Chordoma is a rare form of bone cancer that originates from remnants of the notochord, a flexible rod-like structure present during embryonic development that forms the basis of the spine. While the notochord typically disappears before birth, a small percentage of its cells can remain embedded in the bones of the skull base or spine. These lingering cells can, in rare instances, become cancerous, leading to a chordoma.
Metastatic chordoma refers to the stage where these cancerous cells have spread from their original location to other parts of the body. This spread occurs when cells break away from the primary tumor and travel through the body’s systems. This distinguishes it from localized chordoma, which remains confined to its initial site.
Understanding How Chordoma Spreads
Chordoma cells can spread from the primary tumor through various pathways to reach distant parts of the body. One common route is through the bloodstream, known as hematogenous spread, where cancer cells detach from the original tumor, enter blood vessels, and are carried to new locations.
The lymphatic system also serves as a pathway for metastasis. This network of vessels and nodes transports cancer cells to nearby or distant lymph nodes, from where they can spread further to other organs.
Metastatic chordoma most frequently affects the lungs, accounting for over 50% of metastatic cases. Other common sites include other bones, lymph nodes, the liver, and soft tissues like skin. The reasons these sites are favored for metastasis involve the rich blood supply and suitable microenvironments for cancer cell survival and growth.
Identifying Metastatic Chordoma
The signs and symptoms of metastatic chordoma vary significantly depending on where the secondary tumors are located. If the cancer has spread to the lungs, individuals might experience respiratory issues such as shortness of breath or a persistent cough. When metastases occur in other bones, localized pain, tenderness, or even fractures can develop.
Metastases to the liver might cause abdominal pain, jaundice, or unexplained weight loss, though symptoms may not always be present initially. If the brain or spinal cord is affected, neurological symptoms like headaches, double vision, facial numbness, or weakness in the limbs can arise.
Diagnosis of metastatic chordoma involves a combination of imaging techniques and a biopsy. Magnetic Resonance Imaging (MRI) is used to visualize the tumor and assess its extent, providing detailed images of soft tissues, nerves, and blood vessels. Computed Tomography (CT) scans are also employed, particularly for demonstrating bone destruction and identifying calcifications within the tumor.
Positron Emission Tomography (PET) scans can help detect metastatic lesions throughout the body by identifying areas of increased metabolic activity characteristic of cancer cells. While imaging suggests the presence of chordoma, a definitive diagnosis requires a biopsy. A small tissue sample is removed from the suspected tumor and examined under a microscope by a pathologist, who can confirm the diagnosis and assess specific characteristics of the cancer cells, including the presence of the brachyury protein, which is highly indicative of chordoma.
Managing Metastatic Chordoma
Managing metastatic chordoma involves a tailored approach, often combining different treatment modalities to control disease progression and alleviate symptoms. Systemic therapies, which travel throughout the body, are frequently used for widespread disease. These include targeted therapies, which block specific pathways that drive cancer cell growth, and sometimes chemotherapy, though chordomas are often less responsive to traditional chemotherapy.
Targeted therapies, such as those inhibiting platelet-derived growth factor receptor (PDGFR), vascular endothelial growth factor receptor (VEGFR), or epidermal growth factor receptor (EGFR), disrupt molecular mechanisms that allow chordoma cells to proliferate. While these therapies may not always shrink tumors, they can stabilize disease progression. Immunotherapy, which harnesses the body’s immune system to fight cancer, is also being explored, with some early trials showing promise.
Radiation therapy plays a role in managing metastatic chordoma, particularly for localized lesions or when surgery is not feasible. Particle therapies, such as proton therapy and carbon ion therapy, are favored due to their ability to deliver highly precise radiation doses to the tumor while minimizing damage to surrounding healthy tissues. These advanced techniques can be beneficial for tumors located near sensitive structures like the spinal cord or brainstem.
Surgery may also be considered for managing metastatic lesions, especially to relieve symptoms caused by tumor compression or to remove isolated metastases. The goal of surgery in the metastatic setting is often to improve quality of life or reduce tumor burden rather than achieve a complete cure. A multidisciplinary team of specialists, including oncologists, radiation oncologists, and surgeons, collaborates to develop the most appropriate treatment plan for each individual.
Support and Quality of Life
Living with metastatic chordoma involves ongoing support focused on maintaining well-being and managing the disease as a chronic condition. Palliative care, also known as supportive care, aims to prevent and relieve symptoms of the disease itself and the side effects of its treatments, such as pain, fatigue, and mobility issues.
Palliative care extends beyond physical symptoms to address emotional, psychological, and social needs. This can involve counseling services, support groups, and resources for patients and their families to cope with the challenges of living with a rare cancer. Emotional well-being is a factor, as individuals may experience anxiety, depression, or changes in relationships.
Ongoing monitoring and follow-up care are also routine for individuals with metastatic chordoma. Regular imaging and clinical assessments help track disease progression and adjust treatment strategies as needed. This comprehensive approach aims to optimize quality of life and provide continuous support throughout the disease journey.