Because the majority of patients with pancreatic cancer will experience pain during the course of their disease and treatment, alleviating this symptom has become an integral part of their care.
Patients with pancreatic cancer may experience pain due to the tumor itself or the treatment, noted Nessa Coyle, NP, PhD, FAAN, of the Pain and Palliative Care Service at Memorial Sloan-Kettering Cancer Center. Fortunately, palliative care professionals are able to assess pain and provide a number of options for symptom relief.
With all of the palliative therapies and support available, “there's no reason for a patient to live or die with unrelieved pain,” said Michael Levy, MD, PhD, Director of the Supportive Oncology Care Program at Fox Chase Cancer Center.
Pain can arise from local compression of nerves caused by tumor growth and invasion of surrounding structures, explained Michael Erdek, MD, Assistant Professor of Anesthesiology and Critical Care Medicine at Johns Hopkins Medical Institutions. The tumor can cause pain in the sympathetic nervous symptom, leading to visceral pain in the organs themselves. Visceral abdominal and back pain are classic in the presentation of pancreatic cancer, he noted.
“The classical experience is deep and boring pain into the back, when the mass in the head of the pancreas presses on or invades the celiac plexus, a group of nerves behind the organ,” Dr. Levy said. Patients may also experience discomfort because of biliary or gastric outlet obstruction. The symptom may also arise in the lymph nodes or liver if the cancer spreads there.
“Pain in this population is highly prevalent and pain management is integral to comprehensive care,” Dr. Coyle said. Approximately one third of patients receiving active therapy for their cancer and two thirds of those with advanced disease experience pain.
The majority of patients with pancreatic cancer experience pain, Dr. Erdek agreed, adding, “I would say more than 50% of patients have pain as their first symptom of pancreatic cancer.”
In addition, some individuals who have been cured of their cancer or are living with cancer as a chronic disease will develop a chronic pain syndrome as a consequence of the cancer or its treatment, Dr. Coyle noted.
Treatment of pain begins with an assessment of its intensity and a survey of medications that the patient may already be taking for symptoms, Dr. Levy said. “This allows you to decide which opioid analgesic might provide immediate relief.”
Pain assessment is the underpinning of pain management, and the goal of the evaluation is to prevent pain if possible and identify it immediately should it occur. How well patients communicate with the doctor or nurse about the pain and the adequacy of relief will directly affect how well the pain is controlled, Dr. Coyle said.
In addition to the well-known pain scale of 0 to 10, Dr. Levy and his colleagues also use the Wisconsin Brief Pain Inventory, which provides information about pain intensity and how it interferes with function.
Physicians then perform a secondary assessment to determine the quality of pain, he explained. “Is it pain that gets worse with eating? If so, it may be gastric outlet obstruction. If the pain is associated with itching and jaundice, the patient most likely has a biliary obstruction.”
How the pain is described, whether constant or intermittent, will be compared with qualities found on physical examination and a computed tomography scan, thus allowing physicians to direct their treatment to specific causes of pain.
Having patients keep a diary about their pain can be a helpful tool, Dr. Coyle said, with the information including entries about the pain severity when the patients gets up in the morning and then when going to bed at night.
Patients may also want to include a record of their pain prior to taking scheduled around-the-clock pain medications and one hour afterward; the episodes and severity of breakthrough pain, either spontaneous or in relationship to a particular activity; and the number and effectiveness of rescue doses.
The patient's general activities and other symptoms should also be recorded in the diary. The diary will reflect the pattern of the patient's pain over a 24-hour period, the response to the analgesic regimen or other non-drug approaches, side effects if any, and the person's general activity and mood. Not every symptom is associated with cancer and its treatment, Dr. Coyle noted.
Additionally, many patients gain a sense of control and increased understanding about the triggers for episodes of increased pain, preemptive measures to minimize episodes of breakthrough pain, and reinforcement about why factors such as changes in the site of pain and its characteristics and severity are important pieces of information to relay to the health care team.
Dr. Coyle's patients are encouraged to bring their pain diary to each clinic appointment. A section in the diary can be kept for the physician's or nurses' clearly written instructions regarding drug dose schedule, as well as any other symptom management strategies.
Encouraging patients to bring their diary with them to each clinic visit reinforces the importance of symptom management, Dr. Coyle said. “It is also a reminder to the staff of what is happening to the patient and family at home, where most pain and other symptoms are experienced.”
Reducing the Cancer
Overall, the best way to alleviate pain is to reduce the cancer, Dr. Levy said. If possible, the patient can undergo surgery with or without chemotherapy or radiation before or afterward. Gemcitabine is approved as palliative chemotherapy in pancreatic cancer patients.
Reducing the cancer can alleviate pain caused by nerve compression, explained Glen Justice, MD, Medical Director of Orange Coast Memorial Medical Center's Cancer Center in Fountain Valley, CA, and Professor of Medicine at the University of Southern California Norris Cancer Center.
In addition, inserting stents using endoscopic retrograde cholangiopancreatography (ERCP) to open the common biliary duct can provide palliation in patients with biliary obstruction, while obstruction of the bowel is usually treated with gastrojejunostomy, he said.
Medical oncologists usually use narcotics to treat mild to moderate pain in patients with pancreatic cancer, said Malek Safa, MD, Director of the Gastrointestinal Medical Oncology Program at the University of Cincinnati. Most typically used are long-acting opioids for overall pain relief and short-acting tablet or liquid opioids for breakthrough pain. If patients can't take oral medication, opioid patches are an option.
