At this year’s ESCP Annual Meeting of coloproctologists in Berlin in September, Simon Bach is chairing the symposium, 'What to do with a T2 rectal cancer?' Here, Bach previews the symposium, which will look at the options for treating early rectal cancer and will feature three speakers presenting three different approaches ranging from surgery alone to chemo radiotherapy (CRT) followed by local excision or CRT followed by a period of watch and wait with no surgery.
Simon Bach is a Consultant Colorectal Surgeon at the Queen Elizabeth Hospital Birmingham and also a Senior Lecturer at Birmingham University. He is the chief investigator for the Cancer Research UK TREC and STAR-TREC studies evaluating rectal sparing treatment for early rectal cancer. Mr Bach also chairs the National Cancer Research Institute Colorectal Surgery subgroup, overseeing delivery of the UK’s colorectal cancer research portfolio.
Is total mesorectal excision (TME) still the 'gold standard'?
The key debate in relation to treating early rectal cancer is whether total mesorectal excision (TME) is still the best approach for patients or whether now, with the prevalence of more screening programmes picking up smaller, earlier tumours, less invasive treatments can be used to treat early rectal cancer successfully.
Bach says:
“Removal of the rectum inevitably has an enormous impact on patients’ lives, their ability to work, to attend meetings or their ability to go to the shops.”
“If we can alter treatment to take account of the fact that many tumours now are smaller, we may be able to preserve the rectum. Organ saving treatment avoids a big operation. We hope that organ saving treatment leads to better bowel function, improved quality of life and avoid the need for a temporary or permanent stoma bag. However, organ saving treatments are still unproven and we need more information from studies to reliably know the risks and benefits of this approach.”
The symposium in Berlin will focus on what has been learned from the newer trials about the toxicity of alternative treatment models using (chemo) radiation therapy (CRT) and their ability to cure cancer.
Ivan Dimitrijevic starts by looking at the traditional approach of using total mesorectal excision to treat early rectal cancer and the advantages of this established method.
The second presentation will be from Prof Julio Garcia-Aguilar who led the ACOSOG Z6041 trial which investigated the use of a combination of neoadjuvant chemoradiotherapy (CRT) and local excision.
Prof Geerard Beets will then present learnings from trials where CRT has been administered and followed by a watch and wait policy for patients who have a complete clinical response to the CRT.
Additionally, Eric Rullier will co-chair the session. He led the recently published GRECCAR2 trial which compared local excision and total mesorectal excision in patients with a good response after CRT for low rectal cancer.
“It is undoubtedly the case that we can now successfully preserve the rectum in certain patients with early rectal cancer,” Mr Bach said. “However in some cases we will not achieve this - so we need to understand how often the organ saving approach fails and if this failure harms patients in the long run.”
Bach argues that it’s important for trials to compare standard surgery with the organ saving treatments so that surgeons can be sure that the organ saving approach produces better outcomes for patients. This is what has been done in the randomised STAR-TREC study that Bach is currently leading, which compares conventional TME surgery with mesorectal (chemo)radiation. Treatment response governs the next step, which is either transanal microsurgery or watch and wait.
He goes on:
“We need more high quality data on the differences in terms of patient outcomes for those that have the radical surgery versus those who undergo a course of treatment to preserve their rectum. For example, what is the difference in terms of the risk of incontinence with each different method?”
Prof Garcia-Aguilar will show that local excision can be combined with CRT to remove any residual tumour cells leading to high cure rates for patients. However, up to now combining treatments in this way also leads to unacceptable toxicity for patients.
Selection of patients for organ preservation
Bach points out that in many recent trials,
“Surgeons use the results of radiotherapy to select patients for organ preservation. All patients are exposed to the side effects of radiotherapy treatment, but only some benefit.”
Bach believes the next big question facing the coloproctologists will be how surgeons can best select patients for organ preservation. Bach hopes research into molecular markers and genetics will enable a better understanding from pre-treatment biopsies of the characteristics of patients who respond well to CRT compared to those who won’t benefit. In this way surgeons could avoid exposing patients to the toxicity of CRT if it is destined to fail in their case.
Bach notes that it’s crucial that surgeons are embarking on studies now consider how biomarker analysis can be incorporated into their evaluations. It could prove hugely useful if trials develop tissue banks that allow for genetic analysis to be done on pre-treatment samples and correlate with patient outcomes at the end of the study.
Bach says:
“We want to understand what proportion of patients are cured by CRT, what proportion need local surgery after CRT and what proportion will need to have the radical surgery to be cured. Crucially we also want to understand the genetic profiles of those who responded well to the CRT and those who derived no benefit.”
The symposium takes place at the ESCP Annual Meeting on Friday 22nd September at 11.20am.
