Surgical Outcomes and Guidelines for Management of Metastatic Spinal Cancer (A Point-of-View Review)

A.G Hadjipavlou

M. Szpalski

R. Gunzburg

M. Aebi

K.N. Kakavelakis

P. Katonis

ABSTRACT

The effectiveness and safety of surgery for metastatic cancer of the spine can be evaluated only through patient-outcome studies. Review of the literature reveals that certain outcome instruments have been validated for metastatic spinal disease, such as EORTC, QLQ-L30, EQ-SD, HUI-MARK 3, ESAS, McGill pain questionnaire, VAS, MPAC, and so on. The results of the following reported parameters should be considered important when assessing surgical outcomes: neurologic improvement 55% to 87%; restoration of ambulation, 40% to 100%; restoration of sphincter control, 36% to 89%; pain relief, 47% to 100%; local recurrences, 8% to 31%; complication rates, 16% to 32%; reoperation rates for complications, 7% to 24%; patient satisfaction, 55% to 80%; mortality rates (4 to 6 weeks after surgery), 3% to 10.2%; and mean survival (months), 8% to 15.9%. This information should form the basis for what should be considered acceptable outcomes. Furthermore, certain facts that can influence the final outcomes may be considered prognostic factors (origin of tumor, visceral metastasis, number of affected vertebrae, and state of neurologic dysfunction). The combination of surgical outcomes and prognostic factors is important when considering the construction of clinical guidelines for management of metastatic spinal disease. The combination of the Tokuhashi prognostic scoring system, the Harrington structural and neurologic classification, the Tomita classification of spinal metastasis spread, and the Kostuik instability system form a reasonable and clinically easily applicable guideline system.

INTRODUCTION

It has been reported that in 5% to 10% of all cancer patients, during the course of their disease, spinal metastasis will develop (4,108). The spine is the most common site for skeletal metastasis (50). The original report by Jaffee (50) in 1958, claiming that the incidence of spinal metastasis is 70%, has not been substantiated. Other publications assert that spinal involvement ranges from 56% (82) to 30.6% (77) and 33.4% (21). The frequency of spinal metastasis from different types of cancer that were treated surgically is shown in Table 19.1. The data are gathered from a total of 22 articles (7,16,23,26,36,43,45,47,51,60,64,76,83,89,92,93,94,101,107,110,112) that include 1,517 patients. Obviously this information is skewed by the surgical selection and does not
depict the entire spectrum of spinal metastases. However, it illustrates the gravity of the condition that necessitated surgery. Less-biased statistics may derive from a pool of patients unselected for any particular treatment. Unfortunately, even in this situation, most patients’ data are collected from symptomatic patients who underwent various treatments. Only research from extensive numbers of autopsies can indicate the true incidence of spinal metastasis, and even these are very few (Table 19.2) (21,77,78,99). Various reports suggest that in 10% to 25% of treated patients with preexisting spinal metastasis, spinal cord compression will develop (4,6,12,34,44,81,82,114). Some assert that metastatic disease of the spine, if left untreated, may eventually lead to paraplegia (35,37,67,79). Pain and neurologic deficit are the most dreadful complications of metastatic cancer of the spine. Intractable pain may become a horrific experience, and spinal cord compromise may lead to the devastating consequences of paraplegia. In this situation, surgery plays an important role. Several surgical options exist; however, their indications and outcomes must be scrutinized for better medical care.

TABLE 19.1 Origin of Metastatic Spinal Cancer (Data from 22 Reports, 1,517 pts)

Tumor	N	%
Breast	295	19.4	I: Hosono N et al. (1995) Spine (47)
Lung	258	17.0	II: Sundaresan N et al. (1985) J Neurosurg (92)
Miscellaneous	108	7.1	III: Hatrick N et al. (2000) Radiother Oncol (43)
Renal	214	14.1	VI: Wise JJ et al. (1999) Spine (112)
Thyroid	69	4.5	V: Onimus M et al. (1996) Eur Spine J (76)
Unknown	90	5.9	VI: Weigel B et al. (1999) Spine (110)
Multiple myeloma	70	4.6	VII: Enkaoua E A et al. (1997) Spine (23)
Lymphoreticular system	28	1.8	VIII: Chataigner H et al. (2000) Eur Spine J (16)
Prostate	109	7.2	IX: Bilsky MH et al. (2000) Spine (7)
GI	85	5.6	X: Hertlein H et al. (1992) Eur Spine J (45)
Sarcomas	83	5.5	XI: Wai E K et al. (2003) Spine (107)
Chondrosarcoma	8	0.5	XII: Kocialkowski A et al. (1992) Eur Spine J (60)
+ Ewing + chordoma			XIII: Tomita T et al. (1994) Int Orthop (101)
Uterus + cervix	25	1.6	XIV: Gokaslan Z L et al. (1998) J Neurosurg (36)
Melanoma	13	0.9	XV: Sundaresan N et al. (1991) J Neurosurg (93)
Ovary	2	0.1	XVI: Sundaresan N et al. (1991) J Neurosurg (93)
Hepatobiliary	34	2.2	XVII: Sundaresan N et al. (2002) Spine (94)
Nasopharynlaryngeal	15	1.0	XVIII: Falicov A et al. (2006) Spine (26)
Genitourinary	9	0.6	XIX: Schoeggl A et al. (2002) Spinal Cord (83)
Pancreas	2	0.1	XX: Sioutos PJ et al. (1995) Cancer (89)
TOTAL	1,517	100	XXI: Lewandrowski K et al. (2004) Spine (64)
			XXII: Jansson K A et al (2006) Eur Spine (51)

