ABSTRACT
OBJECTIVE: The relationship of tumour site with post-recurrence course and outcome after primary surgery in resectable colorectal cancer is unclear. This study investigated the prognostic impact of primary tumour location following radical resection without preoperative treatment in Stage I-III colorectal cancer. METHODS: We analyzed 3770 patients with Stage I-III colorectal cancer who underwent curative resection at our hospital during 2000-15. We defined the right-sided colon as the cecum, ascending colon and transverse colon, and the left-sided colon as the descending colon, sigmoid and rectosigmoid junction. Patients were divided into three groups according to tumour site: right-sided colon, left-sided colon and rectum. Endpoints were overall survival, recurrence-free survival by stage and survival after recurrence, respectively. RESULTS: The 5-year overall survival rates of patients with stage I left-sided colon cancer, right-sided colon cancer and rectal cancer were 98.2, 97.3 and 97.2%, respectively (P = 0.488). The 5-year overall survival rates of patients with Stage II left-sided colon cancer, right-sided colon cancer and rectal cancer were 96.2, 88.7 and 83.0, respectively (P = 0.070). The 5-year overall survival rates of patients with Stage III left-sided colon cancer, right-sided colon cancer and rectal cancer were 88.7, 83.0 and 80.2, respectively (P = 0.001). The 5-year recurrence-free survival rates of patients with Stage I left-sided colon cancer, right-sided colon cancer and rectal cancer were 95.1, 94.5 and 90.6% (P = 0.027). The 5-year recurrence-free survival rates of patients with Stage II left-sided colon cancer, right-sided colon cancer and rectal cancer were 85.2, 90.2 and 76.1%, respectively (P < 0.001). The 5-year recurrence-free survival rates of patients with Stage III left-sided colon cancer, right-sided colon cancer and rectal cancer were 75.3, 75.3 and 59.8%, respectively (P < 0.001). Right-sided colon cancer was significantly associated with better recurrence-free survival compared with left-sided colon cancer (HR 1.29, 95% CI 1.03-1.63; P = 0.025) and rectal cancer (HR 1.89, 95% CI 1.51-2.38; P < 0.001) after adjusting for clinical factors. Amongst patients with recurrence, right-sided colon cancer was significantly associated with poorer survival after recurrence compared with left-sided colon cancer (HR 0.68, 95% CI 0.48-0.97; P = 0.036), and showed a tendency towards poorer survival after recurrence compared with rectal cancer (HR 0.79, 95% CI 0.57-1.10; P = 0.164). CONCLUSIONS: In Stage I-III colorectal cancer without preoperative treatment, our results suggest that the three tumour sites (right-sided colon, left-sided colon or rectum) may have prognostic significance for recurrence-free survival and survival after recurrence, rather than sidedness alone.
Subject(s)
Colorectal Neoplasms , Neoplasm Recurrence, Local , Neoplasm Staging , Humans , Male , Female , Retrospective Studies , Aged , Middle Aged , Prognosis , Colorectal Neoplasms/pathology , Colorectal Neoplasms/surgery , Colorectal Neoplasms/mortality , Neoplasm Recurrence, Local/pathology , Survival Rate , Aged, 80 and over , Adult , Disease-Free SurvivalABSTRACT
BACKGROUND: The impact of primary tumour location on the prognosis of patients with peritoneal metastasis (PM) arising from colorectal cancer (CRC) after cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) is rarely discussed, and the evidence is still limited. METHODS: Patients with PM arising from CRC treated with CRS and HIPEC at the China National Cancer Center and Huanxing Cancer Hospital between June 2017 and June 2019 were systematically reviewed. Clinical characteristics, pathological features, perioperative parameters, and prognostic data were collected and analysed. RESULTS: A total of 70 patients were divided into two groups according to either colonic or rectal origin (18 patients in the rectum group and 52 patients in the colon group). Patients with PM of a colonic origin were more likely to develop grade 3-4 postoperative complications after CRS+HIPEC (38.9% vs 19.2%, P = 0.094), but this difference was not statistically significant. Patients with colon cancer had a longer median overall survival (OS) than patients with rectal cancer (27.0 vs 15.0 months, P = 0.011). In the multivariate analysis, the independent prognostic factors of reduced OS were a rectal origin (HR 2.15, 95% CI 1.15-4.93, P = 0.035) and incomplete cytoreduction (HR 1.99, 95% CI 1.06-4.17, P = 0.047). CONCLUSION: CRS is a complex and potentially life-threatening procedure, and we suggest that the indications for CRS+HIPEC in patients with PM of rectal origin be more restrictive and that clinicians approach these cases with caution.
