A Novel Clinical Prediction Model for Prognosis in Malignant Pleural Mesothelioma Using Decision Tree Analysis.

INTRODUCTION: Malignant pleural mesothelioma (MPM) is a rare cancer with a heterogeneous prognosis. Prognostic models are not widely utilized clinically. Classification and regression tree (CART) analysis examines the interaction of multiple variables with a given outcome. METHODS: Between 2005 and 2014, all cases with pathologically confirmed MPM had routinely available histological, clinical, and laboratory characteristics recorded. Classification and regression tree analysis was performed using 29 variables with 18-month survival as the dependent variable. Risk groups were refined according to survival and clinical characteristics. The model was then tested on an external international cohort. RESULTS: A total of 482 cases were included in the derivation cohort; the median survival was 12.6 months, and the median age was 69 years. The model defined four risk groups with clear survival differences (p < 0.0001). The strongest predictive variable was the presence of weight loss. The group with the best survival at 18 months (86.7% alive, median survival 34.0 months, termed risk group 1) had no weight loss, a hemoglobin level greater than 153 g/L, and a serum albumin level greater than 43 g/L. The group with the worst survival (0% alive, median survival 7.5 months, termed risk group 4d) had weight loss, a performance score of 0 or 1, and sarcomatoid histological characteristics. The C-statistic for the model was 0.761, and the sensitivity was 94.5%. Validation on 174 external cases confirmed the model's ability to discriminate between risk groups in an alternative data set with fair performance (C-statistic 0.68). CONCLUSIONS: We have developed and validated a simple, clinically relevant model to reliably discriminate patients at high and lower risk of death using routinely available variables from the time of diagnosis in unselected populations of patients with MPM.

A multicentre non-blinded randomised controlled trial to assess the impact of regular early specialist symptom control treatment on quality of life in malignant mesothelioma (RESPECT-MESO): study protocol for a randomised controlled trial.

BACKGROUND: Malignant pleural mesothelioma is an incurable cancer caused by exposure to asbestos. The United Kingdom has the highest death rate from mesothelioma in the world and this figure is increasing. Median survival is 8 to 12 months, and most patients have symptoms at diagnosis. The fittest patients may be offered chemotherapy with palliative intent. For patients not fit for systemic anticancer treatment, best supportive care remains the mainstay of management. A study from the United States examining advanced lung cancer showed that early specialist palliative care input improved patient health related quality of life and depression symptoms 12 weeks after diagnosis. While mesothelioma and advanced lung cancer share many symptoms and have a poor prognosis, oncology and palliative care services in the United Kingdom, and many other countries, vary considerably compared to the United States. The aim of this trial is to assess whether regular early symptom control treatment provided by palliative care specialists can improve health related quality of life in patients newly diagnosed with mesothelioma. METHODS: This multicentre study is an non-blinded, randomised controlled, parallel group trial. A total of 174 patients with a new diagnosis of malignant pleural mesothelioma will be minimised with a random element in a 1:1 ratio to receive either 4 weekly regular early specialist symptom control care, or standard care. The primary outcome is health related quality of life for patients at 12 weeks. Secondary outcomes include health related quality of life for patients at 24 weeks, carer health related quality of life at 12 and 24 weeks, patient and carer mood at 12 and 24 weeks, overall survival and analysis of healthcare utilisation and cost. DISCUSSION: Current practice in the United Kingdom is to involve specialist palliative care towards the final weeks or months of a life-limiting illness. This study aims to investigate whether early, regular specialist care input can result in significant health related quality of life gains for patients with mesothelioma and if this change in treatment model is cost-effective. The results will be widely applicable to many institutions and patients both in the United Kingdom and internationally. TRIAL REGISTRATION: Current controlled trials ISRCTN18955704. Date ISRCTN assigned: 31 January 2014.