Local recurrence of colorectal cancer: the problem, mechanisms, management and adjuvant therapy

Intensive surveillance following curative treatment of colorectal cancer allows effective treatment of recurrence even if limited to 4 years

BACKGROUND

Current evidence suggests a survival benefit to post-operative surveillance following curative colorectal cancer resection; however, there is still no consensus on the optimal duration and form.

OBJECTIVES

The objective is to prospectively audit outcomes of an intensive colorectal cancer follow-up scheme for time to recurrence and survival.

METHODS

We used a surveillance protocol designed to incorporate regular clinical, biochemical, radiological and endoscopic measures at pre-defined intervals.

SETTING

The setting was a Department of Colorectal Surgery in a Tertiary Academic Centre. Follow-up was led by specially trained colorectal nurses in conjunction with surgeons.

PATIENTS

Consecutive patients who had undergone curative treatment for colorectal cancer were included in this study.

MAIN OUTCOMES

Outcomes were measured in terms of overall survival and disease recurrence.

RESULTS

There were 436 patients entered into follow-up, all treated with curative intent. Mean age 65.9 years (SD 12.9 years) and 240 male (55.0 %). Ninety-four patients (21.5 %) with stage I disease, 119 (27.3 %) stage IIa, 30 (6.9 %) stage IIb, 18 (4.1 %) stage IIIa, 78 (17.9 %) stage IIIb, 45 (10.4 %) stage IIIc and 52 (11.9 %) stage IV. Overall median survival was 37.5 months for all patients, (range 0.0-207.8 months). Ninety-two (21.1 %) cancer-related deaths were recorded during the course of the study. The overall 5-year actuarial cancer-related survival was 81.7 %. There was a 40.3 % 5-year actuarial survival was recorded in patients with 39 a recurrence, 57.7 % in patients treated with further curative 40 intent and 27.7 % in patients who received palliative treatment 41 (P < 0.001). Ninety-seven percent of recurrences were detected within 4 years of curative treatment.

CONCLUSIONS

This follow-up protocol confers an 81 % overall 5-year actuarial survival. Our study suggests that surveillance after curative resection can be limited to 4 years, which would lead to detection of over 97 % of all recurrences.

Significance of R1 resection margin in colon cancer resections in the modern era

AIM

Circumferential resection margin involvement (R1) in rectal cancer is a predictive factor for poor prognosis. The aim of this study was to confirm the prognostic significance of R1 in colon cancer resection and to establish whether the introduction of laparoscopic colorectal surgery influenced this.

METHOD

Prospectively collected data on a patient pathway data manager for sequential patients with colon cancer treated at our specialist unit from January 2005 to December 2010 were analysed. There were 1110 colonic resections (elective 865; emergency 245). A circumferential resection margin involvement of < 1 mm was considered positive.

RESULTS

The total R1 rate was 13.3% (elective 10.4%; emergency 23.6%; P < 0.001). Other statistically significant risk factors for an R1 resection included tumour perforation (P < 0.001), poorly differentiated carcinoma (P < 0.001), T4 tumour (P < 0.001), vascular invasion (P < 0.001), lymph node metastasis (P < 0.001), distant metastasis (P < 0.001) and palliative resection (P < 0.001). Over half of the elective resections were undertaken laparoscopically (486/865; 56.2%). When compared with elective open resection (379/865; 43.8%), the R1 rate was similar (P = 0.491) with similar disease-free survival (DFS) and overall survival (OS). The overall relapse rate was 18.9% in R0 and 55.5% in R1 resections (P < 0.001). Kaplan-Meier survival analysis showed significant improvements in DFS and OS in R0 over R1 patients.

CONCLUSION

The R1 margin in colon cancer resection is an important marker for advanced disease and a prognostic factor for DFS and OS. The introduction of laparoscopic surgery has not influenced the outcome in our unit despite a complex case mix.

Cost-effectiveness analysis of a colonoscopy screening navigator program designed for Hispanic men

Although Hispanic men are at higher risk of developing colon cancer compared to non-Hispanic white men, colonoscopy screening among Hispanic men is much lower than among non-Hispanic white men. University Health System (UHS) in San Antonio, Texas, instituted a Colorectal Cancer Male Navigation (CCMN) Program in 2011 specifically designed for Hispanic men. The CCMN Program contacted 461 Hispanic men 50 years of age and older to participate over a 2-year period. Of these age-eligible men, 370 were screened for CRC after being contacted by the navigator. Using participant and program data, a Markov model was constructed to determine the cost-effectiveness of the CCMN Program. An average 50-year-old Hispanic male who participates in the CCMN Program will have 0.3 more quality-adjusted life-years (QALYs) compared to a similar male receiving usual care. Life expectancy is also predicted to increase by 6 months for participants compared to non-participants. The program results in net health care savings of $1,148 per participant ($424,760 for the 370 CCMN Program participants). The incremental cost-effectiveness ratio is estimated at $3,765 per QALY in favor of the navigation program. Interventions to reduce disparities in CRC screening across ethnic groups are needed, and this is one of the first studies to evaluate the economic benefit of a patient navigator program specifically designed for an urban population of Hispanic men. A colorectal cancer screening intervention which relies on patient navigators trained to address the unique needs of the targeted population (language barriers, transportation and scheduling assistance, colon cancer, and screening knowledge) can substantially increase the likelihood of screening and improve quality of life in a cost-effective manner.

Mesorectal excision: Surgical anatomy of the rectum, mesorectum, and pelvic fascia and nerves and clinical relevance

Biologic behavior and management of rectal cancer differ significantly from that of colon cancer. The surgical treatment is challenging since the rectum has dual arterial blood supply and venous drainage, extensive lymphatic drainage and is located in a bony pelvic in close proximity to urogenital and neurovascular structures that are invested with intricate fascial covering. The rectum is encased by fatty lymphovascular tissue (mesorectum) that is surrounded by perirectal fascia that act as barrier to the spread of the cancer and constitute the surgical circumferential margin. Locoregional recurrence after rectal cancer surgery is influenced by tumor-related factors and adequacy of the resection. Local recurrence is associated with incomplete excision of circumferential margin, violation of perirectal fascia, transmesorectal dissection, presence of isolated deposits in the mesorectum and tumor in regional lymph nodes and incomplete lymph node clearance. Hence to eradicate the primary rectal tumor and control regional disease, the rectum, first area of lymph node drainage and surrounding tissue must be completely excised while maintaining an intact fascial envelope around the rectum and preserving surrounding structures. This is achieved with extrafascial dissection and removal of the entire mesorectum including the portion distal to the tumor (total mesorectal excision) within its enveloping fascia as an intact unit. Total mesorectal excision is the standard of care surgical treatment of mid and low rectal cancer and can be performed in conjunction with low anterior resection, abdominoperineal resection, extralevator abdominoperineal resection, and extraregional dissection. To accomplish such a resection, thorough knowledge of the surgical anatomy of the rectum and pelvic structures and fascial planes is paramount.

