More than just back pain

 A 68-year-old man attended A&E with the ambulance. Prior to admission, he had experienced acute pain in the lower lumbar spine when getting up from bed during a twisting motion. Subsequently, he was unable to move due to pain. He complained of neurological symptoms with reduced sensation in the left thigh.

There is no previous medical history. He smokes 20 cigarettes per day. He has been experiencing chronic back pain for 2 years. Six weeks ago, he saw an orthopaedic specialist who ordered an MRI. He was informed that "cysts" were observed. Based on these findings, an appointment was made at a nearby university hospital.

Findings:

The 63-year-old patient is in good nutritional condition and has an age-appropriate general condition. Mobilization from the stretcher to a seated position cannot be tolerated. Rotation of the spine in a supine position is indicated as painful. There is tenderness on palpation of the spinous processes of the lower lumbar spine during a log-roll manoeuvre. Peripheral circulation and neurological status are normal.

Given the previous abnormal MRI findings, a CT scan of the lumbar spine is being request. It reveals a large lytic lesion in the L5 vertebral body with infiltration of the adjacent soft tissues, suggestive of an unstable fracture.

 In the absence of a known tumor, staging is performed to determine the primary site. Liver metastases are identified on ultrasound. A CT scan of the thorax shows a central bronchial carcinoma with additional rib metastases. Bronchoscopy reveals infiltration of the right main bronchus, from which a histological sample is taken. The histology confirms a mucinous adenocarcinoma.

Therapy and Course:

After an oncological consultation, the patient was transferred to a neurosurgical department for stabilization with spinal fusion of the lumbar vertebral metastasis and initiation of chemotherapy. Local postoperative radiation therapy for the metastasis was discussed.

 Discussion:

The patient had been experiencing back pain for 2 years without any trauma. Diagnostic evaluation at this time revealed the presence of metastatic bronchial carcinoma.

According to guidelines, in the absence of acute treatment-requiring conditions based on history and examination, further diagnostic measures are not indicated for back pain. They are only recommended after a duration of 4 to 6 weeks with guideline-compliant treatment and then only once. Imaging is recommended only if there are indications of a specific condition, e.g.  trauma, tumor in older age, steroid therapy, neurological symptoms, spondylarthritis, general symptoms like recent onset of fever or chills, loss of appetite, rapid fatigue, recent bacterial infection, intravenous drug abuse, immunosuppression, consuming underlying diseases, recent spinal infiltration treatment, or severe nocturnal pain. This was not done for our patient. The symptoms were managed with analgesia as needed but not further investigated.

The guidelines do not consider the patient's age. It can be interpreted that age can be used to rule out specific causes and initiate imaging even at the initial contact. In young patients under 20 and in "older" patients over 55, back pain may indicate a specific origin. Imaging should be used in conjunction with additional investigations depending on the underlying suspected diagnosis. From the age of 20 to under 50, the incidence of back pain is very high, and the course is usually benign and self-limiting (Chou 2011).

However, with increasing age, the causes of extraspinal back pain also increase. This includes mainly abdominal and visceral processes, e.g.  cholecystitis, pancreatitis; vascular changes, particularly aortic aneurysms (Takeyachi 2008), gynecological causes, e.g.  endometriosis, urological causes, e.g.  urolithiasis, kidney tumors, perinephric abscesses, neurological diseases, e.g.  polyneuropathies, and psychosomatic and psychiatric diseases. Their share is estimated at 2% (Deyn 2001). Therefore, a significant portion of these diseases can be promptly detected through additional abdominal ultrasound and urinalysis.

In malignant underlying diseases, back pain is usually a late manifestation due to metastasis, particularly from the stomach, lungs, prostate, kidneys, lymphomas, gastrointestinal tumors, and breast. They account for 80% (Greenberg 2016). Back pain due to metastasis occurs in approximately 10% of cancer patients. Patients in middle age (40-65 years) are particularly affected. In contrast, metastases are very rare in childhood and usually occur intramedullary with brain tumors.

Metastasis primarily occurs hematogenously in the vertebral bodies. With increasing infiltrative growth, the pedicles can also be affected, and the spinal canal can be compressed. Rarely does the tumor invade the dura and spread intradurally (Abeloff 2008).

The thoracic spine is most commonly affected, accounting for 50-60% of cases. The segments affected are T4 to T7. In prostate cancer, on the other hand, metastasis in the lumbar spine is predominant. In more than half of the patients, multiple levels of the spine are affected.

Therapy

The choice of therapy depends primarily on the underlying primary tumor. The treatment of vertebral metastases is determined by the localization, remaining stability, duration and severity of neurological symptoms, and the overall condition of the patient. Classification systems such as the Tomita Score, Tokuhashi Score, or Spinal Instability Neoplastic Score can help in the decision-making process, but they have limited practical applicability and serve more as aids.

The primary goal of therapy is tumor reduction or, ideally, resection to relieve the spinal canal and nerve roots and achieve pain relief.

-        Medical Treatment

Corticosteroids can reduce acute swelling and pressure on the nerve structures.

Bisphosphonates are used to prevent bone loss and thus provide pain relief.

Some tumors grow in a hormone-dependent manner, so hormone preparations can also be used.

-        Radiation Therapy

Radiation therapy reduces tumor cells. This can be done as monotherapy or in combination after surgery.

            - Surgery

- Kyphoplasty or vertebroplasty

- Laminectomy and spinal fusion

During laminectomy, parts of the bony vertebral body are removed to relieve the spinal canal. The tumor may not always be completely removed. The surgery can create instability, which can be supplemented with spinal fusion. Classification systems such as the SINS score are used for assessment. These systems consider the localization of the metastasis, extent of damage, and position of the vertebral bodies relative to each other (Fisher 1976).

 

Prognosis

The overall prognosis depends significantly on the primary tumor and the tumor stage. Pain control is a crucial component of the treatment plan, as well as the stability of the spine to prevent further neurological complications, e.g.  spinal cord compression.

Favorable prognostic factors include solitary metastasis to the spine and primary tumors e.g.  breast cancer, kidney cancer, lymphomas, or multiple myeloma. Unfavorable factors include multiple metastases, the occurrence of pathological fractures, and lung cancer as the primary tumor, as well as neurological symptoms or their loss (Bauer 1996). The location of the metastasis does not have a prognostic value in principle, but it significantly determines the possibilities of surgical intervention.

The preoperative status of neurological functions or other therapies also plays a crucial role in the outcome. In particular, ambulation and sphincter function are important, as complete loss of sphincter function is an unfavorable prognostic factor and is usually irreversible (Greenberg 2016).