What is the risk factor for metachronous colorectal carcinoma?

Risk factors for metachronous colorectal cancer and advanced neoplasia following primary colorectal cancer: a systematic review and meta-analysis

BACKGROUND

Identifying risk factors for metachronous colorectal cancer (CRC) and metachronous advanced neoplasia could be useful for guiding surveillance. We conducted a systematic review and meta-analysis to investigate risk factors for metachronous CRC and advanced neoplasia.

METHODS

Searches were conducted in MEDLINE, Embase, Web of Science and Cochrane Central Registry of Controlled Trials for articles (searching period: 1945 to Feburary, 2021) that reported the results of an association between any factor and metachronous advanced neoplasia or metachronous CRC. There were no restrictions on the publication date or language. Random effects models were fitted to estimate the combined association between the risk factors and metachronous CRC or advanced neoplasia. The Risk of Bias In Non-Randomised Studies of Interventions tool (ROBINS-I) was used to assess the risk of bias of included studies.

RESULTS

In total, 22 observational studies with 625,208 participants were included in the systematic review and meta-analysis. Of these, 13 studies investigated risk factors for metachronous CRC and 9 for advanced neoplasia. The risks of metachronous CRC or advanced neoplasia were higher if the first CRC was diagnosed in the presence of a synchronous advanced lesion (pooled risk ratio (RR) from 3 studies: 3.61, 95% confidence interval (CI): 1.44-9.05; and pooled RR from 8 studies: 2.77, 95% CI: 2.23-3.43, respectively). The risk of metachronous CRC was lower, but the risk of metachronous advanced neoplasia was higher if the first CRC was distal (compared with proximal) (pooled RR from 3 studies: 0.48, 95% CI: 0.23-0.98; and pooled RR from 2 studies: 2.99, 95% CI: 1.60-5.58 respectively). The risk of metachronous advanced neoplasia increased with age (pooled RR from 3 studies: 1.07 per year of age, 95% CI: 1.03-1.11). There was no evidence that any lifestyle risk factors studied were associated with the risk of metachronous CRC or advanced neoplasia.

CONCLUSIONS

The identified risk factors for metachronous CRC and advanced neoplasia might be useful to tailor the existing surveillance guidelines after the first CRC. There were potential limitations due to possible misclassification of the outcome, confounding and risk of bias, and the findings cannot be generalised to high-risk genetic syndrome cases.

Surgical outcomes of left hemicolon sparing resection versus extensive resection in treating synchronous colorectal cancer involving the right-sided colon and sigmoid colon or rectum

BACKGROUND

There are different surgical strategies that can treat synchronous colorectal cancer (SCRC) involving separate segments, namely extensive resection (EXT) and left hemicolon-sparing resection (LHS). We aim to comparatively analyze short-term surgical results, bowel function, and long-term oncological outcomes between SCRC patients treated with the two different surgical strategies.

METHODS

One hundred thirty-eight patients with SCRC lesions located in the right hemicolon and rectum or sigmoid colon were collected at the Cancer Hospital, Chinese Academy of Medical Sciences, and the Peking University First Hospital from January 2010 to August 2021 and divided into EXT group (n = 35) and LHS group (n = 103), depending on their surgical strategies. These two groups of patients were compared for postoperative complications, bowel function, the incidence of metachronous cancers, and prognosis.

RESULTS

The operative time for the LHS group was markedly shorter compared with the EXT group (268.6 vs. 316.9 min, P = 0.015). The post-surgery incidences of total Clavien-Dindo grade ≥ II complications and anastomotic leakage (AL) were 8.7 vs. 11.4% (P = 0.892) and 4.9 vs. 5.7% (P = 1.000) for the LHS and EXT groups, respectively. The mean number of daily bowel movements was significantly lower for the LHS group than for the EXT group (1.3 vs. 3.8, P < 0.001). The proportions of no low anterior resection syndrome (LARS), minor LARS, and major LARS for the LHS and EXT groups were 86.5 vs. 80.0%, 9.6 vs. 0%, and 3.8 vs. 20.0%, respectively (P = 0.037). No metachronous cancer was found in the residual left colon during the 51-month (median duration) follow-up period. The overall and disease-free survival rates at 5 years were 78.8% and 77.5% for the LHS group and 81.7% and 78.6% for the EXT group (P = 0.565, P = 0.712), respectively. Multivariate analysis further confirmed N stage, but not surgical strategy, as the risk factor that independently affected the patients' survival.

