Paul McMurrick

KRAS Mutation Is Associated with Lung Metastasis in Patients with Curatively Resected Colorectal Cancer

Purpose: Oncogene mutations contribute to colorectal cancer development. We searched for differences in oncogene mutation profiles between colorectal cancer metastases from different sites and evaluated these as markers for site of relapse. Experimental Design: One hundred colorectal cancer metastases were screened for mutations in 19 oncogenes, and further 61 metastases and 87 matched primary cancers were analyzed for genes with identified mutations. Mutation prevalence was compared between (a) metastases from liver (n = 65), lung (n = 50), and brain (n = 46), (b) metastases and matched primary cancers, and (c) metastases and an independent cohort of primary cancers (n = 604). Mutations differing between metastasis sites were evaluated as markers for site of relapse in 859 patients from the VICTOR trial. Results: In colorectal cancer metastases, mutations were detected in 4 of 19 oncogenes: BRAF (3.1%), KRAS (48.4%), NRAS (6.2%), and PIK3CA (16.1%). KRAS mutation prevalence was significantly higher in lung (62.0%) and brain (56.5%) than in liver metastases (32.3%; P = 0.003). Mutation status was highly concordant between primary cancer and metastasis from the same individual. Compared with independent primary cancers, KRAS mutations were more common in lung and brain metastases (P < 0.005), but similar in liver metastases. Correspondingly, KRAS mutation was associated with lung relapse (HR = 2.1; 95% CI, 1.2 to 3.5, P = 0.007) but not liver relapse in patients from the VICTOR trial. Conclusions: KRAS mutation seems to be associated with metastasis in specific sites, lung and brain, in colorectal cancer patients. Our data highlight the potential of somatic mutations for informing surveillance strategies. Clin Cancer Res; 17(5); 1122–30. ©2011 AACR.

Blood-Based Protein Biomarker Panel for the Detection of Colorectal Cancer

Background The majority of colorectal cancer (CRC) cases are preventable by early detection and removal of precancerous polyps. Even though CRC is the second most common internal cancer in Australia, only 30 per cent of the population considered to have risk factors participate in stool-based test screening programs. Evidence indicates a robust, blood-based, diagnostic assay would increase screening compliance. A number of potential diagnostic blood-based protein biomarkers for CRC have been reported, but all lack sensitivity or specificity for use as a stand-alone diagnostic. The aim of this study was to identify and validate a panel of protein-based biomarkers in independent cohorts that could be translated to a reliable, non-invasive blood-based screening test. Principal Findings In two independent cohorts (n = 145 and n = 197), we evaluated seven single biomarkers in serum of CRC patients and age/gender matched controls that showed a significant difference between controls and CRC, but individually lack the sensitivity for diagnostic application. Using logistic regression strategies, we identified a panel of three biomarkers that discriminated between controls and CRC with 73% sensitivity at 95% specificity, when applied to either of the two cohorts. This panel comprised of Insulin like growth factor binding protein 2 (IGFBP2), Dickkopf-3 (DKK3), and Pyruvate kinase M2(PKM2). Conclusions Due to the heterogeneous nature of CRC, a single biomarker is unlikely to have sufficient sensitivity or specificity for use as a stand-alone diagnostic screening test and a panel of markers may be more effective. We have identified a 3 biomarker panel that has higher sensitivity and specificity for early stage (Stage I and -II) disease than the faecal occult blood test, raising the possibility for its use as a non-invasive blood diagnostic or screening test.

Local recurrence after curative anterior resection with principally blunt dissection for carcinoma of the rectum and rectosigmoid.

