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Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Type of registration
Prospectively registered

Titles & IDs
Public title
Australasian Decrease in IntraPelvic Obesity for Surgery trial: Efficacy of a very low energy diet (VLED) to reduce weight and improve outcomes in obese patients undertaking laparoscopic rectal cancer surgery
Scientific title
Australasian Decrease in Intra-Pelvic Obesity for Surgery trial - A phase III prospective randomised trial comparing using VLED’s to reduce weight in obese patients undergoing laparoscopic rectal cancer surgery versus usual care prior to laparoscopic rectal cancer surgery
Secondary ID [1] 286891 0
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
obesity 295811 0
rectal cancer 295812 0
Condition category
Condition code
Cancer 295887 295887 0 0
Bowel - Back passage (rectum) or large bowel (colon)
Diet and Nutrition 296073 296073 0 0

Study type
Description of intervention(s) / exposure
The VLED will be using the Optifast product which is an oral, nutritionally complete, very low calorie diet and limits energy intake to less than 800 calories per day.This involves the use of soups and shakes plus low starch vegetables, calorie free fluids and calorie free lollies and mints in small amounts.The duration is 4-6 weeks prior to surgery.The patients will keep a food diary to monitor adherence..
Intervention code [1] 292334 0
Treatment: Other
Intervention code [2] 292506 0
Comparator / control treatment
To determine whether the addition of a Very Low Energy Diet (VLED) in the preoperative phase compared to usual care prior to laparoscopic rectal resection for rectal cancer in obese patients improves short term outcomes. Usual care would be dietary advice to lose weight
Control group

Primary outcome [1] 295562 0
Composite score of surgical factors that are indicative of a standard enhanced recovery following non restorative and restorative proctectomy for rectal cancer.
The composite surgical score of quality will include: Haemaglobin drop of greater than 20g/l and no transfusion, conversion, Anastomotic Leaks or pelvic sepsis, wound complications, 1. No “other” complications (including DVT/PE, cardiac or respiratory complications), ambulation by day 2, tolerating normal diet by day 4, and discharge by day 7. A score out of 8 will be assigned without weighting.
Timepoint [1] 295562 0
Day 7
Secondary outcome [1] 315851 0
Pathological quality:
*Circumferential margin greater than or equal to 1mm.

Timepoint [1] 315851 0
at the end of surgery once procedure completed, assessed by Pathologist
Secondary outcome [2] 315854 0
Oncological Outcomes:
*Disease free survival and local pelvic recurrence (composite outcome)at three and five year visits from review of hospital records

Timepoint [2] 315854 0
3 and 5 years post surgery completion
Secondary outcome [3] 315855 0
Measurement of technical difficulty of the surgery as assessed by the NASA task load index
Timepoint [3] 315855 0
Post-operative - upon surgery completion
Secondary outcome [4] 315856 0
Adipose tissue volume reduction assessed by MRI (abdominal and pelvic)
Timepoint [4] 315856 0
Pre and Post VLED , Pre-operative
Secondary outcome [5] 315857 0
Compliance with VLED (calculated as the number of days the patient maintained a VLED as per the patient diary)
Timepoint [5] 315857 0
Immediately prior to surgery at pre-op visit
Secondary outcome [6] 315858 0
Quality of life (sexual function, bowel and bladder function and recovery parameters) up to 1 year, by questionnaires
FSFI -female sexual function index
IIEF - the international index of erectile function
IPSS - the international prostate symptom score
Timepoint [6] 315858 0
4-6 weeks, 3months, and 12months post op
Secondary outcome [7] 315872 0
Cost-effectiveness, both within the trial period and extrapolated to long-term outcomes by review of labour force and income Questionnaires
Labour force and income impacts of illness - at baseline, 3months, 6months and 12months
Timepoint [7] 315872 0
At completion of the trial
Secondary outcome [8] 316586 0
Pathological quality * Distal resected margin greater than or equal to 2cm (or greater than or equal to 1cm with clear frozen section in the low rectum).
Timepoint [8] 316586 0
Assessed at end of surgery once procedure completed, assessed by Pathologist
Secondary outcome [9] 316587 0
Pathological quality *Completeness of TME (A complete TME is defined as a rectal resection specimen which has an intact mesorectum and covering peritoneal envelope all the way to the level of rectal transaction with no coning in of the mesorectum above the point of transection. The surface of the peritoneal covering should be smooth and shiny with no defects exposing the underlying fat.
Timepoint [9] 316587 0
at the end of surgery once procedure completed, assessed by Pathologist
Secondary outcome [10] 316588 0
Pathological quality *Lymph node yield (after Carnoy’s solution if used)
Timepoint [10] 316588 0
at the end of surgery once procedure completed, assessed by Pathologist
Secondary outcome [11] 316589 0
Oncological outcomes *Overall survival at five years from review of hospital records
Timepoint [11] 316589 0
5 years post surgery