Subject(s)
Colorectal Neoplasms , Hyperthermia, Induced , Peritoneal Neoplasms , Colorectal Neoplasms/drug therapy , Combined Modality Therapy , Cytoreduction Surgical Procedures , Humans , Hyperthermic Intraperitoneal Chemotherapy , Peritoneal Neoplasms/drug therapy , Prognosis , Survival RateABSTRACT
In recently published data, the predictive value of primary tumour location for the treatment of metastatic colorectal cancer with available biologic therapies has been explored. Recognizing the potential effect of those data on clinical practice, we convened a meeting of Canadian experts who treat metastatic colorectal cancer to develop a set of national, evidence-based treatment guidelines based on primary tumour location. This report summarizes the relevant evidence and presents the consensus recommendations of those experts.
ABSTRACT
BACKGROUND: Retrospective subgroup analyses of previous trials in the first-line therapy of RAS wt metastatic colorectal cancer (mCRC) suggested a predictive impact of primary tumour side on the efficacy of anti-epidermal growth factor receptor (EGFR) agents. Recently, new head-to-head trials of doublets/bevacizumab versus doublets/anti-EGFR, PARADIGM and CAIRO5 were presented. PATIENTS AND METHODS: We searched for phase II and III trials comparing doublet chemotherapy plus an anti-EGFR or bevacizumab as the first-line treatment for RAS wt mCRC patients. Overall survival (OS), progression-free survival (PFS), overall response rate (ORR) and radical resection rate result in the overall study populations and, according to the primary side, were pooled together in a two-stage analysis with random effects and fixed effect models. The interaction between sidedness and treatment effect was then analysed. RESULTS: We identified five trials (PEAK, CALGB/SWOG 80405, FIRE-3, PARADIGM and CAIRO5), including 2739 patients, 77% left- and 23% right-sided. Among patients with left-sided mCRC, the use of anti-EGFRs was associated with higher ORR (74% versus 62%, OR = 1.77 [95% confidence interval {CI} 1.39-2.26-0.88], p < 0.0001), longer OS (hazard ratio [HR] = 0.77 [95% CI 0.68-0.88], p < 0.0001) and not significantly longer PFS (HR = 0.92, p = 0.19). Among patients with right-sided mCRC, the use of bevacizumab was associated with longer PFS (HR = 1.36 [95% CI 1.12-1.65], p = 0.002) and not significantly longer OS (HR = 1.17, p = 0.14). A subgroup analysis confirmed a significant interaction effect between the primary tumour side and treatment arm in terms of ORR (p = 0.02), PFS (p = 0.0004) and OS (p = 0.001). No differences in the radical resection rate were found according to treatment and sidedness. CONCLUSIONS: Our updated metanalysis corroborates the role of the primary tumour location in the choice of the upfront therapy for RAS wt mCRC patients, leading to strongly recommend anti-EGFRs in left-sided tumours and to prefer bevacizumab in the right-sided.
Subject(s)
Colonic Neoplasms , Colorectal Neoplasms , Rectal Neoplasms , Humans , Bevacizumab/therapeutic use , Panitumumab/therapeutic use , Colorectal Neoplasms/drug therapy , Colorectal Neoplasms/genetics , Retrospective Studies , Colonic Neoplasms/drug therapy , Rectal Neoplasms/drug therapy , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Cetuximab/therapeutic use , Randomized Controlled Trials as TopicABSTRACT
BACKGROUND: Molecular biomarkers and primary tumour sidedness guide treatment decisions in metastatic colorectal cancer. Comprehensive molecular profiling aims to identify targetable alterations and measure tumour mutational burden (TMB) to enable precision oncology. MATERIAL AND METHODS: FoundationOne® next-generation sequencing identified single-nucleotide variants (SNVs), copy number alterations, high TMB (TMB-H) and high-grade microsatellite instability (MSI-H) in patients treated in the FIRE-3 trial. Data were correlated with objective response rate (ORR), progression-free survival (PFS) and overall survival (OS). RESULTS: Three hundred seventy-three (49.6%) of 752 patients provided material for this analysis. Frequent SNVs included TP53, APC, KRAS, PIK3CA, BRAF, SMAD4 and FBXW7. KRAS, BRAF V600E and SMAD4 mutations were confirmed as prognostic biomarkers by logistic penalised regression for ORR. OS was significantly longer in patients with SMAD4 wild-type (WT) tumours than in those with SMAD4-mutated tumours (hazard ratio = 0.59 [95% confidence interval {CI} = 0.34-1.01], p = 0.05), with a higher probability of ORR [odds ratio, SMAD4 SNV versus WT = 0.32 [95% CI = 0.10-0.98], p = 0.05] when treated with cetuximab. MSI-H (30.0%, p = 0.03) and TMB-H (17.3%, p = 0.003) tumours were enriched by FBXW7 mutations. Numerically lower ORR, OS and PFS were observed in MSI-H tumours. CONCLUSIONS: RAS, BRAF V600E and SMAD4 mutations were identified as poor prognostic biomarkers in patients of the FIRE-3 trial, whereas improved outcome was observed for BRAF non-V600E mutation. SMAD4 mutation might provide predictive relevance for cetuximab efficacy. MSI-H tumours showed numerically lower ORR, OS and PFS.
