Rare tumors in children: a challenge requiring a systematic approach

Session "Rare Tumors" II CIS Orphan Forum | Moscow, June 27, 2025, dedicated to malignant neoplasms in children.

Moderator:

• Tatyana Viktorovna Shamanskaya, MD, PhD, Associate Professor, Head of the Department of Embryonic Tumors, Institute of Oncology, Radiology and Nuclear Medicine, Dmitry Rogachev National Medical Research Center for Pediatric Hematology and Oncology, Ministry of Health of the Russian Federation — emphasized: despite the fact that oncology is rarely mentioned on the agenda of rare diseases, it requires a systematic approach and coordination of efforts — from diagnostics to access to therapy.

• All malignant tumors in children are orphan by definition. Almost 11% of them are ultra-rare (pancreatoblastoma, adrenocortical cancer, rare carcinomas).
• The lack of registries is one of the main problems. Epidemiology is the basis for routing, financing, access to therapy. Registries should work not for the sake of reporting, but as a decision-making tool.
• High risk of diagnostic errors: up to 20% of morphological conclusions on rare tumors are inaccurate. Reference laboratories, biobanks, development of consultation practice are needed, especially for tumors with unclear histology.

Report by Mikhail Aleksandrovich Maschan, MD, Professor, Deputy Director General for Science of the Federal State Budgetary Institution "NMITs DGOI im. Dmitry Rogachev, Director of the Institute of Molecular and Experimental Medicine, was dedicated to the possibilities of CAR-T therapy.

CAR-T has already demonstrated success in hematological tumors, but there are still difficulties with solid forms:

• the complexity of choosing antigens,
• features of tumor biology.

However, partial responses in neuroblastoma are already noted in the 1st phase of clinical trials.  In the discussion, experts emphasized the importance of developing their own solutions in the CIS and forming access models balanced in terms of efficiency and cost.

The report by Vlada Konstantinovna Fedyaeva, NAERES, head of the working group on clinical guidelines of the CIS Orphan Consortium, was dedicated to the RAND/UCLA Appropriateness Method - a tool for structured expert assessment. This approach:

• combines disparate data,
• forms sound clinical recommendations,
• is already used in oncology,
• can be adapted for joint work of the CIS countries.

Experts from Russia and the Republic of Kazakhstan took part in the session.

The main conclusion:patients with rare malignant tumors should not be left outside the framework of the systemic approach. 

Needed:

• unified methodologies,
• registers,
• research of real clinical practice,
• interstate coordination within the CIS.