INSTRUMENTS FOR OUTCOMES ASSESSMENT

In recent years, patient-outcome studies have been introduced to assess the results of treatment to provide patients, physicians, insurance providers, and government agencies with a tool with which to evaluate the different treatment methods. When assessing impaired body function caused by metastatic spinal tumors, health care providers should accumulate
“reproducible objective data” that will form the basis for outcome studies. The objective is to measure how well the results approach the goals of treatment (i.e., restore function and control pain). Clinical examination alone cannot make this determination.

TABLE 19.2 Origin of Metastatic Spinal Cancer

	Unselected Treatment^a		Autopsy^b
Tumor	N	%	N	%
Lung	74	21.3	169	40.5
Breast	39	11.2	64	15.3
Kidney	24	6.9	2	0.5
Genitourinary	11	3.2	0	0.0
Liver	15	4.3	9	2.2
Prostate	34	9.8	31	7.4
Stomach	15	4.3	21	5.0
Rectum	10	2.9	5	1.2
GI	6	1.7	14	3.4
Thyroid	7	2.0	0	0.0
Uterus	6	1.7	8	1.9
Lymphoreticular	0	0.0	40	9.6
Colon	5	1.4	0	0.0
Melanoma	6	1.7	0	0.0
Head & neck	3	0.9	0	0.0
Osteosarcoma + Ewing	4	1.2	0	0.0
Unknown	42	12.1	6	1.4
Other	46	13.3	48	11.5
TOTAL	347	100	417	100
^aTokuhashi Y et al. (2005) Spine (99) ^aPatchel RA et al. (2005) Lancet (78) ^bOrtiz Gomez et al. (1995) Int Orthop (77) ^bDrury RAB et al. (1964) J Clin Pathol (21)

Psychometric instruments are practical tools for evaluating disability from metastatic cancer of the spine. The goals for grading the functional status of the patient should be based on pain assessment, profile of mood states, and overall performance status. The latter depends on the neurologic status, pain, and disability. Therefore a complete neurologic assessment is considered an integral part of the evaluation of patients with metastatic tumor to the spine. Although the neurologic assessment provides reliable and straightforward clinical documentation, the assessment of pain disability and bodily functional performance of the patient can be appreciated only through psychometric questionnaires. The latter should be simple and reproducible (39). Pain is an alarming consequence of metastatic cancer of the spine. Specific efforts should be made to avoid crude assessment and try to quantify and locate the pain. The McGill pain questionnaire is a sensitive tool. A visual analogue scale (VAS) for pain measurement combined with a pain diagram indicating the original site of pain and its spread is a very simple and reliable method for quantifying and depicting pain. The VAS, although a subjective assessment of pain, has been shown to be more reliable than other types of pain assessment (52).

Cancer patients are fraught with emotional and psychological problems. Because anxiety and depression have a direct correlation with pain intensity, these two factors
may need to be addressed. The Zung anxiety scale (117) and the Hamilton Depression scale (40) are suitable instruments in this situation. The Memorial Pain Assessment Card (MPAC) (30) is a modified visual analogue with multidimensional characteristics, practically equivalent to a full assessment combining the McGill pain questionnaire, the Hamilton depression scale, and the Zung anxiety scale (17).

A distinction should be made between radicular pain and axial pain. Even the surgical approach may be responsible for severe pain. A report (36) detailing outcomes of pain demonstrated that in 72 patients who underwent an anterior approach through thoracotomy, 90% had postoperative pain (only 23% achieved complete resolution, 60% had significant improvement, and 8%, no change or worsening of thoracotomy pain). Quantification of pain is useful in monitoring the effectiveness of pain management, as well as in helping establish pain-control goals for the individual patient (17).

