What Is A Spinal Tumour?

Overview

Spinal tumours are within the family of central nervous system cancers; they are, therefore, crucial to understand when concerning the normal function of the nervous system. They can affect our sensory behaviours and result in disability as well as lethality at later stages. Late onset of the disease still has barriers in treatment whereas early stages have significantly better prognosis. Subsequently, it is a serious situation to be aware of the life-saving action of early detection of the symptoms and early diagnosis.

Introduction

Any type of tumour occurring at any location throughout the spine or surrounding tissue is known as a spinal tumour.¹ It is highly important to understand spinal tumours because the spine is the fundamental support provider of our body’s skeleton.² The spine carries our head, weight, and arms and allows us to move in different ways.² Two aspects of spinal tumours make it supremely important to learn about and be aware of them. First of all, being composed of vessel hubs and being close to the lymphatic and venous drainage path provokes the susceptibility of metastasis (cancer spreading).³ Secondly, 97% of the spinal tumour incidences are metastatic. Subsequently, this vital group of tumours requires meticulous attention.

Anatomy of the spine

The spine is made of bones called vertebrae, which start from the head and go down to the bottom of the body as shown in figure 2.4 This hard but flexible structure is called the spinal column.5 The spinal column is a part of the central nervous system (CNS), and it acts as a defensive housing for the spinal cord enclosed within the spinal column. The spinal cord is composed of long and thin tubular tubes, which are built from complex nerve cells.

The spinal cord is also a co-player in the sensory, autonomic, and motor functions of the brain; if this vital organ loses contact with the brain due to any errors, it cannot continue working. If these problems arise, then disability and reduced life expectancy are common, depending on the location of the disorder. 

Types of spinal tumours

Spinal tumours are categorised into two main groups: 1) primary spinal tumours and 2) secondary spinal tumours.³ The primary tumours first appear either within the spinal column or surrounding tissues, whereas secondary spinal tumours relocate to the spine through the circulation of either the blood or lymphatic systems. 

The species of spinal tumours vary from one location of the spine to another: intradural-intramedullary, intradural-extramedullary, and extradural (figure 1).6 Extradural spinal tumours are the most prevalent type, which accounts for 60% of spinal tumour cases. 

Examples of different types of spinal tumours

• Intradural-extramedullary tumours: These arise within the spinal canal (inside the spinal column), but outside of the spinal cord.
  • Meningioma
  • Nerve sheath tumour

• Intradural-intramedullary tumours: Those tumours arise within the spinal cord but in the region of the protective layer called the dura mater.
  • Ependymoma 
  • Astrocytoma

• Extradural tumours: Those tumours arise within the spinal canal, however they are not found within the spinal cord, and do not touch the roots of the nerves. They are usually found within the area between the spine bones and dura mater.
  • Metastases
  • Chordoma
  • Ewing Sarcoma/Osteosarcoma
  • Lymphoma

The tumours of the extradural space have the tendency to move to other locations, which means they are metastatic tumours.⁷ Intradural extramedullary tumours result in the constriction of the spinal cord due to growing inside the canal and occupying the space. On the other hand, intramedullary space tumours are predominantly primary spinal tumours.

Causes and risk factors of spinal tumours

Lung, breast and prostate cancers are the source of metastatic spinal tumours.⁶ However, the cause of primary spinal tumours is still unknown. Nevertheless, the researchers have already suggested a few risk factors that increase the likelihood of getting spinal tumours.

Causes of spinal tumours 

• Genetic Mutations
• Cell abnormalities
• Metastasis
• Radiation exposure
• Neurofibromatosis
• Li-Fraumeni syndrome
• Tuberous sclerosis 

Risk factors of spinal tumours

• Age
• Gender
• Medical history
• Exposure to radiation
• Occupational or environmental exposure
• Family history 
• Race and ethnicity 

Symptoms of spinal tumours 

Pain is the first and the most common symptom of spinal tumours.⁷ Later on, neurological symptoms arise such as paraparesis (partial weakness and difficulty in movement of the legs), and loss of other sensory functions. Radicular and back pain can be experienced at the same time on some occasions. Moreover, the function of your bladder can be lost as well.⁷ Kyphotic posture, which appears as the curving or bowing of the back, can also be seen in some patients who have pathological fractures.³

This list summarises the common symptoms:

• Back pain 
• Radicular pain 
• Sensory loss
• Kyphotic posture
• Nonfunctioning bladder
• Paraparesis  (partial leg paralysis, usually due to leg and hip muscle weakness)

Diagnosis of spinal tumours

• Plain radiographs 
• Computed tomography (CT)
• Magnetic resonance imaging (MRI)
• Biopsy 
• Complete patient history 
• Physical examination^3,8                                                                                   

While taking plain radiographs of all parts of the spine, it is also advised that the pelvis is monitored in addition to the spinal area in pain.3 The most favourable method is CT. However, its effectiveness in soft tissue tumours is debatable. Moreover, MRI is the best technology so far in its ability to determine fine differences between varying tissues. For the cases where the tumour is metastatic, and the primary origin is not known, a biopsy is advised. Along with this, the combination method of imaging techniques to determine the biopsy location is proposed as a convenient diagnosis method.