Key inclusion criteria
Histological diagnosis of adenocarcinoma of the rectum (where the distal margin of the tumour is less than 15cm from the anal verge as measured at rigid sigmoidoscopy).
T 1-3 N0 M0, T1-3 N1 M0 or T1-3 N0-1 M1 disease as determined by pre-treatment CT scans and or pelvic MRI (or endorectal ultrasound if MRI contraindicated) for rectal cancers.
Body Mass Index (BMI) greater than or equal to 30.
Age greater than or equal to 18 years.
Eastern Cooperative Oncology Group (ECOG) Performance Status: 0, 1 or 2.
Able and willing to provide written informed consent
Ability to comply with the study protocol (as judged by the responsible surgeon)
Life expectancy of at least 12 weeks.
Minimum age
18 Years
Maximum age
No limit
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
Pregnancy or breast feeding.
Any uncontrolled concurrent medical condition.
Any co-morbid disease that would increase risk of morbidity.
Participation in any investigational drug study within the previous 4 weeks.
Evidence of T4 disease extending to circumferential margin of rectum or invading adjacent organs.
Evidence of systemic disease (cardiovascular, renal, hepatic, etc.) that would preclude surgery, or other severe incapacitating disease, i.e. ASA IV (a patient with severe systemic disease that is a constant threat to life) or ASA V (a moribund patient who is not expected to survive without the operation).
History of conditions that would preclude use of a laparoscopic approach (e.g. multiple previous major laparotomies, severe adhesions).
Concurrent or previous invasive pelvic malignancy (cervical, uterine and rectal) within five years prior to registration.
Short course radiotherapy

Study design
Purpose of the study
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
On confirmation of eligibility, patients will be recruited through the hospital, clinic or surgeons' rooms at each site. Only authorised staff are eligible to access the randomisation system. Upon verification of site accreditation, patient eligibility, that documentation is correct and complete, a check is performed to ensure that patient duplication will not occur, before allocation to either treatment arm is performed. This allocation is by an electronic randomisation system which generates patient study ID and treatment arm using a computer.
Patients will be randomised to either VLED or usual care prior to laparoscopic resection of rectal carcinoma.
Confirmation of randomisation, patient ID and treatment arm is then established
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Randomisation using a randomisation table created by computer software (i.e. computerised sequence generation)
Stratified allocation by
- BMI =30-40, >40
- Pre-op treatment
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?

The people assessing the outcomes
Intervention assignment
Other design features
Not Applicable
Type of endpoint(s)
Statistical methods / analysis
The primary analysis will be according to the intention-to-treat (ITT) principal. Comparisons on the proportion of successful resections in each treatment group will be performed using a test of proportions and the difference between the control and intervention groups together with the 95% CI will be presented. Non-inferiority will be declared if the lower bound of the one-sided 95% CI for the difference between proportions is 8%. The notional significance level is 5%. Secondary analyses will adjust for significant prognostic factors using suitable regression models. Results will be provided with estimates and the appropriate confidence intervals where feasible. Time to event outcomes will be described using Kaplan-Meier curves (if appropriate) and proportional hazards models will be used to examine the impact of predictors on these outcomes.The outcome tested is mean testing of a composite score for surgical morbidity. This score has been summarized above. The investigators anticipate that a mean of 6.75 out of 8 will be anticipated in the patients who comply with VLED treatment. In the group whom do not take the VLED pre-therapy, we expect a mean score of 4.5 out of 8.
Using a two- sided significance level of 95% with a power estimate of 80%, and with the ratio of sample size of exposed to non-exposed being 1. Using Fleiss calculations for sample size and adjusting for continuity correction we would anticipate requiring 48 patients in each arm, and therefore in total 96 patients. The investigators will therefore aim to accrue 100 patients. This means we will accrue 50 in each arm.

