancer.

Anatomical distribution of colorectal carcinoma in Iran: a retrospective 15-yr study to evaluate rightward shift

BACKGROUND

Although more than two third of colorectal cancers are localized on the left side, recent studies suggest a right ward shift in anatomical distribution with increase in proximal colon cancers. The aim of the present study was to determine the anatomical distribution of colorectal cancer in a referral center over a 15 year period.

METHOD

Records of patients who underwent colectomy in the Cancer Institute of Iran from 1994 to 2009 were retrieved. Data including anatomical localization, year of diagnosis, patient age and gender, tumor histology and differentiation, and disease stage were extracted. Tumors located from the cecum to the distal transverse colon were classified as right side and those occurring from the splenic flexure to the descending colon as left-sided. Cancer of rectum and recto-sigmoid junction were considered as rectal cancers.

RESULTS

A total of 442 patients including 220 (49/8%) men and 222 (50/2%) women with mean age 53 were included. Most patients were in stages II and III (47.1% and 33% respectively). There were 157 (35.5 %) colon cancers and 285 (64.5%) rectal cancers. 43.3% of the colon cancers were right sided and 56.7% were left sided. There was no statistically significant increase in right sided cancer during the period of the study. There were no significant differences in age at diagnosis, gender, grade and stage of tumor between the right and the left sided cancers.

CONCLUSION

No proximal shift over time was identified in our study.

Trends in colorectal cancer incidence rates in New Zealand, 1981-2004

BACKGROUND

Incidence rates of colorectal cancer (CRC) in New Zealand rank among the highest worldwide. Internationally, there has been evidence of a shift in colon cancer from left- to right-sided. The objective of this study was to determine trends in left- and right-sided colon and rectal cancers incidence by sex, age and ethnicity.

METHODS

Using datasets created by linking data from the New Zealand Cancer Registry to the census data, we analysed a total of 47,694 CRCs from 1981 to 2004. Cancers were divided into right-sided colon (cecum to the splenic flexure); left-sided colon (descending and sigmoid colon); and rectal (rectosigmoid junction and rectum).

RESULTS

Left- and right-sided colon, and rectal cancer incidence rates increased by 13-20% among men. In women, colon cancer rates increased by 25% for right-sided cancers, decreased by 8% for left-sided cancers and remained unchanged for rectal cancers. This corresponds with an increase in right-sided cancers from 57% to 65% of total colon cancers in women. The incidence of all CRCs increased at a faster rate among Māori than non-Māori.

CONCLUSION

We identified a left- to right-sided shift in colon cancer limited to women over the age of 65. While Māori trends in site distribution parallel those of their non-Māori counterparts, the rapid increase in Māori incidence rates is noteworthy. It is unclear why such shifts in CRC site distribution are occurring.

Distribution trends of colorectal adenoma and cancer: a colonoscopy database analysis of 11,025 Chinese patients

BACKGROUND AND AIM

A left-to-right shift of colorectal cancer (CRC) has been reported in Western studies. However, few Asian studies have investigated the anatomic distribution of colorectal adenoma and CRC. We aimed to describe the time trends in the distribution of colorectal adenoma and CRC in a Chinese population.

METHODS

A colonoscopy database was reviewed, and all consecutive patients with lower gastrointestinal symptoms who underwent colonoscopy from 1998 to 2009 were identified. Data, including patients' sex, age, symptoms, and the number and anatomic locations of colorectal adenoma and CRC, were documented.

RESULTS

A total of 11,025 patients were included in the final analysis; 1012 and 363 patients were diagnosed with colorectal adenoma and CRC, respectively. Overall, there were more distal than proximal adenomas (54.4% vs 37.9%), and the proportion of proximal adenomas remained stable from 1998-2006 to 2007-2009 (38.2% vs 37.6%). Similarly, there were more distal than proximal CRC (56.5% vs 42.4%), and the proportion of proximal CRC declined from 45.8% in 1998-2006 to 38.4% in 2007-2009. Colorectal adenoma and CRC were equally distributed among both sexes. For elderly patients (> 50 years), there was a non-significant trend towards more proximal adenoma and CRC.