PURPOSE: The aim of this study was to determine the incidence of local pelvic recurrence of carcinoma of the rectum and rectosigmoid (tumors where the lower edge is 18 cm or less from the anal verge) in a consecutive series of patients operated on by a single surgeon. All patients underwent curative anterior resection and a formal anatomic dissection of the rectum where mobilization was achieved through a principally careful blunt manual technique along fascial planes, preserving an oncologic package. METHOD: During the period April 1986 to December 1997, 157 consecutive anterior resections for carcinoma of the rectum and rectosigmoid were performed by one surgeon (ALP). One hundred thirty-eight (87.9 percent) were curative, and 19 (12.1 percent) were palliative. The mean follow-up period was 46±31.6 (range, 2–140) months. Data were retrospectively collated and computer coded by an independent contracted medical research team. Follow-up data were available on all patients. RESULTS: Four (3.1 percent) of the 131 patients undergoing curative anterior resection had local recurrence. Local recurrences occurred between 16 and 38 months from the time of resection, and the cumulative risk of developing local recurrence at five years was 5.2 percent. All tumors in which pelvic recurrence occurred were high grade, and the probability of developing local recurrence at five years for this group was 13.9 percent, which is significantly higher compared with patients who had average or low-grade tumors (P=0.01). The probability of developing local recurrence at five years for Stage I tumors was 0, Stage II was 5.9 percent, and Stage III was 8.9 percent. In addition, there was a significantly higher incidence of local recurrence in the group of patients undergoing ultralow anterior resection (between 3 and 6 cm from the anal verge) as compared with patients undergoing low or high anterior resection (P=0.03). Local recurrence developed in 3 of 28 (10.7 percent) patients having ultralow anterior resection, 1 of 57 (1.8 percent) patients having low anterior resection (between 6 and 10 cm from the anal verge), and no patients having high anterior resection (above 10 cm from the anal verge). The clinical anastomotic leak rate for curative anterior resection was 7 of 131 patients (5.3 percent). Thirty-seven of the 131 (28.2 percent) required a proximal defunctioning stoma; 35 (41.2 percent) of these were established for low or ultralow anterior resections and 2 for high anterior resection. The overall five-year cancer-specific survival rate of the entire group of 131 patients was 81.8 percent, and the overall probability of being disease free at five years including both local and distal recurrence was 72.9 percent. Three local recurrences occurred in the 101 patients (77 percent) who did not receive any form of adjuvant therapy. One local recurrence occurred in the 18 patients (13.7 percent) who had adjuvant chemoradiation. No recurrence occurred in the 12 patients (9.2 percent) who had adjuvant chemotherapy alone. CONCLUSION: Curative anterior resection for carcinoma of the rectum and rectosigmoid with principally blunt dissection of the rectum in this study is associated with a 3.1 percent incidence and a 5.2 percent probability at five years of developing local recurrence. Evidence from this study indicates that, as with sharp pelvic dissection, a low incidence and probability of local recurrence can be achieved by a principally blunt mobilization technique through careful attention to preservation of fascial planes in the pelvis and removal of an oncologic package with selective rather than routine adjuvant or neoadjuvant chemoradiation.

ERBB3 Positively Correlates with Intestinal Stem Cell Markers but Marks a Distinct Non Proliferative Cell Population in Colorectal Cancer.

Several studies have suggested ERBB3/HER3 may be a useful prognostic marker for colorectal cancer. Tumours with an intestinal stem cell signature have also been shown to be more aggressive. Here, we investigate whether ERBB3 is associated with intestinal stem cell markers in colorectal cancer and if cancer stem cells within tumours are marked by expression of ERBB3. Expression of ERBB3 and intestinal stem cell markers (LGR5, EPHB2, CD44s and CD44v6) was assessed by qRT-PCR in primary colorectal tumours (stages 0 to IV) and matched normal tissues from 53 patients. The localisation of ERBB3, EPHB2 and KI-67 within tumours was investigated using co-immunofluorescence. Expression of ERBB3 and intestinal stem cell markers were significantly elevated in adenomas and colorectal tumours compared to normal tissue. Positive correlations were found between ERBB3 and intestinal stem cell markers. However, co-immunofluorescence analysis showed that ERBB3 and EPHB2 marked specific cell populations that were mutually exclusive within tumours with distinct proliferative potentials, the majority of ERBB3+ve cells being non-proliferative. This pattern resembles cellular organisation within normal colonic epithelium where EPHB2 labelled proliferative cells reside at the crypt base and ERBB3+ve cells mark differentiated cells at the top of crypts. Our results show that ERBB3 and intestinal stem cell markers correlate in colorectal cancers. ERBB3 localises to differentiated cell populations within tumours that are non-proliferative and distinct from cancer stem cells. These data support the concept that tumours contain discrete stem, proliferative and differentiation compartments similar to that present in normal crypts.

Cancer 2015: a prospective, population-based cancer cohort-phase 1: feasibility of genomics-guided precision medicine in the clinic

“Cancer 2015” is a longitudinal and prospective cohort. It is a phased study whose aim was to pilot recruiting 1000 patients during phase 1 to establish the feasibility of providing a population-based genomics cohort. Newly diagnosed adult patients with solid cancers, with residual tumour material for molecular genomics testing, were recruited into the cohort for the collection of a dataset containing clinical, molecular pathology, health resource use and outcomes data. 1685 patients have been recruited over almost 3 years from five hospitals. Thirty-two percent are aged between 61–70 years old, with a median age of 63 years. Diagnostic tumour samples were obtained for 90% of these patients for multiple parallel sequencing. Patients identified with somatic mutations of potentially “actionable” variants represented almost 10% of those tumours sequenced, while 42% of the cohort had no mutations identified. These genomic data were annotated with information such as cancer site, stage, morphology, treatment and patient outcomes and health resource use and cost. This cohort has delivered its main objective of establishing an upscalable genomics cohort within a clinical setting and in phase 2 aims to develop a protocol for how genomics testing can be used in real-time clinical decision-making, providing evidence on the value of precision medicine to clinical practice.

