Each year, 100,000 skin cancers are due to excessive UV exposure. If melanomas represent only 2 % to 3 % of cancers, the prevalence explodes: their number has multiplied by four since 1990. They are also the most dangerous. Florian Favier, researcher at the University of Montpellier supported by the League against Cancer, works on the resistance of melanomas with treatments.
Florian Favier, integrated into an IRCM team (Institute for Research in Cancer of Montpellier), is a researcher at the University of Montpellier. His thesis on melanomas is supported by the league against cancer.
Why were you interested in melanomas, which represent 2 % to 3 % of skin cancers, carcinomas being the most frequent?
It is indeed a very small proportion of cancers of the skin but it is the main cause of mortality of skin cancers. Especially with stage 3 or 4 melanomas.
Sometimes they are discovered at this stage?
Yes. Melanoma is cancer that metastasus very often, and surgery is then ineffective.
The majority of skin cancer are treated in “local”, with surgery.
Melanoma and carcinomas are not similar cancers?
There is a difference on cells at the start of cancer. Melanoma comes from the melanocytes group, these cells that will give the skin pigment, which will make you bronze.
Carcinomas have their source in the dermis.
Immunotherapy or targeted therapy
The ABCDE rule is useful for locating them?
Asymmetry, irregular edges, color, diameter and evolution … This rule is also useful for identifying melanoma. But melanoma, which represents only a few percent of the total number of skin cancers, represents more than 80 % of the mortality attributed to this type of cancer.
“We are not sausages”: the shock campaign of the league
“We are not sausages” : the cancer league is launching a shock campaign on the occasion of the summer, recalling that “Toast in the sun is 80,000 skin cancers and 2000 deaths per year”.
Intended for the general public, and declined in the form of visuals broadcast in pharmacies, and video, the campaign wants to reach “The most vulnerable people, young people, travel people and precarious people”explains the Cancer League, which recalls public health data France: 141,200 to 243,500 skin cancers are diagnosed every year in France, between 112,960 and 194,800 cancers caused by excessive UV exposure.
“Skin cancer are thus one of the 40 % of avoidable ductions”concludes the League, which recalls the basic prevention rules: prefer the shadow and avoid exposing themselves between 12 p.m. and 4 p.m. in mainland France, 10 a.m. and 2 p.m. overseas; Wear clothes with tight weaving or anti-UV treated, sunglasses with a CE3 or CE4 standard, and a wide-edge hat; Apply sunscreen with a high protection index, 20 minutes before an exposure and after each swim, even under the clouds; Flee the tanning cabins.
How do we take care of them today?
Before 2010, there was no treatment for metastatic melanomas. The chances of survival were very low.
Two therapies have emerged since: targeted therapy and immunotherapy. Thanks to that, we are 50 % survival rate at 5 years. But these two treatments come up against phenomena of resistance, primary, from the start of treatment, or secondary, after an initially positive response. For what ? How ? I wanted to understand.
What do you know today?
I worked on targeted therapies, which have a very good initial response rate, around 60 to 70 %. But 90 % of patients eventually become resistant.
I often take the image of electrical networks so that one can imagine the organization of a cell: they program the cell, tell him what to do … We can appear their activity in the form of small bulbs, which will light and turn off. In more than 70 % of melanoma cases, there is a failure in these electrical circuits. The bulb no longer dies: the cell proliferates, divides, becomes invasive. This is what characterizes cancer cells.
The targeted therapies come to “turn off” the bulbs. But in 90 % of cases, the cell activates another neighboring circuit, or manages to reactivate the inactivated circuit.
My work has consisted in studying these electrical networks and trying to identify, upstream of treatment, clues that allow us to know if in an individual, the network will be definitively unlikely, or likely to bypass obstacles.
I have promising results on cell lines, in which I have identified cells that have a different circuit, which makes them more resistant. It remains to be seen whether I can apply them to the living to defeat these resistances.
Lung cancers too?
We are still in basic research …
Yes, but the goal is an application to the patient.
What can we offer to patients who have these potentially resistant cells?
They will be offered as a first intention of immunotherapy, which has a less good rate of initial response, but which arouses less resistance. Immunotherapies have the disadvantage of being very toxic and of leaving many side effects.
Ultimately, if I manage to identify a marker specific to these cells, the idea is to eliminate them with another treatment.
Suffice a few resistant cells to “put the bazaar”?
In the cells I studied, there are 1 % of potentially resistant cells. But after treatment, they become the majority and represent 50 % of the cell population.
Can this research apply to other types of cancer?
Yes. The electrical circuit that I study, Mapk, is also responsible for other cancers, certain lung cancers for example.
