Rare Cancer Care in Europe: Guidelines Improve Outcomes, Adherence Varies

The European Society for Medical Oncology (ESMO) and EURACAN, the European Reference Network for rare cancers, are jointly calling for urgent policy changes to standardize care pathways for patients facing rare malignancies. A new analysis, presented at the ESMO Sarcoma and Rare Cancers Congress 2026, reveals inconsistencies in clinical practice across Europe, despite evidence demonstrating that adherence to established guidelines improves patient outcomes. Collectively, rare cancers account for a significant proportion of all cancer diagnoses – over 650,000 new cases annually, representing 24% of the European cancer burden.

The challenge in managing rare cancers stems from several factors, including delayed diagnosis, limited treatment options, and a relative scarcity of research. Because these cancers are individually uncommon, generating robust evidence through large-scale randomized clinical trials is tough. This often necessitates reliance on retrospective studies, patient registries, and expert consensus to develop clinical guidelines. Whereas, increasing collaboration at the EU level, particularly through European Reference Networks like EURACAN, has facilitated the establishment of evidence-based standards in a growing number of rare disease areas.

Guideline Uptake and Areas for Improvement

A recent survey conducted by EURACAN in September-October 2025, encompassing 102 expert healthcare institutions across 25 countries, assessed the practical application of ESMO-EURACAN Clinical Practice Guidelines. Overall uptake was strong, with over 60% of respondents reporting they “always” or “often” utilize the guidelines. The primary application currently is in treatment decision-making. However, the survey highlighted inconsistencies in guideline usage for other crucial aspects of care, including diagnosis, follow-up, research, and teaching. Updating existing guidelines with the latest recommendations similarly remains an area needing improvement.

Parallel literature review supports the benefits of guideline adherence. Studies show that expert centers with high adherence rates demonstrate tangible survival benefits, including reduced mortality in uterine and soft-tissue sarcomas, improved outcomes in penile cancer, and better long-term survival in head and neck cancers. This reinforces the idea that consistent, evidence-based management directly translates to improved patient outcomes across a wide range of rare tumor types.

Beyond Treatment: A Call for Comprehensive Standardization

“For ESMO, which is committed to expanding the development of its Clinical Practice Guidelines, the analysis not only confirms the vital importance of clinical guidelines in the management of rare cancers but also highlights the potential to better serve patients by optimizing the way they are used by doctors and public health decision-makers,” stated Prof. Jean-Yves Blay, Chair of ESMO’s Rare Cancer Working Group, from the Centre Léon Bérard in Lyon, France. ESMO’s press release emphasizes the need to move beyond simply using guidelines for treatment choices.

Prof. Blay added, “More than mere clinical decision-making tools, Clinical Practice Guidelines can, and should, serve as quality assurance and standardization instruments, research references, and resources for continuous update of best practices, particularly crucial for rare cancers.” This broader vision underscores the potential of guidelines to drive improvements across the entire spectrum of rare cancer care.

Specific Policy Recommendations

To translate these insights into tangible improvements for patients, ESMO and EURACAN are urging national health authorities to integrate guideline adherence into care pathways through several key actions:

• Centralize rare cancer surgeries: Concentrating surgical procedures in accredited centers with specialized expertise can improve outcomes.
• Mandate multidisciplinary decision-making: Ensuring that patients benefit from the collective knowledge of a multidisciplinary team, and adhering to time-critical standards throughout diagnosis, treatment, and follow-up, is crucial.
• Track guideline adherence: Implementing national dashboards to monitor adherence to established Clinical Practice Guidelines can provide valuable data for quality improvement initiatives.

Strengthening European Networks and the Beating Cancer Plan

At the European level, the organizations recommend bolstering the ERN–EURACAN network as a central mechanism for ensuring equitable access to evidence-based, guideline-concordant care. This is seen as essential to closing the survival gap not only between rare and common cancers, but also between EU Member States, and to fulfilling the objectives of Europe’s Beating Cancer Plan.

Prof. Blay further emphasized the importance of guidelines in the context of rare cancers: “In rare cancers, where clinical expertise and robust evidence are often limited, well-developed guidelines become a vital instrument to ensure that every patient receives the best possible care. Our findings show that when clinicians follow harmonized, evidence-based recommendations, patient outcomes improve significantly. This underscores the essential role of networks and of the ESMO-EURACAN guidelines in bringing consistency, quality and equity to rare cancer management across Europe.”

What Comes Next: Implementation and Ongoing Evaluation

The call for policy action represents a critical step towards improving care for patients with rare cancers. The next phase will involve national health authorities evaluating their existing care pathways and identifying opportunities to integrate the recommended changes. Continued monitoring of guideline adherence through national dashboards will be essential to assess the impact of these initiatives and identify areas where further improvement is needed. Ongoing research and collaboration within the EURACAN network will be vital to refine guidelines and address emerging challenges in the management of these complex diseases. The European Reference Networks will play a key role in facilitating knowledge sharing and ensuring that best practices are disseminated across Europe.

Rare cancers are defined as those with a prevalence of fewer than 6 cases per 100,000 people per year. Addressing the unique challenges posed by these diseases requires a concerted effort from clinicians, researchers, policymakers, and patient advocacy groups.