Subject(s)
Colorectal Neoplasms/genetics , High-Throughput Nucleotide Sequencing/methods , Polymorphism, Single Nucleotide/genetics , Tumor Burden/genetics , Adult , Aged , Colorectal Neoplasms/pathology , Female , Humans , Male , Microsatellite Instability , Middle Aged , Neoplasm Metastasis , Retrospective StudiesABSTRACT
Purpose: Metastatic colorectal cancer (mCRC) is a group of distinct diseases, with clinical and molecular differences between right-sided and left-sided tumours driving varying prognosis. Methods: Patients with KRAS/RAS-wild type (wt) mCRC treated in first line with epidermal growth factor receptor inhibitors (EGFR-Is) (cetuximab or panitumumab) plus oxaliplatin or irinotecan-based chemotherapy from two phase II randomised trials conducted by the Spanish Cooperative for the Treatment of Digestive Tumours group were included in this retrospective study. The main objective was to analyse the prognostic effect of primary tumour location on objective response rate (ORR), progression-free survival (PFS) and overall survival (OS). Results: Patients with KRAS-wt right-sided tumours (n=52) had significantly lower efficacy as compared with patients with KRAS-wt left-sided tumours (n=209); confirmed ORR (25% vs 47%, respectively; OR 0.4, 95% CI 0.2 to 0.8, p=0.004); and shorter median PFS (7.2 vs 9.9 months; HR 0.6, 95% CI 0.4 to 0.9, p=0.0157) and OS (13.6 vs 27.7 months; HR 0.5, 95% CI 0.3 to 0.7, p<0.0001). Similar results were observed in the RAS-wt populations. The further classification of left-sided tumours as colon or rectum delivered similar survival outcomes, as well as a tendency to diminished ORR in patients with rectum tumours. Conclusion: We observed significantly improved efficacy outcomes in patients with KRAS/RAS-wt mCRC treated with first-line EGFR-I plus chemotherapy in left-sided primary tumours as compared with right-sided primary tumours. Trial registration numbers: NCT01161316 and NCT00885885.
Subject(s)
Antineoplastic Agents, Immunological/therapeutic use , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Colorectal Neoplasms/drug therapy , Adult , Aged , Aged, 80 and over , Antineoplastic Agents, Immunological/pharmacology , Antineoplastic Combined Chemotherapy Protocols/pharmacology , Cetuximab/pharmacology , Cetuximab/therapeutic use , Colorectal Neoplasms/genetics , Colorectal Neoplasms/mortality , Colorectal Neoplasms/pathology , Disease Progression , ErbB Receptors/antagonists & inhibitors , Female , GTP Phosphohydrolases/genetics , Humans , Irinotecan/pharmacology , Irinotecan/therapeutic use , Male , Membrane Proteins/genetics , Middle Aged , Oxaliplatin/pharmacology , Oxaliplatin/therapeutic use , Panitumumab/pharmacology , Panitumumab/therapeutic use , Prognosis , Progression-Free Survival , Proto-Oncogene Proteins p21(ras)/genetics , Retrospective Studies , Time FactorsABSTRACT
BACKGROUND: Epidermal growth factor receptor signalling blockade increases CCL5 expression that regulates either the anti-tumour immune response or tumour progression. We investigated the potential role of CCL5/CCR5 axis in cetuximab-based treatment in metastatic colorectal cancer (mCRC) patients. PATIENTS AND METHODS: Genomic DNA was extracted from 491 samples of two different cohorts with KRAS wild-type mCRC from the FIRE-3 trial: an evaluation cohort of 244 patients receiving cetuximab plus FOLFIRI and a control cohort of 247 patients receiving bevacizumab plus FOLFIRI. Single-nucleotide polymorphisms (SNPs) of CCL5 and CCR5 genes were analysed by polymerase chain reaction-based direct sequencing. RESULTS: Patients in the evaluation cohort with