In the early stages of the disease, some 80 percent of people have pain resulting from the cancer itself or from the procedures designed to arrest its spread. By the time the cancer has reached its final stages, about 70 percent of people report pain, which tends to be intense and persistent. About 80 to 90 percent of cancer patients treated with the preventive approach obtain satisfactory relief, reporting that their discomfort is consistently bearable or, more frequently, gone. Roughly half of the remainder obtain relief with the addition of other therapies. This success rate is remarkable in view of the destructiveness of cancer and the severity of the pain associated with it.
Treatments continue to improve.
There are now special capsules that release morphine slowly and so need to be taken only a few times a day. Also available are electronically controlled, portable pumps that deliver a steady infusion of medication under the skin. Enough evidence has now been collected to demonstrate that the traditional, PRN approach, based as it is on the fear of addiction makes little sense. Let us first consider the problem of marked tolerance, which not only is a sign of possible addiction but is also a medical concern in its own right because the risk of side effects increases as the dose increases. For instance, delivery of extremely large amounts of morphine can induce coma and seriously impair respiration.