CONCLUSIONS

LHS appears to be a more appropriate surgical strategy for SCRC involving separate segments because it exhibited shorter operative time, no increase in the risk of AL and metachronous cancer, and no adverse long-term survival outcomes. More importantly, it could better retain bowel function and tended to reduce the severity of LARS and therefore improve the post-surgery life quality of SCRC patients.

Second Cancer After Additive Chemotherapy in Patients With Colon Cancer

BACKGROUND

Additive chemotherapeutic treatment of UICC-stage -III / IV colon cancer with fluorouracil, leucovorin and oxaliplatin is widely accepted as current standard of treatment after R0-resection. However, as patients.. survival is increasing, long-term side effects of chemotherapeutic agents such as second cancer development are becoming increasingly important.

PATIENTS

We therefore investigated a total of 2 856 Patients with UICC-stage III / IV colon cancer, 223 of whom (7.8%) had developed a subsequent second cancer.

RESULTS

Median follow-up was 73.2 months (range 209.9 months, 95%-CI 69.8-76.9). Most frequent second cancers were prostate cancer (18.4%), colon cancer (16.1%), breast cancers (8.1%), lung cancer (8.1%), rectal cancer (4.9%) and uterine cancer (4.9%). However, in comparison to non-treated patients this did not represent a significantly increased risk for subsequent second cancer in patients after treatment with additive chemotherapy. Of interest, our data suggest a significantly decreased second cancer rate in patients treated with FOLFOX compared to FUFOL for additive treatment.

CONCLUSIONS

Second cancer development was not increased after additive chemotherapy for colon cancer, which is a novel aspect in the ongoing discussions on reduction of adjuvant treatment to 3 months or treatment of lymph node negative patients. Novelty and Impact Statement To our knowledge, this is the first population-based study analyzing second cancer development after additive chemotherapy in patients with UICC III-IV colon cancer. The results have an important impact on the surveillance and long-term follow-up of cancer patients.

[Prevention of gastrointestinal cancer]

Throughout the past decades, considerable progress has been made in the (early) diagnosis and treatment of gastrointestinal cancers. However, the prognosis for advanced stages of gastrointestinal tumors remains limited for many patients and approximately one third of all tumor patients die as a result of gastrointestinal tumors. The prevention and early detection of gastrointestinal tumors is therefore of great importance.For this reason, we summarize the current state of knowledge and recommendations for the primary, secondary and tertiary prevention of esophageal, stomach, pancreas, liver and colorectal cancer in the following.

Metachronous advanced neoplasia after submucosal invasive colorectal cancer resection

Little is known about the incidence of metachronous advanced neoplasia (AN) following resection of submucosal invasive colorectal cancer (SM-CRC). Here, we aimed to assess the occurrence of metachronous AN following SM-CRC resection. We retrospectively reviewed consecutive patients who underwent SM-CRC resection at an academic medical center between 2005 and 2013. Among 343 patients, 250 (72.9%) underwent surgical resection or endoscopic resection followed by surgical resection and 93 (27.1%) underwent only endoscopic resection. During a median follow-up period of 61.5 months, the overall incidence of metachronous AN was 7.6%, and the cumulative incidence at 5 years was 6.1%. The cumulative incidence was significantly higher in the endoscopic resection group than in surgical resection group, in patients with colonic disease than in those with rectal disease, and in patients with synchronous AN than in those without. Multivariate analysis revealed that synchronous AN was the only significant risk factor for metachronous AN (HR 4.35; 95% CI 1.88–10.1). These findings imply that depending on synchronous AN, a surveillance protocol following SM-CRC resection can be changed for better detection of metachronous AN.

[Influence of primary lymph node status of colorectal cancer on the development of pulmonary metastases and thoracic lymph node metastases]

BACKGROUND

The lungs are the second most common organ site for metastases in patients with colorectal cancer (CRC). Lymph node metastasis of CRC represents a prognostic factor for survival.

OBJECTIVE

The present study investigated the influence of CRC lymph node metastasis on lung metastasis, in particular thoracic lymph node metastasis.

MATERIAL AND METHODS

A retrospective analysis of 88 patients (n = 56 male) with curative resection of lung metastases of CRC was performed. Primary endpoint: influence of lymph node status of CRC on lung metastases. Secondary endpoints: disease-free survival and overall survival. Statistical evaluation was carried out with SPSS.

RESULTS

In 48 patients a positive lymph node status of CRC and in 9 patients an N+ status of lung metastases were determined. The lymph node status of the CRC significantly affected the incidence of synchronous metastases (p = 0.03), disease-free interval until formation of metachronous lung metastases (p = 0.012) and the overall survival of patients with CRC (p = 0.048). The 5‑year survival rate for CRC patients with lung metastases was 48.7% after pulmonary metastasectomy. Thoracic lymph node involvement also significantly affected survival (p = 0.001).

