ORCID Profile
0000-0001-7880-2386
Current Organisations
Eaton (Ireland)
,
Peter MacCallum Cancer Centre
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Publisher: Wiley
Date: 22-10-2022
DOI: 10.1111/ANS.17262
Abstract: Transanal total mesorectal excision (taTME) represents a novel approach to rectal dissection. Although many structured training programs have been developed worldwide to assist surgeons in implementing this new technique, the learning curve (LC) of taTME has yet to be conclusively defined. This is particularly important given the concerns regarding the complication profile and oncological safety of taTME. The aim of this review was to provide an up‐to‐date systematic review and meta‐analysis of the LC for taTME, comparing the difference of outcomes between the LC and after learning curve (ALC) groups. An up‐to‐date systematic review was performed on the available literature between 2010–2020 on PubMed, EMBASE, Medline and Cochrane Library databases. All studies comparing taTME procedures before and after LC were analysed. Seven retrospective studies of prospectively collected databases were included, comparing 333 (51.0%) patients in the LC group and 320 (49.0%) patients in the ALC group. There was a significantly reduced number of adverse intra‐operative events, anastomotic leaks and improved quality of mesorectal excision in the ALC group. This review shows that there is a significant improvement in clinical outcomes between the LC and ALC groups which supports the need for careful mastery and ongoing technical refinement during the LC in taTME. This procedure should be performed on a subset of carefully selected patients in the hands of experienced and well‐trained teams dedicated to ongoing audit.
Publisher: Wiley
Date: 28-08-2020
DOI: 10.1111/ANS.16250
Publisher: Wiley
Date: 08-05-2018
DOI: 10.1111/CODI.14106
Abstract: The current standard of care for locally advanced rectal cancer involves neoadjuvant chemoradiotherapy (CRT) followed by total mesorectal excision. There is a spectrum of response to neoadjuvant therapy however, the prognostic value of tumour regression grade (TRG) in predicting disease-free survival (DFS) or overall survival (OS) is inconsistent in the literature. This study was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A systematic search was undertaken using Ovid MEDLINE, Embase and Google Scholar. Inclusion criteria were Stage II and III locally advanced rectal cancer treated with long-course CRT followed by radical surgery. The aim of the meta-analysis was to assess the prognostic implication of each TRG for rectal cancer following neoadjuvant CRT. Long-term prognosis was assessed. The main outcome measures were DFS and OS. A random effects model was performed to pool the hazard ratio (HR) from all included studies. There were 4875 patients from 17 studies, with 775 (15.9%) attaining a pathological complete response (pCR) and 719 (29.9%) with no response. A significant association with OS was identified from a pooled-estimated HR for pCR (HR = 0.47, P = 0.002) and nonresponding tumours (HR = 2.97 P < 0.001). Previously known tumour characteristics, such as ypN, lymphovascular invasion and perineural invasion, were also significantly associated with DFS and OS, with estimated pooled HRs of 2.2, 1.4 and 2.3, respectively. In conclusion, the degree of TRG was of prognostic value in predicting long-term outcomes. The current challenge is the development of a high-validity tests to predict pCR.
Publisher: Wiley
Date: 28-08-2021
DOI: 10.1111/CODI.15868
Abstract: Perforations are a rare but serious complication of colorectal cancer. The current standard of treatment is emergent surgery followed by adjuvant chemotherapy. The concern with this approach is not only the uncertainty of achieving a R0 resection but also potential injury to adjacent vessels, nerves and ureters due to inflamed tissue planes. A subset of this patient population with a contained perforation who are clinically stable may have superior oncological outcomes with local sepsis control, neoadjuvant therapy followed by radical resection. The aim of this study is to report on the pre‐operative safety profile for neoadjuvant therapy in the setting of an abscess from colon cancer perforation and the short‐term oncological surgical quality outcomes. In this retrospective observational study, all consecutive perforated colon cancer receiving neoadjuvant therapy from Jan 2010 to Dec 2019 were included. There were 21 patients that met the inclusion criteria. The most common symptom at presentation was abdominal pain (71.4%) and most common site of perforation was sigmoid colon (61.9%). Local sepsis control was achieved with a combination of radiological or surgical drainage, erting ostomy and/or intravenous antibiotics. Thirteen patients had long‐course chemoradiation and eight patients had neoadjuvant chemotherapy. Of these, 13 (61.9%) had tumour regression, with one patient having a pathological complete response. All patients achieved a R0 resection. In a small subset of patients with colon cancer perforation, this study has demonstrated the potential safe usage of neoadjuvant therapy first before radical surgery to achieve a clear resection margin.
