4.O.01 BONE AND SOFT TISSUE SARCOMAS: A CHALLENGE TO THE MEASUREMENT OF PATIENT-REPORTED OUTCOMES

Abstract

Disease-free survival and local relapse rates in patients with malignant bone tumors are similar following limb salvage and amputation. However, while there has been considerable interest in comparative function after surgery, as assessed by clinicians, there is less information on patient-reported outcomes (PROs). Interest in PROs has evolved from recognizing the usefulness of measures of (health-related) quality of life (HRQL) and the acceptance that the “gold standard” in such assessments is provided by the individual reporting on his/her own health status.

In the context of cancer and cancer-treatment, the importance of PROs is firmly embedded in the conduct of clinical trials, as documented by the Cancer Outcomes Working Group of the National Cancer Institute (NCI) in the USA. The NCI has promoted the development of appropriate instruments for eliciting and evaluating PROs through the Patient Reported Outcomes Measurement Information System (PROMIS). Similar initiatives have been undertaken in Canada, the United Kingdom, Western Europe and elsewhere. This topic was the subject of a series of reviews in a recent issue of the Journal of Clinical Oncology.

Large studies in the United States and Canada revealed that, among survivors of cancer in childhood and adolescence, those who had had brain or bone tumors experienced the greatest compromise in physical performance, psychosocial outcomes and HRQL.

Inclusion of PROs and measures of HRQL are still not routine in the design and conduct of clinical trials, and these are seldom used in regular day-to-day practice by clinical oncologists who have yet to be sufficiently persuaded of the added value provided by such determinations.

However, the orthopedic community lead the way more than 25 years ago with an assessment of HRQL following treatment of sarcomas of the extremities (at that time refuting the commonly held belief that any therapy, no matter how “aggressive”, was better than limb amputation). That study enrolled only a small number of patients and the therapeutic (especially surgical) options have changed substantially in a generation, but a “marker” was established and the challenge to provide current evidence remains.

Measures of HRQL that focus on orthopedic problems have been developed and subjected to recent rigorous review. But assessments are subject to many confounding factors such as age, gender, diagnosticdetails (tumor type, size and location), prior (neo-adjuvant) and subsequent therapy, the era of treatment and the time elapsed since surgical intervention. Sample sizes will need to be very large to address these variables.

Despite the almost consistent problem of small samples, some common findings emerge. Females experience poorer outcomes than males; there can be improvement over time; and, insofar as they are comparable (candidates for amputation are seldom candidates for limb salvage surgery), the differences in HRQL among amputees, patients who had rotationplasties, and those who underwent limb salvage (with endoprostheses or bone grafts) are small.

Measures of functional outcome and HRQL are neither fully inter-changeable nor mutually exclusive, and much remains to be learned from the measurement of PROs in patients with bone and soft tissue sarcomas.