Apical Node Involvement Does Not Influence Prognosis After Potentially Curative Resection for Stage III Colorectal Cancer: A Competing Risks Analysis.

OBJECTIVE: To examine the independent prognostic value of ALN status in patients with stage III CRC. SUMMARY OF BACKGROUND DATA: Early CRC staging classified nodal involvement by level of involved nodes in the operative specimen, including both locoregional and apical node status, in contrast to the American Joint Committee on Cancer/tumor nodes metastasis (TNM) system where tumors are classified by the number of nodes involved. Whether ALN status has independent prognostic value remains controversial. METHODS: Consecutive patients who underwent curative resection for Stage III CRC from 1995 to 2012 at Concord Hospital, Sydney, Australia were studied. ALN status was classified as: (i) ALN absent, (ii) ALN present but not histologically involved, (iii) ALN present and involved. Outcomes were the competing risks incidence of CRC recurrence and CRC-specific death. Associations between these outcomes and ALN status were compared with TNM N status results. RESULTS: In 706 patients, 69 (9.8%) had an involved ALN, 398 (56.4%) had an uninvolved ALN and 239 (33.9%) had no ALN identified. ALN status was not associated with tumor recurrence [adjusted hazard ratio (HR) 1.02, 95% confidence interval (CI) 0.84-1.26] or CRC-specific death (HR 1.14, CI 0.91-1.43). However, associations persisted between TNM N-status and both recurrence (HR 1.58, CI 1.21-2.06) and CRC-specific death (HR 1.59, CI 1.19-2.12). CONCLUSIONS: No further prognostic information was conferred by ALN status in patients with stage III CRC beyond that provided by TNM N status. ALN status is not considered to be a useful additional component in routine TNM staging of CRC.

Recurrence and colon cancer-specific death in patients with large bowel obstruction requiring urgent operation: a competing risks analysis.

AIM: Clinical presentation with large bowel obstruction has been proposed as a predictor of poor long-term oncological outcomes after resection for colorectal cancer. This study examines the association between obstruction and recurrence and cancer-specific death after resection for colon cancer. METHOD: Consecutive patients who underwent resection for colon cancer between 1995 and 2014 were drawn from a prospectively recorded hospital database with all surviving patients followed for at least 5 years. The outcomes of tumour recurrence and colon cancer-specific death were assessed by competing risks multivariable techniques with adjustment for potential clinical and pathological confounding variables. RESULTS: Recurrence occurred in 271 of 1485 patients who had a potentially curative resection. In bivariate analysis, obstruction was significantly associated with recurrence [hazard ratio (HR) 2.23, CI 1.52-3.26, p < 0.001] but this association became nonsignificant after adjustment for confounders (HR 1.53, CI 0.95-2.46, p = 0.080). Colon cancer-specific death occurred in 238 of 295 patients who had a noncurative resection. Obstruction was not significantly associated with cancer-specific death (HR 1.02, CI 0.72-1.45, p = 0.903). In patients who had a noncurative resection, the competing risks incidence of colon cancer-specific death was not significantly greater in obstructed than in unobstructed patients (HR 1.02, CI 0.72-1.45, p = 0.903). CONCLUSION: Whilst the immediate clinical challenge of an individual patient presenting with large bowel obstruction must be addressed by the surgeon, the patient's long-term oncological outcomes are unrelated to obstruction per se.

Src tyrosine kinase phosphorylation of nuclear receptor HNF4α correlates with isoform-specific loss of HNF4α in human colon cancer.

