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Colorectal cancer
Director:
Prof. Michel Ducreux
Contact:
+33 (0)1 42 11 57 99
Email
Understanding the Disease
In most cases, colorectal cancers develop from a polyp—an initially benign lesion of the colon or rectal lining—which can gradually progress to a malignant tumor if left undiagnosed and untreated. When detected at an early (localized) stage, this disease has a five-year survival rate of over 90 percent. However, low participation in the national screening program and the absence of symptoms in the early stages of the disease delay many diagnoses. As a result, this disease remains the third leading cause of cancer-related death in France, among both men and women.
Colorectal Cancer by the Numbers
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47,000
new cases in 2023
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3rd
the most common cancer
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35%
The people concerned participate in the screening
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71 years old
average age at diagnosis
Risk Factors
Gustave Roussy offers oncogenetic consultations for individuals at high or very high risk of colorectal cancer, providing guidance on screening and specific care for young patients with a predisposition to the disease and their family members.
Unbalanced diet: High consumption of red or processed meat and insufficient fiber intake increase the risk.
Sedentary lifestyle and being overweight: Lack of physical activity and obesity—particularly abdominal obesity—are well-established risk factors.
Tobacco and alcohol: Regular consumption of these substances is associated with a significant increase in risk.
Family history: Having a first-degree relative with colorectal cancer increases the risk by a factor of 2 to 3.
Hereditary syndromes: Certain rare genetic mutations, such as Lynch syndrome or familial adenomatous polyposis (FAP), put people at very high risk from a young age.
Intestinal polyps: Certain polyps (adenomas) can develop into cancer if they are not detected and removed in time.
Age: The risk increases significantly after age 50, which is why organized screening is recommended starting at that age in France.
Chronic inflammatory diseases: Crohn’s disease and ulcerative colitis increase the risk, especially if the condition has been present for a long time.
Symptoms
With more than 43,000 people diagnosed each year, colorectal cancer is one of the four most common cancers in France.
Symptoms to watch for include:
- Digestive problems, including worsening constipation and persistent diarrhea.
- Recurrent nausea and vomiting.
- A strong urge to use the restroom.
- Stools that are narrower than usual.
- A feeling that the rectum has not been completely emptied.
- Blood in the stool.
Screening
The national health insurance program offers a screening test for people aged 50 to 74. Unfortunately, between 2021 and 2022, only 34.3% of those eligible took the screening test. The test, which is free and can be done at home, is designed to detect the presence of blood in the stool that is invisible to the naked eye. If the result is positive, the person is advised to undergo a colonoscopy.
For more information on the national colorectal cancer screening program:
- Expanding Colorectal Cancer Screening to Save Lives
- Colorectal Cancer Screening: What You Need to Know
At the same time, for people at high risk of developing colorectal cancer—such as those with Lynch syndrome—the Interception program, developed at the Institute, offers a dedicated care pathway designed to support these individuals and provide personalized follow-up tailored to their lifestyle.
Finally, since March 2026, a pathway within the Interception program has been designed for people at increased risk of colorectal cancer but without a genetic predisposition.
Coverage
Each year, Gustave Roussy treats more than 3,000 patients with colorectal cancer, who are cared for by the Digestive Pathology Committee.
The only test that can diagnose colorectal cancer is a colonoscopy. A virtual colonoscopy—an imaging test similar to an abdominal-pelvic CT scan—is offered only when a colonoscopy is unsuccessful.
The Gastroenterology Department at Gustave Roussy has an endoscopy facility that easily accommodates endoscopies performed under general anesthesia:
- For diagnostic purposes: esophagogastroduodenoscopy, colonoscopy, echoendoscopy
- For therapeutic purposes:
- Removal of colorectal polyps via endoscopic polypectomy and/or mucosectomy, submucosal dissection.
- Treatment of biliary tract strictures (ERCP—endoscopic retrograde cholangiopancreatography—or echoendoscopy—extra-anatomical choledoco-bulbar and choledoco-duodenal anastomoses).
Before any treatment decision is made, additional tests must be performed to assess the size of the tumor and its local spread, to check for the presence of metastases, and to evaluate the patient’s overall condition. A physical examination (clinical assessments, blood tests, ECG) and psychological evaluation are essential.
The COLODÉPIST Program
At Gustave Roussy, a specialized screening consultation, called “Colodépist,” is offered to you if your test is positive or if you have a family history of colon cancer that warrants a colonoscopy.
The Colodépist pathway is available only to patients residing in the Île-de-France region.
This consultation includes a meeting with the anesthesiologist to schedule a colonoscopy as soon as possible: our teams will arrange it within two weeks. This procedure is performed on an outpatient basis—that is, without hospitalization—unless there are contraindications. You will therefore be able to return home that evening and eat normally. The results will be provided to you the same day. Any biopsy analysis will be completed within the week.
To schedule an appointment, please contact the endoscopy department at: +33 (0)1 42 11 57 99
Treatments and Clinical Trials
The choice of treatment for colorectal cancer depends on the stage and location of the cancer, as well as the patient's overall health.