CONCLUSIONS

The present study suggests no distal-to-proximal shift of colorectal adenoma and CRC among the Chinese population in Shanghai over the past 12 years. The distribution pattern of colorectal adenoma and CRC of Chinese patients is different from that of Western patients, who had more colorectal lesions located in the distal part.

Trends in colorectal cancer incidence in Norway 1962-2006: an interpretation of the temporal patterns by anatomic subsite

There have been rapid increases in the incidence of colorectal cancer in Norway since the 1960s, and rates rank among the highest worldwide. The primary objectives are to describe trends in left- and right-sided colon cancer and rectal cancer by calendar period and birth cohort and to generate hypotheses as to the etiological factors in operation. Although the age-adjusted incidence rates of both colon and rectal cancer increased in Norway in both sexes up to the 1980s, subsite- and age-specific analyses reveal a deceleration in the rate of increase thereafter, apparent in the rates of both left-sided colon and rectal cancer. Overall trends in incidence of right-sided colon cancer continue to increase in both sexes. Rates in both left- and right-sided colon cancers have tended to stabilize or decrease among successive generations born after 1950, however, while incidence rates of rectal cancer appear to be increasing in recent generations. The all-ages rates are thus in keeping with the commonly reported "left to right shift" of colon cancer, although standardization masks important observations. The cohort patterns provide further evidence that factors earlier in life are important, and while the complex etiology makes interpretation difficult, modifications in diet, obesity and physical activity in Norway are likely among the drivers of the trends in one or more of the colorectal subsites examined. In summary, the recent downturn in the disease at younger ages provides some reason for optimism, although possible increases in rectal cancer among recent birth cohorts are of concern.

Comparison of 17,641 patients with right- and left-sided colon cancer: differences in epidemiology, perioperative course, histology, and survival

PURPOSE

There is a growing amount of data suggesting that carcinomas of the right and left colon should be considered as different tumor entities. Using the data and analysis compiled in the German multicentered study "Colon/Rectum Cancer," we aimed to clarify whether the existing differences influence clinical and histological parameters, the perioperative course, and the survival of patients with right- vs left-sided colon cancer.

METHODS

During a 3-year period data on all patients with colon cancer were evaluated. Right- and left-sided cancers were compared regarding the following parameters: demographic factors, comorbidities, and histology. For patients who underwent elective surgery with curative intent, the perioperative course and survival were also analyzed.

RESULTS

A total of 17,641 patients with colon carcinomas were included; 12,719 underwent curative surgery. Patients with right-sided colon cancer were significantly older, and predominantly women with a higher rate of comorbidities. Mortality was significantly higher for this group. Final pathology revealed a higher percentage of poorly differentiated and locally advanced tumors. Rate of synchronous distant metastases was comparable. However, hepatic and pulmonary metastases were more frequently found in left-sided, peritoneal carcinomatosis in right-sided carcinomas. Survival was significantly worse in patients with right-sided carcinomas on an adjusted multivariate model (odds ratio, 1.12).

CONCLUSIONS

We found that right- and left-sided colon cancers are significantly different regarding epidemiological, clinical, and histological parameters. Patients with right-sided colon cancers have a worse prognosis. These discrepancies may be caused by genetic differences that account for distinct carcinogenesis and biological behavior. The impact of these findings on screening and therapy remains to be defined.

Colorectal cancer distribution in 220 Indian patients undergoing colonoscopy

AIM

Colorectal cancer is one of the major cancers in the developed world. The incidence of colorectal cancer is low in India. The aim of the present study was to describe the anatomical distribution and age at diagnosis of colorectal cancer in India.

METHODS

Retrospective descriptive analysis of anatomical distribution, age at diagnosis and demography of 220 cases (149 [67.7%] men) of adenocarcinoma of the colon or rectum diagnosed at colonoscopy over a period of five years.

