Long-term Survival and Propensity Score Matched Outcomes of Bilateral vs. Unilateral Diaphragm Interventions in Cytoreductive Surgery plus Intra-peritoneal Chemotherapy

Our plain-English summary of Long-term Survival and Propensity Score Matched Outcomes of Bilateral vs. Unilateral Diaphragm Interventions in Cytoreductive Surgery plus Intra-peritoneal Chemotherapy, by B. Singh, G. Singh, M. Pourgholami, et al (Anticancer Research, 2018).

The study

• Authors: B. Singh, G. Singh, M. Pourgholami, N. Alzahrani, D.L. Morris
• Journal: Anticancer Research
• Published: 2018;38(10):5917-5921
• Cited by: 3 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Background/aim: To assess the impact of short- and long-term outcomes of bilateral vs. unilateral diaphragm interventions in cyto-reductive surgery (CRS) and intra-peritoneal chemotherapy (IPC).

Patients And Methods: A total of 652 CRS/IPC procedures, between 1996 and 2018, required diaphragm interventions. Among these, 388 underwent bilateral intervention. Preoperative heterogeneity was assessed in 6 parameters and addressed with propensity score matching. The association of each respective analysis was assessed with 11 outcomes. Overall survival was assessed based on histology.

Results: CRS/IPC requiring bilateral diaphragmatic interventions illustrated significantly increased operative hours (9.6 vs. 8.6 hours, p<0.001). Postoperatively, there was significantly increased red blood cell (RBC) transfusion (6.37 units vs. 4.47 units, p=0.007) and grade III and IV complications (57.3% vs. 40.6%, p=0.004). No difference was noted in ICU stay, total length of stay, hospital death and return to OT. In terms of respiratory complications, an increased incidence of pneumothorax (16.5% vs. 6.2%, p<0.001) was noted whilst pleural effusions and pneumonia occurrences were non-significant. Overall survival, revealed bilateral interventions in low-grade appendiceal mucinous neoplasm conferred an increased relative risk (p=0.037, RR=2.230, 95%CI=1.052-4.730). They did not have an effect on OS in colorectal cancer and mesothelioma.

Conclusion: Despite the increase in short-term morbidity, bilateral diaphragm interventions resulted in similar long-term survival to unilateral interventions.

Copyright© 2018, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

In plain English

This retrospective cohort study came from one hospital in Sydney, Australia. It does not study asbestos exposure. It compared bilateral (both sides) with unilateral (one side) diaphragm surgery in patients having cytoreductive surgery plus intra-peritoneal chemotherapy for peritoneal-based cancers, including mesothelioma, between 1996 and 2018. Of 1,230 patients, 652 had diaphragm procedures. After matching for diagnosis, prior surgery score and disease extent (165 pairs), the bilateral group had longer operations (9.6 vs. 8.6 hours), more red blood cell transfusion (6.37 vs. 4.47 units), more grade III and IV complications (57.3% vs. 40.6%) and more pneumothorax (16.5% vs. 6.2%). Survival was analyzed on unmatched data. In the authors' regression analysis, bilateral surgery did not significantly affect survival in colorectal cancer or mesothelioma. It was linked to higher risk in low-grade appendiceal mucinous neoplasms (RR=2.230, 95%CI=1.052-4.730). The authors concluded that bilateral interventions resulted in similar long-term survival to unilateral ones despite more short-term complications. They noted limitations including a retrospective design and possible unidentified confounding. The article also contains several inconsistent figures.

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 cohort study at a single center using a prospectively maintained database, with propensity score matching for short-term outcomes and Kaplan-Meier and Cox regression for overall survival
• Who was studied: Patients in the cytoreductive surgery plus intra-peritoneal chemotherapy database at St. George Hospital, Sydney, from September 1996 to March 2018. There were 1,230 patients in total. Of these, 652 had diaphragm procedures (388 bilateral, 262 unilateral), and propensity matching produced 165 matched pairs. Cancer types included colorectal, high- and low-grade appendiceal mucinous neoplasms, mesothelioma, ovarian and other.
• Exposure: Not asbestos. The comparison was bilateral versus unilateral diaphragm intervention during cytoreductive surgery plus intra-peritoneal chemotherapy.
• Main results:
  • In the matched comparison, operative hours were 9.6 (bilateral) vs. 8.6 (unilateral), p less than 0.001, with no difference in completeness of cytoreduction score
  • In the matched comparison, red blood cell transfusion was 6.37 units (bilateral) vs. 4.47 units (unilateral), p=0.007, and grade III and IV complications were 57.3% vs. 40.6%, p=0.004
  • No difference was found between the matched groups in ICU stay, total length of stay, hospital death or return to the operating theatre
  • Pneumothorax occurred in 16.5% (bilateral) vs. 6.2% (unilateral), p less than 0.001. Pleural effusions and pneumonia did not differ significantly.
  • Colorectal cancer (36 bilateral, 87 unilateral; 67 deaths): median survival was 24 vs. 30 months, p=0.467. In Cox regression, the effect was not significant (p=0.945, RR=1.022, 95%CI=0.554-1.884).
  • Mesothelioma (45 bilateral, 19 unilateral; 42 deaths): median survival was 32 vs. 68 months, p=0.685. In Cox regression, the effect was not significant (p=0.926, RR=1.046, 95%CI=0.403-2.713).
  • Low-grade appendiceal mucinous neoplasms (146 bilateral, 46 unilateral; 79 deaths): Kaplan-Meier mean survival was 57 vs. 81 months, which was not significant (p=0.135). In Cox regression, bilateral resection significantly affected survival (p=0.037, RR=2.230, 95%CI=1.052-4.730).
• The authors' conclusion: The authors concluded that, despite more short-term complications, bilateral diaphragm interventions allow complete cytoreduction and result in similar long-term survival to unilateral interventions. They attributed the lower survival in low-grade appendiceal mucinous neoplasms to more advanced infiltrative disease.
• Limitations the authors state:
  • Retrospective, observational design; unidentified confounding factors could influence results
  • Extubation times were not available to assess respiratory failure
  • The sample size may be too small to detect complications with low event rates
  • Single institution; results may not apply to other institutions

Topics

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

Medical terms in this study, explained in our Lexicon: Bilateral, Diaphragm, Cytoreductive Surgery, Chemotherapy, Overall Survival, Histology, Pneumothorax, Pleural Effusion.

Related studies

• Long term survival and perioperative propensity score matched outcomes of diaphragmatic resections compared to stripping in cytoreductive surgery + intra-peritoneal chemotherapy — B. Singh, G. Singh, et al. (2020)
• Long-term survival outcomes of cytoreductive surgery and perioperative intraperitoneal chemotherapy: Single-institutional experience with 1225 cases — L.S. Kyang, N.A. Alzahrani, et al. (2019)
• 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)
• Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy in Asian patients: 100 consecutive patients in a single institution — M.C. Teo, G.H. Tan, et al. (2013)
• Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy: long-term results at St George Hospital, Australia — N. Alzahrani, J.S. Ferguson, et al. (2016)
• Is Cytoreductive Surgery with Hyperthermic Intraperitoneal Chemotherapy Justified for Biphasic Variants of Peritoneal Mesothelioma? Outcomes from the Peritoneal Surface Oncology Group International Registry — K.I. Votanopoulos, P. Sugarbaker, et al. (2018)

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