CONCLUSION

Screening for pulmonary metastases should be included in the staging and follow-up of all patients with CRC, especially in patients with a positive lymph node status of the CRC.

Second primary colorectal cancer after the initial primary colorectal cancer

BACKGROUND

Initial primary colorectal cancer (IPCRC) has a high risk of developing into second primary colorectal cancer (SPCRC). Right-sided colon cancer (RCC) and left-sided colon cancer (LCC) have different characteristics and are considered to be two different entities. However, the different risks for SPCRC in categorized tumor sites and SPCRC subcategorized sites have not been fully elucidated to date. We aimed to compare incidence and survival of IPCRC and SPCRC and characterize the risk factors of SPCRC while also comparing the different SPCRC characteristics.

METHODS

We used the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) data to compute standardized incidence ratios (SIR) in order to estimate risk of SPCRC after IPCRC diagnosis. The most prominent risk factors for SPCRC were measured by multivariate regression analysis and the temporal trend of SPCRC incidence was assessed with Joinpoint regression. Survival of patients with SPCRC and IPCRC was compared by Kaplan-Meier analysis.

RESULTS

Patients with IPCRC were 1.73 times more likely to develop SPCRC (SIR = 1.73, 95% CI 1.69-1.78). SPCRC incidence declined since the first 8 years of IPCRC diagnosis to baseline. We demonstrated poorer survival with SPCRC compared with IPCRC while second RCC resulted in better survival compared with second LCC. Black ethnicity, age range 70-79, and LCC were associated with the highest risk of developing SPCRC.

CONCLUSION

The characteristic differences between second LCC and RCC were relatively narrow. Furthermore, in those with SPCRC, RCC had the best survival outcome.

Various clinicopathological features of patients with metachronous colorectal cancer in relation to different diagnostic intervals

BACKGROUNDS

Clinicopathologic factors relating to developing metachronous colorectal cancer (CRC) have been reported. However, the effects of different diagnostic intervals on these risk factors required further analysis.

PATIENTS AND METHODS

This retrospective study comprised 14,481 patients diagnosed from January 1995 to December 2012. Metachronous CRC was defined as the occurrence of a second colorectal cancer at least 1 year post-operatively.

RESULTS

A total of 153 (1.06%) patients developed metachronous CRCs during the follow-up. Significantly higher rates of developing metachronous cancer occurred in male patients (1.2 vs 0.9%), patients with synchronous CRC (2.0 vs 1.0%), and patients with a positive family history of CRC (1.4 vs 0.9%). Pertaining to diagnostic intervals related to clinicopathological features, more severe staging was significant in the diagnostic interval between 2 and 3 years (35 vs 7.7%, 20.6%, 17.5%, P = .01) compared with other intervals. Male patients were more frequently detected to have CRC within 3 years compared with females (53.1 vs 29.1%, P = .005). For a diagnostic interval ≧ 5 years, a significantly higher rate of metachronous CRC located at the right colon was observed than that located at the left colon (36.6 vs 19.7%, p = 0.03).

CONCLUSIONS

We evinced that a diagnostic interval between 2 and 3 years was a key time for metachronous CRC diagnosis with worse staging distribution. Based on current findings, we recommend the stratification of metachronous CRCs into diagnostic intervals of 1-2, 2-3, and ≧ 3 years, as they exhibit significantly different characteristics.

Adenoma detection rate metrics in colorectal cancer surveillance colonoscopy

BACKGROUND

A target goal for screening adenoma detection rate (S-ADR) of ≥ 25% has been set to define high-quality colonoscopy performance. However, there is no current accepted target goal for ADR in colorectal cancer (CRC) surveillance. This makes quality assessment challenging when physicians perform cancer surveillance colonoscopy but minimal screening procedures.

METHODS

In this cohort study, consecutive colonoscopies performed at either Rush University Medical Center or Rush Oak Park Hospital by a gastroenterologist or colorectal surgeon in average risk screening population and CRC surveillance population were reviewed retrospectively from 2006 to 2012 and prospectively from 2013 to 2016. ADR in first surveillance colonoscopy following surgical resection of CRC (CRC-ADR) was reported in high-quality detectors (HQD) or low-quality detectors (LQD) based on achievement of 25% ADR in consecutive screening colonoscopy in average risk patients. Pearson's correlation was used to describe the association between individual S-ADR and CRC-ADR for colonoscopists.

