The C-Reactive Protein/Albumin Ratio is a Novel Significant Prognostic Factor in Patients with Malignant Pleural Mesothelioma: A Retrospective Multi-institutional Study

Our plain-English summary of The C-Reactive Protein/Albumin Ratio is a Novel Significant Prognostic Factor in Patients with Malignant Pleural Mesothelioma: A Retrospective Multi-institutional Study, by S. Takamori, G. Toyokawa, M. Shimokawa, et al (Annals of Surgical Oncology, 2018).

The study

• Authors: S. Takamori, G. Toyokawa, M. Shimokawa, F. Kinoshita, Y. Kozuma, T. Matsubara, N. Haratake, T. Akamine, F. Hirai, T. Seto, T. Tagawa, M. Takenoyama, Y. Ichinose, Y. Maehara
• Journal: Annals of Surgical Oncology
• Published: 2018;25(6):1555-1563
• Cited by: 21 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Background: Malignant pleural mesothelioma (MPM), a devastating neoplasm, is traditionally considered to be resistant to antitumor therapy. Identification of clinical prognostic indicators is therefore needed. Although the C-reactive protein/albumin ratio (CAR) has been used to predict the prognosis of many types of malignancy, its utility in patients with MPM is unknown.

Methods: The data of 100 patients diagnosed as having MPM from 1995 to 2015 at the National Kyushu Cancer Center and Kyushu University were analyzed. The CAR was calculated as serum C-reactive protein concentration divided by albumin concentration. A cutoff for CAR was set at 0.58 according to a receiver operating characteristics curve for 1-year survival.

Results: Thirty-five of the 100 (35.0%) patients were classified as having a high CAR. A high CAR was significantly associated with advanced clinical stage (p < 0.001) and chemotherapy alone (p = 0.002). Patients with a high CAR had significantly shorter overall survival (OS) (p < 0.001) and disease- or progression-free survival (DFS/PFS) (p < 0.001). These associations between CAR and prognosis remained significant after propensity score-matching. In multivariate analysis, a high CAR was an independent predictor of shorter OS and DFS/PFS (p = 0.003 and p = 0.008, respectively). Multivariate analyses of the subgroups of patients who had received chemotherapy and of patients who had undergone surgery also showed that a high CAR was an independent predictor of shorter OS and DFS/PFS.

Conclusions: CAR is an independent predictor of prognosis in MPM patients. This prognostic index contributes to clinicians' ability to predict benefit from treatment. Further larger, prospective studies are necessary to validate these findings.