The first 1000 patients on an internet-based colorectal neoplasia database across private and public medicine in Australia: development of a binational model for the Colorectal Surgical Society of Australia and New Zealand

BACKGROUND: Collection of multi-institutional data pertaining to the treatment of bowel cancer has been hindered by poor clinician compliance with data entry and the lack of incentive to participate. OBJECTIVE: This study aimed to establish if a novel browser-based model of data collection results in complete data capture. DESIGN: A Web-based data collection interface was custom written, offering automated reporting modules for clinical outcome to participants and an automated reporting system for outstanding data fields, and summary reporting of surgical quality outcomes. The software was combined with a clinical feedback system incorporating fortnightly data review meetings, at the time of clinical multidisciplinary meetings. PATIENTS AND SETTING: Selected were 932 consecutive patients with opt-out consent from 3 hospital sites, including public and private medicine. MAIN OUTCOME MEASURES: The primary outcomes measured were the analysis of data completeness and accuracy and ensuring that the highest-quality data were used for clinical audit of the surgical practices of Australian colorectal surgeons for the purpose of quality assurance. RESULTS: A total of 932 men and women, 22 to 94 years of age, treated for colorectal neoplasia were evaluated. We obtained 100% completion (>27,000 data points) of perioperative data registered by 8 specialist colorectal surgeons and a full-time database manager. CONCLUSIONS: Data completeness and validity are essential for clinical databases to serve the purpose of quality assurance, benchmarking, and research. The results confirm the safety and efficacy of colorectal cancer surgery in both the public and private sector in Australia. The combination of a simple multiuser interface, defined data points, automated result-reporting modules, and data-deficiency reminder module resulted in 100% data compliance in nearly 1000 clinical episodes. The unprecedented success of this model has lead to the Colorectal Surgical Society of Australia and New Zealand adopting this model for data collection for Australia and New Zealand as the binational database.

New Monoclonal Antibodies to Defined Cell Surface Proteins on Human Pluripotent Stem Cells

The study and application of human pluripotent stem cells (hPSCs) will be enhanced by the availability of well‐characterized monoclonal antibodies (mAbs) detecting cell‐surface epitopes. Here, we report generation of seven new mAbs that detect cell surface proteins present on live and fixed human ES cells (hESCs) and human iPS cells (hiPSCs), confirming our previous prediction that these proteins were present on the cell surface of hPSCs. The mAbs all show a high correlation with POU5F1 (OCT4) expression and other hPSC surface markers (TRA‐160 and SSEA‐4) in hPSC cultures and detect rare OCT4 positive cells in differentiated cell cultures. These mAbs are immunoreactive to cell surface protein epitopes on both primed and naive state hPSCs, providing useful research tools to investigate the cellular mechanisms underlying human pluripotency and states of cellular reprogramming. In addition, we report that subsets of the seven new mAbs are also immunoreactive to human bone marrow‐derived mesenchymal stem cells (MSCs), normal human breast subsets and both normal and tumorigenic colorectal cell populations. The mAbs reported here should accelerate the investigation of the nature of pluripotency, and enable development of robust cell separation and tracing technologies to enrich or deplete for hPSCs and other human stem and somatic cell types. Stem Cells 2017;35:626–640

Colorectal Cancer Surgery in the Very Elderly: Nonagenarians.