RESULTS

There was a very strong positive correlation (r = 0.88, p = 0.002) between ADR in average risk screening and first time CRC surveillance. For HQD as defined by S-ADR ≥ 25% (n = 10 colonoscopists), the CRC-ADR was 37.7% (78/207, SD 8%) which was very similar to their respective S-ADR of 33.4% (816/2440, p = 0.22). For LQD (n = 5 colonoscopists), the CRC-ADR was 20.2% (40/198) which was similar to their respective S-ADR of 20.1% (119/591, p = 0.99). The CRC-ADR was significantly higher for HQD than for LQD (37.7 vs. 20.2%, p < 0.0001).

CONCLUSIONS

The major finding of this study is a defined CRC-ADR for HQD based on the ability to achieve S-ADR ≥ 25%. S-ADR strongly correlates with CRC-ADR. CRC-ADR is quite similar to the colonoscopists' respective S-ADR for both HQD and LQD. For colonoscopists who perform limited screening colonoscopies but do perform CRC surveillance colonoscopies, ADR metrics similar to S-ADR to assess quality in colonoscopy could be considered.

Risk factors for metachronous colorectal cancer or polyp: A systematic review and meta-analysis

BACKGROUND AND AIM

We conducted a systematic review and meta-analysis to identify personal, lifestyle, and tumor-related risk factors for metachronous colorectal cancer (CRC) and polyp.

METHODS

Relevant studies were identified by searching MEDLINE, Web of Science and Cochrane Central Register through 15 May 2016. Estimates for associations were summarized using random effects models.

RESULTS

Fifty-five studies were included in the review. For individuals who had a CRC resection, having a synchronous polyp was a risk factor for metachronous CRC or polyp (relative risk [RR], 2.04; 95% confidence interval [CI], 1.48-2.82) and having a synchronous CRC (RR, 1.90; 95% CI, 1.25-2.91) and proximally located CRC (RR, 2.12; 95% CI, 1.24-3.64) were risk factors for metachronous CRC. For individuals who had a polypectomy, larger size (RR, 4.26; 95% CI, 2.11-8.57) or severe dysplasia of the initial polyp (RR, 5.15; 95% CI, 2.02-13.14), and having a synchronous polyp (RR, 2.52; 95% CI, 1.35-4.73) were risk factors for metachronous CRC; and a family history of CRC (RR, 1.90; 95% CI, 1.26-2.87), having a synchronous polyp (RR, 2.47; 95% CI, 1.74-3.50) and a larger size (RR, 1.49; 95% CI, 1.03-2.15) and proximal location of the initial polyp (RR, 1.20; 95% CI, 1.02-1.40) were risk factors for metachronous polyp. Meta-regression showed duration of follow-up was not a source of heterogeneity for most associations. There was no evidence that lifestyle factors were associated with metachronous CRC or polyp risk.

CONCLUSION

A comprehensive list of risk factors identified for metachronous CRC or polyp may have important clinical implications.

Frequent co-occurrence of high-grade dysplasia in large flat colonic polyps (>20 mm) and synchronous polyps

Background

Large colonic polyps are associated with advanced dysplasia, but prevalence and characteristics of synchronous polyps in patients with large flat colonic polyps are poorly investigated. This study aims to characterize clinicopathological features of large flat colonic polyps and their impact on occurrence and characteristics of synchronous polyps.

Methods

A total of 802 patients that underwent endoscopic mucosal resection (EMR) of flat colonic polyps >20 mm from 2003 to 2014 in an academic endoscopy unit were retrospectively analyzed for size, location and histology of large polyps and synchronous polyps.

Results

Average size of large polyps was 34.1 mm (range 20–150 mm, standard deviation 16.1 mm). Histology included 52.5 % adenomas with low-grade dysplasia (LGD), 26.7 % with high-grade dysplasia (HGD), 9.6 % serrated polyps and 11.2 % adenocarcinomas. The majority of large polyps were localized in the proximal colon (61 %). 72.2 % of adenocarcinomas were found in the distal colon, while 80.5 % of all serrated polyps were detected in the proximal colon. Increase in polyp size, advanced age and location in the distal colon were associated with presence of HGD/adenocarcinoma in large polyps, as identified by multivariate analysis. Synchronous polyps were detected in 67.2 % of patients undergoing complete colonoscopy during EMR. Presence of HGD/adenocarcinoma in the large polyp, localization of any synchronous polyp in the rectosigmoid colon and occurrence of multiple synchronous polyps were associated with presence of HGD/adenocarcinoma in synchronous polyps.

Conclusions

Synchronous polyps are frequently found in patients with large flat colonic polyps. The prevalence of synchronous polyps with high grade dysplasia is highest in patients with large flat polyps containing HGD/adenocarcinoma.