RESULTS

The mean age at diagnosis was 58.4 years (SD 13.3; range 23-85 years). Twenty-eight (12.7%) cases were below the age of 40 years. The majority (31.8%) cases were aged between 61-70 years. Most of the tumors (n=163, 74%) were located distal to the splenic flexure. Multivariate logistic regression analysis showed that bleeding per rectum (OR 2.8; 95% CI 1.2-6.2) was associated with distal cancer, and palpable mass (OR 3.9; 95% CI 1.7-8.6) was associated with proximal cancer.

CONCLUSIONS

Almost one-third of the colorectal cancers in this series occurred in the seventh decade and were located distal to the splenic flexure.

Colorectal cancer, one entity or three

Understanding of the mechanism of colorectal carcinogenesis has been gaining momentum for some years on account of its high incidence and impact on the lives of individuals affected. Different genetic abnormalities have been found in colorectal cancers from different sites. For example, proximal colon cancer is usually related to the nucleotide instability pathway, as microsatellite instability (MSI). However, distal colon cancer is usually associated with specific chromosomal instability (CIN). The development of cancer at the rectum, though similar to that at the colon, displays its own unique features. These differences might be partially attributed to different embryological development and physiological circumstances. Environmental factors such as diet and alcohol intake also differ in their role in the development of tumors in the three segments, proximal colon, distal colon, and rectum. "Proximal shift" of colon cancer has been known for some time, and survival rates of colorectal cancer are higher when rectal cancers are excluded, both of which emphasize the three different segments of colorectal cancer and their different properties. Meanwhile, colonic and rectal cancers are distinctive therapeutic entities. The concept of three entities of colorectal cancer may be important in designing clinical trails or therapeutic strategies. However, the dispute about the inconsistency of data concerning the site-specific mechanism of colorectal carcinoma does exist, and more evidence about molecular events of carcinogenesis and targeted therapy needs to be collected to definitely confirm the conception.

The anatomical distribution of colorectal cancer in Korea: evaluation of the incidence of proximal and distal lesions and synchronous adenomas

OBJECTIVE

The incidence of colorectal cancer throughout the Republic of Korea has been rising over the last 25 years. The change in incidence is supposed to be due to the westernized life style. We evaluated the anatomical distribution of colorectal cancer and the properties of synchronous adenomatous polyps in the Korean population which were known to be different from those in Western countries.

MATERIALS AND METHODS

From January 1997 to December 2006, 896 cases of colorectal cancer were reviewed retrospectively.

RESULTS

A total of 25.1% were proximally located cancer with a modest female predominance (odds ratio 1.5). Synchronous adenomatous lesions were accompanied in 31.9% of all colorectal cancer cases. In the distal colorectal cancer patients, 18.8% had proximally located synchronous adenomas. In those with proximal colon cancer, only 20.5% of patients had distally located adenomas. The likelihood of a proximal colon cancer without distal sentinel lesions was higher in females (odds ratio 3.0).

CONCLUSION

There has been a steep rise in the incidence of colorectal cancer in Korea and distal colon cancer is more prevalent than in Western countries. However, as over 20% of proximal colon cancers can exist without distal colonic synchronous or sentinel lesions, a total colonoscopic examination should be considered first in surveillance.

The changing distribution of colorectal cancer in Barbados: 1985-2004

PURPOSE

Recent reports have suggested a shift to the right in older female patients of colon cancer. This is believed to be representative of more accessible national endoscopic screening programs.

METHODS

We report the demographic shift in colorectal cancer based on an analysis of resection specimens during four five-year time periods from 1985 to 2004 at the University Hospital, Barbados. Differences in population-based colorectal cancer incidence, age, gender, site, stage, and presentation (emergency vs. elective) are analyzed.

RESULTS

A total of 1,014 specimens obtained from 993 patients were analyzed, showing a progressive population-based increase in colorectal cancer in Barbados during this 20-year time period. There was an increase in right-sided tumors (P < 0.0001) without a concomitant decline in left-sided tumors. There was a significant increase in Dukes A cancers (P < 0.0001) without gender predilection. During the time period, there was a significant reduction in right-sided tumors presenting as emergencies (P < 0.005) without an effect of stage or gender.