Learning curve for the management of recurrent and locally advanced primary rectal cancer: a single team's experience

AIM

The study aimed to define the learning curve required to gain satisfactory training to perform pelvic exenterative surgery for recurrent or locally advanced primary rectal cancer.

METHOD

Consecutive patients undergoing exenterative pelvic surgery for recurrent and locally advanced primary rectal cancer, by one surgical team, between 2006 and 2011 were studied. They were divided into quartiles (Q1-Q4) according to the date of surgery. A risk-adjusted cumulative sum (RA-CUSUM) model was used to evaluate the learning curve. The chi-squared test with gamma ordinal was used to assess the change with time in the four quartiles.

RESULTS

One hundred patients (70 males; median age 61 (25-85) years; 55 primary cancers) were included in the study. Thirty patients underwent abdominosacral resection. The number of patients who underwent plastic reconstruction (n = 53) increased from 12 in Q1 to 15 in Q4 (P = 0.781). The median operation time, intra-operative blood loss and hospital stay were 8 (3-17) h, 1.5 (0.1-17) l and 15 (9-82) days respectively. There was no significant change with time. Complete resection (R0) was achieved in 78 patients. Microscopic (R1) or macroscopic (R2) residual disease was present in 15 and seven patients respectively. The number of major complications was 20, and minor 30. RA-CUSUM analysis demonstrated an improvement in any complications after 14, in major after 12 and in minor after 25 operations.

CONCLUSION

Pelvic exenterative surgery for recurrent or locally advanced primary rectal cancer is complex and requires a minimum of 14 cases for an expert colorectal surgeon to gain the desirable training and experience to improve morbidity.

A practical review of the performance and interpretation of staging magnetic resonance imaging for rectal cancer

OBJECTIVES

The purpose of this article was to outline key technical considerations in performing rectal magnetic resonance imaging (MRI) along with a practical, systematic approach to the interpretation of rectal MRI.

CONCLUSIONS

Following validation by the Magnetic Resonance Imaging and Rectal Cancer European Equivalence Study group, rectal MRI is mandatory for the local staging of rectal cancer in many countries. The systematic interpretation of high-quality, high-resolution T2-weighted images should form the basis for discussing the management of patients with rectal cancer, including aiding surgical planning and enabling the appropriate use of neoadjuvant therapy. In this article, we discuss the methods for obtaining high-quality rectal magnetic resonance images and a systematic approach for the accurate interpretation of these images.

Evaluation of lateral pelvic nodes in patients with advanced rectal cancer

OBJECTIVE

The purpose of this article is to discuss the importance of lateral pelvic lymph node metastasis as a predictor of local recurrence and survival in patients with advanced rectal cancer.

CONCLUSION

Prediction of lateral pelvic nodal staging on MRI shows high accuracy compared with the other imaging modalities. Diffusion-weighted MRI or (18)F-FDG PET/CT may be helpful to assesses lateral pelvic lymph node metastasis.

Anastomotic leak increases distant recurrence and long-term mortality after curative resection for colonic cancer: a nationwide cohort study

OBJECTIVE

To investigate the impact of anastomotic leak (AL) on disease recurrence and long-term mortality in patients alive 120 days after curative resection for colonic cancer.

BACKGROUND

There is no solid data as to whether AL after colonic cancer surgery increases the risk of disease recurrence.

METHODS

This was a nationwide cohort study of 9333 patients, prospectively registered in the database of the Danish Colorectal Cancer Group and merged with data from the Danish Pathology Registry and the National Patient Registry. Multivariable Cox regression analysis was used to adjust for confounding.

RESULTS

The incidence of AL was 6.4%, 744 patients died within 120 days. Of the remaining 8589 patients, 861 (10.0%) developed local recurrence with no association to AL [adjusted hazard ratio (HR) = 0.78; 95% confidence interval (CI): 0.55-1.12; P = 0.184]. Distant recurrence developed in 1281 (14.9%) patients and more frequently after AL (adjusted HR = 1.42; 95% CI: 1.13-1.78; P = 0.003). AL was also associated with increased long-term mortality (adjusted HR = 1.20; 95% CI: 1.01-1.44; P = 0.042). In 2841 patients with stage III cancer, AL was associated with both decreased likelihood of receiving adjuvant chemotherapy (adjusted HR = 0.58; 95% CI: 0.45-0.74; P < 0.001) and a delay to initial administration (16 days; 95% CI: 12-20 days; P < 0.001).

CONCLUSIONS

AL was significantly associated with increased rates of distant recurrence and long-term all-cause mortality. Cancelled or delayed administration of adjuvant chemotherapy may partly account for these findings.

Fluorescently labeled chimeric anti-CEA antibody improves detection and resection of human colon cancer in a patient-derived orthotopic xenograft (PDOX) nude mouse model

BACKGROUND AND OBJECTIVES

The aim of this study was to evaluate a new fluorescently labeled chimeric anti-CEA antibody for improved detection and resection of colon cancer.

METHODS

Frozen tumor and normal human tissue samples were stained with chimeric and mouse antibody-fluorophore conjugates for comparison. Mice with patient-derived orthotopic xenografts (PDOX) of colon cancer underwent fluorescence-guided surgery (FGS) or bright-light surgery (BLS) 24 hr after tail vein injection of fluorophore-conjugated chimeric anti-CEA antibody. Resection completeness was assessed using postoperative images. Mice were followed for 6 months for recurrence.

RESULTS

The fluorophore conjugation efficiency (dye/mole ratio) improved from 3-4 to >5.5 with the chimeric CEA antibody compared to mouse anti-CEA antibody. CEA-expressing tumors labeled with chimeric CEA antibody provided a brighter fluorescence signal on frozen human tumor tissues (P = 0.046) and demonstrated consistently lower fluorescence signals in normal human tissues compared to mouse antibody. Chimeric CEA antibody accurately labeled PDOX colon cancer in nude mice, enabling improved detection of tumor margins for more effective FGS. The R0 resection rate increased from 86% to 96% with FGS compared to BLS.