Recruitment status
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment in Australia
Recruitment state(s)
Recruitment hospital [1] 4049 0
The Alfred - Prahran
Recruitment hospital [2] 4050 0
Cabrini Hospital - Malvern - Malvern
Recruitment hospital [3] 4055 0
Royal Prince Alfred Hospital - Camperdown
Recruitment hospital [4] 4056 0
Royal Brisbane & Womens Hospital - Herston
Recruitment hospital [5] 6491 0
The Wesley Hospital - Auchenflower
Recruitment hospital [6] 6492 0
St Andrew's War Memorial Hospital - Brisbane
Recruitment hospital [7] 6493 0
Holy Spirit Northside - Chermside
Recruitment hospital [8] 6902 0
John Hunter Hospital - New Lambton
Recruitment hospital [9] 6903 0
Newcastle Private Hospital - New Lambton Heights
Recruitment hospital [10] 9211 0
Peter MacCallum Cancer Centre - Melbourne
Recruitment hospital [11] 9212 0
Gold Coast University Hospital - Southport
Recruitment hospital [12] 11974 0
Nepean Hospital - Kingswood
Recruitment postcode(s) [1] 9982 0
2050 - Camperdown
Recruitment postcode(s) [2] 14570 0
2305 - New Lambton
Recruitment postcode(s) [3] 14571 0
2305 - New Lambton Heights
Recruitment postcode(s) [4] 24121 0
2747 - Kingswood
Recruitment postcode(s) [5] 17866 0
3000 - Melbourne
Recruitment postcode(s) [6] 9979 0
3144 - Malvern
Recruitment postcode(s) [7] 9978 0
3181 - Prahran
Recruitment postcode(s) [8] 14056 0
4000 - Brisbane
Recruitment postcode(s) [9] 9983 0
4006 - Herston
Recruitment postcode(s) [10] 14057 0
4032 - Chermside
Recruitment postcode(s) [11] 14055 0
4066 - Auchenflower
Recruitment postcode(s) [12] 17867 0
4215 - Southport
Recruitment outside Australia
Country [1] 8108 0
New Zealand
State/province [1] 8108 0
Takapuna, Auckland

Funding & Sponsors
Funding source category [1] 291651 0
Name [1] 291651 0
Cabrini Foundation
Address [1] 291651 0
181-183 Wattletree Road
Malvern VIC 3144
Country [1] 291651 0
Funding source category [2] 294329 0
Name [2] 294329 0
Colorectal Surgical Society of Australia and New Zealand
Address [2] 294329 0
9 Church St,
Hawthorn 3122
Country [2] 294329 0
Funding source category [3] 297802 0
Name [3] 297802 0
Private donor
Address [3] 297802 0
Country [3] 297802 0
Primary sponsor type
Monash University
Suite 27
Cabrini Medical Centre
Isabella St,
Malvern VIC 3144
Secondary sponsor category [1] 290320 0
Name [1] 290320 0
Address [1] 290320 0
Country [1] 290320 0

Ethics approval
Ethics application status
Ethics committee name [1] 293178 0
Alfred HREC
Ethics committee address [1] 293178 0
Alfred Health
55 Commercial Road
Melbourne VIC 3004
PO Box 315 Prahran
VIC 3181 Australia
Ethics committee country [1] 293178 0
Date submitted for ethics approval [1] 293178 0
Approval date [1] 293178 0
Ethics approval number [1] 293178 0

Brief summary
The primary purpose of this study is to determine whether a very low energy diet (VLED) can reduce weight and improve outcomes in obese patients undergoing surgery for rectal cancer. Who is it for? You may be eligible to join this study if you are aged 18 years or over with a BMI greater than or equal to 30 and have been diagnosed with adenocarcinoma of the rectum for which surgery has been prescribed. Study details Participants will be randomly allocated (by chance) to either the Optifast diet treatment, or the usual care treatment. Participants on the Optifast diet treatment will be restricted to 800 calories or less per day for 4 - 6 weeks before the surgery, using the Optifast diet products including nutritionally complete soup sand shakes. Participants in the usual care treatment group will receive care and advice prior to their surgery as normal. Patient outcomes will then be assessed at visits in the hospital stay at day three, then at day 14, four to six weeks, 3 months, 6 months, 9 months, 12 months, 18 months and 24 months after discharge. Further long-term follow-up will be conducted annually for an additional three (3) years after the 24 months follow up visit at which participants will undergo a blood sample and physical examination. It is hoped that the findings of this trial will increase understanding of the potential benefits of a VLED prior to surgery in obese patients with rectal cancers.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 58002 0
Mr Stephen Bell
Address 58002 0
Suite 27
Cabrini Medical Centre
Isabella St,
Country 58002 0
Phone 58002 0
+61 3 9509 8033
Fax 58002 0
Email 58002 0
Contact person for public queries
Name 58003 0
Mr Stephen Bell
Address 58003 0
Suite 27
Cabrini Medical Centre
Isabella St,
Country 58003 0
Phone 58003 0
+61 3 9508 3525
Fax 58003 0
Email 58003 0
Contact person for scientific queries
Name 58004 0
Mr Stephen Bell
Address 58004 0
Suite 27
Cabrini Medical Centre
Isabella St,
Country 58004 0
Phone 58004 0
+61 3 9508 3525
Fax 58004 0
Email 58004 0

No information has been provided regarding IPD availability
Summary results
No Results