Proximal shift of colorectal cancer in the Australian Capital Territory over 20 years

Survival rates and prognostic factors in right- and left-sided colon cancer stage I-IV: an unselected retrospective single-center trial

PURPOSE

Colorectal cancer revealed over the last decades a remarkable shift with an increasing proportion of a right- compared to a left-sided tumor location. In the current study, we aimed to disclose clinicopathological differences between right- and left-sided colon cancer (rCC and lCC) with respect to mortality and outcome predictors.

METHODS

In total, 417 patients with colon cancer stage I-IV were analyzed in the present retrospective single-center study. Survival rates were assessed using the Kaplan-Meier method and uni/multivariate analyses were performed with a Cox proportional hazards regression model.

RESULTS

Our study showed no significant difference of the overall survival between rCC and lCC stage I-IV (p = 0.354). Multivariate analysis revealed in the rCC cohort the worst outcome for ASA (American Society of Anesthesiologists) score IV patients (hazard ratio [HR]: 16.0; CI 95%: 2.1-123.5), CEA (carcinoembryonic antigen) blood level > 100 µg/l (HR: 3.3; CI 95%: 1.2-9.0), increased lymph node ratio of 0.6-1.0 (HR: 5.3; CI 95%: 1.7-16.1), and grade 4 tumors (G4) (HR: 120.6; CI 95%: 6.7-2179.6) whereas in the lCC population, ASA score IV (HR: 8.9; CI 95%: 0.9-91.9), CEA blood level 20.1-100 µg/l (HR: 5.4; CI 95%: 2.4-12.4), conversion to laparotomy (HR: 14.1; CI 95%: 4.0-49.0), and severe surgical complications (Clavien-Dindo III-IV) (HR: 2.9; CI 95%: 1.5-5.5) were identified as predictors of a diminished overall survival.

CONCLUSION

Laterality disclosed no significant effect on the overall prognosis of colon cancer patients. However, group differences and distinct survival predictors could be identified in rCC and lCC patients.

Colorectal cancer-global burden, trends, and geographical variations

BACKGROUND

The aim of this study is to describe the trends and variations in the global burden of colorectal cancer (CRC).

METHODS

Data (2012-2030) relating to CRC was extracted from GLOBOCAN 2012 database and analyzed.

RESULTS

The results of our study demonstrate a rising global burden of colorectal cancer which persists until the year 2035 and likely beyond. The rise in the global burden is not uniform with significant variations influenced by geographic location, socio-economic status, age, and gender. Although the EURO region has the highest burden, Asia as a continent continues to bear the heaviest brunt of the disease. Although the burden of disease is higher in more developed regions, mortality is considerably higher in less developed regions and this gap widens over the next two decades. The disease predominantly affects the male gender across all regions of the world. Age has a complex relation with the burden of CRC and is affected by the cross-influences relating to socio-economic status.

CONCLUSIONS

The results of our study demonstrate a rising global burden of CRC with some unique variations. Knowledge of this data can increase awareness and help strategic targeting of efforts and resources.

Colorectal cancer incidence in 5 Asian countries by subsite: An analysis of Cancer Incidence in Five Continents (1998-2007)

Colorectal cancer is the fourth most common cancer in Asia. However, the trends in colorectal cancer incidence by subsite have not been analyzed across Asian countries. We used the most recent, high quality data from 6 cancer registries for two 5-year periods, 1998-2002 and 2003-2007, from Cancer Incidence in Five Continents to estimate colorectal cancer incidence by subsite in 5 Asian countries. Cases with overlapping lesions or otherwise unspecified colon cancer were re-distributed as proximal or distal colon cancer. Age-standardized incidence rates (ASRs) per 100,000 population and incidence rate ratios from 1998 to 2002 to 2003-2007 were calculated for each subsite. For 2003-2007, men in Miyagi, Japan, had the highest ASR for cancer in the proximal colon, distal colon and rectum. Men of Jewish ancestry in Israel had a high ASR for proximal and distal colon cancer, but the lowest ASR for rectal cancer. The proportion of rectal cancer was highest among Korean men (51.39%) and lowest among Israeli women (26.6%). From 1998-2002 to 2003-2007, rectal cancer incidence did not significantly change in most registries, except for men in Miyagi, Japan, and both sexes in Korea. However, during the same period cancer incidence in the proximal and distal colon increased in most registries. In conclusion, there was substantial variation in subsite distributions of colorectal cancer in Asian registries and increases in overall incidence of colorectal cancer could be attributed to increases in colon cancer.

