**8. Breakthrough pain**

Breakthrough pain is a common problem in patients with cancer, being associated with significant morbidity. Currently, there is no universally accepted definition of ''breakthrough pain". Portenoy et al. have defined breakthrough pain as ''a transitory exacerbation of pain experienced by the patient who has relatively stable and adequately controlled baseline (background) pain" (Portenoy et al., 2004).

Breakthrough pain is usually classified into one of two categories:


Breakthrough pain is associated with poor overall pain control (Bruera et al., 1995) as well as decreased patient satisfaction with overall pain management (Zeppetella et al., 2000). In addition, breakthrough pain may result in a number of physical (e.g., immobility), psycho‐ logical (e.g., insomnia, anxiety, depression) and social (e.g., unemployment, social isolation) complications (Skinner et al., 2006). Indeed, the presence of breakthrough pain may have a significant impact on the quality of life (Skinner et al., 2006).[68]

## **9. Pain assessment**

Dysregulation of cortisol release results in peripheral vasoconstriction and limbs muscles catabolism. The inadequate cortisol regulation and the consequent loss of muscle mass can as well affect the amount of adipose tissue, leading to a relative increase of the latter. Chronic pain often predisposes to a complex series of physiological and psychosocial changes, which are an integral part of the chronic pain issue, being added to the existing burdens occurring to

> Multifocal bone pain, vertebral pain syndrome in epidural spinal cord compression, pain syndrome related to pelvis and hip, base of skull

Headache and facial pain, ear and eye pain, pleural pain, muscle cramps

syndrome, malignant perineal pain, ureteric obstruction

enteritis, lymphedema pain, osteoradionecrosis

Breakthrough pain is a common problem in patients with cancer, being associated with significant morbidity. Currently, there is no universally accepted definition of ''breakthrough pain". Portenoy et al. have defined breakthrough pain as ''a transitory exacerbation of pain experienced by the patient who has relatively stable and adequately controlled baseline

**1.** Spontaneous pain (''idiopathic pain") – the episodes are not related to any identifiable

**2.** Incident pain (''precipitated pain") – the episodes are related to an identifiable precipitant

factor. Incident pain is usually sub-classified into one of three categories:

Neuropathic pain due to malignancy Radiculopathies, mononeuropathies, plexopathies, neuralgias, peripheral

neuropathy

Breakthrough pain is usually classified into one of two categories:

Hepatic distention syndrome, chronic bowel obstruction, midline retroperitoneal

Peripheral neuropathy, chronic post-surgical pain (eg.mastectomy, thoracotomy, neck dissection, pelvic surgeries), phantom limb pain, chronic radiation myelopathy, chronic radiation plexopathy, chronic radiation proctitis and

those who suffer. [67]

72 Updates on Cancer Treatment

Nociceptive somatic pain due to

Nociceptive visceral pain due to

Antineoplastic therapies (i.e. chemotherapy, radiation therapy, hormonal treatments, surgery)

**Table 1.** Chronic pain syndrome

**8. Breakthrough pain**

precipitant factors.

(background) pain" (Portenoy et al., 2004).

Nociceptive somatic pain due to soft

bone metastases

tissue involvement

malignancy

**7. Chronic pain syndromes**

**Causes Disorders**

Clinical practice guidelines developed by the National Comprehensive Cancer Network (NCCN) [69] and American Pain Society (APS) emphasize the essential need of a comprehen‐ sive pain assessment. [70]

A careful evaluation of pain should include history, pain description (in particular, establish‐ ing whether it worsens during the sleep), precipitating and alleviating factors, functional impairment, psychological associated factors, psychosocial history as well as patient's beliefs, physical examination, and a general knowledge of the different features of cancer-induced and nonmalignant pain; such evaluation will allow a comprehensive assessment of pain. Con‐ versely, an inadequate measurement and assessment of pain poses a significant obstacle to any effective pain management strategy.

Patient interview:

**Figure 4.** Pain assessment: Interview

An adequate pain assessment requires a thorough pain anamnesis as well as physical exami‐ nation prior to any radiographic study or physiological testing. Failing to collect a compre‐ hensive anamnesis and performing a correct physical examination will result in frequent mistakes, as correspondence between pain severity, as reported by the patient, and presence of underlying pathology, as revealed by imaging studies, is often poor. Location, radiation, quality, intensity and temporal pattern of pain should be ascertained along with provocative and palliative factors associated with pain; afterwards, the physician should map the source of pain and investigate any clues to a possible cause; finally, the following pain features should be identified:


Physical examination should be focused on the area of pain without overlooking areas of referred pain (such as the right shoulder in case of hepatic metastases).

Physical examination is followed by specific maneuvers in order to provoke or improve pain.

For instance, pain due to bone metastases may be provoked through local palpation and manipulation. Spinal cord compression resulting from epidural tumor extension represents a known challenge. Accordingly, a comprehensive neurologic examination, coupled with manual muscle testing, percussion of point of tenderness, evaluation of joint mobility, and inspection of muscle symmetry are crucial steps of any physical examination.