Publisher: Wiley
Date: 2023
DOI: 10.1111/ANS.18142
Publisher: Wiley
Date: 15-04-2019
DOI: 10.1111/ANS.15081
Abstract: Colorectal cancer resection in the obese (OB) patients can be technically challenging. With the increasing adoption of laparoscopic surgery, the benefits remain uncertain. Hence, the aim of this study is to assess the short- and long-term outcomes of laparoscopic compared to open colorectal cancer resection in the OB patients. A systematic review and meta-analysis was performed according to the PRISMA guidelines. The outcome measures were 5-year disease-free survival, overall survival, circumferential resection margin and local and distant recurrence. A total of 20 studies were included, with a total number of 6779 participants, of whom 1785 (26.3%) were OB and 4994 (73.7%) were non-obese (NOB) participants. The OB patients had higher R1 resection (OB 6.9% versus NOB 3.1% P = 0.011) and lower mean number of lymph nodes harvested, with standard mean difference of -0.29 P = 0.023, favouring the NOB patients. However, there was no statistical difference for local (OB 2.8% versus NOB 3.4%) or distant recurrence (OB 12.9% versus NOB 15.2%) rate between the two cohorts. There was no difference in 5-year disease-free survival (OB 81% versus NOB 77.4% odds ratio 1.25, P = 0.215) and overall survival (OB 89.4% versus NOB 87.9% odds ratio 1.16, P = 0.572). Lastly, the OB group had higher mean total blood loss, total operative time and length of hospital stay when compared to NOB patients. From a pooled non-randomized study, laparoscopic colorectal cancer resection is safe in OB patients with equivalent long-term outcomes compared to NOB patients. However, there is a higher morbidity rate with an increased demand on hospital resources for the OB cohort.
Publisher: Wiley
Date: 06-10-2022
DOI: 10.1111/ANS.18078
Abstract: The development of peritoneal metastases (PM) in patients with colorectal cancer (CRC) connotates a poor prognosis. Circulating tumour (ctDNA) is a promising tumour biomarker in the management CRC. This systematic review aimed to summarize the role of ctDNA in patients with CRC and PM. Following the Preferred Reporting Items for Systematic Reviews and Meta‐analyses (PRISMA) guidelines, a systematic review of the literature until June 2022 was performed. Studies reporting on the utility of ctDNA in colorectal PM were included. A total of eight eligible studies were identified including a total of 167 patients. The findings from this review suggest an evolving role for ctDNA in CRC with PM. ctDNA can be isolated from both plasma and peritoneal fluid, with peritoneal fluid preferred as the liquid biopsy of choice with higher mutation detection rates. Concordance rates between tissue and plasma eritoneal ctDNA mutation detection can vary, but is generally high. ctDNA has a potential role in monitoring anti‐EGFR treatment response and resistance, as well as in predicting future prognosis and recurrence. The detection of ctDNA in plasma of patients with isolated PM is also possibly suggestive of occult systemic disease, and patients exhibiting such ctDNA positivity may benefit from systemic treatment. Limitations to ctDNA mutation detection may include the size of peritoneal lesions, as well as the fact that PM poorly shed ctDNA. While these findings are promising, further large‐scale studies are needed to better evaluate the utility of ctDNA in this subset of patients.