Electronic supplementary material

The online version of this article (doi:10.1186/s12876-015-0312-4) contains supplementary material, which is available to authorized users.

Risk of second primary colorectal cancer among colorectal cancer cases: a population-based analysis

BACKGROUND

Patients with history of colorectal cancer (CRC) are at increased risk for developing a second primary colorectal cancer (SPCRC) as compared to the general population. However, the degree of risk is uncertain. Here, we attempt to quantify the risk, using data from the large population-based California Cancer Registry (CCR).

MATERIALS AND METHODS

We analyzed the CCR data for cases with surgically-treated colon and rectal cancer diagnosed during the period 1990-2005 and followed through up to January 2008. We excluded those patients diagnosed with metastatic disease and those in whom SPCRC was diagnosed within 6 months of the diagnosis of the primary CRC. Standardized incidence ratios (SIR) with 95% confidence intervals (CI) were calculated to evaluate risk as compared to the underlying population after taking into account age, sex, ethnicity, and time at risk.

RESULTS

The study cohort consisted of 69809 cases with colon cancer and 34448 with rectal cancer. Among these patients there were 1443 cases of SPCRCs. The SIR for developing SPCRC was higher in colon cancer survivors (SIR=1.4; 95% CI: 1.3 to 1.5) as compared to the underlying population. The incidence of SPCRC was also higher in females (SIR=1.5; 95% CI: 1.3 to 1.6) and Hispanics (SIR=2.0; 95% CI: 1.7 to 2.4) with primary colon cancer. The SIR for developing an SPCRC was higher only among those whose initial tumor was located in the descending colon (SIR=1.6; 95% CI: 1.3 to 2.0) and proximal colon (SIR=1.4; 95% CI: 1.3 to 1.6).

CONCLUSIONS

Our results confirm that CRC patients, especially females and Hispanics, are at a higher risk of developing SPCRC than the general population. Differential SPCRC risk by colorectal tumor subsite is dependent on gender and ethnicity, underscoring the heterogeneous nature of CRC.

Advanced synchronous adenoma but not simple adenoma predicts the future development of metachronous neoplasia in patients with resected colorectal cancer

BACKGROUND

Patients with resected colorectal cancer remain at a high risk for developing metachronous neoplasia in the remnant colorectum. The aim of this study was to identify baseline clinical and colonoscopic features predictive of metachronous neoplasia after curative resection of colorectal cancer.

METHODS

The baseline clinical and colonoscopic data and follow-up details of 503 patients who had colonoscopic surveillance after curative colorectal resection between January 2000 and October 2005 in a single tertiary institution were analyzed. Univariate and multivariate analyses were done to identify risk factors for metachronous adenoma.

RESULTS

Metachronous adenomas were diagnosed in 176 patients (35.0%) and advanced adenomas in 39 (7.8%) during the follow-up period (35.7+/-20.9 mo). Among the clinical and colonoscopic factors at baseline, advanced age (> or = 60 y) (odds ratio (OR)=3.64; 95% confidence intervals (CI), 1.55-8.52), the presence of advanced synchronous adenoma (OR=4.38; 95% CI, 1.77-10.85), and longer total follow-up period (OR=1.03; 95% CI, 1.01-1.04) were independently correlated with developing advanced metachronous adenoma. Patients who had synchronous tubular adenoma without advanced features at baseline were not found to have an increased risk for future development of advanced metachronous adenoma compared with those in the synchronous adenoma-free group (OR=1.75; 95% CI, 0.69-4.43, P=0.650).

CONCLUSIONS

Our data showed that patients with advanced synchronous adenoma at baseline were identified to have an increased risk of advanced metachronous neoplasia during a longer follow-up period but those with tubular adenoma without advanced features at baseline were not.

[Do metachronous colorectal adenomas show proximal shift?]

OBJECTIVE

To study the possibility of shift toward more proximal sites in colorectal cancer (CRC) after resection of tumors and synchronous lesions.

MATERIAL AND METHODS

We reviewed 382 resected CRC diagnosed and followed-up with complete colonoscopies. The localization of metachronous adenomas was compared with that of synchronous lesions overall and by sex, tumoral size and the number of synchronous lesions. The frequency of exclusively proximal localization in first-, second- and third-generation metachronous adenomas was compared with that of synchronous adenomas.

