Cytoreductive surgery with intraperitoneal chemotherapy to treat pseudomyxoma peritonei at nonspecialized hospitals

The Prognostic Impact of Pathology on Patients With Pseudomyxoma Peritonei Undergoing Debulking Surgery: A Systematic Review and Meta-Analysis of Retrospective Studies

Background: Pseudomyxoma peritonei (PMP) is a rare clinical condition with fatal outcomes, which is characterized by the progressive accumulation of mucinous ascites and peritoneal implants. Some studies have reported the effect of PMP biology on patient outcome. The objective of this study was to analyze published articles focusing on the impact of pathology on the prognosis of PMP patients undergoing debulking.

Methods: Data from all studies regarding the prognosis of patients, with different pathologies, who underwent debulking surgery were analyzed. We searched PubMed, the Wiley Online Library, Ovid, and the Cochrane Library (through January 2020). Studies were confined to those articles written in English. Five studies were identified, and the differences in 5-year survival rates were analyzed according to the Kaplan–Meier survival curves. The hazard ratios (HRs) of the 5-year survival rates were calculated.

Results: The mean and median 5-year survival rates of all patients were 39 and 40%, respectively. The median overall survival was 49.3 months. The mean 5-year survival rates of low-grade PMP was 45.2%. The five studies had sufficient data to calculate HRs from the 5-year survival rates data, and three had HRs lower than 1. The total HRs was 0.54, with a 95% CI between 0.33 and 0.89 (P = 0.01).

Conclusions: Among PMP patients receiving debulking surgery who are not able to undergo complete cytoreductive surgery, low-grade biological PMP had a better prognosis than high-grade PMP.

Estimating the Prevalence of Pseudomyxoma Peritonei in Europe Using a Novel Statistical Method

Background

The determination of the incidence and prevalence of rare diseases is important for economists and health-care providers. Pseudomyxoma peritonei (PMP) is a rare, slow-growing abdominal cancer that represents a substantial burden on both patients and health-care systems. The incidence rate was previously approximated at 1–2 people per million per year; this incidence has never been challenged, and the prevalence has not been estimated.

Methods

Epidemiological data from Norway and England were obtained and analysed to calculate a minimum incidence rate based on the number of patients having a first surgical intervention for PMP. A novel method was then used to determine a prevalence rate for PMP, incorporating incidence, death, and cure rates in a multi-year analysis that accounted for the increasing population of Europe over a 10-year period.

Results

An incidence rate of 3.2 people per million per year was calculated, with a corresponding estimated prevalence rate of 22 people per million per year. By this calculation, 11,736 people in Europe were estimated to be living with PMP in 2018.

Conclusion

Incidence and prevalence are essential tools for assessment of the financial and human cost of a disease. For rare diseases, such as PMP, the lack of accurate registries presents a particular challenge in determining such health-related statistical parameters. Based on our calculations, a significant number of people are living with PMP in Europe, underlining the need for appropriate resource allocation to ensure that adequate health-care measures are provided.

Positive peritoneal washing cytology is a potential risk factor for the recurrence of curatively resected colorectal cancer

PURPOSES

Whether free peritoneal cancer cells should be considered peritoneal dissemination in colorectal cancer patients remains controversial. The aim of this study was to investigate the clinical significance of positive peritoneal washing cytology (PWC) in patients with colorectal cancer.

METHODS

We retrospectively analyzed the records of 771 sequential patients diagnosed with stage 0-III colorectal cancer who underwent R0 resection and had no distant metastases or peritoneal dissemination.

RESULTS

PWC was performed on all 771 patients. Sixty-eight patients experienced metastasis recurrence, 10 of whom experienced peritoneal recurrence. Of the 10 patients with peritoneal recurrence, 6 had positive PWC. Out of the 771 patients, 21 had positive PWC. Of these 21 patients, 6 had peritoneal recurrence, while 4 had distant metastasis and no peritoneal recurrence during the observation period. The 5-year disease-free survival was 89.0 % in the patients with negative PWC vs. 46.8 % in the patients with positive PWC (p < 0.0001, log-rank test). A Cox proportional hazards model revealed that positive PWC was the strongest independent risk factor for cancer-specific recurrence.

CONCLUSIONS

Our study highlights PWC as a useful prognostic tool in patients undergoing curative surgery for colorectal cancer, since positive PWC was shown to be a potential risk factor for recurrence.

Pseudomyxoma peritonei as an intractable disease and its preoperative assessment to help improve prognosis after surgery: A review of the literature

Pseudomyxoma peritonei (PMP) is a rare and intractable disease with an estimated incidence of one per million population per year. Many aspects of PMP need to be fully and precisely understood; these include its preoperative assessment, i.e. diagnosis, early diagnosis, pathologic classification, and staging according to the peritoneal cancer index, and its surgical treatment. This review focuses on elements of preoperative assessment and surgery using the Sugarbaker procedure to help improve the prognosis for patients with PMP. Accurate data on the incidence of PMP must be based on large populations rather than estimates, and much work needs to be done especially in China. Special attention should be paid to its preoperative assessment. Also proposed here are steps to manage PMP with an emphasis on preoperative assessment.