Spinal metastases patients with low serum albumin and elevated platelet-lymphocyte ratio (PLR) should be advised regarding the impact of these laboratory markers on outcomes, including survival, a recent study has found. Efforts should also be made to optimise nutrition and platelet-lymphocyte ratio before treatment, to minimise the potential for development of adverse events, the study has suggested.
The paper, authored by Andrew J Schoenfeld (Brigham and Women’s Hospital, Harvard Medical School, Boston, USA) and colleagues, was published recently in The Spine Journal and was awarded Outstanding Paper in Surgical Science at the 34th Annual Meeting of the North American Spine Society (NASS 2019; 25–28 September, Chicago, USA).
The authors note that laboratory values have been found to be useful predictive measures of survival following spinal surgery, although their ability to predict outcomes among patients with spinal metastases has not previously been studied. The investigators sought to determine the prognostic capacity of values including white blood cell (WBC) count, serum albumin and platelet-lymphocyte ratio in patients with spinal metastases.
Schoenfeld and colleagues used retrospective data taken from the electronic medical records of patients, aged 40–80, treated at Brigham and Women’s Hospital (Boston, USA) and Massachusetts General Hospital (Boston, USA) for spinal metastases between 2005 and 2017. This included patients who had received operative or non-operative management for spinal metastatic disease at one, or both of the study centres.
Overall patient survival was assessed as well as mortality rates at six months and one-year following presentation. The primary outcome was length of survival. Mortality at six months and one-year, complications, readmissions, and the composite measure for treatment failure were considered secondary outcomes.
Multivariable Cox proportional hazard regression analysis was used to analyse the relationship between laboratory values and length of survival. Multivariable logistic regression was used in analyses related to six-month and one-year mortality, complications, readmissions, and treatment failure. Primary predictors in the study were white blood cell count, albumin and platelet-lymphocyte ratio at presentation. A scoring rubric was developed based on the performance of laboratory values in the multivariable tests. White blood cell count was dropped from the final scoring rubric based on its performance in the multivariable models.
A total of 1,216 patients were included in the study, 23% of patients were diagnosed with lung cancer and 19% had breast cancer. Lung metastases were documented in 20% of the cohort with liver metastases and additional bone metastases present in 23% and 49% of the population. Forty one per cent of patients presented with some degree of neurologic symptoms, whereas 16% required assistive devices for ambulation and 7% were non-ambulators. Thirty seven per cent of patients received a surgical intervention and 63% were treated non-operatively.
Patients with platelet-lymphocyte ratio ≤180, when compared with those with platelet-lymphocyte ratio >180, were found to have lower rates of six-month (22% vs 42%) and one-year mortality (34% vs 58%), as well as hospital readmission (32% vs 42%). They were also less likely to experience treatment failure (32% vs. 52%) with complication rates relatively comparable (27% vs 32%). Individuals with albumin >3.5 g/dL, when compared with patients with albumin ≤3.5 g/dL, also experienced lower rates of six-month (24% vs. 58%) and one-year mortality (39% vs 72%) as well as reduced rates of treatment failure (35% vs 68%), complications (27% vs 36%) and readmissions (35% vs 42%).
The authors comment: “In this investigation, we found that PLR and serum albumin at presentation were significantly associated with survival, as well as six-month and one-year mortality and our composite measure for treatment failure in a large series of patients treated for spinal metastatic disease. Indeed, there also appears to be a synergistic effect between these laboratory measures, with stepwise significant increases in the likelihood of the adverse events we examined in individuals who presented low serum albumin and an elevated PLR.”
Results of the study could be used to aid in initial counselling and discussions of natural history, treatment contingencies, and anticipated outcomes at the time a patient presents with spinal metastases, the authors say. Looking forward, the study notes that a line of further research on the efficacy of targeted interventions directed at improving these laboratory markers could be assessed.