CONCLUSION

Improved conjugating efficiency and labeling with chimeric fluorophore-conjugated antibody resulted in better detection and resection of human colon cancer in an orthotopic mouse model.

Early detection of colorectal cancer recurrence in patients undergoing surgery with curative intent: current status and challenges

Despite advances in neoadjuvant and adjuvant therapy, attention to proper surgical technique, and improved pathological staging for both the primary and metastatic lesions, almost half of all colorectal cancer patients will develop recurrent disease. More concerning, this includes ~25% of patients with theoretically curable node-negative, non-metastatic Stage I and II disease. Given the annual incidence of colorectal cancer, approximately 150,000 new patients are candidates each year for follow-up surveillance. When combined with the greater population already enrolled in a surveillance protocol, this translates to a tremendous number of patients at risk for recurrence. It is therefore imperative that strategies aim for detection of recurrence as early as possible to allow initiation of treatment that may still result in cure. Yet, controversy exists regarding the optimal surveillance strategy (high-intensity vs. traditional), ideal testing regimen, and overall effectiveness. While benefits may involve earlier detection of recurrence, psychological welfare improvement, and greater overall survival, this must be weighed against the potential disadvantages including more invasive tests, higher rates of reoperation, and increased costs. In this review, we will examine the current options available and challenges surrounding colorectal cancer surveillance and early detection of recurrence.

Predictive factors and the prognosis of recurrence of colorectal cancer within 2 years after curative resection

PURPOSE

Because predicting recurrence intervals and patterns would allow for appropriate therapeutic strategies, we evaluated the clinical and pathological characteristics of early and late recurrences of colorectal cancer.

METHODS

Patients who developed recurrence after undergoing curative resection for colorectal cancer stage I-III between January 2000 and May 2006 were identified. Early recurrence was defined as recurrence within 2 years after primary surgery of colorectal cancer. Analyses were performed to compare the clinicopathological characteristics and overall survival rate between the early and late recurrence groups.

RESULTS

One hundred fifty-eight patients experienced early recurrence and 64 had late recurrence. Multivariate analysis revealed that the postoperative elevation of carbohydrate antigen 19-9 (CA 19-9), venous invasion, and N stage correlated with the recurrence interval. The liver was the most common site of early recurrence (40.5%), whereas late recurrence was more common locally (28.1%), or in the lung (32.8%). The 5-year overall survival rates for early and late recurrence were significantly different (34.7% vs. 78.8%; P < 0.001). Survival rates after the surgical resection of recurrent lesions were not different between the two groups.

CONCLUSION

Early recurrence within 2 years after surgery was associated with poor survival outcomes after colorectal cancer recurrence. An elevated postoperative CA 19-9 level, venous invasion, and advanced N stage were found to be significant risk factors for early recurrence of colorectal cancer.

Survival benefit of lateral lymph node dissection according to the region of involvement and the number of lateral lymph nodes involved

PURPOSE

The effectiveness of lateral lymph node dissection for extending the survival of patients with advanced lower rectal cancer remains unclear. The purpose of this study was to clarify the survival benefit of lateral lymph node dissection according to the region of involvement and the number of lateral lymph nodes involved.

METHODS

We reviewed 131 consecutive patients with advanced lower rectal cancer, who had undergone curative resection with total mesorectal excision plus extended lateral lymph node dissection at Wakayama Medical University Hospital. Twenty-six (19.1 %) of these patients had lateral lymph involvement. We performed univariate and multivariate analyses for the 3-year disease-free and overall survival of these patients.

RESULTS

Multivariate analysis revealed that the number (>1) and the region (common iliac artery region or external iliac artery region) of lateral lymph node metastasis are independent predictive factors for recurrence and survival. The Kaplan-Meier analysis demonstrated that patients with one lymph node metastasis in the internal iliac artery or obturator region had better survival.

CONCLUSIONS

Lateral lymph node dissection resulted in survival benefit for patients with single lateral lymph node involvement in the internal iliac artery region or the obturator region.

Local colorectal cancer recurrence: pelvic MRI evaluation

Surveillance of colorectal cancer is currently based on dosage of tumoral markers, colonoscopy and multidetector row computed tomography. However, pelvic magnetic resonance imaging (MRI) and PET-CT are two second-line useful imaging modalities to assess colorectal cancer local recurrence (LR). The anatomical information derived from MRI combined to the functional information provided by diffusion-weighted imaging currently remain of value. Pelvic MRI is accurate not only for detection of pelvic colorectal recurrence but also for the prediction of absence of tumoral invasion in pelvic structures, and it may thus provide a preoperative road map of the recurrence to allow for appropriate surgical planning. As always, correlation of imaging and clinical findings in the multidisciplinary forum is paramount. MRI can also be used to follow-up LR treated with radiofrequency ablation. The aim of this review is to discuss clinical practice and application of MRI in the assessment or pelvic recurrence from colorectal cancer.

Disseminated tumour cells in bone marrow in experimental colon cancer: metastatic or resident?

AIM

There are conflicting data on the biological and prognostic significance of disseminated tumour cells (DTCs) in the bone marrow of colorectal cancer patients since bone metastasis is rare in this disease. The study aimed to determine the origin of bone marrow DTCs using human colorectal cancer cells in in vivo and in vitro experimental settings.

METHOD

CD1 nude female mice were xenotransplanted with SW620 cells (a colorectal cancer cell line isolated from a male patient) injected in the colon wall. At autopsy, the presence of SW620 in the bone marrow (BM), colon and other organs/tissues was recognized by detection of the epithelial marker cytokeratin-19 (CK19) and Y chromosome. In addition SW620 cells or their conditioned medium were cultured with human BM cells.

RESULTS

Macroscopically evident CK19+/Y-chromosome-positive tumours developed only in five mice receiving SW620 cells while putative DTCs (CK19+) were found in the bone marrow of all treated mice. Most of these CK19+ cells were Y chromosome negative, only few being Y chromosome positive. In vitro SW620 cells or their conditioned medium induced CK19 expression in cultured human bone marrow cells.

CONCLUSION

Experimental colorectal cancer can induce the appearance of two distinct CK19+ cell populations in the bone marrow, one of metastatic origin and the other of murine origin. These findings suggest that bone marrow cells may undergo phenotypic modifications induced by cancer cells.

Evaluation of the presence of intraluminal cancer cells following rectal washout in rectal cancer surgery

BACKGROUND

The presence of intraluminal tumour cells in colorectal cancer is known, as is their ability to implant in colorectal anastomoses, causing perianastomotic tumour growth. There is no consensus as to the volume and agent to use for rectal washout. The purpose of this study was to assess the efficacy of our current routine for rectal washout in eliminating intraluminal tumour cells.