In plain English

This retrospective study looked at the records of 100 patients with malignant pleural mesothelioma treated with chemotherapy, surgery, or both from 1995 to 2015 at two centers in Fukuoka, Japan. It tested whether a routine pretreatment blood index was linked to survival. The index was the C-reactive protein/albumin ratio (CAR), which reflects inflammation and nutrition. Asbestos exposure records existed for 47 patients, and 39 of them had been exposed. With a cutoff of 0.58, 35 of the 100 patients had a high CAR. A high CAR was associated with advanced stage and with receiving chemotherapy alone. Patients with a high CAR had significantly shorter overall survival and shorter disease- or progression-free survival. This held after matching the groups on stage, tumor type, physical condition and treatment. In multivariate analysis, the hazard ratio for a high CAR was 2.14 (95% CI 1.30 to 3.50) for overall survival and 1.92 (1.19 to 3.07) for disease- or progression-free survival. The authors concluded that a high CAR is associated with a poor prognosis. They noted that the patients differed widely, that the cutoff came from their own data, and that larger prospective studies are needed.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Retrospective two-institution study of patient records (prognostic factor analysis), including propensity score matching
• Who was studied: Of 125 patients diagnosed with malignant pleural mesothelioma from 1995 to 2015 at the National Kyushu Cancer Center and Kyushu University (Fukuoka, Japan), 25 who received only best supportive care were excluded. That left 100 patients: 89 from the cancer center and 11 from the university. Median age was 59 (range 31 to 81), and 78 were men.
• Exposure: The factor studied was the pretreatment C-reactive protein/albumin ratio (serum CRP divided by albumin), dichotomized at 0.58. Asbestos exposure was recorded for only 47 patients, of whom 39 had been exposed. No fiber types or doses were reported.
• Main results:
  • Based on a ROC curve for 1-year survival, the authors set the cutoff at 0.58, with 80.0% sensitivity, 67.9% specificity and an area under the curve of 0.782.
  • 35 of the 100 patients (35.0%) had a high CAR.
  • A high CAR was significantly associated with advanced clinical stage (III/IV, p less than 0.001) and with chemotherapy alone (p = 0.002).
  • In all 100 patients, the high CAR group had significantly shorter overall survival (p less than 0.001). This remained after propensity score matching of 30 patients per group (p = 0.008).
  • In multivariate analysis of overall survival, a CAR above 0.58 had a hazard ratio of 2.14 (95% CI 1.30 to 3.50, p = 0.003). Sex, clinical stage and performance status were also independent predictors.
  • In multivariate analysis of disease- or progression-free survival, a CAR above 0.58 had a hazard ratio of 1.92 (95% CI 1.19 to 3.07, p = 0.008). Clinical stage was also an independent predictor.
  • In the chemotherapy subgroup, CAR was an independent predictor of overall survival (p = 0.008) and progression-free survival (p = 0.005).
  • In the surgery subgroup, CAR was an independent predictor of overall survival (p = 0.001) and disease-free survival (p = 0.028).
  • In patients with stage I/II disease, the survival-curve differences between high and low CAR groups were not statistically significant (p = 0.079 and p = 0.062). In multivariate analysis, however, CAR was an independent predictor (p = 0.005 and p = 0.006).
• The authors' conclusion: The authors concluded that a high CAR is significantly associated with a poor prognosis in patients with malignant pleural mesothelioma. They suggested it may help select patients who will benefit from treatment, and said the findings should be evaluated in further large prospective studies.
• Limitations the authors state:
  • The patients and surgical procedures were heterogeneous: both extrapleural pneumonectomy and pleurectomy with decortication were included.
  • 14 of the 65 chemotherapy patients (21.5%) had stage I/II disease but did not have surgery because of severe complications or social reasons.
  • The CAR cutoff was derived from this study's own survival data and was higher than cutoffs used in previous studies.
  • The small sample size precludes definitive conclusions from the subgroup analyses.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Mesothelioma.

Medical terms in this study, explained in our Lexicon: Pleural Mesothelioma, Neoplasm, Prognosis, Chemotherapy, Overall Survival, Progression-Free Survival, Multivariate Analysis.

Related studies

• ASO Author Reflections: C-Reactive Protein/Albumin Ratio as a Prognostic Factor in Patients with Malignant Pleural Mesothelioma: What Does the Novel Index Represent? — S. Takamori, M. Takenoyama (2018)
• Serum albumin as a significant prognostic factor in patients with malignant pleural mesothelioma — Z.H. Yao, G.Y. Tian, et al. (2014)
• The C-Reactive Protein/Albumin Ratio May Predict the Long-Term Outcome in Patients with Malignant Pleural Mesothelioma — N. Yoshida, H. Baba (2018)
• Pretreatment serum C-reactive protein levels predict benefit from multimodality treatment including radical surgery in malignant pleural mesothelioma: a retrospective multicenter analysis — B. Ghanim, M.A. Hoda, et al. (2012)
• Combined grade and nuclear grade are prognosis predictors of epithelioid malignant peritoneal mesothelioma: a multi-institutional retrospective study — N. Benzerdjeb, P. Dartigues, et al. (2021)
• Survival and prognostic factors in malignant pleural mesothelioma: a retrospective study of 314 patients in the west part of Japan — S. Nojiri, K. Gemba, et al. (2011)

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