Publisher: Wiley
Date: 12-2022
DOI: 10.1111/ANS.17971
Publisher: Wiley
Date: 09-05-2022
DOI: 10.1111/ANS.17761
Abstract: The prevalence of elderly patients with resectable colorectal peritoneal metastases (CRPM) is increasing. This study aimed to compare short and long-term outcomes of cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) for CRPM in patients above and below 70 years of age. This was a retrospective, 10-year analysis of 90-day major morbidity and mortality, and long-term survival. Thirty-two (21.3%) of 150 consecutive patients who underwent CRS and HIPEC during the study period were aged 70 and older. PCI (P = 0.04), perioperative chemotherapy use (P < 0.01) and organ resections (rectum P = 0.04, diaphragm P = 0.03) were less in the over 70 group. There was no significant differences in major morbidity (P = 0.19) and mortality (P = 0.32). There was also no difference in 5-year overall survival (OS) (≥70: 26% vs. <70: 39% P = 0.68) and disease-free survival (DFS) (≥70: 25% vs. <70: 14% P = 0.22). Age above 70 was not independently associated with worse OS (HR 1.55, P = 0.20) and DFS (HR 1.07, P = 0.81). The surgical management of CRPM appears safe and feasible in this elderly population. Appropriate selection of elderly patients for such radical intervention is reinforced by the comparable survival with those under 70.
Publisher: Wiley
Date: 10-2019
DOI: 10.1111/ANS.15256
Publisher: Wiley
Date: 08-06-2022
DOI: 10.1111/ANS.17830
Abstract: The technical difficulty an operation creates for a surgeon is difficult to measure. Current measures are poor surrogates. In both research and teaching settings it would be valuable to be able to accurately measure this degree of difficulty. The National Aeronautics and Space Administration Task Load Index (NASA TLX) is a multi-dimensional scale designed to obtain workload estimates relating to a task. This study aimed to evaluate the NASA TLX as an objective measure of technical difficulty of an operation. Seven surgeons performed 127 pre-defined operations (minimally invasive right hemicolectomy & re-do bariatric surgery) and recorded a NASA TLX score after each operation. These scores were compared to numerous clinical parameters and the score was correlated with the subjective measure of whether the surgeon categorized the operation as "easy", "moderate" or "difficult". The NASA TLX score was significantly correlated with operative duration, blood loss, previous abdominal surgery and the surgeons' assessment of difficulty. It did not correlate with intra-operative or post-operative complications, conversion to open surgery or length of stay. The NASA TLX score provides a graded numerical score that that correlated significantly with the surgeon's assessment of the technical difficulty, and with operative duration, intra-operative blood loss and previous abdominal surgery. This novel application of this tool could be employed in both research and teaching settings to score surgical difficulty and monitor a trainee's proficiency over time.
Publisher: Springer Science and Business Media LLC
Date: 27-09-2021
Publisher: Wiley
Date: 27-02-2020
DOI: 10.1111/CODI.15003
Abstract: Peritoneal metastases from colorectal cancer confer the worst survival among all metastatic sites. The adoption of cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) can offer selected patients with isolated colorectal peritoneal metastases (CRPM) a favourable long‐term survival. There are numerous factors postulated to influence survival in patients undergoing CRS and HIPEC. The aim of this study was to identify the key perioperative prognostic factors that influence survival in patients undergoing CRS and HIPEC for isolated CRPM. A systematic review and meta‐analysis were conducted to evaluate prognostic factors influencing survival in patients undergoing CRS and HIPEC for isolated CRPM. Thirty‐three studies fitted the inclusion criteria for the systematic review, with 25 studies included in the meta‐analysis. On pooled analysis, incomplete cytoreduction, increasing peritoneal carcinoma index (PCI) and lymph node involvement were significantly associated with a worse survival. Additionally, a rectal primary [hazard ratio (HR) 1.93, 95% CI 1.10–3.37], adjuvant chemotherapy (HR 0.71, 95% CI 0.54–0.93) and perioperative grade III/IV morbidity (HR 1.59, 95% CI 1.17–2.16) were also found to significantly influence survival. Notably, tumour differentiation and signet ring cell histology did not influence survival on pooled analysis. This meta‐analysis confirms that in patients undergoing CRS and HIPEC for isolated CRPM, incomplete cytoreduction, high PCI and lymph node involvement have a negative influence on survival. In addition, a rectal primary, adjuvant chemotherapy use and grade III/IV morbidity are important factors that also significantly influence survival.