any CCL5 rs2280789G allele had shorter overall survival (OS) compared with those with the A/A variant (hazard ratio 1.56, P = 0.024). Patients carrying any CCR5 rs1799988T allele had a trend toward lower response rate than those with the C/C variant (68 vs. 81%, P = 0.078). In the analysis based on primary tumour location (left-sided [L]: right-sided [R]), remarkable differences in outcomes were observed between patients with L-CCR5 SNPs C/C variant (L-C/C), L-any T, R-T/T and R-any C as follows: median OS, 38.5, 30.6, 27.1 and 15.8 months, P < 0.001; response rate, 91, 66, 92 and 48%, P < 0.001. Median OS for CCL5 SNPs including L-A/A, L-any G, R-A/A and R-any G groups were 38.3, 21.7, 21.9 and 18.3 months, P < 0.001. The findings were not significant in the control cohort. CONCLUSION: Genetic variants of CCL5 and CCR5 SNPs may predict outcomes in mCRC patients receiving cetuximab-based treatment depending on tumour location.
Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Chemokine CCL5/genetics , Colorectal Neoplasms/drug therapy , Colorectal Neoplasms/genetics , Polymorphism, Single Nucleotide , Receptors, CCR5/genetics , Adult , Aged , Aged, 80 and over , Bevacizumab/administration & dosage , Biomarkers, Tumor/genetics , Case-Control Studies , Cetuximab/administration & dosage , Cohort Studies , Colorectal Neoplasms/pathology , ErbB Receptors/antagonists & inhibitors , Female , Follow-Up Studies , Humans , Leucovorin/administration & dosage , Male , Middle Aged , Neoplasm Metastasis , Prognosis , Survival RateABSTRACT
Background: Evidence from a retrospective analysis of multiple large phase iii trials suggested that primary tumour location (ptl) in RAS wild-type metastatic colorectal cancer (wtRAS mcrc) might have predictive value with respect to response to drug therapies. Recent studies also show a potential preferential benefit for epidermal growth factor inhibitors (egfris) for left-sided tumours. In the present study, we aimed to determine the incremental cost-effectiveness ratio (icer) for the first-line use of an egfri for patients with left-sided wtRAS mcrc. Methods: We developed a state-transition model to determine the cost effectiveness of alternative treatment strategies in patients with left-sided mcrc:â Standard of careâ Use of an egfri in first-line therapyThe cohort for the study consisted of patients diagnosed with unresectable wtRAS mcrc with an indication for chemotherapy and previously documented ptl. Model parameters were obtained from the published literature and calibration. The perspective was that of a provincial ministry of health in Canada. We used a 5-year time horizon and an annual discount rate of 1.5%. Results: Selecting patients for first-line egfri treatment based on left-sided location of their colorectal primary tumour was more effective than the standard of care, resulting in an increase in quality-adjusted life-years (qalys) of 0.226 (or 0.644 life-years gained). However, the strategy was also more expensive, costing an average of $60,639 more per patient treated. The resulting icer was $268,094 per qaly. A 35% price reduction in the cost of egfri would be needed to make this strategy cost-effective at a willingness-to-pay threshold (wtp) of $100,000 per qaly. Conclusions: Selective use of an egfri based on ptl was more cost-effective than unselected use of those agents; however, based on traditional wtp thresholds, it was still not cost-effective. While awaiting the elucidation of more precise predictive biomarkers that might improve cost-effectiveness, the price of egfris could be reduced to meet the wtp threshold.