Treatment options for spinal tumour

The standard care that is most commonly applied is the removal of the whole tumour, known as complete resection.¹ This method is also for the prevention of the disease returning. However, even if complete resection is possible for most primary tumours, metastatic ones prevent complete resection.⁹ Therefore, partial resection is applied to reduce the symptoms and improve the quality of life in terms of neurological deficits arising accordingly with tumour compression of the spine.

In cases where either the effectiveness of the surgery is low, or surgery is not possible, chemotherapy treatment is applied using chemo drugs.⁹ Another method is using radiotherapy by delivering radioactive ways to the tumour side. 

These methods have drawbacks, however, such as chemotherapy not being a standardised treatment due to failure to achieve a recognizable success in spinal tumour treatment. Additionally, radiotherapy for spinal tumours has resulted in gastrointestinal, fertility as well and birth defects, such as early delivery of the baby in patients.

Instead of chemotherapy and radiotherapy, another option called immunotherapy is also in use. It is a way of augmenting the body's immune system to help tackle the tumour. On the flip side, immunotherapy has neurotoxic effects, difficulties in overcoming the blood-spinal cord barrier, and the strong ability of the spinal tumour microenvironment to inhibit immune responses.⁹

Emerging research hopes in treatment

1. Immunotherapy using vaccines has been proposed to be a harmless and achievable goal in treatment.⁹
2. Targeted therapy is another promising option, in which specific molecules in the tumour microenvironment are targeted to overcome the resistance of spinal tumours toward immunotherapeutic approaches.⁹
3. Fluorescence-guided surgery (FGS) aims to improve the visualisation of the tumour area during surgery to further enhance complete resection.¹⁰
4. Laser interstitial thermal therapy (LITT) uses heat to kill tumours using laser technology and helps the possibility of carrying out less invasive surgery.¹⁰
5. Gene edition methods such as the CRISPR-Cas9 method, which has provided a Nobel Prize for two gorgeous woman scientists Emmanuelle Charpentier and Jennifer A. Doudna, are also being investigated for spinal tumours.¹⁰

Prognosis and survival rates 

Prognostic evaluation: 

The prognosis of spinal tumours is extremely challenging to forecast due to their complexity and having highly varying subtypes.¹¹ Therefore, globally accepted grading systems are insufficient for proper estimation of the prognosis. Physicians still use one of the most popular classification methods called Tumour Nodes Metastasis (TNM), however, they further solidify the classification with additional assessments. TNM can be simply explained as an evaluation of the size of the tumour and status of the invasion into nearby tissues (T), whether the regional lymph nodes contain tumours or not (N), and the presence of metastasis at distant places (M).¹²

• TNM Scoring
• Anatomical Evaluation
• Neurological Involvement and Spine Instability Evaluation Spinal Instability Neoplastic Score (SINS)
• Status of the Disease Before and After Treatment 
• Molecular Profile (presence of specific genetic abnormalities)^11,13,14         

Survival rates

The survival rate in 5 years with a malignant spinal tumour is 95%.¹⁵ However, this varies situationally, and numbers are generalisations of the outcome. The survival rates with metastatic spinal tumours are highly poor. A case study has revealed that 50% of the patients with primary tumours of melanoma, upper gastrointestinal cancer, and lung cancer, which had metastasised to the spine, died within 90 days post-surgery.¹⁵

Rehabilitation and recovery 

The patients who have access to rehabilitation have been shown to have initiated functionality, mood, quality of life, and survival.¹⁶ The main aim of rehabilitation is to achieve a good recovery to gain functional independence and greater life quality. The determination of rehabilitation changes according to complications patients had from the treatment.

Here are a few examples of rehabilitation methods in use:

• Iron supplements, erythropoietic (red blood cell) stimulating agents, or transfusion for anaemia or fatigue after treatment.
• Electrical stimulation, cold or hot compress for pain reduction.
• For pain prevention, non-steroidal anti-inflammatory drugs, anticonvulsants, tricyclic antidepressants, steroids, and opioids are also in use.
• Medication for smoothing the stool and laxatives to help ease the constipation and bowel problems.
• Counselling for sexual dysfunction and oral medications.

Summary

• Spinal tumours are highly prevalent central nervous system cancers. 
• Survival rates within 5 years of early diagnosed spinal tumours are as high as 95%.
• Metastatic spinal tumours are highly challenging for the multidisciplinary treatment needed.
• Early diagnosis is highly life-threatening due to obstacles in treatment for the later stages.
• Being aware of the rehabilitation for spinal tumours provides an improved quality of life as well as longer survival, as proposed by studies.