BACKGROUND/RATIONALE:
Survival estimates for advanced cancer patients are currently based upon the Karnofsky Performance Status (KPS) and clinician estimates. However, their ability to predict survival is poor. Although KPS is reasonably reliable in predicting imminent death if low ( KPS<50), a high KPS does not automatically mean a long survival. The survival is usually overestimated by both clinicians and cancer patients. Advanced cancer patients tend to choose life-extending therapy if they think their survival is more than 6 months. The survival prediction models with higher accuracy and better predictive performance are needed. A better survival prediction will facilitate decision making processes related to treatment plans for advanced cancer patients. In our previous study, the recursive partitioning analysis (RPA) results suggest that KPS and patient- rated QOL (physical wellbeing) and physical symptom distress can be combined to refine estimates of prognosis. We have identified four distinct prognostic subgroups with clear cutoff point for each significant variable. The median survival time for each survival group was 29 days, 146 days, 292 days and 1.7 years. A Cox model found different survival predictors in addition to KPS and physical wellbeing; these were psychological symptom distress, global distress index and age. These two models (RPA and Cox models) need to be further validated. We proposed to develop new multidimensional survival prediction models by combining additional important variables from a multilevel QOL model.
OBJECTIVE(S):
(1) To validate newly developed survival models with the KPS, symptom distress and QOL variables from a prospective cohort of patients. We would like to describe patterns of hazards and survival in the prospective cohort and in such stratified patient demographic groups as age, race/ethnicity and spouse status; compare the patterns with those in the existing sample. We will examine the extent to which KPS, physical wellbeing and physical symptom distress are associated with survival in the prospective cohort; compare the patterns of associations with those in the existing sample. (2) To develop a complete multidimensional model by adding the physiological variables and individual characteristics to models developed for objective 1. The survival model developed from our previous study did not include all the important variables suggested by the literature, especially in the physiological dimension and individual characteristics. We will test the potential links between survival and the additional dimensions in the prospective cohort and examine the mechanisms by which the multidimensional measures are associated with survival through independent paths, mediation or moderation.
METHODS:
This is a prospective longitudinal study. A total of 360 consecutive metastatic cancer patients who have failed standard or experimental chemotherapy with KPS < 80, or who do not wish to receive antineoplastic therapy, will be recruited and stratified by KPS, PWB and PHYS based on our pilot study result. All patients will be followed for survival. Each participant will be interviewed once with the following validated instruments: Memorial Symptom Assessment Scale-Short Form (MSAS-SF), Functional Assessment of Cancer Therapy (FACT-G) and European Quality of Life Scale (EuroQOL) and observer rated instruments - KPS, Memorial Delirium Assessment Scale and Barthel Index. Weight and laboratory tests (CBC, chemistry profile) will be obtained. We expect each interview will last for 15 minutes.
FINDINGS/RESULTS:
The study was initiated in August, 2003 at VANJHCS and we have recruited a total of 222 patients. We have demonstrated the feasibility of instruments used in the study and enrollment procedure. We have completed accrual in prognostic subgroups 1 and 2. Accrual is ongoing for subgroups 3 and 4. We will develop new ways to identify eligible patients as patients in subgroups 3 and 4 are increasingly scarce in medical oncology settings. Both accrual and our ability to store and process data have been significantly affected by the recent HSR&D shutdown.
IMPACT:
The models developed form our study may be used by clinicians to enhance clinical decision making, and in clinical trial settings for patient stratification. These findings can eventually be easily applied throughout VA and implemented on computer systems, to increase efficiency and decrease costs. The methodology may be applicable in developing survival models for patients with other terminal illnesses.
PUBLICATIONS:
Journal Articles
- Chang VT, Sorger B, Rosenfeld KE, Lorenz KA, Bailey AF, Bui T, Weinberger L, Montagnini M. Pain and palliative medicine. Journal of Rehabilitation Research and Development. 2007; 44(2): 279-94.
- Buffum MD, Hutt E, Chang VT, Craine MH, Snow AL. Cognitive impairment and pain management: review of issues and challenges. Journal of Rehabilitation Research and Development. 2007; 44(2): 315-30.
- Chang VT, Xia Q, Kasimis B. The Functional Assessment of Anorexia/Cachexia Therapy (FAACT) Appetite Scale in veteran cancer patients. Journal of Supportive Oncology. 2005; 3(5): 377-82.