Src tyrosine kinase has long been implicated in colon cancer but much remains to be learned about its substrates. The nuclear receptor hepatocyte nuclear factor 4α (HNF4α) has just recently been implicated in colon cancer but its role is poorly defined. Here we show that c-Src phosphorylates human HNF4α on three tyrosines in an interdependent and isoform-specific fashion. The initial phosphorylation site is a Tyr residue (Y14) present in the N-terminal A/B domain of P1- but not P2-driven HNF4α. Phospho-Y14 interacts with the Src SH2 domain, leading to the phosphorylation of two additional tyrosines in the ligand binding domain (LBD) in P1-HNF4α. Phosphomimetic mutants in the LBD decrease P1-HNF4α protein stability, nuclear localization and transactivation function. Immunohistochemical analysis of approximately 450 human colon cancer specimens (Stage III) reveals that P1-HNF4α is either lost or localized in the cytoplasm in approximately 80% of tumors, and that staining for active Src correlates with those events in a subset of samples. Finally, three SNPs in the human HNF4α protein, two of which are in the HNF4α F domain that interacts with the Src SH3 domain, increase phosphorylation by Src and decrease HNF4α protein stability and function, suggesting that individuals with those variants may be more susceptible to Src-mediated effects. This newly identified interaction between Src kinase and HNF4α has important implications for colon and other cancers.

KRAS mutations and CDKN2A promoter methylation show an interactive adverse effect on survival and predict recurrence of rectal cancer.

Colonic and rectal cancers differ in their clinicopathologic features and treatment strategies. Molecular markers such as gene methylation, microsatellite instability and KRAS mutations, are becoming increasingly important in guiding treatment decisions in colorectal cancer. However, their association with clinicopathologic variables and utility in the management of rectal cancer is still poorly understood. We analyzed CDKN2A gene methylation, CpG island methylator phenotype (CIMP), microsatellite instability and KRAS/BRAF mutations in a cohort of 381 rectal cancers with extensive clinical follow-up data. BRAF mutations (2%), CIMP-high (4%) and microsatellite instability-high (2%) were rare, whereas KRAS mutations (39%), CDKN2A methylation (20%) and CIMP-low (25%) were more common. Only CDKN2A methylation and KRAS mutations showed an association with poor overall survival but these did not remain significant when analyzed with other clinicopathologic factors. In contrast, this prognostic effect was strengthened by the joint presence of CDKN2A methylation and KRAS mutations, which independently predicted recurrence of cancer and was associated with poor overall and cancer-specific survival. This study has identified a subgroup of more aggressive rectal cancers that may arise through the KRAS-p16 pathway. It has been previously shown that an interaction of p16 deficiency and oncogenic KRAS promotes carcinogenesis in the mouse and is characterized by loss of oncogene-induced senescence. These findings may provide avenues for the discovery of new treatments in rectal cancer.

Mural and extramural venous invasion and prognosis in colorectal cancer.

BACKGROUND: Extramural venous invasion is a known independent predictor of poor prognosis after resection of colorectal adenocarcinoma, but the prognostic value of mural venous invasion alone and the association between venous invasion and prognosis within tumor stages has received little research attention. OBJECTIVE: This study aimed to determine whether associations between mural and extramural venous invasion and outcome differ among tumor stages after adjustment for other factors known to influence prognosis. DESIGN: This study is a retrospective analysis of prospectively collected data. SETTINGS: Data were drawn from a registry of 3040 consecutive patients undergoing resection between 1980 and 2005 under the care of specialist surgeons in a tertiary referral public hospital and an affiliated private hospital. A standardized protocol was used for the pathological assessment of specimens. MAIN OUTCOME MEASURES: The primary outcomes measured were overall survival, cancer-specific survival, and recurrence. RESULTS: There was no significant association between venous invasion and survival in stages A (n = 544) or B (n = 1078). In stage C (n = 899), overall survival time was significantly shorter in patients with mural invasion alone or extramural invasion (both p < 0.001) than in those without invasion, and this persisted after adjustment for other prognostic variables. Equivalent bivariate associations were found in stage D, but only the effect of extramural invasion persisted after adjustment. LIMITATIONS: Our findings arise from the experience of a single surgical group and may not be generalizable to other settings. Only hematoxylin and eosin staining was used. CONCLUSIONS: The association between venous invasion and prognosis was stage specific. Both mural venous invasion alone and extramural venous invasion independently predicted overall survival in patients with stage C tumors, but not in patients with stages A, B, or D tumors. Although mural invasion alone was rare, the separate reporting of both mural and extramural invasion in patients with stage C tumor is informative and desirable.

The cost of teaching an intern in New South Wales.