CONCLUSIONS

There has been a steady increase in both right-sided and left-sided colonic cancers without gender predilection. The increase in early-stage tumors and reduction in emergency presentations during the latter part of the study suggests value in instituting a formal national colonoscopic screening program to assess its prospective effect on these parameters.

Colorectal cancer in Asians: a demographic and anatomic survey in Malaysian patients undergoing colonoscopy

BACKGROUND

Colorectal cancer is one of the most common forms of gastrointestinal cancer in the world today. In the Asia-Pacific area, it is the fastest emerging gastrointestinal cancer.

AIM

To determine the basic demographic features of patients with colorectal cancer and the anatomic distribution and characteristics of the tumour in a local Asian population.

METHODS

We conducted a review of consecutive patients who had undergone colonoscopy from 1999 to 2003 at the University of Malaya Medical Center, Kuala Lumpur, Malaysia.

RESULTS

Analysis was carried out on 3404 patients who underwent colonoscopy. A total of 228 patients (7%) were diagnosed with carcinoma. The mean age of diagnosis (+/-s.d.) was 64.4 +/- 13.1 years. The male to female ratio was 1.15. Polyps were noted in 470 patients (14%). Polyps detected concomitantly with a colorectal cancer were noted in 55 patients (2%). Four patients (0.1%) were diagnosed to have familial adenomatous polyposis coli. Of the 228 patients 209 (92%) had tumours at only one site whereas 19 (8%) had synchronous lesions. Tumours were mainly left sided [198 of 248 patients (80%)] with the majority located in the recto-sigmoid region. Detailed records of treatment were available only in 176 patients. A total of 147 of 176 patients (84%) underwent surgery and 50 (28%) also received adjuvant or palliative chemotherapy (28%). Seven of 154 patients (5%) were diagnosed to have stage A cancers, 64 (42%), stage B, 23 (15%), stage C and 60 (39%), stage D. Multivariate analysis using multiple logistic regression analysis showed that age > or =65 years (OR = 1.78; 95% CI: 1.35- 2.36) and Malay (OR = 2.09; 95% CI: 1.30-3.35) and Chinese (OR = 1.77; 95% CI: 1.77-2.69) race were significant independent predictive factors for colorectal cancer.

CONCLUSIONS

The demography of colorectal cancer is different from western patients. Tumours were mainly left sided in our patients. However, no differences in anatomic location were found between races, men and women and younger and older age groups. Colorectal cancer presented in an advanced stage in the majority of patients.

Anatomical distribution of colorectal cancer over a 10 year period in a district general hospital: is there a true "rightward shift"?

INTRODUCTION

Recent studies of patients with colorectal cancer have suggested a shift towards the proximal colon and an increase in the incidence of right sided colon cancer. This study aimed to determine the anatomical distribution of colorectal cancer over a 10 year period in a district general hospital.

METHODS

Records of patients diagnosed with primary colorectal cancer from 1993 to 2002 were reviewed for demographic data, histology subtype, and anatomical location of the tumour. Tumours located at and proximal to the splenic flexure were defined as right sided cancer and tumours arising distal to the splenic flexure were defined as left sided cancer.

RESULTS

A total of 763 patients were included in the study, of whom all had adenocarcinoma and 99% were white. Sixty nine percent of cancers were left sided and 31% were right sided. Although there was a 4% increase in the proportion of right sided cancers, there was no statistically significant increase using logistic regression analysis. Mann-Whitney U test revealed no significant difference in age at diagnosis between the right and left sided cancers. Although a higher proportion of females were diagnosed with right sided cancer compared with left sided cancer, this was not statistically significant.

CONCLUSION

The anatomical distribution of colorectal cancer has been fairly stable at this hospital with no evidence of a shift towards the proximal colon. No differences were identified in the tumour distribution with respect to gender and age at diagnosis. Our findings support the initial application of flexible sigmoidoscopy for investigating patients with suspected colorectal malignancy and follow up colonoscopy for selected patients to exclude right sided pathology.