Rectal and colon cancer: Not just a different anatomic site

Due to differences in anatomy, primary rectal and colon cancer require different staging procedures, different neo-adjuvant treatment and different surgical approaches. For example, neoadjuvant radiotherapy or chemoradiotherapy is administered solely for rectal cancer. Neoadjuvant therapy and total mesorectal excision for rectal cancer might be responsible in part for the differing effect of adjuvant systemic treatment on overall survival, which is more evident in colon cancer than in rectal cancer. Apart from anatomic divergences, rectal and colon cancer also differ in their embryological origin and metastatic patterns. Moreover, they harbor a different composition of drug targets, such as v-raf murine sarcoma viral oncogene homolog B (BRAF), which is preferentially mutated in proximal colon cancers, and the epidermal growth factor receptor (EGFR), which is prevalently amplified or overexpressed in distal colorectal cancers. Despite their differences in metastatic pattern, composition of drug targets and earlier local treatment, metastatic rectal and colon cancer are, however, commonly regarded as one entity and are treated alike. In this review, we focused on rectal cancer and its biological and clinical differences and similarities relative to colon cancer. These aspects are crucial because they influence the current staging and treatment of these cancers, and might influence the design of future trials with targeted drugs.

A comparative study of colorectal surgical outcome in a national audit separated by 15 years

AIM

The Wales-Trent Bowel Cancer Audit (WTBA) was carried out in 1993, and since 2001 Welsh Bowel Cancer Audits (WBCA) have taken place annually. Screening for bowel cancer in Wales was introduced in 2008. This study compared patient variables, the role of surgery and operative mortality rates over the 15-year interval between the WTBA and the last WBCA before the introduction of population screening.

METHOD

Data from the WTBA in 1993 were compared with those of the WBCA including patients diagnosed between April 2007 and March 2008.

RESULTS

In 1993, 1536 patients were diagnosed with colorectal cancer (CRC) compared with 1793 in 2007-2008. Patient demographics and American Society of Anesthesiology (ASA) score did not change during these periods. Surgical treatment for CRC decreased (93% in 1993 vs 80% in 2007-2008; P < 0.001) particularly in the use of resectional surgery (84% in 1993 vs 71% in 2007-2008; P < 0.001). The 30-day postoperative mortality rate fell from 7.4% in 1993 to 5.9% in 2007-2008 (P = 0.097). Advanced disease at operation was more prevalent in the WTBA (25% of all operated patients were Stage IV in 1993 vs 13% in 2007-2008; P < 0.001). The use of surgery in patients with metastatic disease also declined over this period.

CONCLUSION

Surgery is used less frequently in the management of CRC compared with 15 years previously, and is a factor in the reduction of the interpreted 30-day operative mortality.

Increasing prevalence of advanced colonic polyps in young patients undergoing colonoscopy in a referral academic hospital in Hong Kong

AIM: To investigate the distribution and frequency of advanced polyps over eight years.

METHODS: 6424 colonoscopies were reviewed during the study period 1998 to 2005. The study period was subdivided into period I: 1998 to 2001 and period II: 2002-2005.

RESULTS: 1856 polyps (33% advanced polyps) and 328 CRCs were detected. The mean ages of the patients with advanced polyps and cancer were 69.2 ± 12.0 and 71.6 ± 13.8 years, respectively. Advanced polyps were mainly left sided (59.5%). Advanced polyps were found in patients ≤ 60 years from 17.7% in periodI to 26.3% in period II (P < 0.05), especially in male subjects ≤ 60 years (21.6% vs 31.6%, P < 0.05). Advanced tubulovillous polyps rose from 21.5% in period I to 29.5% in period II (P < 0.05). Whereas cancers in male patients ≤ 60 years were similar in both periods: 23.2% vs 16.5% (P > 0.05).

CONCLUSION: Advanced polyps increased significantly in the younger male group in the most recent period and there seems to be a shift towards a proximal location.

Prospective audit of colorectal resections in a peripheral public hospital

BACKGROUND

Colorectal disease requiring surgery is common in New Zealand where there is no established national colorectal screening programme. We established an audit to review our current practice in colorectal surgery.

METHODS

Prospective audit data were collected on consecutive patients undergoing colorectal resection between April 2003 and December 2004, using a standardized pro forma.