Subject(s)
Antineoplastic Agents/economics , Bevacizumab/economics , Biological Products/economics , Colorectal Neoplasms/economics , Protein Kinase Inhibitors/economics , Antineoplastic Agents/therapeutic use , Antineoplastic Combined Chemotherapy Protocols/economics , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Bevacizumab/therapeutic use , Biological Products/therapeutic use , Camptothecin/analogs & derivatives , Camptothecin/economics , Camptothecin/therapeutic use , Cetuximab/economics , Cetuximab/therapeutic use , Colorectal Neoplasms/drug therapy , Colorectal Neoplasms/genetics , Colorectal Neoplasms/pathology , Cost-Benefit Analysis , ErbB Receptors/antagonists & inhibitors , Fluorouracil/economics , Fluorouracil/therapeutic use , Humans , Leucovorin/economics , Leucovorin/therapeutic use , Organoplatinum Compounds/economics , Organoplatinum Compounds/therapeutic use , Protein Kinase Inhibitors/therapeutic use , ras Proteins/geneticsABSTRACT
BACKGROUND: Primary tumour location has long been debated as a prognostic factor in colorectal cancer patients with liver metastases (CRLM) undergoing liver resection. This retrospective study was conducted to clarify the prognostic value of tumour location after radical hepatectomy for CRLM and its underlying causes. METHODS: We retrospectively analysed clinical data from 420 patients with CRLM whom underwent liver resection between January 2002 and December 2015. Right-sided (RS) tumours include tumours located in the cecum, ascending colon, and transverse colon, and left-sided (LS) tumours include those located in the splenic flexure, descending colon, sigmoid colon, and rectum. RESULTS: Both overall survival (OS) and disease-free survival (DFS) were similar between patients with RS and LS primary tumours (5-year OS: 46.5% vs 38.3%, P = 0.699; 5-year DFS: 29.1% vs 22.4%, P = 0.536). Specifically, RAS mutation rate was significantly higher in patients with RS tumours (P = 0.007). Subgroup analysis showed that the RAS mutation on the LS and RS tumours have different prognostic impact for CRLM patients on long-term survival after hepatic resection (RS, OS: P = 0.437, DFS: P = 0.471; LS, OS: P < 0.001, DFS: P = 0.002). The multivariable analysis showed that RAS mutant is an independent factor influencing OS in patients with LS primary tumour only. CONCLUSIONS: The site of the primary tumour has no significant impact on the long-term survival in patients with CRLM undergoing radical surgery. However, prognostic value of RAS status differs depending on the site of the primary tumour.
Subject(s)
Colorectal Neoplasms/pathology , Hepatectomy/methods , Liver Neoplasms/secondary , Aged , China/epidemiology , Colorectal Neoplasms/mortality , Diffusion Magnetic Resonance Imaging , Disease-Free Survival , Female , Follow-Up Studies , Humans , Liver Neoplasms/diagnosis , Liver Neoplasms/surgery , Male , Middle Aged , Neoplasm Metastasis , Positron Emission Tomography Computed Tomography , Retrospective Studies , Survival Rate/trendsABSTRACT
BACKGROUND: The major prognostic relevance of primary tumour location (LPT) in advanced colorectal cancer was shown in large retrospective studies, but quantitative estimates are highly heterogeneous, and there is still limited information about its impact within the framework of biomarker-guided treatment strategies. Therefore, we analysed LPT in relation to other clinical and molecular parameters, based on mature survival data from the recent randomised AIO KRK0207 trial. METHODS: Patients uniformly received first-line induction treatment with a combination of bevacizumab, oxaliplatin and fluoropyrimidine. LPT was retrospectively determined using surgical reports, pathology reports and endoscopy reports. The prognostic analyses were performed using Kaplan-Meier estimations and log-rank tests, while hazard ratios (HRs) and multivariable results were derived from Cox models. RESULTS: Among 754 patients with unequivocal information on LPT, patients with left-sided tumours showed a median overall survival of 24.8 months compared with the right-sided cohort with 18.4 months (HR: 1.54, 95% confidence interval: 1.30-1.81, P < 0.0001). In a multivariable model, LPT proved to be the strongest prognosticator (HR 1.60), with performance status, number of metastatic sites, baseline carcinoembryonic antigen (CEA) and platelets independently retaining prognostic significance. In the subgroup of patients with known RAS/BRAF status (n = 567, 75%), a BRAF mutation showed the greatest unfavourable impact (HR 3.16). Although BRAF is strongly correlated to LPT, the latter remained a significant prognosticator in the BRAF wild-type subgroup. In contrast, no major impact of LPT was seen on tumours carrying RAS mutations. CONCLUSIONS: Within the framework of a uniform treatment strategy according to the current standards, LPT proved to have an important, although not solely dominating, relevance for survival prognosis. Its impact seems to be low in tumours with a RAS mutation. REGISTRATION: ClinicalTrials.govNCT00973609.
Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Colon/drug effects , Colorectal Neoplasms/drug therapy , Rectum/drug effects , Adult , Aged , Aged, 80 and over , Bevacizumab/administration & dosage , Colon/metabolism , Colon/pathology , Colorectal Neoplasms/genetics , Female , Humans , Kaplan-Meier Estimate , Maintenance Chemotherapy , Male , Middle Aged , Mutation , Oxaliplatin/administration & dosage , Prognosis , Proto-Oncogene Proteins B-raf/genetics , Rectum/metabolism , Rectum/pathology , Retrospective Studies , Young Adult , ras Proteins/geneticsABSTRACT
BACKGROUND: Retrospective subgroup analyses suggest that primary tumour location (PTL) has a prognostic importance and relates to response to targeted therapy. METHODS: We conducted a meta-analysis of first-line clinical trials available up to October 2016, which assessed the relevance of PTL in patients with metastatic colorectal cancer (mCRC). Right- and left-sided colorectal cancers were differentiated (RC and LC). RESULTS: In 13 first-line randomised controlled trials and one prospective pharmacogenetic study, RC was associated with a significantly worse prognosis compared with LC (hazard ratio [HR] for overall survival: 1.56; 95% confidence interval [CI]: 1.43-1.70; P < 0.0001). A meta-analysis of PRIME and CRYSTAL study suggests that PTL was predictive of survival benefit from addition of anti-EGFR antibody to standard chemotherapy in patients with RAS wild-type tumour (overall survival, HR for LC: 0.69; 95% CI: 0.58-0.83; P < 0.0001 and HR for RC: 0.96; 95% CI: 0.68-1.35; P = 0.802). A meta-analysis of FIRE-3/AIO KRK0306, CALGB/SWOG 80405 and PEAK study indicates that patients with RAS wild-type LC had a significantly greater survival benefit from anti-EGFR treatment compared with anti-VEGF treatment when added to standard chemotherapy (HR 0.71; 95% CI: 0.58-0.85; P = 0.0003). By contrast, in patients with RC, benefit from standard therapy was poor and bevacizumab-based treatment was numerically associated with longer survival (HR 1.3; 95% CI: 0.97-1.74; P = 0.081). CONCLUSIONS: The present meta-analysis demonstrates that PTL is prognostic in mCRC. Further, it supports the conclusion that patients with left-sided RAS wild-type mCRC should be preferentially treated with an anti-EGFR antibody. In right-sided mCRC, chemotherapy plus bevacizumab is a treatment option, but optimal treatment has yet to be defined.
Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Colorectal Neoplasms/drug therapy , Colorectal Neoplasms/pathology , Angiogenesis Inhibitors/therapeutic use , Antibodies, Monoclonal/therapeutic use , ErbB Receptors/antagonists & inhibitors , Humans , Prognosis , Randomized Controlled Trials as Topic , Retrospective Studies , Survival Analysis , Vascular Endothelial Growth Factor A/antagonists & inhibitorsABSTRACT
BACKGROUND: No previous Australian population-based studies have described or quantified the progression of colorectal cancer (CRC) to metastatic disease. We describe patterns of progression to metastatic disease for an Australian cohort diagnosed with localised or regional CRC. METHODS: All localised and regional CRC cases in the New South Wales Cancer Registry diagnosed during 2000-2007 were followed to December 2011 for subsequent metastases (identified by subsequent disease episode notifications) or CRC death. Cox regression was used to identify factors associated with metastatic progression. RESULTS: After a median 5.3 years follow-up, 26.4% of the 12757 cases initially diagnosed with localised or regional colon cancer had developed metastatic disease, as had 29.5% of the 7154 rectal cancer cases. For both cancer sites, risk of metastatic progression was significantly higher for those initially diagnosed with regional disease (adjusted hazard ratio [aHR] 3.49 for colon, 2.66 for rectal cancer), and for older cases (e.g. aHR for >79years vs <60years: 1.38 for colon, 1.69 for rectal cancer). Risk of disease progression was significantly lower for females, and varied by histology type. For colon cancer, the risk of disease progression decreased over time. For rectal cancer, risk of metastatic progression was significantly higher for those living in more socioeconomically disadvantaged areas compared with those in the least disadvantaged area. CONCLUSIONS: An understanding of the variation in risk of metastatic progression is useful for planning health service requirements, and can help inform decisions about treatment and follow-up for colorectal cancer patients.