Challenges and opportunities in rare tumor research

Frontiers JournalsJul 22 2024

Ning Li et al., at Chinese Academy of Medical Sciences and Peking Union Medical College, China, provides a comprehensive review on the challenges and opportunities in the field of rare tumor research and management. Despite advances in sequencing technologies and therapies extending the lives of many cancer patients, rare tumors remain a significant challenge in modern oncology. The definition of rare tumors is initially explored, with a focus on incidence rates rather than prevalence, due to the genetic, environmental, and lifestyle variations that lead to differences in tumor incidence and molecular profiles across populations.

In the United States, rare tumors are defined by the FDA and National Cancer Institute as those with an incidence of less than 15 per 100,000 people per year. In Europe, the threshold is set at 6 per 100,000 by the European Society for Medical Oncology and European Medicines Agency. In China, a rate of 2.5 per 100,000 per year is used to define rare tumors after a comprehensive analysis of epidemiological data and availability of standardized treatments.

The article emphasizes the value of rare tumor research, which has led to significant biological and medical discoveries, such as the study of retinoblastoma leading to the identification of the RB1 gene and the double-hit hypothesis. However, the understanding of rare tumors is advancing slowly due to limited patient numbers, lack of experience in medical centers, and reluctance from the pharmaceutical industry and researchers to invest in translational studies and randomized controlled trials.

The review highlights the need for increased attention to rare tumors, outlining the current status of research and management in China and globally. It proposes guideline recommendations for the diagnosis and treatment of listed rare tumors and suggests ways to inspire more multilateral trials for developing novel therapies that address the unique challenges faced by traditional rare tumor studies.

The article further discusses the current state of rare tumor diagnosis and treatment worldwide, noting that while rare tumors collectively account for a significant proportion of all cancer diagnoses, their five-year survival rates are lower than those of common cancers. It underscores the importance of molecular tools in facilitating pathology confirmations and identifying potential target genes, providing a flowchart for the diagnosis of newly identified rare tumor patients.

The challenges in rare tumor treatment strategies are also discussed, with a focus on the lack of treatment recommendations for the majority of rare tumors. The article calls for more comprehensive and precise translational and clinical investigations, such as genetic sequencing studies and drug trials, to fill the gap in current clinical guidelines and improve outcomes for rare tumor patients.

Clinical trials are presented as an essential treatment option for rare tumors, with recommendations for inclusive enrollment to improve survival chances. The article provides a detailed analysis of the proper timing for clinical trial enrollment for patients with rare tumors, emphasizing the need for real-world data to inform treatment decisions and support the development of therapies.

In conclusion, the article outlines the numerous challenges faced by researchers and clinicians in the field of rare tumors, including the lack of clear definitions, therapeutic guidelines, and evidence-based interventions. By categorizing 515 cancer types as rare tumors in China and summarizing their current treatment strategies, the authors aim to provide a clear protocol for diagnosis and treatment and inspire the enrollment of rare tumor patients in clinical trials. The hope is to update the innovative design of targeted therapies and immunotherapies based on genome sequencing techniques, improving the situations for rare tumor patients in a precise and efficient manner.