BACKGROUND: Surgery in the very elderly is a topic that has not been well studied, despite the steady rise in this population. With the rise in this population, there is now discussion on the safety of surgery in this cohort for colorectal cancer. OBJECTIVE: The purpose of this study was to investigate elective and nonelective colorectal cancer surgery outcomes in patients aged ≥90 years at both private and public hospitals in Melbourne, Victoria, Australia. DESIGN: This was a retrospective analysis of patients aged ≥90 years who were included in the prospectively maintained Cabrini Monash University Department of Surgery colorectal neoplasia database for patients entered between January 2010 and February 2015. Comorbidity, ASA score, acuity of surgery, treatment, mortality, morbidity, and survival were analyzed. SETTINGS: This study was conducted in a tertiary referral hospital. PATIENTS: A total of 48 patients were identified from the database. The majority of these patients were women (58.0%), ASA score III to IV (91.7%), and treated in an elective setting (79.2%). The median age was 91.8 years. MAIN OUTCOME MEASURES: We measured 30-day mortality, 180-day mortality, and perioperative morbidity. RESULTS: Thirty-day mortality rate was 2.1%. The 180-day mortality rate was 10.4%. A total of 29.2% of patients had a perioperative complication. Median follow-up was 21 months (range, 13–54 months). In 180-day mortality, minimally invasive surgery was associated with a lower mortality rate vs open surgery (p = 0.043). Perioperative complications were associated with nonelective surgery (p = 0.045), open surgery procedures (p = 0.014), and higher stages of disease (p = 0.014). A total of 81.3% of patients were able to return home after surgery. LIMITATIONS: This was a retrospective study with the usual limitations; however, these have been minimized with the use of a high-quality, prospective data collection database. The median follow-up was 21 months. CONCLUSIONS: Colorectal surgery was generally safe for nonagenarians in this study. This study demonstrates that excellent outcomes can be achieved in a selected group. Additional prospective studies with larger numbers and 5-year follow-up are recommended.

Complete Pathological Response After Neoadjuvant Long-course Chemoradiotherapy for Rectal Cancer and Its Relationship to the Degree of T3 Mesorectal Invasion

BACKGROUND: Many studies have shown significantly improved outcomes (reduced local recurrence and improved overall survival) for patients achieving a complete pathological response from neoadjuvant chemoradiotherapy. OBJECTIVE: This study aimed to document the complete pathological response rate and outcomes in patients receiving preoperative long-course chemoradiotherapy stratified for the extent of T3 mesorectal invasion measured on preoperative imaging. DESIGN: This is a retrospective study of prospectively collected data, of patients with rectal cancer in the Cabrini Monash University Department of Surgery colorectal neoplasia database, incorporating data from Cabrini Hospital and The Alfred Hospital, identifying patients entered between January 2010 and June 2014. PATIENTS AND SETTINGS: One hundred eighteen patients with T3 rectal cancer met the selection criteria for the study; 26 achieved complete pathological response (22%). MAIN OUTCOME MEASURES: Outcomes in terms of complete pathological response and oncological outcomes such as disease-free and overall survival were analyzed. RESULTS: Patients with complete pathological response had significantly less preoperative invasion than those with no complete pathological response (p < 0.001). Depth of invasion was the only variable associated with complete pathological response (p < 0.002), and the likelihood of complete pathological response decreased by 35% for every millimeter of invasion. Complete pathological response was associated with increased disease-free survival (p = 0.018) and a lower risk of cancer progression (p = 0.046). Depth of invasion was associated with an increased risk of death after surgery; HR increased by 1.07 (95% CI, 1.00–1.15) for each 1-mm increase in invasion. LIMITATIONS: This was a retrospective study with the usual limitations, although these were minimized through the use of a clinician-driven prospective database. CONCLUSIONS: The smaller the degree of T3 invasion, the higher the chance of achieving complete pathological response (up to 35%), which is associated with improved disease-free and overall survival. A higher complete pathological response rate is observed in early T3 disease in comparison with more extensive T3 invasion.

Analysis of 32 Blood-Based Protein Biomarkers for their Potential to Diagnose Colorectal Cancer

Colorectal cancer (CRC) is largely viewed as a preventable disease but the prevalence is increasing worldwide. Although many faecal and blood-based biomarkers have been proposed as potential diagnostic markers, none have been successful in large cohort studies. In this study, ELISA was used to evaluate 32 candidate protein biomarkers in a single cohort of CRC patients (n=95) and age/sex matched controls (n=50). Of these, 12 markers differed statistically between cases and controls. Receiver operating characteristic analysis identified IL8, Mac2BP, TIMP1, and OPN as the best performing markers for overall CRC diagnosis. However, further analysis determined that IL6, TGFB1, TIMP2 and IGF2 were most accurate at identifying early stage disease. We also assessed the correlation between markers and determined that the strongest correlations existed between VEGFA and TGFB1 (r=0.65, p<0.0001), M30 and M65 (r=0.59, p<0.001), and between TGFB1 and TIMP1 (r=0.55, p<0.0001). This analysis provides a consistent baseline for identifying a potential panel of diagnostic protein biomarkers in blood. Our results highlight protein biomarker combinations that reflect the disease process and which may provide the sensitivity and specificity required a reliable diagnosis of CRC.