OBJECTIVE: To determine the cost of formal and informal teaching specifically provided for interns and to determine how much of an intern's time is spent in these activities. DESIGN, SETTING AND PARTICIPANTS: Costs of formal teaching for 2012 were obtained from the New South Wales Health Education and Training Institute (HETI) and costs of informal teaching by a survey of all interns in a random sample of prevocational networks. MAIN OUTCOME MEASURES: The cost of formal intern education provided by HETI; the number of hours of formal teaching provided to interns in hospital; intern estimates of the amount of non-timetabled teaching received in a typical week. RESULTS: The cost of formal teaching was $11 892 per intern per year and the cost of informal teaching was $2965 per intern per year (survey response rate, 63%) - a total of $14 857. Interns spent 2 hours per week in formal teaching and 28 minutes per week in informal teaching, representing 6.2% of a 40-hour week. CONCLUSION: The time of professionals paid by NSW Health represents most of the expenditure on teaching interns. An increase in time spent on intern teaching beyond the current 6.2% of an intern's 40-hour week would be an investment in better health care.

Risk factors for prolonged ileus after resection of colorectal cancer: an observational study of 2400 consecutive patients.

OBJECTIVE: Prolonged ileus-the failure of postoperative ileus to resolve within a few days after major abdominal surgery-leads to significant medical consequences for the patient and costs to the hospital system. The aim of this retrospective analysis of prospectively collected data was to identify independent preoperative and intraoperative risk factors for prolonged ileus in a large consecutive series of patients who had undergone resection for colorectal cancer. METHODS: Patients were drawn from a hospital registry of 2400 consecutive resections over the period 1995-2009. Thirty-four potential predictors of prolonged ileus were analyzed by logistic regression. RESULTS: Prolonged ileus occurred in 14.0% of patients. Statistically significant independent predictors of prolonged ileus were male sex (OR: 1.7, P < 0.001), peripheral vascular disease (OR: 1.8, P < 0.001), respiratory comorbidity (OR: 1.6, P < 0.001), resection at urgent operation (OR: 2.2, P < 0.001), perioperative transfusion (OR: 1.6, P < 0.010), stoma constructed (OR: 1.4, P < 0.001), and operation lasting ≥3 hours (OR: 1.6, P < 0.001). CONCLUSIONS: These features can be used to alert medical and nursing staff to patients likely to experience prolonged ileus after bowel resection so that they can be monitored closely in the postoperative period and available treatments targeted toward them. These features may also be useful in the research context to facilitate the more efficient selection of high-risk patients as subjects in clinical trials of prevention or treatment.

Preoperative neutrophil/lymphocyte ratio predicts overall survival but does not predict recurrence or cancer-specific survival after curative resection of node-positive colorectal cancer.

BACKGROUND: The preoperative ratio of neutrophils to lymphocytes (NLR) has been proposed as a marker of poor outcome in patients having a resection for colorectal cancer (CRC). This study investigated the association between NLR and overall survival, cancer-specific survival and recurrent cancer in patients who had a potentially curative resection for node-positive CRC. METHODS: Data on 322 patients were drawn from a prospectively recorded registry operated on between 1999 and 2007. Analyses of survival involved the Kaplan-Meier method, Cox regression and competing risks Cox regression. RESULTS: Increasing NLR as a continuous variable was independently though weakly associated with diminishing overall survival after adjustment for other prognostic variables (HR 1.06, 95% CI 1.01-1.11, p = 0.013). Receiver operating characteristic analysis to dichotomize NLR as a predictor of overall survival yielded relatively poor sensitivity (55%), specificity (66%) and positive predictive value (56%, CI 47%-64%). Competing risks regression also showed that NLR was not independently associated with recurrence at any site (HR 1.04, CI 0.97-1.11, p = 0.241) or CRC-specific mortality (HR 1.02, CI 0.92-1.12, p = 0.782) but was associated with non-CRC mortality (HR 1.09, CI 1.03-1.15, p = 0.004). CONCLUSION: In patients with stage C tumor the weak link between NLR and overall mortality was not specific to CRC but apparently arose because patients with an elevated inflammatory status preoperatively were likely to progress to earlier death but not necessarily because of their cancer.

Glutathione S-transferase Pi expression predicts response to adjuvant chemotherapy for stage C colon cancer: a matched historical control study.