METHODS

Sixty consecutive patients undergoing low anterior resection or low Hartmann's procedure for rectal cancer at our unit were included. After the pelvic dissection was completed, the bowel was cross-clamped distal to the tumour and the prewashout sample (no. 1), was obtained by instilling 50 ml of saline and collecting the return fluid. A rectal washout followed using 500 ml of sterile water, 2 × 500 ml of 70 % ethanol and 500 ml of sterile water (sample no. 2-4) and the postwashout sample (no. 5) was obtained by using 50 ml of saline. The samples were examined and categorized as non-malignant or malignant at the Department of Pathology. The usual pathology report information was also assessed.

RESULTS

In 33 of the 60 patients, cancer cells were identified in the prewashout sample. The rectal washout eliminated intraluminal cancer cells in 30 of the 33 patients. All of the remaining 3 had a higher blood loss (p = 0.026) and a tendency towards more polypoidal tumours (p = 0.053).

CONCLUSIONS

A rectal washout volume larger than 2,000 ml might be necessary to eliminate all intraluminal tumour cells in total mesorectal excision for rectal cancer.

Pelvic exenteration for rectal cancer: a systematic review

BACKGROUND

Pelvic exenteration is a potentially curative treatment for locally advanced primary or recurrent rectal cancer.

OBJECTIVE

This systematic review examines the current evidence regarding clinical and oncological outcomes in patients with locally advanced primary and recurrent rectal cancer who undergo pelvic exenteration.

DATA SOURCES

A literature search of PubMed, Medline, and the Cochrane library was undertaken, and studies published in the English language from January 2000 to August 2012 were identified.

STUDY SELECTION

Prospective and retrospective studies that report outcomes of pelvic exenteration for primary advanced and locally recurrent rectal cancer with or without subgroup evaluation were included for examination.

MAIN OUTCOME MEASURES

Oncological outcomes included 5-year survival, median survival, and local recurrence rates. Clinical outcomes included complication rates and perioperative mortality rates.

RESULTS

A total of 23 studies with 1049 patients were reviewed. The complication rates ranged from 37% to 100% (median, 57%) and the perioperative mortality rate ranged from 0% to 25% (median, 2.2%). The rate of local recurrence ranged from 4.8% to 61% (median, 22%). The median survival for primary advanced rectal cancers was 14 to 93 months (median, 35.5 months) and 8 to 38 months (median, 24 months) for locally recurrent rectal cancer.

LIMITATIONS

Our review was limited by the small sample sizes from single-institutional studies reporting outcomes over long periods of time with heterogeneity in both the disease and treatments reported.

CONCLUSIONS

Although the human costs and risks are significant, the potentially favorable survival outcomes make this acceptable in the absence of other effective treatment modalities that would otherwise result in debilitating symptoms that afflict patients who have advanced pelvic malignancy.

Variable clonal repopulation dynamics influence chemotherapy response in colorectal cancer

Intratumoral heterogeneity arises through the evolution of genetically diverse subclones during tumor progression. However, it remains unknown whether cells within single genetic clones are functionally equivalent. By combining DNA copy number alteration (CNA) profiling, sequencing, and lentiviral lineage tracking, we followed the repopulation dynamics of 150 single lentivirus-marked lineages from 10 human colorectal cancers through serial xenograft passages in mice. CNA and mutational analysis distinguished individual clones and showed that clones remained stable upon serial transplantation. Despite this stability, the proliferation, persistence, and chemotherapy tolerance of lentivirally marked lineages were variable within each clone. Chemotherapy promoted the dominance of previously minor or dormant lineages. Thus, apart from genetic diversity, tumor cells display inherent functional variability in tumor propagation potential, which contributes to both cancer growth and therapy tolerance.

Pelvic exenteration: surgical approaches

Although the incidence of local recurrence after curative resection of rectal cancer has decreased due to the understanding of the anatomy of pelvic structures and the adoption of total mesorectal excision, local recurrence in the pelvis still remains a significant and troublesome complication. While surgery for recurrent rectal cancer may offer a chance for a cure, conservative management, including radiation and chemotherapy, remain widely accepted courses of treatment. Recent improvement in imaging modalities, perioperative care, and surgical techniques, including bone resection and wound coverage, have allowed for reductions in operative mortality, though postoperative morbidity still remains high. In this review, the techniques, including surgical approaches, employed for management of locally recurrent rectal cancer are highlighted.

Scatter spectroscopic imaging distinguishes between breast pathologies in tissues relevant to surgical margin assessment

PURPOSE

A new approach to spectroscopic imaging was developed to detect and discriminate microscopic pathologies in resected breast tissues; diagnostic performance of the prototype system was tested in 27 tissues procured during breast conservative surgery.

EXPERIMENTAL DESIGN

A custom-built, scanning in situ spectroscopy platform sampled broadband reflectance from a 150-μm-diameter spot over a 1 × 1 cm(2) field using a dark field geometry and telecentric lens; the system was designed to balance sensitivity to cellular morphology and imaging the inherent diversity within tissue subtypes. Nearly 300,000 broadband spectra were parameterized using light scattering models and spatially dependent spectral signatures were interpreted using a cooccurrence matrix representation of image texture.

RESULTS

Local scattering changes distinguished benign from malignant pathologies with 94% accuracy, 93% sensitivity, 95% specificity, and 93% positive and 95% negative predictive values using a threshold-based classifier. Texture and shape features were important to optimally discriminate benign from malignant tissues, including pixel-to-pixel correlation, contrast and homogeneity, and the shape features of fractal dimension and Euler number. Analysis of the region-based diagnostic performance showed that spectroscopic image features from 1 × 1 mm(2) areas were diagnostically discriminant and enabled quantification of within-class tissue heterogeneities.

CONCLUSIONS

Localized scatter-imaging signatures detected by the scanning spectroscopy platform readily distinguished benign from malignant pathologies in surgical tissues and showed new spectral-spatial signatures of clinical breast pathologies.

