Current challenges in cancer pain management: does the WHO ladder approach still have relevance?

In traditional pain management teaching, several arbitrary distinctions are usually created. Cancer pain, chronic (so-called ‘nonmalignant’ pain) and acute pain are viewed as distinct clinical entities with somewhat unique treatment strategies. In fact, these ‘distinct clinical entities’ represent slightly different aspects of common pathophysiologic states, which blend together in a disease continuum.

The approach to cancer pain generally consists of application of the WHO ladder concept, which basically involves treating with simple analgesics then moving to stronger opioids and adjuvants until pain control is achieved. In a systematic review, Azevedo et al. found that by utilizing the WHO ladder, analgesia was considered adequate in 45–100% of patients analyzed in the studies [1].

While the authors agree that in many cases of progressive cancer this is appropriate, the WHO concept is far too oversimplified to advocate its continued widespread application for cancer pain. Pain strategies long reserved for chronic pain, including holistic therapies, physiotherapy, cognitive–behavioral and other psychological therapies, the judicious application of pharmacotherapy (including opioids and adjuvants) and procedural pain medicine techniques may be appropriate in most cases of early stage or highly curable cancers.

A clinical example may help clarify this point by contrasting what we will term ‘the WHO approach’ and ‘the new pain treatment approach’. Under the WHO approach, a patient undergoing mastectomy under general anesthesia will receive an opioid patient-controlled analgesia pump postoperatively with a transition to oral opioids. Under the new pain treatment approach, pain prevention begins with surgery conducted under paravertebral blockade with very little opioid required perioperatively. Postoperative recovery is facilitated with early physiotherapy to retain shoulder range of motion. The widespread application of regional anesthetic techniques in the perioperative period in addition to the use of perioperative anti-inflammatories and anticonvulsants leads to faster recovery times, less pain and less opioid intake [2].

Next, if pain flares or persists in the radiation or adjuvant chemotherapy time frame, instead of the automatic WHO opioid ramp up, chronic pain approaches are utilized including early application of adjuvant medications with an emphasis on preserving functionality rather than a focus primarily on pain score.

Even in cases of progressive or incurable cancer, the authors advocate a careful assessment of the pain syndrome prior to the automatic WHO opioid ramp up. In cases amenable to advanced interventional therapies, such as pancreatic tumors, vertebral fractures or other fairly discrete nidus of pain such as chest wall tumors, application of interventional pain techniques should accompany any analgesic plan. Evidence shows early application of these techniques (such as celiac plexus block) provides clear and sustained analgesia, thereby avoiding early opioid tolerance and other opioid-related side effects for as long as possible [3]. Some have acknowledged a fourth step to the WHO ladder, namely interventional pain techniques [4]. The stepwise approach depicted in the WHO ladder and practiced widely, subjects the patient to unnecessary pain, side effects and suffering while working up the ladder. The real challenge in treating pain in cancer patients is shifting this long-practiced paradigm. The WHO cancer pain relief ladder should be turned upside down with earlier application of selected interventional pain techniques, only to resort to higher dose, step III analgesics later as needed. With the advance of interventional pain medicine techniques and technology, a better job could be done of achieving adequate pain relief, minimizing side effects, simplifying treatment regimens and perhaps improving patient outcomes. Therapeutic options reserved as a last resort by the WHO ladder may offer pain control, fewer adverse effects and better overall outcome.

Several examples of these techniques include intrathecal analgesia, celiac plexus blockade, vertebroplasy and others, which have consistently been shown to effectively treat refractory cancer pain.

It must be noted that any approach to treating cancer pain might be impaired by numerous obstacles, including financial constraints, access to medications and technologies, and other factors which vary considerably from one country to another.

While we view the WHO ladder as a major advance when it was developed; currently, chronic pain approaches utilizing a complex multidisciplinary algorithm of care should be applied in many cancer pain states [5]. Chronic pain treatment strategies in most cases should be complementary and consistent with palliative care strategies. We believe that cancer patients deserve an approach that utilizes the best techniques borrowed from the realms of traditional cancer, chronic and acute pain strategies. Finally, we strongly believe that the use of interventional pain strategies is consistent with humanistic palliative approaches. ‘Hi-tech’ and ‘hi-touch’ therapies are not exclusive. Our cancer pain patients deserve both.

Financial & competing interests disclosure

Allen W Burton has conducted sponsored research for Archimedes, Ltd, Kyphon, Inc. and Elan, Inc., is a consultant for Stryker, Inc., Advanced Bionics, Inc., Kyphon, Inc. and Pfizer, Inc. and is a founder/shareholder/consultant for Vapogenix, Inc. Basem Hamid acts as a consultant for Eli Lilly and Pfizer, Inc. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

No writing assistance was utilized in the production of this manuscript.