Variation in the peritoneal cancer index scores between surgeons and according to when they are determined (before or after cytoreductive surgery)

Our plain-English summary of Variation in the peritoneal cancer index scores between surgeons and according to when they are determined (before or after cytoreductive surgery), by D. Elias, A. Souadka, F. Fayard, et al (European Journal of Surgical Oncology, 2012).

The study

• Authors: D. Elias, A. Souadka, F. Fayard, A. Mauguen, F. Dumont, C. Honore, D. Goere
• Journal: European Journal of Surgical Oncology
• Published: 2012;38(6):503-8
• Cited by: 35 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Introduction: The prognosis of peritoneal carcinomatosis (PC) is highly dependent on the extent of the PC. This extent is calculated by the peritoneal cancer index (PCI). In the future, the indications for complete cytoreductive surgery (CRS) + hyperthermic intraperitoneal chemotherapy (HIPEC) should be partially based on the PCI. This raises the question of the concordance between the PCI scores calculated by different surgeons, and a possible variation before and after CRS.

Objective: To analyze variations in the PCI score between surgeons and according to when it is determined (before and after surgery).

Patients And Methods: Prospective recording of the PCI score independently calculated by senior and junior surgeons, before CRS (when the surgeon decided to perform this procedure), and after CRS, in 75 consecutive patients. A concordance analysis was conducted.

Results: The origins of the PC were colorectal (n = 38), pseudomyxoma (n = 22), mesothelioma (n = 8) and miscellaneous lesions (n = 7). Concordance between the PCI score was very high (close to 90%) among the senior surgeons and junior surgeons before and after CRS. After CRS, the mean PCI score increased by 1.75 (IC-95%: 2.09-1.41). This high concordance was similar whatever the level of the PCI score and whatever the origin of the tumor.

Conclusion: The PCI is a reliable tool for measuring the extent of PC. It is easy to use and inter-surgeon concordance is high. It increases by approximately 2 before and after CRS.

Copyright © 2012 Elsevier Ltd. All rights reserved.

In plain English

This prospective French study examined how consistently surgeons scored the peritoneal cancer index (PCI). The PCI, scored 0 to 39, measures how widely cancer has spread over the abdominal lining. It included 75 consecutive patients treated with cytoreductive surgery plus heated intraperitoneal chemotherapy from June 2009 to September 2010. The disease came from colorectal cancer in 38, pseudomyxoma in 22, mesothelioma in 8 and other lesions in 7. During each operation, a senior and a junior surgeon independently scored each patient twice: after the initial exploration, when tumor removal was judged feasible, and after tumor removal. The study did not examine asbestos and gave no separate mesothelioma results. Agreement between surgeons was high: Kendall scores were 0.89 for the first score and 0.91 for the second (1 means perfect agreement). The second score was never lower than the first. For the senior surgeon the mean increase was 1.75 points (95% confidence interval 1.41 to 2.09). The authors concluded that the PCI is a reliable, easy-to-use tool. They noted that scoring was not fully blind, as surgeons might remember their first score.

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: Prospective study of agreement (concordance) between surgeons' scores, and between scores given at two points during the operation (before and after cytoreductive surgery)
• Who was studied: 75 consecutive patients undergoing complete cytoreductive surgery plus hyperthermic intraperitoneal chemotherapy for peritoneal carcinomatosis, June 2009 to September 2010, at the Institut Gustave Roussy, Villejuif, France. Origins: colorectal in 38, pseudomyxomas in 22, mesotheliomas in 8 and other lesions in 7. Two senior surgeons and six junior surgeons took part.
• Exposure: Not applicable: the study did not examine asbestos or any other exposure. It compared peritoneal cancer index scores given by senior and junior surgeons during the operation. The first score was given after the initial exploration phase, when cytoreductive surgery was judged feasible. The second was given after the end of cytoreductive surgery.
• Main results:
  • Agreement between the senior and junior surgeon on the PCI score was high. Kendall scores were 0.89 before cytoreductive surgery (after the initial exploration) and 0.91 after cytoreductive surgery.
  • Agreement between the two surgeons on the number of invaded areas gave Kendall scores of 0.88 before cytoreductive surgery and 0.94 after it.
  • Median PCI was 12 before cytoreductive surgery and 14 after it, for both the senior and the junior surgeons.
  • When scores were grouped into three categories (under 10, 10 to 20, over 20), the two surgeons placed patients in the same category in 59 of 75 (79%) before cytoreductive surgery (kappa 0.84). After it, they did so in 65 (87%) (kappa 0.80).
  • The PCI score before cytoreductive surgery was always lower than or equal to the score after it.
  • For the senior surgeon, the mean increase in PCI from before to after cytoreductive surgery was 1.75 points (95% confidence interval printed as 2.09 to 1.41). The authors reported that the junior surgeon's results were similar.
  • For 95% of patients the before-to-after difference was 4 points or less. Only 3 patients (4%) had a really different PCI score.
  • Among 10 patients scored 16 to 20 by the senior surgeon before cytoreductive surgery, 4 (40%) were finally classified with a PCI score greater than 20. A pre-cytoreduction score of 20 resulted in a post-cytoreduction score of at least 22.
  • In the 38 patients with peritoneal carcinomatosis from colorectal cancer, 37 (97%) were classified the same way by both surgeons after cytoreductive surgery (kappa 0.96). Only 7 (18%) were upgraded after cytoreductive surgery.
• The authors' conclusion: The authors concluded that the PCI is a reliable tool for measuring the extent of peritoneal carcinomatosis. They found it easy to use, with high agreement between surgeons, and reported a mean increase of 1.75 points from before to after cytoreductive surgery. They also proposed that future treatment decisions be based on the score determined before cytoreductive surgery, with 18 as the limit.
• Limitations the authors state:
  • The before-and-after scoring was not completely blind. After many hours of surgery, a surgeon might remember the initial score and be influenced by it.

Topics

Medical terms in this study, explained in our Lexicon: Peritoneal Cancer Index (PCI), Cytoreductive Surgery, Prognosis, HIPEC, Mesothelioma.

Related studies

• Evolution of locoregional treatment for peritoneal carcinomatosis: single-center experience of 308 procedures of cytoreductive surgery and perioperative intraperitoneal chemotherapy — T.C. Chua, W. Liauw, et al. (2011)
• Institutional learning curve of cytoreductive surgery and hyperthermic intraperitoneal chemoperfusion for peritoneal malignancies — P.M. Polanco, Y. Ding, et al. (2015)
• 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)
• A Novel Tool for Predicting Major Complications After Cytoreductive Surgery with Hyperthermic Intraperitoneal Chemotherapy — J.M. Baumgartner, T.G. Kwong, et al. (2016)
• Conversion to Complete Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy for Malignant Peritoneal Mesothelioma After Bidirectional Chemotherapy — F. Le Roy, M. Gelli, et al. (2017)
• Long-term Survival and Propensity Score Matched Outcomes of Bilateral vs. Unilateral Diaphragm Interventions in Cytoreductive Surgery plus Intra-peritoneal Chemotherapy — B. Singh, G. Singh, et al. (2018)

Browse more research in European Journal of Surgical Oncology, or return to medical research.