Speaker: Dr. Wansuk Kim, EWHA Woman's University, Seoul, Korea
Important Takeaways
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Oligometastatic blood cancer is an evolving concept – Positioned between localized and metastatic stages, requiring a tailored diagnostic and therapeutic approach.
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Systemic therapy remains crucial – The importance of systemic treatment alongside surgery or local therapies was highlighted for managing metastatic disease effectively.
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Role of surgery and radiation therapy – Surgery (metastasectomy) and targeted radiation showed benefits in survival for select patients with limited metastasis.
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Recent advancements in systemic treatments – Immunotherapy and new targeted drugs are becoming integral to managing oligometastatic cases.
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Need for more clinical validation – Further studies are essential to refine the selection of candidates for surgery and local therapies.
Key Highlights
Concept and Definition: Oligometastatic disease represents an intermediate stage between localized cancer and widespread metastasis, where the cancer's potential to spread is limited. This concept has evolved to suggest that some metastatic cancers may remain manageable with targeted interventions. It was first described in 1995 and still requires clinical validation, especially in blood cancers, to determine which patients are ideal candidates for these focused treatments.
Consensus Criteria: The European Society reached a consensus that oligometastatic cancer includes cases with no more than three lesions, though there are no limitations on the number of organs affected. This broad definition helps identify patients for whom localized treatment could be beneficial.
Classification of Oligometastatic Disease:
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Synchronous Oligometastasis: Occurs within 6 months of primary diagnosis. Systemic therapy is crucial, and surgery alone is unlikely to be effective.
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Metachronous Recurrence: Develops after 6 months, often following primary tumor treatment, such as resection or radiation. Surgery or localized therapy can provide significant benefits in these cases.
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Metachronous Progression: Occurs after systemic treatment but indicates limited response to localized therapies, as the disease has progressed despite ongoing management.
Importance of Systemic Therapy:
CheckMate 901 trial showed improved survival with systemic therapies, particularly when combined with new drugs like EV (Enfortumab Vedotin) and PAB. These therapies have redefined the treatment landscape, making systemic treatment an essential part of oligometastatic cancer management.
Role of Surgery (Metastasectomy):
Surgery has shown significant survival benefits, particularly in patients with isolated metastasis in the lung or lymph nodes. In studies, patients undergoing metastasectomy had a median survival of 42 months compared to only 10 months without surgery.
Long-term survival improvements were noted in some patients who remained disease-free for over 10 years following surgery.
The MD Anderson Cancer Center identified favorable surgical candidates as those with slow-growing tumours, good responses to systemic therapy, and resectable disease.
Radiation Therapy in Oligometastatic Disease:
Stereotactic Body Radiation Therapy (SBRT) showed impressive local control rates, with response rates ranging from 72% to 100%. It is particularly effective when applied as part of a multimodal strategy, offering better outcomes compared to palliative radiation.
Consolidative radiation following systemic therapy demonstrated better survival outcomes than palliative treatments alone, supporting its role in treatment protocols.
Guideline Changes:
EA and NC guidelines now recognize oligometastatic cancer as a distinct entity, recommending the integration of local therapies, such as radiation or surgery, with systemic treatments for eligible patients.
Dr. Kim concluded that, current evidence, though limited, supports the role of surgery in a subset of patients with oligometastatic blood cancer who achieve durable local control. Accurate pathological staging and a multidisciplinary treatment approach are critical for improving outcomes.
There is a pressing need to refine patient selection methods to identify those with low-volume disease who will benefit most from surgery, especially following a measurable response to chemotherapy.
Further research is essential to determine the optimal role of surgery in the evolving landscape of immunotherapy and targeted therapies, particularly for metastases in pelvic, lung, and regional lymph nodes.
Société Internationale d'Urologie Congress, 23-26 October 2024, New Delhi, India.