Opioids can cause sedation, nausea, and dizziness, as well as confusion in older patients, he said. Constipation is another common side effect, although this can be managed with stool softeners prescribed at the outset of treatment. Clinicians need to determine whether such side effects are due to the pain medication or to other treatments the patient is receiving, such as chemotherapy.
Systemic opioids may be needed to treat liver pain, which results from tumors interfering with intercostal nerves. A morphine pump for infusion of morphine and bupivicaine into the spinal canal to reduce the side effects of systemic opioids is an option, but this hasn't become standard of care, Dr. Levy said. Many patients don't want to undergo another procedure to implant the pump, he explained.
In addition to opioids, other pain medications are available to treat nerve damage and inflammatory pain.
If opioid therapy does not help to relieve pain, patients may need to undergo a procedure that blocks nerves located behind the pancreas, Dr. Erdek said. “One of the first things we offer them, assuming opioids aren't effective or have bad side effects such as nausea or sedation, is a celiac plexus block.”
If patients have classic pain boring into the back, and if they do not have significant lymph node or liver involvement, a celiac block can be effective in reducing both pain and the need for opioids, Dr. Levy said. However, the best way to perform a celiac block has yet to be determined, and randomized controlled trials of various procedures are lacking.
The procedure usually involves the percutaneous diagnostic injection of a local anesthetic in the vicinity of the celiac plexus under imaging guidance such as x-ray or computed tomography. If the patient has a temporary reduction in pain, the next step is a block using alcohol to cause neurolysis.
Gastroenterologists may perform the procedure with an endoscope and ultrasound guidance, pushing a needle through the duodenum and into the celiac plexus to inject alcohol, Dr. Levy said. Radiofrequency lesioning can also be used to destroy nerve endings.
Physicians may also perform a celiac plexus block during open surgery to remove a tumor or for another procedure, Dr. Justice said. “Sometimes when doctors go in surgically, no one thinks to put a block in there.”
Studies to date show variable long-term success, with pain relief occurring in 30% to 60% of patients, Dr. Safa noted.
Citing a meta-analysis in 1995, though (Anesth Analg 1995;80:290–295), Dr. Justice noted that about 70% to 90% or patients experience dramatic pain relief three months after the procedure.
The initial rate of effectiveness of a celiac block is likely high, Dr. Erdek said, but during a patient's remaining lifespan, the disease may progress or the block may wear off, so the effectiveness still depends on a number of factors.
The literature also indicates improvements in quality of life and that patients need less opioid therapy, Dr. Justice said. “We still use opioids in conjunction with celiac plexus blocks, but we generally need far less.”
Overall, celiac plexus blocks have a low risk of adverse reactions, Dr. Levy said. The procedure can also help to relax the bowel, counteracting constipation associated with opioids. Performing the procedure before patients undergo chemotherapy or radiation can help lower the risk of infection and bleeding.
“The celiac plexus block is underutilized, but we need a controlled trial to see who would most benefit from the various ways to perform the procedure,” he said.
If patients have received opioid medication and a celiac block, but still have pain, physicians will consider using an intrathecal catheter to administer an opioid such as morphine directly into the central nervous system, Dr. Erdek said.
This can provide more direct pain relief compared with oral administration and offers more potency with less medication. Intrathecal therapy allows physicians to create enough pain relief so patients can enjoy meaningful interaction in their lives, he said.
Addiction and Other Concerns
There are a variety of concerns that patients and physicians may have about managing pain, those interviewed for this article said. For example, it is still the case that some patients are concerned that using opiates will cause addiction.
This apprehension exists among health care providers as well, Dr. Justice said. “It's rare, however, to run into drug dependency and addiction in cancer patients, and the literature bears this out.”
About 10% of the general public has problems with drug dependency, and the percentage is even lower in cancer patients because they generally want to take care of their health, he said.
Because of the unfortunate situation that survival after a diagnosis of pancreatic cancer is usually short, addiction to narcotics should not be a concern, Dr. Safa said. “If we cannot cure pancreatic cancer, we should at least be able to control pain. It is patients' biggest complaint.”
Patient education about the safety and effectiveness of prescribing opioids can help to alleviate misconceptions about addiction and help protect patients at high risk for aberrant drug use, Dr. Levy said.
Patients may have also have misconceptions about tolerance to pain relief medications. “Patients are sometimes afraid that if they take morphine now, there will be nothing for them to take when their disease progresses. But morphine does not have a fixed-dose ceiling, and clinical tolerance is rarely an issue.”
Pain correlating with the extent of disease is another misconception that patients have. “Patients sometimes think, ‘I have so much pain, so I must have a really bad cancer,’” Dr. Levy said. Sometimes this pain is related to where the cancer is located, and patients may also be experiencing residual pain from surgery, radiation, or chemotherapy.
There is not always a correlation between pain and the extent of the disease, Dr. Erdek agreed. “You can do a CT scan and not have extensive disease, but the patient may have decent amounts of pain.” However, if patients start experiencing more pain after a nerve block and medication, physicians often suspect that the disease has progressed.
Patients may also be concerned that side effects such as constipation, sleepiness, and nausea cannot be controlled, Dr. Coyle said.
The Bottom Line
Overall, pain and palliative care experts would like to see pain intervention begin at diagnosis. “If we get earlier referrals and treat it at onset, we may see some improved outcomes,” Dr. Erdek said. “We may be able to minimize side effects and improve quality of life.”