To treat chordoma of the sacrum adrotherapy as effective as a scalpel but with fewer effects

Chordoma of the sacrum is a rare bone tumour characterised by slow growth. Its 'silent' nature means that it is often only diagnosed when it reaches a considerable size, showing the first symptoms. Every year in Italy there are approximately 60 new diagnoses of chordoma starting in the sacro-coccygeal region. For this pathology, a major international study sponsored by Italy, the first of its kind in the world, compared the standard surgical approach with Hadrontherapy (carbon ions or protons), an advanced form of high-precision radiotherapy. The results show comparable efficacy between the two procedures: three years after treatment, both approaches showed 90% overall survival and 70% local disease control. However, a decisive advantage for Hadrontherapy emerges in terms of quality of life. Unlike surgery, which can severely impair bladder, bowel, motor and sexual functions, treatment with carbon ions preserves them, sparing the patient from severe side effects.

The data emerged from the SACRO study ('SAcral Chordoma: a Randomized & Observational study on surgery versus definitive radiation therapy in primary localised disease'), an international multicentre study promoted by the Italian Sarcoma Group and coordinated by the IRCCS Istituto Nazionale dei Tumori (INT) Foundation in Milan. CNAO (Centro Nazionale di Adroterapia Oncologica - National Centre for Oncology Hadrontherapy) in Pavia played a key role, participating as a reference centre for enrolment and exclusive treatment with carbon ions. "Although hadrontherapy with carbon ions has been used since the 1990s in Japan for this pathology, a rigorous comparison with the surgical option was lacking in the scientific literature," explains Maria Rosaria Fiore, radiotherapist physician at the CNAO and Principal Investigator of the study for the hadrontherapy part. The SACRO study was created to fill this gap. Preliminary data, based on a median follow-up of three years on 153 of the 170 patients enrolled, indicate superimposable results between surgery and Hadrontherapy in terms of overall survival and local disease control. The advantage of Hadrontherapy, however, is evident in terms of quality of life, as the patient avoids a complex surgery potentially associated with disabling sequelae. This is a study of great value and complexity, both in terms of the difficulty of enrolment due to the rarity of the disease and the extent of the results. Its scientific impact was recognised internationally with the award for the best abstract at PTCOG in Buenos Aires, the world's most important congress on particle therapy'.

"CNAO is the only Italian centre and one of only eight in the world capable of performing Hadrontherapy with both protons and carbon ions," says Gianluca Vago, President of CNAO and Director of the Department of Oncology and Haemato-Oncology at the University of Milan. "Since 2013, more than 200 patients suffering from chordoma of the sacrum have been treated with Hadrontherapy with carbon ions at CNAO. With carbon ion beams it is possible to target the tumour with three times the power of X-rays and with great precision, as these particles only release their energy in the vicinity of the diseased cells, reducing the impact and side effects on healthy tissue. The SACRO study highlights CNAO's ability to build research bridges at an international level and our commitment to charting new paths even for the treatment of very rare cancers. Thirty-four treatment centres from different countries such as France, Spain, Austria, Germany, Norway, England, Switzerland and Japan were involved.""The sacrum is the base of the spinal column and contains the last nerve roots, responsible for leg movement, control of the sphincters of the intestine and bladder, and sexual function," emphasises Alessandro Gronchi, international coordinator of the SACRO study, Director of Sarcoma Surgery and of the Department of Surgery at the Fondazione IRCCS Istituto Nazionale dei Tumori (INT) in Milan. "If the tumour is limited to certain parts of the sacrum, it is possible to preserve these nerve structures. When the disease is extensive, surgical removal with wide resection margins is essential to achieve long-term disease control, but may imply the impairment of the patient's motor, sphincter and sexual activity, with a negative impact on the patient's quality of life. Hence the importance of the SACRO study, which for the first time has demonstrated the equal efficacy of adrotherapy with carbon ions'.

Chordomas account for 5% of all bone sarcomas, while over 50% of chordoma cases involve the sacral location. 'Chordoma of the sacrum is a slow-growing, but very insidious malignant tumour,' concludes Silvia Stacchiotti, President of the Italian Sarcoma Group and oncologist of Medical Oncology 2 Mesenchymal Tumours of the Adult and Rare Tumours at the INT in Milan. 'The initial symptom is pain, typically in a sitting position. But the signs are very blurred, similar to lumbago, sacralgia or sciatica, and can be confused with those typical of benign spinal pathologies. Later the tumour growth may result in the appearance of a swelling in the sacral region, associated with neurological disturbances of the sexual sphere, bladder or rectal function due to the involvement of nerve structures. The first therapeutic strategy, whether surgical or radiotherapeutic, is decisive, because an incorrect approach can cause serious disabilities. Hence the importance of the results of the SACRO study'.