Microarray Analyses of Genes Differentially Expressed by Diet (Black Beans and Soy Flour) during Azoxymethane-Induced Colon Carcinogenesis in Rats

We previously demonstrated that black bean (BB) and soy flour (SF)-based diets inhibit azoxymethane (AOM)-induced colon cancer. The objective of this study was to identify genes altered by carcinogen treatment in normal-appearing colonic mucosa and those attenuated by bean feeding. Ninety-five male F344 rats were fed control (AIN) diets upon arrival. At 4 and 5 weeks, rats were injected with AOM (15 mg/kg) or saline and one week later administered an AIN, BB-, or SF-based diet. Rats were sacrificed after 31 weeks, and microarrays were conducted on RNA isolated from the distal colonic mucosa. AOM treatment induced a number of genes involved in immunity, including several MHC II-associated antigens and innate defense genes (RatNP-3, Lyz2, Pla2g2a). BB- and SF-fed rats exhibited a higher expression of genes involved in energy metabolism and water and sodium absorption and lower expression of innate (RatNP-3, Pla2g2a, Tlr4, Dmbt1) and cell cycle-associated (Cdc2, Ccnb1, Top2a) genes. Genes involved in the extracellular matrix (Col1a1, Fn1) and innate immunity (RatNP-3, Pla2g2a) were induced by AOM in all diets, but to a lower extent in bean-fed animals. This profile suggests beans inhibit colon carcinogenesis by modulating cellular kinetics and reducing inflammation, potentially by preserving mucosal barrier function.

Potentially functional genetic variants in KDR gene as prognostic markers in patients with resected colorectal cancer

Angiogenesis plays a key role in the development and treatment response of various tumors. The signaling transductions mediated by the binding of vascular endothelial growth factor (VEGF) to its receptor KDR (kinase insert domain receptor) is the most important pathway in tumor angiogenesis. Single nucleotide polymorphisms (SNPs) in VEGF have been extensively implicated in the etiology and treatment outcome of colorectal cancer (CRC). However, no study has been reported evaluating the role of KDR SNPs in CRC prognosis. We herein assessed the association between four potentially functional KDR SNPs and tumor recurrence in a Chinese population with 408 surgically resected CRC patients. The most significant SNP was for rs10013228 located in the KDR gene promoter. Compared with the homozygous wild-type genotype, the variant-containing genotypes of this SNP were significantly associated with a reduced recurrence risk with a hazard ratio (HR) of 0.53 (95% confidence interval [CI] 0.30-0.95, P = 0.032). Moreover, a borderline significant association was noted for another promoter SNP, rs2071559, with an HR of 0.67 (95% CI 0.42-1.07, P = 0.092). In stratified analysis, the associations of both SNPs were more prominent in patients receiving chemotherapy (HR = 0.47, 95% CI 0.23-0.94, P = 0.033 for rs10013228 and HR = 0.55, 95% CI 0.32-0.95, P = 0.032 for rs2071559). Further analysis revealed a protective effect on patient recurrence by chemotherapy (HR = 0.56, 95% CI 0.32-1.01, P = 0.046), which was more evident in patients with the variant-containing genotypes of each of the two SNPs (HR = 0.09, 95% CI 0.02-0.55, P = 0.009 for rs10013228 and HR = 0.39, 95% CI 0.18-0.86, P = 0.020 for rs2071559). Collectively, our findings suggest SNPs in the KDR gene modulate CRC recurrence, especially in those receiving chemotherapy.

The effect of erythropoietin on anastomotic healing of irradiated rats

AIM

The aim of the present study is to evaluate the possible protective effects of erythropoietin (EPO) on anastomotic wound healing after preoperative radiotherapy according to its pleiotropic mechanism of action.

METHODS

Thirty-two male Wistar albino rats were randomized into four groups containing eight rats each: ANAS group, standard resection plus anastomosis; RT+ANAS group, radiation plus standard resection plus anastomosis; ANAS+EPO group, standard resection plus anastomosis plus EPO; RT+ANAS+EPO, radiation plus standard resection plus anastomosis plus EPO. All animals were sacrificed by cardiac puncture, and anastomotic healing was measured by bursting pressure, hydroxyproline (OHP) levels, myeloperoxidase (MPO) activity and histopathological evaluations. Malondialdehyde (MDA), tumor necrosis factor-alpha (TNF-α), and matrix metalloproteinase-9 (MMP-9) were also measured in serum specimens.

RESULTS

OHP levels in the RT+ANAS + EPO group were significantly increased compared with other groups (p < .05). In contrast, MPO activity in the RT+ANAS+EPO group was significantly decreased compared with other groups (p < .05). Serum MDA levels were found to be decreased in the ANAS+EPO and RT+ANAS+EPO groups (p < .05). Group comparisons demonstrated that bursting pressure was significantly higher in EPO treated rats (p < .05). The histopathology results revealed that EPO treatment improves anastomotic wound healing though decreased necrosis and inflammatory cell infiltration and increased fibroblast activity.

CONCLUSION

The findings of the present study indicate that EPO contributes to wound healing and the strength of colon anastomosis following radiation due to its antioxidant and anti-inflammatory effects, but further studies are needed to explore the significance of these effects.

Nodal staging of rectal cancer: high-resolution pelvic MRI versus ¹⁸F-FDGPET/CT

AIM

To compare high-resolution pelvic magnetic resonance imaging (MRI) with positron emission tomography (PET)/computed tomography (CT) for the preoperative assessment of nodal staging in rectal cancer.

MATERIALS AND METHODS

Thirty patients who had surgery for rectal cancer were retrospectively enrolled during a 6-month period. Each patient underwent high-resolution pelvic MRI and PET/CT preoperatively within the same week. An experienced radiologist predicted nodal staging on MR, and an experienced nuclear medicine physician similarly predicted nodal staging on PET/CT. Their predictions were compared with pathologic staging results, retrospectively.

RESULTS

The accuracies of nodal status prediction from MR and PET/CT were 83% and 70%, respectively. Magnetic resonance imaging had a sensitivity of 94% and a specificity of 67%, whereas PET/CT had a sensitivity of 61% and a specificity of 83%. A combination of MRI and PET/CT revealed a sensitivity of 94%, a specificity of 83%, and an accuracy of 90%.

CONCLUSION

High-resolution pelvic MRI was more accurate than PET/CT for the prediction of regional nodal status. Magnetic resonance imaging had a high sensitivity and PET/CT had a high specificity for N staging in rectal cancer.

The influence of fecal diversion and anastomotic leakage on survival after resection of rectal cancer

BACKGROUND

We analyzed factors associated with the occurrence of anastomotic leakage (AL) and its impact on long-term survival in patients who have undergone resection for rectal cancer. We also investigated the effect of fecal diversion on survival.