RESULTS

A total of 54.5% of patients with CRC had synchronous adenomas. After a median follow-up of 48 months, with 2.74+/-1.47 colonoscopies/case, 42.4% developed metachronous adenomas, 16.8% second-generation adenomas and 7.3% third-generation lesions. Proximal shift was found in metachronous adenomas in both sexes, independently of tumoral size and the number of initial lesions. The frequency of exclusively proximal localization in adenomas was 21.2% in synchronous lesions, 39.5% in first-generation metachronous adenomas (p=0.0001; OR=2.46 [1.50-3.95]), 42.6% in second-generation metachronous adenomas (p=0.0008; OR=2.77 [1.44-5.31]) and 39.3% in third-generation metachronous lesions (p=0.0003; OR=2.41 [0.97-5.93]).

CONCLUSIONS

We found a high incidence of synchronous and metachronous adenomas. Metachronous adenomas showed a proximal shift, independently of sex, tumoral size and the number of synchronous lesions. This tendency was maintained in successive generations of metachronous adenomas, thus demonstrating the need to perform complete colonoscopies throughout the postoperative follow-up period.

Second primary colorectal cancers (SPCRCs): experiences from a large Australian Cancer Registry

BACKGROUND

We examined the rate of second primary colorectal cancer (SPCRC) in a cohort of 29 471 patients first diagnosed with colorectal cancer (CRC) from 1987 to 1996, in New South Wales (NSW), Australia.

METHODS

The 5-year age group, date and site of first and subsequent CRC diagnoses as well as death dates were obtained from the NSW Central Cancer Registry. The time to SPCRC and standardised incidence ratios (SIRs) were generated.

RESULTS

Six hundred and sixty patients (2.1%) developed SPCRCs and the cumulative incidence at 18 years was 5.5%, 95% confidence interval (CI) 4.9% to 6.3%. The risk of SPCRC was increased in patients with a CRC history compared with the general population (SIR = 1.5, 95% CI 1.4-1.6) and inversely related to age at first diagnosis (30-49 years, SIR = 5.1, 95% CI 3.6-7.1 versus >/=80 years, SIR = 1.1, 95% CI 0.9-1.4). The excess absolute risk of SPCRC was greater for females aged 50-69 years at first diagnosis than for males in the same age group. SPCRC was also increased in individuals with right-sided first primaries (SIR = 2.0, 95% CI 1.6-2.4).

CONCLUSIONS

The SPCRC rate was increased during the first 5 years after first diagnosis but remained increased for up to 10 years in females, in patients with right-sided cancers and in patients <60 years at first diagnosis. These findings support active surveillance up to 10 years in these risk groups.

Q&A on diagnosis, screening and follow-up of colorectal neoplasia

The impressive and brisk evolution of medical science prevents many physicians from a thorough update on all the research fields. Colorectal cancer diagnosis, screening and follow-up is well known to require a multi-disciplinary approach, as it is faced by several specialties such as primary care physicians, gastroenterologists, non-gastroenterologist internists, radiologists and surgeons. To address this issue in a mutual perspective, we focused on the main points of the epidemiology, diagnosis, screening and follow-up of colorectal neoplasia by using a simple "Question & Answers" structure.

Detection of metachronous neoplasms in colorectal cancer patients: identification of risk factors

PURPOSE

Patients with colorectal cancer have a high risk of developing metachronous neoplasms. Identification of predictive factors associated with such conditions would allow individualized follow-up strategies in these patients. This study was designed to identify individual and familial factors associated with the development of metachronous colorectal neoplasms in patients with colorectal cancer.

METHODS

In the context of a prospective, multicenter, general population-based study-the EPICOLON project-all patients with colorectal cancer attended in ten Spanish hospitals during a one-year period were included. Patients with familial adenomatous polyposis or inflammatory bowel disease were excluded. All patients were monitored by colonoscopy within two years of the diagnoses. Demographic, clinical, pathologic, molecular (microsatellite instability status and immunohistochemistry for MSH2 and MLH1), and familial characteristics (fulfillment of Amsterdam I or II criteria, and revised Bethesda guidelines) were analyzed.

RESULTS

A total of 353 patients were included in the study. At two years of follow-up, colonoscopy revealed the presence of adenomas in 89 (25 percent) patients and colorectal cancer in 14 (3.9 percent) patients, in 7 cases restricted to anastomosis. Univariate analysis demonstrated that development of metachronous neoplasm (adenoma or colorectal cancer) was associated with personal history of previous colorectal cancer (odds ratio, 5.58; 95 percent confidence interval, 1.01-31.01), and presence of previous or synchronous adenomas (odds ratio, 1.77; 95 percent confidence interval, 1.21-3.17). Although nonstatistical significance was achieved, metachronisms were associated with gender (P<0.09) and differentiation degree (P<0.08). Multivariate analysis identified previous or synchronous adenomas (odds ratio, 1.98; 95 percent confidence interval, 1.16-3.38) as independent predictive factor. Neither presence of tumor DNA microsatellite instability nor family history correlated with the presence of metachronous neoplasms.

