Substance Abuse Issues in Cancer Patients:

Among the most challenging problems in medicine is the management of patients with simultaneous cancer, pain, and psychological chemical dependency (substance abuse). It has been our experience at the UT

M. D. Anderson Cancer Center Pain Clinic that patients with pain and concurrent substance abuse require intensive care. Much demand is placed on staff and institutional resources due to the psychiatric diagnoses, psychosocial needs, and legal problems of these patients. They are more likely to have poor family and social support systems, and are apt to need extensive social services, such as financial assistance, transportation arrangements, housing and legal aid. It is important to remember, however, that substance abuse is not restricted to the lower socioeconomic stratum.

At the M. D. Anderson Pain Clinic, a retrospective review of 2,100 patients showed that fewer than 1% displayed the overt behavior problem that would identify them as substance abusers.[1] As the prevalence of substance abuse in the general population increases, it becomes clear that some patients with substance abuse cannot be identified by observation. Yet, early identification of substance abuse is important because these patients are thought to be at greater risk for aberrant drug use during medical therapy with abusable drugs. Also, these patients are at greater risk for certain cancers, such as head and neck, lung, and gastrointestinal malignancies.

As discussed in the paper by Passik et al, a concurrent diagnosis of substance abuse complicates pain management. Prior clinical work in this area is limited, with little data on which to base a nonabstinence model of treatment. However, there is extensive literature on related subjects, such as the neurobiology of addiction, treatment of chemical dependency, opioid analgesics for malignant and nonmalignant pain, psycho-oncology, and quality of life.

Program for Managing Cancer Patients With Substance Abuse
At M. D. Anderson Cancer Center, we structured a program to address this population. A broad institutional policy was endorsed by the hospital administration, and a multidisciplinary management team and community resources were identified. Rules for prescribing and documentation were set. For example, meticulous record-keeping of details of prescriptions, limiting prescribing authority to one physician or a designee, and written agreements were instituted (see below).

In this program, patients are first evaluated for concurrent substance abuse by routine screening questions in the medical history. At times, they present in a “crisis” situation. At other times, substance abusers are identified via self-administered questionnaires, confidential structured interviews, provider observations of patient behaviors, and screening of body fluids.

When the index of suspicion for concurrent substance abuse is high, psychiatric and neurospychological evaluations are recommended, in order to facilitate diagnosis of comorbid conditions. Controlled prescribing, with frequent intervals and limited quantities, may be necessary.

The written patient care agreement or “contract” details an individualized agreement between patient and provider, and may address problem behaviors, such as lack of impulse control and “splitting” of staff (different behaviors and varying communications directed at different members of the care team). Clear documentation of diagnosis, treatment, and behavior must be recorded in the event that a patient must be dismissed from the clinic.[2] (Note that the written patient care agreement is not strictly an informed consent document.)

Substance Abuse Patient Population Data
A retrospective review of 84 patients with substance abuse problems at M. D. Anderson Cancer Center Pain Clinic showed that 90% were between the ages of 20 and 60 years, with a preponderance being male (58%). Almost all (97%) had a diagnosis of cancer-related pain, and 98% had been prescribed opioids. Polysubstance abuse was noted in 33% and alcohol(Drug information on alcohol) abuse alone in 14%; 9% had a positive family history of substance abuse; and unsanctioned dose escalation occurred in 9%. There was a known criminal history in 5%, and prescription drug abuse in 2%. Two or more of these problems occurred in 28% of the patients. The majority had undergone a psychiatric evaluation, with depression diagnosed in 28%, anxiety in 11%, and personality disorder in 6%. Seventeen (20%) of these patients were given a written “care agreement,” whereas overall, fewer than 5% of pain clinic patients are managed with written care contracts or agreements.

Body fluid screening is useful to confirm the presence or absence of prescribed controlled substances and nonprescribed drugs (licit or illicit). The limitations of most routine drug screening tests require that pain clinicians and laboratory staff collaborate to ensure that the drugs of interest are screened, and that detection thresholds for specific drugs are adequate. Allowing for laboratory error, it is advisable to obtain more than one test for clinical decision-making.

Legal and Personal Issues
In the case of patients on methadone(Drug information on methadone) maintenance therapy, Passik et al suggest that methadone administered for opioid dependency be titrated to analgesia. It is my preference to consider methadone as if it were an endogenous opioid, keep the methadone dose stable, and use a different opioid for the analgesic regimen. Although this approach may be more complicated pharmacologically, it respects the legal restrictions on prescribing for opioid maintenance, ie, the requirement for special registration as a methadone clinic. Periodic communication with the methadone clinic staff is still necessary to inform them of agents prescribed, but the need for repeated communications regarding analgesic titration is reduced.

There are several other medicolegal considerations that arise in the management of these patients. Legal counsel may be necessary to address information regarding a patient’s illicit activities. When overt illicit behaviors are viewed as a contraindication to prescribing controlled substances, a patient complaining of pain may go untreated. The prescribers’ obligations and the patients’ rights may then come into conflict, and ethical issues must be addressed.

Summary
At M. D. Anderson Cancer Center, we have learned that these patients can make distinctions between analgesia and other psychoactive effects. They understand that they must cope with the many stresses of chronic pain, complex cancer treatment decisions, the threat of tumor progression or recurrence, and many other personal losses. Some patients have responded positively to the more strictly structured approach to their pain management outlined above.

Ten-year follow-up data of 132 M. D. Anderson patients with genitourinary cancers and substance abuse indicated that survival was comparable to patients without substance abuse. These preliminary studies reveal that while substance abuse may not lead to poorer survival from cancer, it does complicate pain assessment and treatment. Earlier identification of substance abuse permits psychological interventions that may improve compliance with analgesic therapy.

Again, it is important to recognize the exceptional care that patients with cancer pain and substance abuse require. Our aim is to maintain the best therapeutic alliance by reestablishing trust and thus furthering our goals of pain relief and improved quality of life for these suffering patients. Individuals without pain who require treatment solely for chemical dependency are best referred to outside dependency treatment centers.