A validation study of the WHO analgesic ladder: a two-step vs three-step strategy

The aims of the present study were to verify whether an innovative therapeutic strategy for the treatment of mild-moderate chronic cancer pain, passing directly from step I to step III of the WHO analgesic ladder, is more effective than the traditional three-step strategy and to evaluate the tolerability and therapeutic index in both strategies.

Patients aged 18 years or older with multiple viscera or bone metastases or with locally advanced disease were randomized. Pain intensity was assessed using a 0-10 numerical rating scale based on four questions selected from the validated Italian version of the Brief Pain Inventory. Treatment-specific variables and other symptoms were recorded at baseline up to a maximum follow-up of 90 days per patient.

Fifty-four patients were randomized onto the study, and pain intensity was assessed over a period of 2,649 days. The innovative treatment presented a statistically significant advantage over the traditional strategy in terms of the percentage of days with worst pain > or =5 (22.8 vs 28.6%, p < 0.001) and > or =7 (8.6 vs 11.2%, p = 0.023). Grades 3 and 4 anorexia and constipation were more frequently reported in the innovative strategy arm, although prophylactic laxative therapy was used less in this setting.

Our preliminary data would seem to suggest that a direct move to the third step of the WHO analgesic ladder is feasible and could reduce some pain scores but also requires careful management of side effects.