METHOD

Clinical data of patients who received surgery for rectal cancer were reviewed. The difference in AL incidence among different groups was compared and survival rates were calculated. Cox's proportional hazards model was used to compare survival in patients who developed AL or received diversion stoma with those who did not.

RESULTS

Of 999 patients who received resection and anastomosis, 53 patients experienced AL. Multivariate analysis revealed advanced age (P = 0.009) and operative method (P = 0.002) were independent risk factors for AL. Anastomotic leakage was an independent risk factor for overall recurrence (HR 2.30; 95% CI 1.12-4.73). Anastomotic leakage and fecal diversion were independent prognostic factors of overall survival (P = 0.002 and P < 0.001, respectively), cancer-specific survival (P = 0.002 and P < 0.001, respectively), and disease-free survival (P < 0.001, respectively).

CONCLUSIONS

Patients who are older and have anastomosis at the anorectal junction or dentate line have an increased risk of AL. A diversion stoma does not appear to decrease the incidence of anastomotic leakage, but may decrease the need of reoperation when leakage occurred. Anastomotic leakage and fecal diversion are independent prognostic factors of overall, cancer-specific, and disease-free survival.

Melanoma-associated antigen (MAGE) expression in the normal mucosa around colorectal cancer after curative resection: presence of undetectable free cancer cells

PURPOSE

Curative surgical resection is of great importance and some trials have been performed to identify free undetectable cancer cells using molecular markers. The aim of this study is to investigate melanoma-associated antigen (MAGE) expression in normal mucosa around colorectal cancer and its clinical significance.?

MATERIAL AND METHOD

From October 2003 to June 2004, we collected 46 colorectal cancer and matched normal mucosal tissues within 20 mm, 20 to 50 mm and more than 50 mm from tumors after the curative operation. Twenty-two mucosal tissues were harvested from patients with benign colorectal diseases as controls. MAGE expression was assayed using nested RT-PCR of MAGE A1-6 mRNA.?

RESULTS

The MAGE expression rates in cancer tissue and adjacent normal mucosa were 65.2%, 6.5% (<20 mm), 2.2% (20-50 mm) and 0.0% (>50 mm), respectively, while MAGE was not expressed in the mucosa of benign diseases. The MAGE-positive cases in the normal mucosa around tumors were located in the left colon or rectum, and one patient showed anastomotic mucosal site recurrence.?

CONCLUSIONS

MAGE expression in normal-appearing mucosa around colorectal cancer showed some clinical findings suggesting the presence of undetectable free cancer cells after curative resection.

[Surgical approach to the locoregional recurrence of cancer of the rectum]

A literature review has been made on the pelvic recurrence of rectal cancer using the MedLine, Ovid, EMBASE, Cochrane and Cinahl data bases. Assessment of the locoregional recurrence must be made using imaging tests in order to rule out the presence of metastasis, as well as for locating its exact location within the pelvis. As the only curative treatment should be complete resection of the recurrence with negative margins, a pre-operative CT, NMR, endorectal ultrasound and PET-CT must be performed to determine its resectability. For a potential cure, radical resections must be made, with the technique varying according to whether the location is central (axial), posterior (presacral) or lateral, as well as treatment directed at the primary tumour. Neoadjuvant treatments, brachiterapy and intra-operative radiotherapy improve the local control results and survival in these patients.

Prospective evaluation of a colorectal cancer nurse follow-up clinic

AIM

Colorectal Nurse Specialist (CNS) clinics for postoperative follow up of colorectal cancer aim to maintain clinical efficacy while reducing costs. We prospectively studied the efficacy and financial implications of such a clinic.

METHOD

This was a prospective study of all patients attending CNS clinics over 3 years. A lower-risk protocol for patients with Dukes A was used over 3 years and a higher-risk protocol for patients with Dukes B, C or D was used over 5 years. Department of Health Pricing Charts were used to cost the follow-up protocols, and adjustment was performed to calculate the cost of each quality adjusted life year (QALY) gained.

RESULTS

One hundred and ninety-three patients entered into this nurse-led follow-up protocol implemented by the CNS clinic between 2005 and 2007. The Dukes stages and proportions of patients in each stage were as follows: stage A, 13%; stage B, 8%; stage C, 36.3%; and stage D, 9.3%. Ninety-seven per cent underwent curative treatment and 2.6% had palliative treatment. Twenty-one per cent of patients developed recurrent disease. Overall actuarial 5-year survival was 80% and recurrences had a 30% 5-year actuarial survival. The total cost per patient for 3 years of follow up was £1506 and £1179 for lower-risk rectal and nonrectal cancers, respectively. The adjusted cost for each QALY gained for lower-risk tumours was £1914. The total cost per patient with higher-risk tumours was £1814 and £1487 for rectal and nonrectal tumours, respectively. The adjusted cost for each QALY gained was £2180 for higher-risk tumours.

CONCLUSIONS

This clinic demonstrated cost-effective detection of recurrent disease. Computed tomography (CT) was the most sensitive alert test. As all recurrences were detected within 4 years, we suggest that this is the indicated time to follow up.

Experimental study of radioimmunotherapy versus chemotherapy for colorectal cancer

BACKGROUND

Radioimmunotherapy (RIT) has been shown to reduce the incidence of local recurrence of colorectal cancer in an experimental model. The aim of the present study was to investigate the survival benefit of RIT compared with chemotherapy.

METHODS

An anastomosis was constructed in male Wag/Rij rats after intraluminal injection of CC531 tumour cells. The therapeutic efficacy of (177) Lu-labelled MG1 (single intravenous dose of 300 MBq/kg, n = 20) was compared with that of 5-fluorouracil-based chemotherapy (6 weekly cycles administered intraperitoneally, n = 20) and no treatment (n = 20). The primary endpoint was survival. Toxicity was monitored by bodyweight measurement.

RESULTS

Both chemotherapy and RIT affected bodyweight, but the weight of animals in the RIT group remained significantly higher than in the chemotherapy group (median slope of bodyweight plot 0·48 versus 0·30 g/day; P < 0·001). Kaplan-Meier analysis showed that overall survival in the RIT and chemotherapy groups was significantly better than that in the control group (50 and 46 per cent versus 25 per cent respectively after 170 days; P = 0·024 and P = 0·029). Survival after treatment with RIT did not differ from that after chemotherapy (P = 0·911).

CONCLUSION

RIT is as effective as chemotherapy in experimental colorectal cancer.

Risk factors of rectal cancer local recurrence: population-based survey and validation of the Swedish rectal cancer registry

AIM

Despite advances in rectal cancer treatment, local recurrence (LR) remains a significant problem. To select high-risk patients for different treatment options aimed at reducing LR, it is essential to identify LR risk factors.