Pain and neurologic deficit contribute to disability of everyday activities. Therefore instruments to evaluate the quality of life should also be included when assessing patients with metastatic disease to the spine. As surgical procedures to treat metastatic disease to the spine have increased, a greater interest has been expressed in the overall quality-of-life assessment and outcomes studies. However, few published reports exist on the assessment of these patients’ health-performance status after surgery. The treating physician should keep in mind that patients with spinal metastasis differ from non-cancer patients or cancer patients undergoing potentially curative treatment (14), therefore limiting the sensitivity of these instruments to monitor changes (11,15). Instruments for assessing the patient’s function and guidelines for treatment should be flexible and applicable to all sorts of cancer-treatment modalities available in the armamentarium of medicine, not only to evaluate the surgical aspects of tumor management but also to better compare the different treatments. A number of instruments are available to measure global quality of life in patients with cancer.

The Edmonton Symptom Assessment Scale (ESAS) is a validated patient-centered questionnaire designed specifically to address the overall quality of life in patients with terminal cancer (11,15,53). The questionnaire is multidimensional and measures nine domains (pain, tiredness, nausea, depression, anxiety, drowsiness, appetite, well-being, and shortness of breath). After surgery, the largest improvement is seen in the domain of pain (107).

The Townsend questionnaire is a physician-determined categories assessment of the patient’s physical disability. Patients are classified into one of the four categories: (a) normal, pain-free function, (b) normal function with pain, (c) significantly limited function requiring some type of assistance (e.g., a walker, cane), and (d) nonfunctional (e.g., wheelchair bound, or bedridden) (104).

TABLE 19.3 HUI-MARK 3

Description		Scale
•	Free of pain and discomfort	1
•	Mild to moderate pain	2
•	Pain does not prevent activity
•	Moderate pain	3
•	Pain prevents few activities
•	Moderate to severe	4
•	Pain prevents some activities
•	Severe pain	5
•	Pain prevents most activities

Other validated outcome measures in cancer patient are EORTC QLQ-C30 (27), HUI-MARK 3 (28), and EQ-SD (20). These have been successfully applied in cancer patients with metastases to the spine (26). The HUI-MARK 3 contains one question relating to pain and measures pain on a scale 1 to 5 (Table 19.3). Two studies (26,84) compared the VAS pain scale with HUI pain, demonstrating that on the VAS pain scale, 1 to 4 corresponds to mild pain, 5 to 6 to moderate pain, and 7 to 10 to severe pain.

The overall distribution of HUI-MARK 3 utility calculated quality-adjusted life years (QALY) during
the 1-year postoperative period (26). The QLQ-C30 measures quality of life and has one global health status (QL2), five functional scales, physical functions (PF2), role functions (RF2), emotional function (EF), cognitive functions (CF), and social functioning (SF), as well as nine symptom scales.

TABLE 19.4 Eastern Cooperative Oncology Group (ECOG) Performance Status Measurement

Description of function
•	Fully active.
•	Able to perform pre-disease activities.
•	No restrictions
•	Ambulatory and able to perform light work.
•	Restricted in physically strenuous activity.
•	Ambulatory and capable of all self-care.
•	Unable to perform work activities.
•	Bedridden less than 50% of the time.
•	Capable of only limited self-care.
•	Bedridden more than 50% of the time.
•	Completely disabled, not capable of any self-care.
•	Bedridden 100% of the time.
•	Dead
Oken MM et al. (1982) Am J Clin Oncol [75]

Performance status can be assessed by the Eastern Cooperative Oncology Group (ECOG) grading system or the Karnofsky performance status. The ECOG (Table 19.4) performance status (109) measures functional performance on a scale from 0 to 4 and is a good index of assessing the preoperative functional status (26).

The condition of the patient’s health status can be detailed by using the Karnofsky performance status (PS) (54). The rating for the criteria of the PS is shown in Table 19.5. The score ranges from 0 to 100%. Scoring between 0 and 10% indicates poor health and total dependency on others, from 50% to 70%, inability to work and requires assistance, and 80% to 100%, ability to carry on with normal activities. This was successfully applied by Tokuhashi et al. (98) in clinical guidance for predicting cancer patient outcomes.

Functional outcomes for neurologic assessment can be graded by the Frankel (33) or the American Spinal Injury Association (ASIA) impairment scores (2). However, these systems are not specific enough to describe nuances of the physical state of locomotion.

TABLE 19.5 Criteria of Karnofsky Performance Status (PS)

Only gold members can continue reading. Log In or Register to continue