BACKGROUND: This study examined the association between overall survival and Glutathione S-transferase Pi (GST Pi) expression and genetic polymorphism in stage C colon cancer patients after resection alone versus resection plus 5-fluourouracil-based adjuvant chemotherapy. METHODS: Patients were drawn from a hospital registry of colorectal cancer resections. Those receiving chemotherapy after it was introduced in 1992 were compared with an age and sex matched control group from the preceding period. GST Pi expression was assessed by immunohistochemistry. Overall survival was analysed by the Kaplan-Meier method and Cox regression. RESULTS: From an initial 104 patients treated with chemotherapy and 104 matched controls, 26 were excluded because of non-informative immunohistochemistry, leaving 95 in the treated group and 87 controls. Survival did not differ significantly among patients with low GST Pi who did or did not receive chemotherapy and those with high GST Pi who received chemotherapy (lowest pair-wise p = 0.11) whereas patients with high GST Pi who did not receive chemotherapy experienced markedly poorer survival than any of the other three groups (all pair-wise p <0.01). This result was unaffected by GST Pi genotype. CONCLUSION: Stage C colon cancer patients with low GST Pi did not benefit from 5-fluourouracil-based adjuvant chemotherapy whereas those with high GST Pi did.

Clinicopathological correlates and prognostic significance of glutathione S-transferase Pi expression in 468 patients after potentially curative resection of node-positive colonic cancer.

AIMS: This study investigated the association between glutathione S-transferase Pi (GST Pi) expression, histopathology and overall survival in 468 patients after resection of stage C colonic adenocarcinoma. METHODS AND RESULTS: Data were drawn from a prospective hospital registry of consecutive bowel cancer resections with a minimum follow-up of 5 years. Nuclear and cytoplasmic GST Pi expression, assessed by both intensity of staining and percentage of stained cells at both the central part of the tumour and the invasive tumour front, were evaluated retrospectively by tissue microarray immunohistochemistry on archival specimens. The most effective measure of GST Pi expression was the percentage of immunostained nuclei in central tumour tissue, where >40% stained was associated significantly with high grade, invasion beyond the muscularis propria, involvement of a free serosal surface or apical node, and invasion into an adjacent organ or structure. After adjustment of other predictors, GST Pi expression remained independently prognostic for reduced overall survival (hazard ratio 1.4, P = 0.002). CONCLUSIONS: In patients with clinicopathological stage C colonic cancer, GST Pi expression is associated with features of tumour aggressiveness and with reduced overall survival. Further appropriately designed studies should aim to discover whether GST Pi can predict response to adjuvant chemotherapy.

Clinicopathological staging of colorectal cancer: Evolution and consensus-an Australian perspective.

In 1991 this journal published the report of an international working party to the World Congress of Gastroenterology regarding the clinicopathological staging of colorectal cancer. Since that time staging has continued to evolve as further prognostic factors in colorectal cancer have been elucidated in studies of increasingly large databases in several countries. This review summarizes several of the key issues that have arisen during this evolutionary process and raises matters which still remain controversial in staging at the present time.

Clinicopathological correlates and prognostic significance of maspin expression in 450 patients after potentially curative resection of node-positive colonic cancer.

AIMS: The tumour suppressor maspin has been investigated for its association with conventional histopathological features in colorectal cancer and for its potential as an independent predictor of survival and response to adjuvant chemotherapy. The aim of this study was to examine associations between maspin expression, other histopathology and survival in a large consecutive series of patients after potentially curative resection of node-positive colonic adenocarcinoma. METHODS AND RESULTS: Nuclear and cytoplasmic maspin expression in both superficial and deep parts of the tumour were assessed retrospectively by tissue microarray and immunohistochemistry in specimens from 450 patients whose other histopathology had been recorded in a prospective hospital registry of large bowel cancer resections from 1971 to 2001 with a minimum follow-up of 5 years. Among 13 clinicopathological features examined, the only associations that persisted across all four maspin assessments were stronger expression in right- than in left-sided tumours (P=0.001-0.011) and stronger expression in high-grade tumours (P<0.001-0.007). There was no significant association between intensity of maspin expression and overall survival. CONCLUSIONS: In this large and thoroughly documented series of patients with clinicopathological stage C colonic tumour, maspin expression was correlated with few other conventional histopathology variables and was not a significant prognostic factor.

