According to Canadian researchers, fecal samples could help people with cutaneous melanoma to better respond to immunotherapy treatment. They are preparing to launch a clinical trial.
Between 1980 and 2012, the number of new cases of skin cancer more than tripled in France. This disease now affects nearly 80,000 new people every year. In 10% of cases, people diagnosed have melanoma. If this form of skin cancer is the rarest, it is also the most aggressive. With 15,404 new cases of cutaneous melanoma estimated in 2017 in metropolitan France (8,061 men and 7,343 women) and 1,783 deaths (1,036 men and 747 women), this disease represents nearly 4% of all cancers and 1.2% of cancer deaths.
Cutaneous melanoma is of good prognosis if detected early enough, hence the importance of early diagnosis, explains the National Cancer Institute. The treatment is based on surgical excision. On the other hand, diagnosed late, the patient is much less likely to escape. Indeed, this cancer has high metastatic potential: it can spread rapidly to ganglionic relays and other organs. Doctors then try complementary treatments such as ganglion dissection, radiotherapy, chemotherapy, excision of metastases or immunotherapy.
The latter is intended to stimulate the immune system of a patient to attack and destroy cancer. While these treatments can greatly improve the survival of patients with melanoma, they are effective in only 40 to 50% of them. For this reason, researchers at the Lawson Health Research Institute in Canada are studying the impact of fecal implantations on the longevity of patients with cutaneous melanoma treated with immunotherapy. They are preparing to launch a clinical trial, as indicated in the press release issued on August 16 on their official website.
Preliminary research has shown that the human microbiome, the various collections of microbes in our body, could play a role in the patient's response to immunotherapy treatment. "The microbiome of the gut helps build the immune system at an early age, so it makes sense that a healthy gut can improve the response to immunotherapy," says Dr. Jeremy Burton, a scientist specializing in research on the immune system. microbiome. "This led us to consider the potential of faecal transplants," he continues. The goal is to transplant the microbiome of the donor so that the healthy bacteria colonize the patient's intestine.
"Our institute is well placed to move forward"
In a first phase of the clinical trial, the researchers studied the use of faecal transplants to alter the microbiome of patients and improve their response to immunotherapy treatments. From now on, after collecting stool from healthy donors, the researchers will transplant them to 20 Britons with cutaneous melanoma. In detail, patients will ingest oral capsules specially prepared for their attention. Over time, researchers will assess the evolution of their cancer, microbiome, immune system and general health status.
"Melanoma is the least common skin cancer but the most lethal and death rates are rising," says Dr. John Lenehan who will participate in the study. "Anti-PD1 immunotherapy drugs can be extremely effective, but we want to help more patients respond, which is our goal."
If researchers are now focusing on cutaneous melanoma, they also see a potential for other cancers. "We are one of the first teams in the world to study fecal transplants in cancer patients, a state-of-the-art study of potential applications for multiple types of diseases," notes Dr. Saman Maleki, a Lawson research associate specializing in cancer immunology. "With experts in microbiology, infectious diseases, cancer and immunology, our institute is well positioned to move forward," he says.
Potential for the treatment of other diseases
"Fecal transplants have saved the lives of countless patients with recurrent Clostridium difficile colitis," said Dr. Michael Silverman, a pioneer in the field of stool transplants. "We are starting to see its potential for treating other diseases," he explains. Today, Lawson researchers are planning fecal transplant studies for many other diseases, including non-alcoholic fatty liver disease, multiple sclerosis (MS), and cancer treatment toxicity. "But to do this research, we need stool donors," says Dr. Silverman.
Recall that melanoma can appear on healthy skin in 70 to 80% of cases or result from the malignant transformation of a mole. Hence the importance of having your suspicious moles regularly screened by a dermatologist. It is also possible to refer to the ABCDE rule (for Asymmetric, Edges, Color, Diameter and Evolution), a self-detection technique developed by specialists. According to the latter, a task or a mole with any of the following characteristics may be suspect: Asymmetry, Irregular Edges, Uneven Color, Increasing Diameter, or Rapidly Evolving.