Welcome to the new Gustave Roussy website

A new website designed to offer you a simpler, clearer, and more intuitive experience. Patients, caregivers, healthcare professionals, and donors: find information, news, and services more easily.

Types of Cancer

Rare Cancers

Director: Prof
. Antoine Italiano

Understanding the Disease

In Europe, a cancer is considered rare when its incidence is less than 6 new cases per 100,000 people per year. Its rarity may be related to its anatomical location, its histological type, or a combination of both. Cancers in children and adolescents are all rare on a population-wide scale and fall under the purview of a specialized pediatric oncology program.

Cancers in Children and Adolescents

Cancers in children and adolescents are, as a group, rare. Some types are exceptionally rare and require national or international expertise, as well as care at a center specializing in pediatric oncology.

→ Learn more about cancers in children and adolescents.

Rare Cancers in Adults

Rare cancers in adults can manifest in various ways:

  • In organs or parts of the body where cancer is unusual, with rare cellular or tissue characteristics.
  • In an organ or part of the body very rarely affected by tumors. This is the case, for example, with the salivary glands. 

Rare Cancers: By the Numbers

  • Less than 6

    new cases per 100,000 people per year 

  • Nearly 200

    separate entities

  • 1/4

    Collectively, rare cancers account for nearly a quarter of new cancer diagnoses in Europe.

Prof. Antoine Italiano

Medical oncologist specializing in sarcomas and precision medicine. 

Rare cancers present specific challenges in terms of diagnosis and treatment. Each case must be able to quickly benefit from the expertise of the relevant national network and be discussed in a specialized multidisciplinary consultation meeting. This approach helps ensure an accurate diagnosis, determine the most appropriate treatment strategy, and, when relevant, recommend participation in a clinical trial.

Pr Antoine Italiano

Coverage

Given their unique characteristics, rare cancers require highly specialized care. Gustave Roussy, the leading French and European center in the fight against cancer, recognized for its expertise in rare and complex tumors, treats patients—both adults and children—with rare cancers at all stages of the disease. 

Care for Children and Adolescents

Children and adolescents with rare cancers are treated by the Department of Pediatric and Adolescent Oncology. There, they receive tailored and specialized care.

New Strategies for Head and Neck Rhabdomyosarcomas

At Gustave Roussy, patients with rhabdomyosarcoma of the head or neck can benefit from a treatment strategy combining reconstructive oncological surgery and, depending on the indication, proton therapy. “These strategies achieve a local disease control rate of 80%, compared to 50 to 60% with standard techniques,” according to Prof. Véronique Minard-Colin, a pediatric oncologist. 

Expertise in the Treatment of Genitourinary Sarcomas

For more than 20 years, Gustave Roussy has developed internationally recognized expertise in the local treatment of genitourinary sarcomas in young children. This approach enables excellent local control and, above all, minimizes long-term effects. The treatment combines brachytherapy and surgery.

→ Learn more about Pediatrics

Care for Adults

Adult patients with rare cancers receive multidisciplinary care that brings together Gustave Roussy’s various diagnostic and therapeutic areas of expertise. Their cases may be discussed in a specialized multidisciplinary consultation meeting, in collaboration with the national reference network corresponding to their disease.

→ Learn more about the Department of Medical Oncology 

Gustave Roussy, a leader in the treatment of rare cancers

Since 2009, care for rare cancers has been organized through national clinical networks, accredited by the National Cancer Institute (INCa) and comprising various healthcare facilities. Following the new accreditation process in 2025, INCa now recognizes 18 national reference networks for a period of five years.

Gustave Roussy serves as the coordinating center for two networks:

  • Rythmic, for thymic tumors;

  • Mesoclin, for mesotheliomas. 

The Institute is also the national reference center for the following networks: 

  • NETSARC+ (sarcoma).

  • CARARE (rare kidney cancer).

  • CARADERM (rare skin cancers).

  • REFCOR (rare ENT tumors).

  • RENAPE (rare peritoneal tumors).

  • ENDOCAN (endocrine tumors).

  • TMRG (rare gynecological malignancies).

These networks ensure that every patient, even those with rare cancers, has access to specialized expertise.

Research That Is Making Progress

To advance understanding of these cancers and their associated treatment options, Gustave Roussy is actively dedicated to developing new therapies specifically targeting these diseases. Thanks to its strong involvement in networks and the collaborative efforts between its organ-specific committees and its Department of Therapeutic Innovation and Early-Phase Trials (DITEP), Gustave Roussy collaborates with academic and industrial sponsors to develop clinical trials tailored to rare cancers and to facilitate the recruitment of patient cohorts, thereby enabling patients to access innovative treatments.

New Prospects Thanks to Immunotherapy

For several rare cancers, immunotherapy and targeted therapies have opened up new treatment options. However, their effectiveness and indications depend on the tumor type, the stage of the disease, and, in some cases, the tumor’s molecular profile. Their development requires dedicated clinical trials and national and international collaborations. 

For further reading