Publisher: Wiley
Date: 05-10-2020
DOI: 10.1111/ANS.16338
Publisher: Oxford University Press (OUP)
Date: 09-01-2021
DOI: 10.1093/BJS/ZNAA098
Abstract: Transanal total mesorectal excision (taTME) aims to overcome some of the technical challenges faced when operating on mid and low rectal cancers. Specimen quality has been confirmed previously, but recent concerns have been raised about oncological safety. This multicentre prospective study aimed to evaluate the safety of taTME among early adopters in Australia and New Zealand. Data from all consecutive patients who had taTME for rectal cancer from July 2014 to February 2020 at six tertiary referral centres in Australasia were recorded and analysed. A total of 308 patients of median age of 64 years underwent taTME. Some 75.6 per cent of patients were men, and the median BMI was 26.8 kg/m2. The median distance of tumour from anal verge was 7 cm. Neoadjuvant chemoradiotherapy was administered to 57.8 per cent of patients. The anastomotic leak rate was 8.1 per cent and there was no mortality within 30 days of surgery. Pathological examination found a complete mesorectum in 295 patients (95.8 per cent), a near-complete mesorectum in seven patients (2.3 per cent), and an incomplete mesorectum in six patients (1.9 per cent). The circumferential resection margin and distal resection margin was involved in nine patients (2.9 per cent), and two patients (0.6 per cent) respectively. Over a median follow-up of 22 months, the local recurrence rate was 1.9 per cent and median time to local recurrence was 30.5 months. This study showed that, with appropriate training and supervision, skilled minimally invasive rectal cancer surgeons can perform taTME with similar pathological and oncological results to open and laparoscopic surgery.
Publisher: Wiley
Date: 09-01-2022
DOI: 10.1111/ANS.17429
Abstract: Rectal cancer is a challenging disease process to manage, with a rising incidence in young adults. Several clinical advances have been made in the past decade with regards to optimal treatment strategies in early-stage (T1-2, node negative tumours) and locally advanced cancers (T3-4 and/or nodal positivity) utilizing a multimodal approach of surgery, neoadjuvant chemoradiotherapy, and adjuvant chemotherapy, all aiming to optimize oncological outcomes, while minimizing associated morbidity. This narrative review aimed to summarize trial level evidence apropos the management of early and locally advanced rectal cancer. All relevant prospective clinical trials were identified through a computer-assisted search of PubMed, EMBASE, Medline databases between 1990 and 30 June 2021. With regards to early rectal cancer, there is limited trial-level evidence in the literature. Total mesorectal excision (TME) is the current standard of care, but local excision could be considered in select patients with pT1 tumours, or patients with near or complete clinical response to neoadjuvant CRT. As for locally advanced rectal cancer, the current standard of care consists of long-course chemotheradiotherapy or short-course radiotherapy, followed by TME. However, the role of total neoadjuvant therapy is promising, with respect to both oncological outcomes, as well as in reducing toxicity. Both induction and consolidation chemotherapy treatment approaches have been described in literature, with encouraging early results. The optimal management of rectal cancer is constantly evolving. More research is needed to investigate the long-term oncological and functional outcomes following new multimodal therapies in the management of early-stage and locally advanced rectal cancer.
