Palliative Surgical Research-Challenges and Solutions

Abstract

Surgeons are frequently asked to evaluate advanced cancer patients with symptoms attributable to their disease or treatment. The frequency of these consultations varies but can represent up to 40% of all inpatient consultations at major cancer centers. As opposed to the standard outcome measures of survival and recurrence for potentially- curative cancer surgery, the appropriate outcome measures for palliative surgical oncology have not been fully defined. In addition, there are many challenges to performing palliative surgical research such as frequent and early death in the study population. This review article summarizes the current research in palliative surgical oncology with a focus on these challenges and barriers to research. Lastly, this article will review some of the work attempting to current these limitations and future areas of analysis. Palliative surgery is typically defined as any procedure performed to reduce symptoms or improve quality of life in a patient with an advanced malignancy, excluding operations for potential cure (1-3). Palliative surgery has been shown to represent 13% of all operations performed by surgical oncologists and over 1000 procedures per year at tertiary cancer centers (2,4). The definition of palliative surgical consultation, similarly, is a consultation with patients with advanced malignancy who had symptoms attributable to their malignancy or complications/toxicity of treatment of their malignancy (5). Palliative consultations have been reported to constitute 40% of all surgical consultations at a major U.S. cancer center (5). These statistics demonstrate the frequency of palliative surgical consultations and surgery but fail to fully describe the clinically challenging nature of these scenarios, increased risk of surgery in this population, and lack of high-quality prospective research upon which to base treatment decisions. The considerable morbidity and mortality rates associated with palliative surgery have been well described. Mortality rates of approximately 10% are standard, with rates as high as 21% for subgroups such as malignant bowel obstruction (2,5,6). Morbidity has also been consistently described as 30-40% across several studies (2,5,7). Morbidity and mortality rates are important in outlining the risk during preoperative discussions and informed consent, but are obviously only half of the risk-benefit ratio. The lack of clearly established outcome measures and thus benefit can lead to ambiguity in patient education and preoperative assessment. As a result, there has been a lack of evidence-based guidelines and algorithms for treatment. The challenges of future research are to break this cycle with clearly established outcomes and high-quality follow-up. Clear evidence that the majority of recent literature focuses on the risk of surgery and infrequently on the benefit is outlined in a review of 348 articles published on surgical palliation of cancer (8). The authors reported that few studies included outcome measures other than survival, morbidity, or mortality. Outcome measures noted in this review included morbidity and mortality in 61%, survival in 64%, physiologic response in 69%, need to repeat the intervention in 59%, quality of life in 17%, pain control in 12%, and cost in 2%. In addition, the majority of these studies were retrospective case series (72%) while a minority was prospective (9%). The remainders of the included articles in this analysis were either reviews (10%) or case reports (9%). The simplest solution to the deficiencies noted in the current literature would seem to be corrected with prospective evaluation of quality of life measures. There has been a recent body of work that includes quality of life outcomes with a high rate of follow-up. Podnos et al. (9) reported a prospective study of 104 patients that underwent palliative surgery including outcome measures of physical, psychological, social, and spiritual aspects. The authors found that improvement in symptoms, as measured by a distress severity score, were significant and durable but that quality of life continued to decline as a result of disease progression. Recognizing the heterogeneity of this study that included many different types of cancers and palliative operations, the authors went on to focus on surgical interventions for gastrointestinal cancers with similar results (10). Other authors have addressed the difficulty in prospective analysis by prospectively identifying patients but then defining symptom improvement retrospectively. In the largest prospective study of this nature to date, over 1000 patients were identified over a one-year period (2). The population included multiple types of cancers over many different specialties to include both operations and procedures involving the musculoskeletal, genitourinary, neurologic, and respiratory symptoms. Retrospective symptom improvement was noted in the majority of patients as defined utilizing pre-defined criteria and the absence of documented complaints in the medical record. An important finding was that symptom recurrence occurred in 25% and 29% suffered new symptoms that required further treatment.