METHOD

Local recurrence and survival rates of 4153 patients registered 1995-1997 in the Swedish Rectal Cancer Registry were analysed. LR risk factors were analysed by multivariate methods. For LR patients the registry was validated and additional data retrieved.

RESULTS

The 5-year overall and cancer-specific survival rates were 45% and 62% respectively. LR was registered in 326 (8%) patients. After R0-resections for tumours in TNM stages I-III, LR developed in 10% of tumours at 0-5 cm, 8% at 6-10 cm and 6% at 11-15 cm above the anal verge. Preoperative radiotherapy (RT) reduced the LR rate irrespective of height [0-5 cm: OR 0.50 (0.30-0.83), 6-10 cm: OR 0.42 (0.25-0.71), and 11-15 cm: OR 0.29 (0.13-0.64)]. Patients without preoperative RT had significantly higher LR risk after rectal perforation [OR 2.50 (1.48-4.24)], and almost significantly decreased LR risk when rectal washout was performed [OR 0.65 (0.43-1.00)]. Preoperative RT prolonged time to LR but did not significantly influence the survival among LR patients. LR was an isolated tumour manifestation in 103 (39%) patients with validated LR.

CONCLUSION

Preoperative RT should be considered for rectal cancer also in the upper third of the rectum. Intraoperative perforation should be avoided, and rectal washout is indicated as valuable. Follow-up for the detection of isolated LR is important. Extended follow up should be considered for patients treated with RT.

Clinical algorithms for the surgical management of locally recurrent rectal cancer

PURPOSE

Advances in surgical practice have helped expand the options for patients with locally recurrent rectal cancer through improvements in reconstructive options, management of operative complications, addition of intraoperative adjuvant therapies, and postoperative care. This review outlines the presentation and management of patients with locally recurrent rectal cancer, and it describes easy-to-apply clinical algorithms to aid management.

METHODS

The electronic literature was searched for studies reporting outcomes for locally recurrent rectal cancer limited to the English language.

RESULTS

Prospective and retrospective case series and single-center experiences were identified. A total of 106 articles were selected for full-text review of which 82 fulfilled the inclusion criteria. No randomized studies were identified. We found that multimodality treatment of locally recurrent rectal cancer can improve 5-year survival from 0% to over 40%, and selected patients may survive up to 10 years. A mixture of imaging modalities is used in patient selection for surgery. An R0 resection is consistently a favorable prognostic factor. R1 resection and surgery in the setting of oligometastases compare favorably with nonoperative palliation. Although mortality figures remain low, morbidity is significant and mostly wound related.

CONCLUSIONS

Improvements in radiological imaging modalities and technical improvements in surgical and reconstructive options have facilitated more accurate staging, better selection of patients for surgery, reduced morbidity and mortality, and higher R0 resections. Optimal management is in specialist units with a multidisciplinary approach with the use of multimodal therapy.

Intensive or not surveillance of patients with colorectal cancer after curative resection

It is common practice to follow patients with colorectal cancer for some years after resection and/or adjuvant treatment. Data are lacking about how often patients should be seen, what tests should be performed, and what surveillance strategy has a significant impact on patient outcome. Seven randomized trials have addressed this issue, but none had sufficient statistical power. Four published meta-analyses have established that overall survival is significantly improved for patients in the more intensive programs of follow-up. This improvement amounts to a risk difference of 7% (95% CI: 3%-12%, P = 0.002) in 5-year survival. This should be partly attributable to more frequent reoperation for cure of asymptomatic recurrence, or more intense follow-up, as well other factors, such increased psychosocial support and well-being, diet and lifestyle optimization, and/or improved treatment of coincidental diseases. A large-scale multicenter European study [Gruppo Italiano di Lavoro per la Diagnosi Anticipata (GILDA)] is underway to answer the question of what constitutes optimal surveillance for patients after primary therapy, based on an adequately powered study.

Imaging as a surveillance tool in rectal cancer

Despite advances in diagnosis and treatment, half of patients with treated rectal cancer will die owing to recurrent disease. There is no evidence of benefit on survival from an intensive surveillance program, even if presymptomatic recurrent disease is detected. The aim of this article is to review the results described for the different imaging techniques in diagnosing rectal cancer recurrence in different sites and to discuss their relative clinical impact. The sensitivity of imaging techniques is related to the performance of the machines and the site being examined. Computed tomography is the most used technique owing to its availability, speed, panoramic images and ease of use, while MRI of the pelvis and the liver produces the highest resolution, sensitivity and specificity in these anatomical areas. Owing to its high cost, [(18)F] fluorodeoxyglucose-PET should be used as a third-level examination, a 'problem-solving' method when the site of recurrence is unknown or to rule out other possible sites of recurrence before a second surgery, and, finally, because it offers the possibility to investigate the whole body. The follow-up must be designed for individual patients, taking into account a number of factors. In the near future, whole-body imaging, probably by MRI, that is free from radiation will become the method of choice for screening for recurrent disease.

PET/CT pattern analysis for surgical staple line recurrence in patients with colorectal cancer

OBJECTIVE

The purpose of our study was to determine whether (18)F-FDG PET/CT interpretation with metabolic-anatomic pattern analysis can be used to accurately assess for surgical staple line recurrence after colorectal cancer resection.

MATERIALS AND METHODS

Seventy-nine consecutive patients with previous surgical resection of colorectal cancer were studied retrospectively. The surgical anastomotic or Hartmann's pouch staple lines were evaluated for presence or absence of tumor recurrence with FDG PET/CT metabolic-anatomic pattern analysis. Focal, eccentric, or perianastomotic CT masses with any associated PET pattern were regarded as positive for staple line recurrence. If the perianastomotic CT abnormality was presacral in location, then FDG uptake at least as intense as normal liver was required for positive interpretation. Eccentric or perianastomotic PET patterns matched with normal or diffuse thickening CT patterns were regarded as indeterminate. Presence or absence of recurrent tumor was confirmed by pathology, surgery, colonoscopy, imaging follow-up of at least 3 months, or clinical follow-up of at least 1 year.

RESULTS

Nine patients (11.4%) had staple line recurrence and 70 (88.6%) did not. FDG PET/CT interpretation yielded sensitivity, specificity, positive predictive value, negative predictive value, and accuracy results of 100% (9/9), 97.1% (68/70), 81.8% (9/11), 100% (68/68), and 97.5% (77/79), respectively. All nine patients with staple line recurrence showed perianastomotic or eccentric masses on CT, eight with matching perianastomotic or eccentric FDG uptake patterns. Background, diffuse, curvilinear, or focal FDG uptake patterns, regardless of FDG uptake intensity, paired with normal findings or diffuse mural thickening on CT were seen only in patients without staple line recurrence.

