Preoperative Thrombocytosis Predicts Shortened Survival in Patients with Malignant Peritoneal Mesothelioma Undergoing Operative Cytoreduction and Hyperthermic Intraperitoneal Chemotherapy

Our plain-English summary of Preoperative Thrombocytosis Predicts Shortened Survival in Patients with Malignant Peritoneal Mesothelioma Undergoing Operative Cytoreduction and Hyperthermic Intraperitoneal Chemotherapy, by Y.C. Li, T. Khashab, J. Terhune, et al (Annals of Surgical Oncology, 2017).

The study

• Authors: Y.C. Li, T. Khashab, J. Terhune, R.L. Eckert, N. Hanna, A. Burke, H. Richard Alexander
• Journal: Annals of Surgical Oncology
• Published: 2017;24(8):2259-2265
• Cited by: 24 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Background: This study was designed to determine the clinical significance of preoperative thrombocytosis in patients with malignant peritoneal mesothelioma (MPM) undergoing operative cytoreduction (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). CRS and HIPEC have been associated with prolonged survival in patients with MPM and is the preferred treatment in select patients. However, patient selection criteria remain ill-defined for this operation that is also associated with significant morbidity and mortality. Preoperative thrombocytosis has been associated with poor outcomes in various malignancies but never studied in MPM.

Methods: Between January 2006 and December 2015, 100 patients with high-grade epithelioid MPM were evaluated and selected for CRS and HIPEC at our center (M: 53, F: 47; mean age: 54 years [range 17-81 years]). We analyzed various patient and treatment related factors potentially associated with overall survival (OS).

Results: The median actuarial overall survival was 32.8 months; the actuarial 1-, 3-, 5-year survivals were 70, 49, and 36%, respectively. On multivariate analysis, suboptimal resection (CCR > 1), high tumor burden (PCI > 20), and elevated preoperative platelet count (>367,000/mm3) were independently associated with shortened OS (P < 0.05). Median OS in patients with elevated versus normal platelet counts were 13 and 58 months, respectively (P < 0.001). Compared with patients with normal platelet counts, patients with elevated counts had significantly greater residual disease after operation (P = 0.008).

Conclusions: Elevated preoperative platelet count is independently associated with poor outcome. Notably, thrombocytosis reflects aggressive tumor biology and should be considered a factor in patient selection for CRS and HIPEC.

In plain English

This study reviewed records of 100 University of Maryland patients with high-grade epithelioid malignant peritoneal mesothelioma (cancer of the abdominal lining) treated in 2006 to 2015 with tumor-removal surgery plus heated chemotherapy inside the abdomen (CRS and HIPEC). The authors asked whether a high platelet count before surgery (thrombocytosis, above 367,000 per cubic millimeter) was linked to survival. Asbestos exposure was not reported. Overall median survival was 32.8 months. Of 97 patients with a preoperative count, 29 had a high count. Weighing several factors together, a high count, suboptimal tumor removal (more than 100 small deposits, or any over 5 millimeters, left) and a large tumor burden were each independently associated with shorter survival. Median survival was 13 months with a high count and 58 with a normal count. High-count patients more often had suboptimal removal. Even among patients with complete or near-complete removal, median survival was 27 months with a high count versus 77 with a normal count. The authors concluded that patients with thrombocytosis are not good candidates for immediate CRS and HIPEC, noting that this group was small.