The assessment of psychiatric and psychosocial co-morbidities is crucial to address factors that may adversely affect pain perception and worsen patient's distress. Radiographic studies should be guided by the anamnesis and the physical examination, as well as stage of disease, patient performance status, therapeutic options, and care endpoints. When dealing with terminally ill patients, or when little would be gained by radiographic procedures, palliative measures should be implemented without putting the patient through painful, unnecessary testing. Whenever appropriate, pain treatment should be started as early as possible so that patients may be comfortable and able to complete the diagnostic procedure. Plain radiographs of painful areas may be of value.

Magnetic resonance imaging (MRI) of the spine and brain and computed tomography (CT) scanning of the chest and abdomen often provide the greatest amount of information. In case of pericardial effusions or biliary or urinary tract obstruction, ultrasonography may be easily accomplished with a portable device, thus avoiding radiation exposure. Electrophysiologic studies may be useful to distinguish mononeuropathies and entrapment neuropathies from plexopathies, as well as ulnar and peroneal entrapment syndromes from brachial and lumbar plexopathies, respectively. Conduction velocities, specific latencies, amplitudes, duration, and configurations of sensory and motor evoked potentials are the keys to identify and locate the neural pathology. Importantly, it should be remembered that results of electrophysiologic studies may be normal even with significantly damaged non-myelinated fibers.

The ability to measure pain implementing valid and standardized approaches has improved in the last years, increasing our ability to quantify the impact of adequate care in terms of outcomes. The use of standardized instruments (scales), both of a specific type (focused on the pain) and of a generic type (quality measures of life), as well as the implementation of other measures aimed to capture the results in terms of consumption of resources and medical care, has made it possible, when required, to assess the overall impact of pain on the health and life of patient. Initial and ongoing assessment of pain includes the evaluation of pain intensity using a visual or numerical rating scale ranging from 0 (absence of pain) to 10 (presence of the worst imaginable pain). Other relevant factors in pain assessment include ascertaining the quality of pain, onset, and duration as well as any actions that may worsen or relive the pain. Careful patient interviews should also evaluate the extent of patient distress resulting from pain as well as various psychological or social factors.

The Pain Research Group of the WHO Collaborating Centre for Symptom Evaluation in Cancer Care has developed the Brief Pain Inventory (BPI), a pain assessment tool devised for cancer patients. The BPI measures both the intensity of pain (sensory dimension) and the interference of pain with the patient's daily activities (reactive dimension). It also queries the patient about pain relief, pain quality, and patient perception of the cause of pain.

The BPI is a powerful tool and, having demonstrated both reliability and validity across different cultures and populations, it has been adopted in many countries for clinical pain assessment, epidemiological studies, and in studies evaluating the effectiveness of pain treatment.


**Figure 5.** Pain assessment: Objective

mistakes, as correspondence between pain severity, as reported by the patient, and presence of underlying pathology, as revealed by imaging studies, is often poor. Location, radiation, quality, intensity and temporal pattern of pain should be ascertained along with provocative and palliative factors associated with pain; afterwards, the physician should map the source of pain and investigate any clues to a possible cause; finally, the following pain features should

Physical examination should be focused on the area of pain without overlooking areas of

Physical examination is followed by specific maneuvers in order to provoke or improve pain.

For instance, pain due to bone metastases may be provoked through local palpation and manipulation. Spinal cord compression resulting from epidural tumor extension represents a known challenge. Accordingly, a comprehensive neurologic examination, coupled with manual muscle testing, percussion of point of tenderness, evaluation of joint mobility, and

The assessment of psychiatric and psychosocial co-morbidities is crucial to address factors that may adversely affect pain perception and worsen patient's distress. Radiographic studies should be guided by the anamnesis and the physical examination, as well as stage of disease, patient performance status, therapeutic options, and care endpoints. When dealing with terminally ill patients, or when little would be gained by radiographic procedures, palliative measures should be implemented without putting the patient through painful, unnecessary testing. Whenever appropriate, pain treatment should be started as early as possible so that patients may be comfortable and able to complete the diagnostic procedure. Plain radiographs

Magnetic resonance imaging (MRI) of the spine and brain and computed tomography (CT) scanning of the chest and abdomen often provide the greatest amount of information. In case of pericardial effusions or biliary or urinary tract obstruction, ultrasonography may be easily accomplished with a portable device, thus avoiding radiation exposure. Electrophysiologic studies may be useful to distinguish mononeuropathies and entrapment neuropathies from plexopathies, as well as ulnar and peroneal entrapment syndromes from brachial and lumbar plexopathies, respectively. Conduction velocities, specific latencies, amplitudes, duration, and configurations of sensory and motor evoked potentials are the keys to identify and locate the neural pathology. Importantly, it should be remembered that results of electrophysiologic

The ability to measure pain implementing valid and standardized approaches has improved in the last years, increasing our ability to quantify the impact of adequate care in terms of outcomes. The use of standardized instruments (scales), both of a specific type (focused on the

studies may be normal even with significantly damaged non-myelinated fibers.

**•** Type of pain (nociceptive, neuropathic, psychogenic);

**•** Intensity (mild, moderate, severe).

of painful areas may be of value.

**•** Temporal characteristics (acute, chronic, intense episodic);

referred pain (such as the right shoulder in case of hepatic metastases).

inspection of muscle symmetry are crucial steps of any physical examination.

be identified:

With regard to specific assessment tools, the main validated scales used in oncology are the followings:

