Factors correlating with shorter survival after treatment: Aiding oncologists to choose who (not) to receive palliative systemic therapy

Abstract

Background: A rising number of metastatic cancer patients are receiving palliative systemic therapy close to end of life. Patients started on such treatment are typically judged by oncologists to have at least 12 weeks survival, however, accurate survival prediction on individual patients is difficult. Systemic therapy started too late may not benefit patient, but rather, adversely affect patient’s quality of life and may even shorten survival due to treatment-related side effects. Our objective is to identify factors correlating with a shorter (≤6 weeks) non-malignancy related survival in metastatic cancer patients receiving palliative systemic therapy, so as to aid oncologist in the decision-making of starting treatment or not. Methods: A review of deceased metastatic cancer patients treated with palliative systemic therapy and died between January 2013 and December 2014 was carried out. They were subcategorized into dying within or after 6 weeks since starting their last line of palliative systemic therapy, and also by cause of death (malignancy-related or non-malignancy related causes). Demographics, clinical characteristics, and type of systemic therapy used were assessed using non-parametric Mann Whitney-U tests for continuous variables and χ2 tests for categorical variables. Univariable analyses were carried out to determine associations of different variables with non-malignancy related death that happened within 6 weeks of starting their last line of palliative systemic therapy. Multivariable analyses were carried out with significant factors in univariable analyses to determine their independent effect. Results: Seven hundred and fifty-four patients were analyzed. Mean age was 63.6 (range, 21–102); female 48.7%. Older age (75 years) (P=0.007) and active liver metastasis (P=0.042) were significant predictors for early (≤6 weeks) non-malignancy related death in multivariable analysis. They have 2.012 and 1.115 times higher chance respectively to die of non-malignant causes within 6 weeks since the start of their last line of palliative systemic treatment. Conclusions: Oncologists should exercise extra caution when encountering elderly patients with active liver metastasis, especially with regard to the issue of starting palliative systemic therapy.