A groundbreaking vaccine for early-stage bowel cancer is set to undergo clinical trials through a collaborative effort between medical professionals in Surrey, Hampshire, and Australia.
Dr Tony Dhillon, the chief investigator of the trial and a consultant oncologist at the Royal Surrey NHS Foundation Trust, anticipates that the vaccine could receive licensing approval within two years. This development offers patients a ray of hope in their battle against the disease. Bowel cancer ranks as the third most prevalent cancer type globally.
The trial will be conducted by the Cancer Research UK Southampton clinical trials unit at the University of Southampton, in conjunction with the Royal Surrey and the Queen Elizabeth Hospital in Adelaide, spanning four sites in the UK and an additional six sites in Australia.
Here, the chief investigator Dr Dhillon, a cancer specialist, particularly focusing on bowel, liver, and pancreatic cancer, spoke to Asian Voice, sharing his insight about the trial.
In layman's terms, can you like give an overview of what this vaccine trial is all about? How does it differ from all the existing treatments?
This cancer vaccine is designed to treat cancer, not to prevent it and that's quite unique in itself. The vaccine is specifically for patients with bowel cancer. About 15% of the bowel cancer population has a unique subtype, having a high concentration of immune cells surrounding the cancer. However, these immune cells, although recognising the cancer as a foreign body, are unable to act because the cancer produces chemicals to suppress the immune response.
What this vaccine does is, it activates the immune system to attack the cancer. Normally, patients diagnosed with bowel cancer would undergo surgery. Here, we administer three doses of the vaccine two weeks apart before the surgery hoping that it will shrink the tumours or, in some cases, completely eradicate them and that's what makes it unique. We believe it will make surgery easier and, in some cases, may even eliminate the need for surgery altogether. We are among the first to conduct trials for this type of treatment. I know there are other cancer vaccines out there, but they are not at this stage of development.
What are the eligibility criteria for patients to participate in the trial?
The eligibility criteria would be a stage two or stage three colon cancer and they have to have this special subtype, which is called defective mismatch repair. This is tested when the patients have their colonoscopy. Apart from that, they have to have had no surgery yet but their cancer should be possible to remove via surgery, which is the case for about 15% of patients. Lastly, the participant should be an adult. The unique aspect of this special subtype is personalised medicine, where we tailor treatments to match the specific biology of each patient. It's crucial to recognise that there's no one-size-fits-all approach because bowel cancer varies significantly among individuals. While 15% may seem like a relatively small proportion, considering that bowel cancer is one of the most prevalent cancers globally, that 15% still represents a substantial number, especially on an international scale.
How do you anticipate this vaccine will impact the current landscape of bowel cancer treatment?
I believe this study is just one of many in this field, suggesting a potential shift away from immediate surgery towards drug-based treatments or vaccines. This would represent a significant change in the management of this type of cancer, considering that the current standard of care typically involves surgery as the first-line treatment. Traditionally, upon diagnosis of bowel cancer through colonoscopy and confirmation via CT scan, the standard protocol involves proceeding directly to surgery, a practice that has been in place for approximately 60-70 years. However, for this 15% subset of patients, we are challenging this standard approach by recommending drug-based treatment or a vaccine before surgery. The rationale behind this approach is twofold: first, to potentially shrink the cancer before surgery, and second, to improve the chances of a successful cure. Even with surgery, the cure rate for bowel cancer is approximately 70%, meaning that 30% of patients experience recurrence. Therefore, we hope that administering the vaccine before surgery and conducting long-term follow-up studies will show an improvement in survival/cure rates. While reducing the size of the cancer prior to surgery is promising, it's essential to determine whether this translates into a higher likelihood of cure over time, which we aim to ascertain through long-term patient follow-up, extending up to three years post-treatment.
How can individuals who are interested in learning more about the trial or potentially participating in it get involved or find more information?
Participants would need to reside primarily in southern Australia or in the UK. We’ll likely to engage participants from the Royal Surrey NHS Foundation in Guildford, Manchester, where I work, and potentially another site. In Australia, trial centres will be established in some of the southern cities, so they would need to connect with these trial centres. Once we begin recruiting, a trial website will be set up, which will happen quite soon.
How can individuals become more aware of conditions like prostate cancer and bowel cancer?
Regarding cancer screening, there are specific protocols in place, such as bowel cancer screening starting at the age of 55, where individuals receive a home testing kit to check for blood in their stool. It's crucial that if you receive this kit, you use it and send it back for analysis.
While certain cancers have routine screening programs, many do not. Symptoms to watch out for include unexplained weight loss and persistent pain that doesn't subside after a few days. However, the challenge often lies in getting a timely diagnosis. Many patients I see have visited their GP multiple times over several months before undergoing necessary scans. Patients need to advocate for themselves and express concerns to their GP, especially if they suspect cancer.
Once a suspicion of cancer arises, there are pathways in place to expedite investigations. However, the issue with current screening methods, particularly for cancers like pancreatic cancer, is that they often detect cancer at advanced stages. While advancements in blood tests for detecting cancer DNA show promise, they present a dilemma when a positive result doesn't correlate with findings on a scan. This highlights the need for further refinement in cancer screening methods to ensure early detection and appropriate intervention.