These treatments may include:
- Surgery, which involves removing the segment of the colon where the tumor is located. Thanks to the expertise of its teams and a state-of-the-art surgical robot, Gustave Roussy performs certain procedures using robot-assisted surgery to minimize postoperative complications as much as possible and preserve patients’ quality of life to the greatest extent possible.
- Radiation therapy.
- Chemotherapy.
- Targeted therapies.
Join a clinical trial
Many clinical trials are open to patients with cancer. Participating in a clinical trial provides access to innovative treatments while contributing to the development of new therapies.
Search
The research team led by Fanny Jaulin at Gustave Roussy specializes in the biological modeling of colorectal cancers. This work relies on the use of organoids—miniature replicas of tumors grown in the laboratory from tumor cells collected directly from the patient, usually via biopsy. The tumor cells are then cultured in the laboratory to create a tumor model specific to each patient.
These organoids are designed to help us understand the mechanisms by which cancer cells invade tissues, as well as their ability to spread throughout the body and form metastases—the leading cause of cancer-related deaths. But these models are also used to test the effectiveness of different treatments early on in order to identify which one would be most effective for each patient. Researchers are not limiting themselves to standard, validated treatments for colorectal cancer, but are expanding their research to include drugs used for other cancers, in order to determine whether they might be effective for a given patient.
What is an organoid?
An organoid is a miniature replica of a tumor, grown in a laboratory from cells collected directly from the patient via biopsy. As a true tumor model, it faithfully reproduces the biological characteristics specific to each patient.
Contact
Director: Prof. Michel Ducreux
Contact:
Phone: +33 (0)1 42 11 57 99
Appointments and Second Opinions
Testimonial
Voices of Those Affected
Olivier, in remission from colorectal cancer
It was at the Institute that I was told my tumor was linked to a genetic mutation, because I have Lynch syndrome.
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Dépistage du cancer colorectal : ce qu’il faut savoir
Mars bleu, mois de sensibilisation dédié au cancer colorectal, est l’occasion de rappeler l’importance du dépistage national organisé en France autour de cette pathologie. Simple et efficace, il est entièrement gratuit et réalisable à la maison. Malheureusement, il est encore trop peu suivi, avec seulement 30 % des personnes éligibles qui le réalisent. Pour répondre à cette problématique, Gustave Roussy va déployer durant tout le mois de mars une campagne de sensibilisation et d’information porteuse d’un message simple et percutant : « Même si ça te fait chier, fais-toi dépister ». La Dr Marine Valéry, oncologue médicale au sein du comité d’oncologie digestive de Gustave Roussy, apporte son éclairage.
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Gustave Roussy, expert dans la prise en charge des cancers du rectum
Mars Bleu, mois de sensibilisation au dépistage du cancer colorectal, est l’occasion de revenir sur l’engagement de Gustave Roussy pour permettre aux patients atteints d’un cancer du rectum d’avoir accès aux dernières innovations dans le traitement de cette pathologie. L'Institut a par exemple commencé à traiter certains patients avec l’appareil de radiothérapie de contact Papillon +, permettant d’améliorer nettement leur qualité de vie.
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Prévention personnalisée, diagnostic optimisé et IA : Gustave Roussy déploie son expertise contre les cancers colorectaux
Mars Bleu, mois dédié à la sensibilisation et au dépistage des cancers colorectaux, est l’occasion de ne pas remettre à plus tard la réalisation du test de dépistage de sang dans les selles, Hemoccult. Ce test s’inscrit dans le cadre du dépistage national organisé en France, mais il est actuellement effectué par seulement un tiers des personnes concernées. Durant tout le mois de mars, avec la campagne digitale #RendezVousAuxToilettes, Gustave Roussy enjoint tous les Français âgés de 50 à 74 ans à y prendre part.
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Les questions à poser si vous êtes diagnostiqué d’un cancer colorectal
Le cancer colorectal est à l’origine de 47 500 nouveaux cas chaque année en France [1]. Il s’agit de la 2e pathologie cancéreuse la plus fréquente chez la femme et la 3e chez l’homme. À l’annonce du diagnostic, plusieurs questions peuvent être posées à votre oncologue afin de mieux comprendre votre cancer, mais également pour connaître votre éligibilité à un essai clinique pouvant donner accès à des traitements innovants. À l’occasion de Mars Bleu, le Pr Michel Ducreux, chef du comité de pathologie digestive de Gustave Roussy, répond.
Frequently Asked Questions
This is a cancer that develops in the colon or rectum from small growths called polyps. It is one of the most common cancers in France, but also one of the most curable if detected early.
Blood in the stool, a lasting change in bowel habits (unusual diarrhea or constipation), persistent abdominal pain, or unexplained fatigue. These symptoms do not necessarily indicate cancer, but they warrant a medical evaluation.
Anyone can be affected, but the risk increases after age 50. Having a close relative who has had this cancer, suffering from inflammatory bowel disease, or leading a sedentary lifestyle with a diet low in fiber are also risk factors.
In France, a free screening test is offered every two years to people aged 50 to 74. This simple test is done at home using a small stool sample. If the result is positive, a colonoscopy is then performed.
Yes, in most cases, if it is treated early. When detected at an early stage, the 5-year survival rate exceeds 90%. That is why regular screening is essential, even in the absence of symptoms.