Tumor budding and survival after potentially curative resection of node-positive colon cancer.

PURPOSE: The aim of this study was to investigate the relationship between tumor budding and other pathology features and overall survival after resection of clinicopathological stage III colon cancer. METHODS: The number of buds and other histopathological features were assessed in 477 patients who were operated on between 1971 and 2001, with follow-up to December 2006. Overall survival was analyzed using the Kaplan-Meier method and Cox regression. RESULTS: The number of buds was dichotomized as low (0 to 8) vs high (>or=9). High budding was more common in men, in high-grade tumors, in the presence of venous invasion, and where the tumor had involved a free serosal surface, but budding was not associated with 8 other clinical and pathological features. The 5-year survival rate for patients with 0 to 8 buds was 51.0% (95% confidence interval, 44.9-55.1), whereas that for patients with 9 or more buds was 33.9% (95% confidence interval, 25.2-42.8). This association, however, disappeared after adjustment for other variables independently associated with survival (hazard ratio, 1.2; 95% confidence interval, 0.94-1.54; P = .139). CONCLUSION: In stage III colon cancer, tumor budding did not provide additional independent prognostic information beyond that given by routine pathology reporting.

HLA-DR expression is associated with better prognosis in sporadic Australian clinicopathological Stage C colorectal cancers.

Predicting patient outcome for colorectal carcinoma (CRC) with lymph node but not distant metastases remains challenging. Various prognostic markers have been identified including microsatellite instability (MSI) and possibly expression of the MHC Class II protein, HLA-DR. About 15% of sporadic CRC exhibits MSI associated with methylation of the DNA mismatch repair gene hMLH1 promoter. In addition, a significant proportion of unselected CRC demonstrates expression of HLA-DR. We sought to examine the relationship between HLA-DR expression, MSI status and prognosis in sporadic Australian Clinicopathological (ACP) Stage C CRC. Two hundred seventy consecutive patients with sporadic ACP Stage C CRC were treated at Concord Repatriation General Hospital between 1986 and 1992. None of these patients received adjuvant chemotherapy and all were followed for a minimum of 5 years or until death. DNA was extracted from paraffin sections and MSI status determined by PCR. HLA-DR expression was determined immunohistochemically using an antibody against the HLA-DR alpha chain. MSI status could be assigned in 235 cases: 176 CRCs (74.9%) were microsatellite stable, whereas 23 (9.8%) had high levels of MSI (MSI-H) and 36 (15.3%) had low levels of MSI (MSI-L). HLA-DR expression by CRC cells was seen in 148 (60.1%) cases and correlated with the presence of tumor-infiltrating lymphocytes (p = 0.0005) and peritumoral lymphocytes (p = 0.003), but not other clinicopathological features or MSI status. HLA-DR-positive CRCs were strongly associated with better patient outcome (p < 0.0001).

The importance of tumor stage and relative survival analysis for the association between sex and survival after resection of colorectal cancer.

OBJECTIVE: The aim of this study was to determine whether the previously noted poorer survival of men after resection of colorectal cancer varied among clinicopathological tumor stages. SUMMARY BACKGROUND DATA: The question of whether sex is independently associated with prognosis after resection of colorectal cancer has been examined in numerous studies over the past 2 decades, but with conflicting results. METHODS: Data on 3,301 patients were drawn from a comprehensive, prospective hospital registry of all resections for colorectal cancer performed between January 1971 and December 2005. Statistical analysis employed Kaplan Meier estimation and relative survival analysis to adjust for differential male/female life expectancy in the general population. RESULTS: The relative survival of males was significantly less than that of females (P = 0.004) only in stage B. This was not accounted for by other negative pathology features and cause of death did not differ significantly between males and females. However, men with stage B tumor were more likely than women to experience postoperative morbidity, particularly a respiratory complication or a surgical complication requiring urgent reoperation. The sex difference in relative survival persisted among patients who had either a respiratory complication or an urgent reoperation (P = 0.003) but disappeared among those who had neither (P = 0.193). CONCLUSION: The poorer survival of men with stage B tumor was attributable to their greater postoperative morbidity which led to the earlier death of some due to causes unrelated to their colorectal cancer.

