Over the past two decades, numerous trials have assessed the safety an
d efficacy of patient-controlled analgesia (PCA). Advantages over conv
entional parenteral narcotics reported from these trials include equiv
alent to superior pain relief, superior patient satisfaction, decrease
d sedation and anxiety, faster return to normal functional status, and
reduction in nursing time and hospitalization. The majority of these
trials have been conducted in the postoperative patient population. In
the mid to late 1980s, interest arose in applying PCA technology to t
he management of cancer pain. Factors that served as an impetus for th
e use of PCA in cancer pain included favorable reports from the postop
erative setting and the often-cited statistics regarding the magnitude
of the cancer pain problem. Advances in PCA technology coupled with a
dvances in vascular access technology that allow the placement of long
-term ports and catheters to facilitate intravenous, epidural, or intr
athecal administration of opioid analgesics have made the applicabilit
y of PCA in ambulatory cancer patients an attractive option. The great
est breakthrough in PCA technology came with the introduction of devic
es making it possible to choose between intermittent (demand bolus) an
d continuous administration (continuous infusion) or both intermittent
and continuous modes. A comparison of these types of PCA devices is d
escribed. The limitations of the literature involving PCA therapy in c
ancer patients make it difficult to identify optimal patient selection
criteria, PCA administration schedules, drug selection and dosing, an
d optimal route of administration. The current status and pertinent is
sues related to these topics are addressed.