CONCLUSION

FDG PET/CT pattern analysis enables accurate assessment for staple line recurrence in patients with previous resection of colorectal cancer. The most reliable PET/CT pattern predicting staple line recurrence is an eccentric or perianastomotic mass on CT with corresponding eccentric or perianastomotic FDG uptake on PET. Background, diffuse (on one or both sides of the staple line), curvilinear, and focal patterns of FDG uptake do not correlate with recurrence in the absence of a mass on CT.

Radioimmunotherapy prevents local recurrence of colonic cancer in an experimental model

Background

Radioimmunotherapy (RIT) is suitable for the treatment of microscopic residual disease and might therefore have an adjuvant role after colonic cancer surgery.

Methods

An anastomosis was constructed in male Wag/Rij rats after intraluminal injection of 2 × 106 CC531 tumour cells. The biodistribution of 111In-labelled MG1 monoclonal antibody was assessed after intraperitoneal administration. The therapeutic efficacy of 177Lu-labelled MG1 (74 MBq per rat), administered on the day of surgery (D0, n = 13) or 5 days later (D5, n = 13), was compared with that of carrier only (n = 13). The primary endpoint was perianastomotic tumour growth 28 days after surgery.

Results

111In-labelled MG1 preferentially accumulated in perianastomotic CC531 tumours. RIT resulted in a transient reduction in bodyweight in both treatment groups compared with controls, but there were no other signs of clinical discomfort. No macroscopic or microscopic perianastomotic tumour growth was found in eight of 11 animals in the D0 group and 11 of 13 in the D5 group, whereas 11 of 13 controls had macroscopic tumour (P = 0·011 and P = 0·001 respectively).

Conclusion

This study suggests that RIT may be an effective adjuvant treatment for preventing local recurrence after resection of colonic cancer.

Presentation and prognosis of local recurrence after total mesorectal excision

OBJECTIVE

The aim of this study was to describe the presentation, treatment and prognosis of local recurrences following total mesorectal excision for rectal adenocarcinoma.

METHOD

Between 1999 and 2002, 201 patients were treated with total mesorectal excision for mid or low rectal cancer and were followed up prospectively.

RESULTS

Overall 2-year survival was 85%. The 2-year recurrence rate was 8%. Eighteen patients developed local recurrence at 3-60 months. Nine recurrences originated from the pelvic sidewall. These recurrences were symptomatic in 90% of patients. Only two patients were reoperated with a R0 resection and were alive without local recurrence after 19 and 31 months. The seven others died within 9 months. Nine recurrences originated from an anastomotic suture line. Only two had symptoms. A R0 surgical resection was performed in all patients with a 67% sphincter conservation rate. After 26-months of median follow-up (range 7-58), all patients were alive.

CONCLUSION

Half of the local recurrence after total mesorectal excision was located at the anastomotic site. Rectoscopic examination should be performed regularly to detect these anatomotic recurrences that are accessible to a R0 itérative resection.

Simplification of total mesorectal excision with colonic J-pouch anal anastomosis for middle and lower rectal cancer: one surgeon's experience

PURPOSE

The introduction of total mesorectal excision (TME) has dramatically improved local control of rectal cancer. Yet, despite its complexity, there is no clear technical explanation of this procedure in the text references. Thus, we attempted to simplify the TME procedure according to its original concept.

METHODS

Our procedure has three principles: posterolateral dissection, which is helpful for performing complete TME with autonomic nerve preservation; detachment of the hiatal ligament, which enables mobilization of the whole mesorectum and transection of the distal rectum just above the anal canal; and colonic J-pouch anal anastomosis to support fecal continence. We evaluated our modified TME, focusing on one surgeon's experience.

RESULTS

Between 1993 and 2006, 164 patients underwent modified TME, performed by one surgeon (M.K.). Intraoperative blood loss and operating time were both significantly lower than for conventional resection (P<0.01), and the rate of anastomotic leakage was less than 1%. Modified TME combined with radiotherapy or chemotherapy, or both, also improved prognosis considerably.

CONCLUSION

We have succeeded in simplifying the original TME procedure and improved its outcome even further, based on our familiarity with its anatomyoriented elements.

Should the surgeon or the general practitioner (GP) follow up patients after surgery for colon cancer? A randomized controlled trial protocol focusing on quality of life, cost-effectiveness and serious clinical events

BACKGROUND

All patients who undergo surgery for colon cancer are followed up according to the guidelines of the Norwegian Gastrointestinal Cancer Group (NGICG). These guidelines state that the aims of follow-up after surgery are to perform quality assessment, provide support and improve survival. In Norway, most of these patients are followed up in a hospital setting. We describe a multi-centre randomized controlled trial to test whether these patients can be followed up by their general practitioner (GP) without altering quality of life, cost effectiveness and/or the incidence of serious clinical events.

METHODS AND DESIGN

Patients undergoing surgery for colon cancer with histological grade Dukes's Stage A, B or C and below 75 years of age are eligible for inclusion. They will be randomized after surgery to follow-up at the surgical outpatient clinic (control group) or follow-up by the district GP (intervention group). Both study arms comply with the national NGICG guidelines. The primary endpoints will be quality of life (QoL) (measured by the EORTC QLQ C-30 and the EQ-5D instruments), serious clinical events (SCEs), and costs. The follow-up period will be two years after surgery, and quality of life will be measured every three months. SCEs and costs will be estimated prospectively. The sample size was 170 patients.

DISCUSSION

There is an ongoing debate on the best method of follow-up for patients with CRC. Due to a wide range of follow-up programmes and paucity of randomized trials, it is impossible to draw conclusions about the best combination and frequency of clinic (or family practice) visits, blood tests, endoscopic procedures and radiological examinations that maximize the clinical outcome, quality of life and costs. Most studies on follow-up of CRC patients have been performed in a hospital outpatient setting. We hypothesize that postoperative follow-up of colon cancer patients (according to national guidelines) by GPs will not have any impact on patients' quality of life. Furthermore, we hypothesize that there will be no increase in SCEs and that the incremental cost-effectiveness ratio will improve.

TRIAL REGISTRATION

This trial has been registered at ClinicalTrials.gov. The trial registration number is: NCT00572143.