Publisher: Wiley
Date: 03-05-2022
DOI: 10.1111/ANS.17749
Abstract: Colon cancer resection can be technically difficult in the obese (OB) population. Robotic surgery is a promising technique but its benefits remain uncertain in OB patients. The aim of this study is to compare OB versus non‐obese (NOB) patients undergoing robotic colon surgery, as well as OB patients undergoing robotic versus open or laparoscopic colonic surgery. A systematic review and meta‐analysis was performed. Primary outcome measures included length of stay (LOS), surgical site infection (SSI) rate, complications, anastomotic leak and oncological outcomes. A total of eight studies were included, with five comparing OB and NOB patients undergoing robotic colon surgery included in meta‐analysis. A total of 263 OB patients and 400 NOB patients formed the s le for meta‐analysis. There was no significant difference between the two groups in operative time, conversion to open, LOS, lymph node yield, anastomotic leak and postoperative ileus. There was a trend towards a significant increase in overall complications and SSI in the OB group (32.3% OB versus 26.8% NOB for complications, 14.2% OB versus 9.9% NOB for SSI). The three included studies comparing surgical techniques were too heterogeneous to undergo meta‐analysis. Robotic colon surgery is safe in obese patients, but high‐quality prospective evidence is lacking. Future studies should report on oncological safety and the cost‐effectiveness of adopting the robotic technique in these challenging patients.
Publisher: Wiley
Date: 04-05-2018
DOI: 10.1111/CODI.14107
Abstract: Obesity is common in Western countries and its prevalence is increasing. Colorectal cancer is common, and surgery for colorectal cancer is technically more challenging in obese patients. Laparoscopic surgery for colon cancer has been shown to be oncologically equivalent, with improved short- term outcomes. Laparoscopic surgery for rectal cancer has proven technically challenging, and recent results have raised concerns about oncological equivalence. Our aim was to evaluate the effect of body mass index (BMI) on the clinical and oncological outcomes of surgery for colorectal cancer, including the rate at which laparoscopic surgery is attempted and the rate at which laparoscopic surgery is converted to open surgery. A retrospective analysis of prospectively collected data from two tertiary institutions was performed. Data were obtained from the Cabrini Monash University colorectal neoplasia database for patients having surgical resection for colon and rectal cancers between 1 January 2010 and 30 June 2015. Surgical and medical complications, tumour recurrence and overall survival and laparoscopic surgery and conversion rates were investigated. This large case series of 1464 patients undergoing elective surgery for colorectal cancer has demonstrated that an elevated BMI is associated with a lower likelihood of attempting laparoscopic surgery and a higher conversion rate to open surgery when laparoscopy is attempted. Conversion was 1.9 times more likely in obese patients with colon cancer and 4.1 times more likely in obese patients with rectal cancer. The critical BMI for colon cancer patients was > 35 kg/m In the surgical management of colorectal cancer, obesity is associated with a lower likelihood of laparoscopic surgery being attempted, a higher likelihood of conversion to open surgery when laparoscopic surgery is attempted, and a higher rate of surgical complications.
Publisher: Wiley
Date: 12-07-2021
DOI: 10.1111/CODI.15778
Abstract: Appendiceal pseudomyxoma peritonei (PMP) is a rare entity, with recurrence rates up to 26% despite optimal cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). Evidence specific to PMP originating from non‐infiltrative appendiceal mucinous neoplasms (low grade ‐ LAMN and high grade ‐ HAMN) is lacking. The aim of this study was to identify patterns of recurrence and predictive factors for patients appropriate for iterative surgery. A bi‐institutional retrospective analysis was performed on patients undergoing complete cytoreduction and HIPEC for PMP derived from perforated LAMN or HAMN. Multivariate logistic regression was performed to identify independent predictors for re‐do CRS. Five‐year overall survival (OS) was stratified according to surgical intervention, and 5‐year disease‐free survival (DFS) was stratified according to histological PMP grade. Cox regression analysis was performed to identify independent predictors for OS and DFS. Sixty of 239 (25.1%) patients developed peritoneal recurrence between 2007 and 2020. The median time to recurrence was 20.7 months. The risk of disease recurrence was highest with high‐grade PMP ( P .001) and increasing PCI ( P .001). Patients with high‐grade histology from their index procedure and aged over 60 years were less likely to be offered iterative surgery on multivariate analysis. Patients who underwent iterative CRS and HIPEC had a 5‐year survival of 100%. Iterative CRS and HIPEC is feasible in selected patients with recurrent PMP, displaying good oncological outcomes. Age, index histology and level of abdominal quadrant involvement are predictive of proceeding to re‐do surgery.