Trend of incidence, subsite distribution and staging of colorectal neoplasms in the 15-year experience of a specialised cancer registry

BACKGROUND

Two-thirds of colorectal malignancies are localised in the left colon and rectum. Recent studies suggest a trend towards an increase of right-sided tumours which might have important implications for screening and surveillance. A colorectal cancer registry was set up in Modena, northern Italy, with the purpose of examining incidence, subsite distribution and staging of colorectal malignancies over a 15-year period.

PATIENTS AND METHODS

From 1984 to 1998, 2517 tumours in 2462 patients were detected and staged with the tumour node metastasis (TNM) system. The 'right colon' was considered from caecum to splenic flexure; the 'left colon' included descending and sigmoid colon; and the 'rectum' included rectosigmoid junction, ampulla and anus.

RESULTS

Cancer incidence showed an overall increase. Considering the various subsites, an increase of 33.7% in all colonic segments was shown whereas rectal tumours tended to decline. TNM staging showed a gradual increase of localised lesions (41.2% in 1984 versus 53.3% in 1998), with a proportional reduction of advanced tumours.

CONCLUSIONS

Our study indicates an increase of tumour incidence in all colonic segments more than a shift to the right colon. TNM staging tended to improve with an appreciable increase of localised lesions. These findings could be consequent to a more extensive use of colonoscopy.

Changes in colorectal cancer over a 15-year period in a single United States city

OBJECTIVE

The aim of this study was to identify colorectal cancer trends in different patient groups in one region.

METHODS

We reviewed the records of all patients with colorectal cancer who were seen at two hospitals in Columbia, SC, between 1981 and 1995. Patients were divided into three 5-yr cohorts (cohort 1, 1981-1985; cohort 2, 1986-1990; and cohort 3, 1991-1995). We recorded demographic data, histological type, tumor stage, grade, and survival.

RESULTS

A total of 1395 patients were diagnosed, of whom 1252 had adenocarcinoma. Mean age of diagnosis was 64.5 yr in black and 66 in white patients (p = 0.036). Adenocarcinoma proximal to the splenic flexure was found in 62% of women and 49% of men (p < 0.001), and in 51% of black and 44% of white patients (p = 0.08). Proximal cancers accounted for 61%, 48%, and 32% of cohorts 1, 2, and 3, respectively. The proportions of patients with advanced stage (III and IV) adenocarcinoma in the three cohorts were 54%, 47%, and 40%, respectively (p = 0.001). Median survival for adenocarcinoma was 23.7, 23.5, and 23.1 months in cohorts 1, 2, and 3 (p = 0.9).

CONCLUSIONS

The prevalence and demographics of colorectal cancer have been fairly stable at this center. There has been a significant decrease in proximal cancers. Although adenocarcinoma is being diagnosed at an earlier stage, this has not affected survival. Colonoscopy may be the most appropriate screening method in women and in black patients, in whom proximal cancers are more often found.

Continued change in the distribution of colorectal carcinoma

BACKGROUND

The aim of this study was to determine whether the previously reported shift in carcinoma from the left colon to the right colon has progressed.

METHODS

The charts of 2169 patients admitted to one institution between 1979 and 1994 with a diagnosis of colorectal carcinoma were reviewed retrospectively. The study was divided into four equal intervals. The large bowel was divided into five regions: right, transverse, left, sigmoid and rectum.

RESULTS

Right-sided lesions increased from 20.6 to 29.9 per cent (P = 0.001) and rectal lesions decreased from 22.0 to 11.3 per cent (P = 0.0002) from the first to the fourth study interval. The frequency of transverse, left and sigmoid colon lesions remained relatively constant.

CONCLUSION

The continuing trend of increased incidence of right-sided lesions and decreased incidence of rectal lesions was documented. Any screening examination for carcinoma requires total examination of the colon.