CONCLUSIONS

Patients with previous or synchronous colorectal adenoma have an increased risk of developing metachronous colorectal neoplasms. Accordingly, this subgroup of patients may benefit from specific surveillance strategies.

Temporal trend in relative risk of second primary colorectal cancer

BACKGROUND

Patients with colorectal cancer (CRC) are at a higher risk for developing a second primary. Factors (such as survival rate, rate of receipt of surveillance procedures, and the overall incidence of CRC) with potential impact on the risk for second primary CRC have changed over the last three decades. Thus, it is likely that the risk for second primary CRC also has changed over the years.

OBJECTIVES

We used the Surveillance, Epidemiology, and End Results public-use database to assess whether the relative risk of second primary CRC has changed in patients with initial primary CRC.

METHODS

The temporal trend in the standardized incidence ratio (SIR) for a second primary CRC was estimated. Also, the clinical features of the second primary CRC were compared in two subgroups based on the year of diagnosis of the first primary CRC: Group A (1973-1977) and Group B (1988-1992).

RESULTS

During the period of 1973 to 2002, 216,751 patients developed a primary CRC and over a follow-up period of 1,250,687 person-years, 5,595 of these patients developed a second primary CRC, with an SIR of 1.36 (95% CI 1.32-1.39). In a Cox regression model, the period of diagnosis of the first primary CRC was an independent risk factor for a subsequent primary CRC, with a relative hazard of second colon cancer in Group B compared with Group A being 1.18 (95% CI 1.06-1.31), after controlling for age at diagnosis, site, stage of first primary, gender, and race.

CONCLUSION

The relative risk of the second primary CRC has increased since early 1990s. These subsequent cancers are being diagnosed at an earlier stage. Increased surveillance may be one of the factors contributing to this temporal difference.

Aktuelle Behandlungsstrategien beim Rektumkarzinom

In the last ten years, considerable progress has been achieved in the treatment of rectal cancer. According to improved interdisciplinary staging, rectal carcinomas can be treated based on a stage-dependent concept: "low-risk" pT1 (G1/G2) carcinomas can be cured by local full wall excision, while "high-risk" pT1 (G3/G4) and pT2 carcinomas require transabdominal resection. In contrast, locally advanced rectal cancers in cUICC-II/-III stages (T3/T4 or N(+)) should receive long-term, 5-FU-based, neoadjuvant chemoradiotherapy according to the excellent results of the CAO/AIO/ARO-94 trial of the German Rectal Cancer Study Group. High-quality resection must be based on radical oncologic principles such as "no-touch" technique, radicular dissection of vessels, and total mesorectal excision. Multimodal treatment is completed with adjuvant 5-FU-based chemotherapy. This therapeutic approach led to a reduction in the 5-year local recurrence rate to 6% and disease-free survival of approximately 68% in advanced rectal cancer (overall survival: 76%).

Proximal location of colon cancer is a risk factor for development of metachronous colorectal cancer: a population-based study

PURPOSE

This study was undertaken to assess the incidence of 1) metachronous colorectal cancer and 2) subsequent extracolonic cancers, in relation to the location (proximal or distal to the splenic flexure) of the first primary colorectal tumor.

METHODS

In this population-based study, a cancer registry database was used to identify patients diagnosed with colorectal adenocarcinoma between 1970 and 1999. Patients with familial adenomatous polyposis and those with hereditary nonpolyposis colorectal cancer syndrome were excluded from the study, as were patients with nonepithelial tumors. Location of the first tumor was established according to International Classification of Diseases-Oncology-02 classification. The registry covers a population of 500,000 residents.

RESULTS

A total of 5,006 patients had sporadic adenocarcinoma of the colon or rectum during this period of time, with 1,703 first primary tumors (34 percent) being located proximal to the splenic flexure. One hundred twenty occurrences of second primary colorectal cancer were observed in this population (2.39 percent). The risk for developing a second incidence of primary colorectal cancer was higher in patients whose initial tumor was located in the proximal colon (3.4 percent vs. 1.8 percent; odds ratio, 1.92; 95 percent confidence interval, 1.33-2.77; P < 0.001). The risk for each segment of the large bowel was as follows: cecum, 3.4 percent; right colon, 3 percent; transverse colon, 3.8 percent; left colon, 2.8 percent; sigmoid colon, 1.7 percent; and rectum, 1.8 percent. By contrast, the risk for developing a second, extracolonic tumor did not differ between patients with proximal and distal tumors (13.7 percent vs. 13.4 percent, P = 0.73).

