Understanding the effect of chemotherapy on microbial composition of pancreatic ductal adenocarcinoma (PDAC) patients

Principal Investigator: Prof David Goldstein

Tumour: Pancreatic Cancer

Pancreatic cancer is the fourth most common cause of cancer death in Australia and it is critical to develop a new treatment for patients with pancreatic cancer who have limited life expectancy. Increasing body of research suggest that bacteria within human body may be responsible for the development and survival of pancreas cancer. There is an emerging idea that changing gut bacteria may improve the effects of chemotherapy.

The MASTERPLAN Microbiome study is a translational research substudy within the MASTERPLAN trial to collect serial bacterial samples from patients receiving chemotherapy as part of MASTERPLAN trial. The main goal is to describe how the gut bacteria will change before and after chemotherapy.

Pancreatic cancer is associated with a high prevalence of weight loss and malnutrition, and evidence suggests that changes in body composition, which means changes in the amount of muscle, fat, fluid and/or other tissues in our body, affects outcomes in all stages of pancreatic cancer. A loss of muscle tissue can impact general function and well-being, as well as the development of side effects from cancer treatment. Identifying and treating this early, through improved assessment techniques, could lead to improved outcomes for patients with PC.

A simple measurement of weight, or body mass index (BMI), as is currently commonly used, does not accurately identify those at most risk, or changes in muscle tissue. The most accurate way to measure body composition, using CT scans, requires skilled staff and is time consuming. In comparison, malnutrition and loss of muscle mass can be identified with a quick-to-use tool called the Patient Generated Subjective Global Assessment (PG-SGA). The PG-SGA is commonly used by dietitians when completing nutrition assessments in patients with pancreatic cancer. The relationship between the PG-SGA malnutrition diagnosis and CT-diagnosed low muscle mass has not yet been investigated in pancreatic cancer. Given the PG-SGA tool is widely accessible and low cost, comparing its use to the gold standard CT-assessed body composition is warranted. This may improve the management of patients with pancreatic cancer in the future.

This substudy of MASTERPLAN aims to identify how a standard instrument used by dietitians to assess for malnutrition performs against a gold standard.

RANDoMS is currently recruiting at select MASTERPLAN sites.

Fear of Recurrence Substudy

Principal Investigator: A/Prof Sue-Ann McLachlan

Tumour: Colorectal Cancer and Rectal Cancer

Fear of Cancer Recurrence (FCR) is defined as “fear, worry, or concern relating to the possibility that cancer will come back or progress” and is one of the most common unmet needs for help amongst cancer survivors. Previous research also suggests that FCR is not associated with objective risk of recurrence; rather that FCR may remain high in some individuals even when risk of recurrence is low. The availability of a growing number of genomic assays to predict risk of cancer recurrence across several cancer types no studies have investigated the relationship of being informed of high-risk of recurrence based on genomic profiling or forgoing standard therapy based on a low- risk genomic profile, and FCR.

Personalised medicine is likely to bring about new challenges with respect to FCR. A better understanding will allow clinicians to detect and direct those with significant FCR to psychological help and supportive care. This study will provide the first information about FCR when using molecular information to determine adjuvant chemotherapy for patients with stage III colon cancer and advanced rectal cancer.

The aim the Fear of Recurrence Substudy is to assess Fear of Cancer Recurrence levels using a validated self-reporting questionnaire in the context of a randomised clinical trial (the DYNAMIC-III study and DYNAMIC-Rectal).

Fear of Recurrence substudy is currently recruiting at DYNAMIC-III and DYNAMIC-Rectal sites.

ASCOLT TR substudy

ASCOLT circulating tumour DNA (“ActDNA”) translational study: prediction of minimal residual disease in a large Phase III randomised adjuvant colorectal cancer trial

Principal Investigator: Eva Segelov

Tumour: Colorectal Cancer

Cancer can unfortunately come back in up to half of patients with early-stage bowel cancer following treatments including surgery with or without chemotherapy and radiotherapy. As part of the international ASCOLT trial, we collected blood samples at various times. This study uses some of those samples to see if we can predict even as early as when the patient has started the study, as to whether their cancer will come back (relapse).

The ASCOLT trial is looking at whether taking aspirin helps reduce the chance of the cancer returning in the future, for patients with early-stage bowel cancer once they have finished the usual treatment (surgery, chemotherapy and/or radiotherapy). Whilst we are waiting for the final study results, we can study the blood samples to see if we can find clues to see which patients will have relapse of their cancer.

Current methods of detecting whether the cancer will come back include some blood tests (the CEA marker) which is not very accurate, as well as regular CT scans, which cause patients anxiety and are again sometime inaccurate. Recently, there is evidence that a special blood test measuring circulating tumour DNA (ctDNA; also called a liquid biopsy) can detect tiny amounts of cancer-related genetic material (DNA) in the blood. If ctDNA is present in the blood, it may be an indicator that cancer is more likely to come back as there may be small collections of cancer cells left behind (these are not usually visible on CT scans).

Therefore, ctDNA has the potential to predict recurrence earlier and more accurately than current methods. If proven, ctDNA results can help to relieve patients’ fear of recurrence and also give strategies for earlier treatment of recurrence and guide the intensity of post-treatment monitoring (how many blood tests and scans) according to an individual patient’s risk.