Pathological outcomes in rectal cancer following laparoscopic surgery.

AIM: This study examined pathological quality-of-surgery indicators in laparoscopic and open rectal cancer resection specimens. METHODS: Retrospective analysis of consecutive, prospectively recorded laparoscopic (LR) or open (OR) resections for rectal cancer. Indicators included integrity of the perirectal fascial envelope, circumferential margin clearance, lymph node yield and distal margin clearance. RESULTS: Between January 2007 and December 2013, 168 LR and 189 OR were performed. Univariate analysis showed that the presence of tumor within 1 mm of the circumferential margin was lower in LR (13/168 vs 28/189 cases, P = 0.039) as was a distal margin of clearance of < 1 cm (3/165 vs 12/186, P = 0.032). There was no difference in the surgical disruption of the fascial envelope (P = 0.091) or the percentage of specimens with a lymph node yield < 12 (P = 0.576) between the LR and OR groups. Multivariate analysis did not reveal any significant differences in pathological outcomes. CONCLUSION: With careful case selection, laparoscopic surgery has similar pathological outcomes to open surgery for rectal cancer.

Competing risks analysis of the effect of local residual tumour on recurrence and cancer-specific death after resection of colorectal cancer: implications for staging.

The pTNM staging system for colorectal cancer (CRC) is not entirely effective in discriminating between potentially curative and non-curative resections because it does not account for local residual tumour in patients with stages I, II or III. This study aimed to evaluate the prognostic importance of histologically verified tumour in any line of resection of the bowel resection specimen (TLR) in relation to pTNM stages and to demonstrate how TLR may be integrated into pTNM staging. Information on patients in the period 1995 to 2010 with complete follow-up to the end of 2015 was extracted from a prospective database of CRC resections. The outcome variables were the competing risks incidence of CRC recurrence and CRC-specific death. After exclusions, 2220 patients remained. In 1930 patients with pTNM stages I-III tumour, recurrence was markedly higher in those with TLR than in those without (HR 6.0, 95% CI 4.2-8.5, p < 0.001) and this persisted after adjustment for covariates associated with recurrence. CRC-specific death was markedly higher in the presence of TLR (HR 7.7, CI 5.3-11.2, p < 0.001), which persisted after adjustment for relevant covariates. These results justify removing patients with TLR from pTNM stages I to III and placing them in stage IV, thereby allowing the categorisation of all patients with any known residual tumour into three prognostically distinct groups. This study demonstrates how TLR may be integrated into pTNM staging, thus improving the definition of the three stages which are considered potentially curable (I, II and III).

Pathology reporting of resected colorectal cancers in New South Wales in 2000.

BACKGROUND: The aim of this study was to determine the extent to which pathology reporting of colorectal cancers notified to the New South Wales Central Cancer Registry during 2000 conformed to guidelines promulgated by the National Health and Medical Research Council. METHODS: De-identified reports for 2233 resected specimens of primary invasive colorectal carcinoma were coded according to a standardized system to compile information on 28 clinical and pathology features. An overall score for each report was calculated by computing the number out of 13 essential features specified in the guidelines for which data had been recorded explicitly and unambiguously in the report. RESULTS: The overall score ranged from 3 to 13 features with a mean of 9. No more than 7 features were reported explicitly in just less than one quarter of the reports and no more than 10 in three quarters. There were only 110 reports (4.9%) that included all features. Information on direct spread and nodal metastasis was well reported; resection margins less so. Many reports lacked information on metastases beyond the operative field, the involvement of deep or circumferential resection margins and tumour stage. CONCLUSION: In some respects pathology reports of resected colorectal cancer specimens displayed a high level of completeness. Some important features, however, were poorly described. Reporting could be improved if surgeons were to use a standardized form to convey clinical information to the pathologist and if pathologists were to report in a structured or synoptic format, explicitly recording the presence or absence of each feature in a standard list.