CONCLUSION

Patients with a first tumor located within the proximal colon are at twice the risk for developing metachronous colorectal cancer. From an epidemiologic standpoint, these data are in accordance with 1) the increasing incidence and 2) the better prognosis of proximal colon cancer in various populations. Our results confirm that proximal colon cancer is a distinct entity, which justifies the reporting of cases of colon cancer according to their location proximal or distal to the splenic flexure.

Clinical features, diagnosis, treatment and prognosis of multiple primary colorectal carcinoma

AIM: To investigate the clinical features, diagnosis, treatment and prognosis of multiple primary colorectal carcinomas (MPCC).

METHODS: A retrospective analysis of 37 patients with MPCC from 1974 to 1998 was carried out.

RESULTS: The incidence of MPCC was 2.74% (37/1348) in patients with primary colorectal carcinomas, 15 cases of them were patients with synchronous carcinomas (SC) and 22 cases were diagnosed as metachronous carcinomas (MC). Most tumors were located in the right colon and rectum. Fifty-five percent (12/22) of MC were diagnosed within 3 years after tumor resection and 41% (9/22) of MC occurred after 8 years. Radical resections were performed in all patients except for 1 case. The 5-year survival rate of SC was 72.7% (8/11) and that of MC after the first cancer and second cancer was 71.4% (15/21) and 38.9% (7/18), respectively.

CONCLUSION: The results indicate the importance of complete preoperative examination, careful intraoperative exploration and periodic postoperative surveillance. Early diagnosis and radical resection can increase survival rate of MPCC.

Colon cancer: detection and prevention

Recent data have advanced our ability to detect, survey, and manage patients with colonic neoplasia. Current studies and consensus statements increasingly support the role of colonoscopic screening over less invasive testing such as FOBT or FS for appropriately selected individuals. There are many issues, however, that remain unresolved. What is the appropriate surveillance of an individual with a single family member who had colon cancer at an early age? How should family members of suspected HNPCC kindreds be managed? There has yet to be a prospective cohort validation of the Bethesda criteria in directing clinical practice, with the endpoint of mortality reduction. Questions regarding prophylaxis with dietary supplements and medications are exciting areas that are currently under study. As newer technologies become clinically available for molecular diagnostics and screening, and virtual colonoscopy with computed tomography and magnetic resonance disseminates, there will undoubtedly be new questions to be answered regarding their ability to aid in the detection and management of colon cancer.

Contrast-enhanced CT colonography in recurrent colorectal carcinoma: feasibility of simultaneous evaluation for metastatic disease, local recurrence, and metachronous neoplasia in colorectal carcinoma

OBJECTIVE

Contrast-enhanced CT colonography has the potential to detect local recurrence, metachronous disease, and distant metastases in patients with a history of invasive colorectal cancer. The purpose of our study was to determine whether colonic anastomoses prohibit adequate colonic distention on contrast-enhanced CT colonography and to estimate the performance of contrast-enhanced CT colonography in detecting recurrent colorectal carcinoma.

MATERIALS AND METHODS

Fifty patients with a history of resected invasive colorectal carcinoma underwent contrast-enhanced CT colonography and colonoscopy. Colonic distention was graded for different colonic segments. Two radiologists evaluated for the presence of local recurrence, metachronous disease, and metastatic disease. Results were compared with colonoscopy, histology, and clinical follow-up.

RESULTS

Most patients had adequate colonic inflation (37/50, 74%). Eleven of 13 patients with inadequate distention had collapse in the sigmoid colon, usually associated with ileocolic anastomoses. Contrast-enhanced CT colonography detected local recurrences with an accuracy of 94% (95% confidence interval, 83-99%). The accuracy of contrast-enhanced CT colonography for metachronous lesions greater than or equal to 1 cm was 92% (95% confidence interval, 80-98%), but there was only one such lesion, which was missed on initial colonoscopy. Stool, granulation tissue, and inflammation can mimic the CT appearance of local recurrence or metachronous disease and account for false-positive examinations. Contrast-enhanced CT colonography identified five patients with metastatic disease.

CONCLUSION

Suboptimal sigmoid distention can be seen on contrast-enhanced CT colonography, predominantly in patients with right hemicolectomies. Contrast-enhanced CT colonography is a promising method for detecting local recurrence, metachronous disease, and distant metastases in patients with prior invasive colorectal carcinoma. The technique can also serve as a useful adjunct to colonoscopy by detecting local recurrences or metachronous disease that are endoscopically obscure or by serving as a full structural colonic examination when endoscopy is incomplete.