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 single-institution review of patients treated with surgery (cytoreduction) and heated intraperitoneal chemotherapy, analysing factors associated with overall survival
• Who was studied: 100 patients with histologically proven high-grade epithelioid malignant peritoneal mesothelioma treated with CRS and HIPEC at the University of Maryland School of Medicine, Baltimore, January 2006 to December 2015; 53 men and 47 women, mean age 54 years (range 17 to 81)
• Exposure: Not an asbestos exposure study. The factor studied was preoperative platelet count, with thrombocytosis defined as more than 367,000/mm3 based on the institution's normal range of 153,000 to 367,000/mm3. Other factors examined were sex, age, race, previous chemotherapy, completeness of cytoreduction (CCR) and peritoneal cancer index (PCI).
• Main results:
  • For all 100 patients, median actuarial overall survival was 32.8 months (range 0 to 103). Actuarial 1-, 3- and 5-year survival was 70, 49 and 36%.
  • Of 97 patients with available preoperative counts, 68 had normal platelet counts and 29 had elevated counts.
  • In multivariate analysis, three factors were independently associated with shorter overall survival. Elevated platelet count had a hazard ratio of 2.42 (95% CI 1.30 to 4.49). Suboptimal resection (CCR greater than 1, meaning more than 100 lesions under 5 mm, any lesion over 5 mm, or residual tumor over 1 cm) had a hazard ratio of 2.70 (1.32 to 5.51). PCI greater than 20 had a hazard ratio of 2.81 (1.10 to 7.22).
  • Median overall survival was 13 months in patients with elevated pretreatment platelet counts and 58 months in those with normal counts (P less than 0.001).
  • Patients with elevated platelet counts had significantly more suboptimal resection (CCR greater than 1) than patients with normal counts (P = 0.008). Optimal resection (CCR 1 or less) was achieved in 59 of 66 patients with normal platelets and 18 of 27 with thrombocytosis.
  • Among patients with optimal cytoreduction (CCR 1 or less, that is, complete or near-complete), median overall survival was 27 months with preoperative thrombocytosis and 77 months with normal platelet counts (P = 0.02).
  • Apart from completeness of cytoreduction, no other factor examined (including PCI and previous chemotherapy) was significantly associated with baseline platelet count.
  • Across all 100 patients, 39 had at least one perioperative complication and 10 were returned to the operating room. Perioperative mortality was 2%.
• The authors' conclusion: The authors concluded that elevated preoperative platelet count is independently associated with poor outcome. They wrote that it appears to reflect aggressive tumor biology and that patients with baseline thrombocytosis are not good candidates for immediate CRS and HIPEC.
• Limitations the authors state:
  • The small number of patients with thrombocytosis (29) limits in-depth analysis of that group.
  • The relationship between thrombocytosis and histologic features had not yet been assessed.
  • The prognostic significance of CA 125 was not evaluated.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Lung cancer, Mesothelioma, Peritoneal mesothelioma.

Medical terms in this study, explained in our Lexicon: Peritoneal Mesothelioma, Cytoreductive Surgery, HIPEC, Epithelioid, Overall Survival, Multivariate Analysis, Tumor Burden.

Related studies

• The Role of Ki-67 and Pre-cytoreduction Parameters in Selecting Diffuse Malignant Peritoneal Mesothelioma (DMPM) Patients for Cytoreductive Surgery (CRS) and Hyperthermic Intraperitoneal Chemotherapy (HIPEC) — S. Kusamura, P.A. Torres Mesa, et al. (2016)
• Iterative cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for recurrent or progressive diffuse malignant peritoneal mesothelioma: clinicopathologic characteristics and survival outcome — C. Ihemelandu, L. Bijelic, et al. (2015)
• Recurrence of Optimally Treated Malignant Peritoneal Mesothelioma with Cytoreduction and Heated Intraperitoneal Chemotherapy — D.R. Heller, C. Chiuzan, et al. (2017)
• A Novel Tool for Predicting Major Complications After Cytoreductive Surgery with Hyperthermic Intraperitoneal Chemotherapy — J.M. Baumgartner, T.G. Kwong, et al. (2016)
• What made hyperthermic intraperitoneal chemotherapy an effective curative treatment for peritoneal surface malignancy: A 25-year experience with 1,125 procedures — G. Passot, D. Vaudoyer, et al. (2016)
• Peritoneal carcinomatosis from unusual cancer origins: Is there a role for hyperthermic intraperitoneal chemotherapy? — C. Honoré, D. Goéré, et al. (2016)

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