Pain is one of the most common and worrisome symptoms faced by people with cancer. Pain may be caused by cancer itself or the other complications and illnesses that are associated with it. Most of the times the pain arises as the cancerous tumor press against other body organs. Moreover, the tests and procedures used to diagnose cancer, for example biopsy can itself be quite painful. The treatment of cancer can also be associated with acute and chronic pain. Overall people suffering from cancer often need to visit their health care professional (HCP) with a complaint of pain.
The severity and intensity of cancer pain depends upon the type, stage, and the treatment of cancer. Therefore, it is important to understand the nature and type of pain, causes, and factors that contribute to pain. This can help the HCPs to suggest appropriate pain relieving treatment.
Prevalence of Cancer Pain
• Approximately 25 to 50 percent of people with cancer complain of pain at the time of diagnosis, which increases to 75 percent as the cancer progresses.
• In the US, cancer affects nearly 1.2 million people and more than half of these suffer from pain. In most of the cancer patients, pain is so severe that it interferes with their normal activities of daily living (ADLs).
• According to recent estimates from Italy, the prevalence of cancer pain was 73 percent at the time of diagnosis.
• Another study from the UK revealed that the prevalence of neuropathic pain ranged from 18 to 21 percent in cancer patients.
• Pain symptoms are highly variable and individualized. The intensity of pain differs based on the type of cancer, for example bone cancer pain is associated with the highest moderate to severe pain, while leukemia has the lowest (see Table 1).
Table 1 : Prevalence of Pain in Different Types of Cancer
(Genitourinary: organs of reproductive and urinary system)
Pathophysiology of Cancer Pain
The pathophysiology of cancer pain is same as that for non-cancer pain.(Read the Mechanism of Pain) However, the cancer pain presents a mixed mechanism of neuropathic, visceral, or somatic pain syndrome. The development of cancer pain gets complex over time depending on cancer type, treatment regimes, and underlying concurrent morbidities.