RESULTS

In all, 170 colorectal resections were carried out of which 117 (69%) were for malignancy and 120 (71%) were elective. Median patient age was 72 years (interquartile range 62-78 years) and median length of stay was 10 days (interquartile range 8-14 days). Colonoscopy was the most common method of investigation. In elective patients with malignancy, the average delay between onset of symptoms and surgery was 25 weeks. Duke's stage C was the most common stage at presentation (44%). Complications developed in 83 (49%) of patients including 20 (12%) patients returned to theatre, 5 (3%) anastomotic leaks and 8 deaths (5%). In patients undergoing surgery aged over 80 (n = 40) the median length of stay was 10 days (7-14) with a complication rate of 21 (55%) including 5 (13%) who were returned to theatre and 6 (16%) deaths.

CONCLUSION

This audit has confirmed that there is an acceptable level of care at Taranaki Base Hospital when compared with those in published work. Elective patients with malignancy have a delay of nearly 6 months between the onset of symptoms and surgery. Patients in Taranaki are more likely to present with an advanced stage of tumour compared with other unscreened populations.

Changing sites of colorectal cancer in the Israeli Jewish ethnic populations and its clinical implications

Countries at risk for colorectal cancer noted an increase in right-sided colorectal cancer. We examined this in the Israeli Jewish populations. Israel Cancer Registry data, 1982-2001, were computed by sex, age, ethnic group and colorectal cancer site: 'rectal cancer' included the recto-sigmoid junction, 'right-sided' colorectal cancer included proximal colon up to and including the splenic flexure. In both sexes, colorectal cancer trends increased significantly owing to colonic cancer (P<0.01) whereas rectal cancer decreased (P<0.01). Left and right colorectal cancer trends decreased in Israel born people (P<0.01), but in Asia-Africa born people increases were seen at both sites in the male (P=0.02 and 0.06, respectively) and female (P=0.03 and 0.01, respectively) population. In those > or =65 years old, right colorectal cancer trends increased in all men (P=0.05) and women (P=0.01). On comparing data from 1982-1986 with that from 1997-2001 right colorectal cancer showed an increase in both sexes (P<0.01): to 32.7% of male colorectal cancer and 57.6% of female colorectal cancer. In the period 1997-2001, the total male population > or =65 years had increased relatively by 7.5% (P<0.01), and women by 22.6% (P<0.01) and the proportion of right colorectal cancer in > or =65 years olds increased relatively by 10.9% in the male population, and 18.2% in the female population, with one-third of this increase occurring in Russian immigrants arriving after 1990. In conclusion, there is a trend for right colorectal cancer in Jews aged > or =65 years. The proportion and amount of colorectal cancer increased most significantly in older women, which was partially explained by their increasing numbers and by colorectal cancer occurring in recent immigrants from Russia, who were at high-risk for colorectal cancer. These results should influence colorectal cancer screening and diagnostic methodologies used.

Thirty-day mortality after surgery for colorectal cancer in Denmark

OBJECTIVE

This study aimed to estimate the 30-day mortality after colorectal cancer (CRC) surgery in Denmark. Mortality was compared to other studies, and between departments, unadjusted and adjusted for case-mix.

MATERIALS AND METHODS

All patients in Denmark with a first-time colorectal adenocarcinoma operated between 1 May 2001 and 31 December 2002 were eligible, 5187 patients were included. Mortality was adjusted for age, sex, urgency, tumour location, Dukes' stage and ASA-score.

RESULTS

The 30-day mortality in Denmark after CRC-surgery was 9.9%. Adjusted for case-mix, four departments had significantly higher mortality than average. The variation between the 44 departments was significant both for radically operated (P = 0.02) patients and for all operated patients (P = 0.01).

CONCLUSION

The 30-day mortality in Denmark seems to be higher than in studies from other countries, but the lack of comparable nationwide studies makes it difficult to evaluate. To uncover the reasons for the departments to diverge significantly from average, further studies are needed.

Environmental factors affect colon carcinoma and rectal carcinoma in men and women differently

BACKGROUND AND AIMS

Colon cancer is thought to be more closely associated with environmental factors than rectal cancer, but evidence is currently insufficient. We examined whether there are differences in the degree of environmental effect on colon cancer and rectal cancer in Japan.

METHODS

We performed a birth cohort analysis for colon and rectal cancers using Japanese vital statistics from 1950 to 1998 and analyzed time trends by cancer site and gender.

RESULTS

The mean annual increase in age-adjusted mortality rate from colon cancer was greater than that from rectal cancer and was greater in men than in women. In men left colon cancer showed the greatest rate of increase whereas cancer of the right colon showed only a slight change. Although left colon cancer rapidly increased until the middle 1980s and thereafter showed no change, right colon cancer showed no change until the middle 1980s and thereafter rapidly increased in men. However, the rates of increase in left colon cancer were greater than those in right colon cancer until the middle 1980s, after which a reversal in trend was seen in women. Birth cohort analysis indicates that for all cohorts the mortality rates at the same age were higher in the recent cohorts than in the previous ones. This trend was more marked for colon cancer than for rectal cancer and was stronger among men than among women.

CONCLUSION

Colon cancer is more closely associated than rectal cancer with environmental factors, and this association is more pronounced in men than in women. Consequently cancers at these two sites should not be combined in studies of the role of lifestyle factors in causing these neoplasms. Furthermore, the causes of these diseases may differ in men and women.

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Racial differences in the anatomical distribution of colorectal cancer: a study of differences between American and Chinese patients

AIM: To compare the racial differences of anatomical distribution of colorectal cancer (CRC) and determine the association of age, gender and time with anatomical distribution between patients from America (white) and China (oriental).

METHODS: Data was collected from 690 consecutive patients in Cleveland Clinic Florida, U.S.A. and 870 consecutive patients in Nan Fang Hospital affiliated to the First Military Medical University, China over the past 11 years from 1990 to 2000. All patients had colorectal adenocarcinoma diagnosed by histology and underwent surgery.

RESULTS: The anatomical subsite distribution of tumor, age and gender were significantly different between white and oriental patients. Lesions in the proximal colon (P < 0.001) were found in 36.3% of white vs 26.0% of oriental patients and cancers located in the distal colon and rectum in 63.7% of white and 74% of oriental patients (P < 0.001). There was a trend towards the redistribution from distal colon and rectum to proximal colon in white males over time, especially in older patients (> 80 years). No significant change of anatomical distribution occurred in white women and Oriental patients. The mean age at diagnosis was 69.0 years in white patients and 48.3 years in Oriental patients (P < 0.001).

CONCLUSION: This is the first study comparing the anatomical distribution of colorectal cancers in whites and Chinese patients. White Americans have a higher risk of proximal CRC and this risk increased with time. The proportion of white males with CRC also increased with time. Chinese patients were more likely to have distal CRC and developed the disease at a significantly earlier age than white patients. These findings have enhanced our understanding of the disease process of colorectal cancer in these two races.

Are there two sides to colorectal cancer?

Colorectal carcinomas (CRC) that arise proximal (right) or distal (left) to the splenic flexure exhibit differences in incidence according to geographic region, age and gender. Together with observations that tumours in the hereditary cancer syndromes HNPCC and FAP occur predominantly in the right and left colon, respectively, the existence of 2 categories of CRC based on site of origin in the large bowel was proposed more than a decade ago. Differences between normal right and left colonic segments that could favour progression through different tumourigenic pathways are summarized in this review. Accumulating evidence suggests that the risk of CRC conferred by various environmental and genetic factors is different for proximal and distal tumours. Right- and left-sided tumours also exhibit different sensitivities to fluorouracil-based chemotherapy. Such differences are probably related to the molecular characteristics of the tumours, with the microsatellite instability and CpG island methylator phenotypes being associated with right-sided tumours and chromosomal instability with left-sided tumours. Future molecular-based classification systems for CRC that rely upon distinctive gene expression patterns may allow a clearer discrimination of subgroups than that provided by tumour site alone. Until then however, the existence of 2 broadly different groups of cancer defined by site of origin in the colon should be considered in the design of future epidemiologic studies as well as in the design of new clinical trials aimed at testing novel adjuvant therapies.

Different mechanisms in the tumorigenesis of proximal and distal colon cancers

Environment or genetic constitutions can lead to an increase of genetic or epigenetic events and increase the risk for malignancy. Genomic instability is seen in most types of malignancies. Two forms of genetic instability have been described in colorectal cancer: chromosomal instability (CIN), and microsatellite instability (MIN). Almost all sporadic MIN tumors occur in the proximal colon, whereas most sporadic CIN tumors are distributed in the distal colon. The two familial syndromes, familial adenomatous polyposis and Lynch syndrome, constitute models for the different carcinogenic mechanisms in CIN and MIN tumors, respectively. This article reviews the principal differences between CIN and MIN tumors, evidence for a proximal and distal route in carcinogenesis, gender differences, and aspects of methylation in CIN and MIN colorectal tumorigenesis.