Publisher: Wiley
Date: 14-03-2021
DOI: 10.1002/CTA.2931
Publisher: Wiley
Date: 16-07-2021
DOI: 10.1111/ANS.17071
Abstract: The COVID-19 pandemic has resulted in global disruptions to the delivery of healthcare. The national responses of Australia and New Zealand has resulted in unprecedented changes to the care of colorectal cancer patients, amongst others. This paper aims to determine the impact of COVID-19 on colorectal cancer diagnosis and management in Australia and New Zealand. This is a multicentre retrospective cohort study using the prospectively maintained Binational Colorectal Cancer Audit (BCCA) registry. Data is contributed by over 200 surgeons in Australia and New Zealand. Patients receiving colorectal cancer surgery during the pandemic were compared to averages from the same period over the preceding 3 years. There were fewer operations in 2020 than the historical average. During April to June, patients were younger, more likely to have operations in public hospitals and more likely to have urgent or emergency operations. By October to December, proportionally less patients had Stage I disease, proportionally more had Stage II or III disease and there was no difference in Stage IV disease. Patients were less likely to have rectal cancer, were increasingly likely to have urgent or emergency surgery and more likely to have a stoma created. This study shows that the response to COVID-19 has had measurably negative effects on the diagnosis and management of colorectal cancer in two countries that have had significantly fewer COVID-19 cases than many other countries. The long-term effects on survival and recurrence are yet to be known, but could be significant.
Publisher: Oxford University Press (OUP)
Date: 19-06-2020
DOI: 10.1002/BJS.11753
Publisher: Wiley
Date: 20-10-2020
DOI: 10.1111/ANS.16392
Abstract: Small bowel obstruction (SBO) is a common general surgical presentation and there has been a shift towards non‐operative management (NOM) for patients with previous abdominal surgery. Historically, exploratory surgery has been mandated for SBO in patients with a virgin abdomen. However, there is increasing evidence for NOM in this group of patients. A systematic review was performed according to Preferred Reporting Items for Systematic Reviews and Meta‐Analyses guidelines. A search was undertaken between 1995 and 2020 on Ovid MEDLINE, EMBASE and PubMed. Primary outcome measures were success and failure rates, whereas secondary outcome measures were morbidity, mortality rates and identifying underlying aetiologies. Six observational studies were included, with 205 patients in the NOM and 211 patients in the operative group. There was a high success rate of 95.6% and low morbidity rate of 3.1% in the NOM group compared to 88.6% and 26% in the operative group, respectively. Both groups reported no mortalities. The most common aetiologies for SBO in a virgin abdomen were adhesions (63%), malignancy (11%), foreign body/bezoar (5%), internal hernia (4%) and volvulus (4%). NOM for SBO is a safe and feasible option for a select group of clinically stable patients with a virgin abdomen without features of closed‐loop obstruction. Adhesions are the most common cause of SBO in this group of patients. Further large‐scale prospective clinical studies with standardized NOM modality, homogenous clinical resolution indicators and long‐term follow‐up data are warranted to allow for quantitative analysis to reinforce this evidence.
No related grants have been discovered for Priyabrata Shaw.