Ki67 (MIB-1) as a Prognostic Marker for Clinical Decision Making Before Extended Pleurectomy Decortication in Malignant Pleural Mesothelioma

INTRODUCTION: The role of surgery for early stage malignant pleural mesothelioma (MPM) remains controversial. Current expert opinion is only to treat patients surgically as part of multimodality therapy. It is still challenging to identify patients who will not benefit from surgery. We specifically evaluated tumor-related parameters in combination with clinical parameters to identify prognostic markers for survival. METHODS: Clinical data of 27 consecutive patients with MPM treated with extended pleurectomy and decortication within a multimodality approach were collected and analyzed. Several tumor (immuno-)histopathologic characteristics were determined on resected tumor material, among which MTAP and Ki67 (MIB-1). Univariable and multivariable analyses served to correlate clinical and tumor-related parameters to overall survival (OS) and progression-free survival (PFS). RESULTS: The median PFS (mPFS) was 15.3, and the median OS (mOS) was 26.5 months. Patients with a Ki67 score greater than 10% had a significantly shorter PFS (mPFS = 8.81 versus 25.35 mo, p = 0.001) and OS (mOS 19.7 versus 44.5 mo, p = 0.002) than those with a Ki67 score less than or equal to 10. Receiver operating characteristic curve analysis for Ki67 revealed an area under the curve of 0.756 with a sensitivity of 90% and specificity of 71% for a cutoff of 10% for Ki67. Patients with loss of MTAP had a significantly shorter mPFS (9 versus 21.1 mo, p = 0.014) and mOS (19.7 versus 42.6 mo, p = 0.047) than those without MTAP loss. CONCLUSIONS: In our study, Ki67 was prognostic for OS and PFS in patients with MPM treated with extended pleurectomy/decortication in a multimodality approach. Determination of Ki67 before surgery combined with specific clinical parameters could assist in clinical decision making by identifying patients, with high Ki67, who are unlikely to benefit from surgery

Intraperitoneal pharmacokinetics of systemic oxaliplatin, 5-fluorouracil and bevacizumab in patients with colorectal peritoneal metastases

Background: Peritoneal metastases (PM) commonly occur in colorectal cancer patients. Systemic chemotherapy yields poor outcomes for these patients. It is hypothesised that traditional systemic chemotherapy is not very effective for this patient population. This study investigates to what extent systemic anti-cancer therapy crosses the peritoneal barrier. Methods: In a Phase I study, eighteen patients received systemic oxaliplatin, 5-FU, and bevacizumab. Plasma and peritoneal fluid samples were collected to measure drug concentrations. A non-compartmental analysis determined the Area Under the Curve (AUC) for oxaliplatin and 5-FU in both matrices. Intraperitoneal (IP) and intravenous (IV) exposure ratios were calculated, along with the bevacizumab concentration IP/IV ratio. The relationship between tumour load and IP/IV ratios and the correlation between the IP/IV ratios of different treatments were assessed statistically. Results: A total of 438 5-FU samples and 578 oxaliplatin samples were analysed in plasma and peritoneal fluid. Bevacizumab was quantified with 17 measurements in plasma and 15 measurements IP. Median IP/IV ratios were 0.143, 0.352 and 0.085 for 5-FU, oxaliplatin and bevacizumab, respectively. Oxaliplatin exhibited a longer IP half-life than 5-FU. A correlation was found between oxaliplatin and bevacizumab IP/IV ratios (R=0.69, p=0.01). No statistical correlations were found between the other investigated drugs. Conclusions: Our findings indicate that only a small percentage of systemically administered anti-cancer treatment reaches the IP cavity, questioning their efficacy against PM. This strengthens the hypothesis for repeated intraperitoneal chemotherapy to reach adequate anti-cancer drug levels.</p

Intraperitoneal pharmacokinetics of systemic oxaliplatin, 5-fluorouracil and bevacizumab in patients with colorectal peritoneal metastases

Background: Peritoneal metastases (PM) commonly occur in colorectal cancer patients. Systemic chemotherapy yields poor outcomes for these patients. It is hypothesised that traditional systemic chemotherapy is not very effective for this patient population. This study investigates to what extent systemic anti-cancer therapy crosses the peritoneal barrier. Methods: In a Phase I study, eighteen patients received systemic oxaliplatin, 5-FU, and bevacizumab. Plasma and peritoneal fluid samples were collected to measure drug concentrations. A non-compartmental analysis determined the Area Under the Curve (AUC) for oxaliplatin and 5-FU in both matrices. Intraperitoneal (IP) and intravenous (IV) exposure ratios were calculated, along with the bevacizumab concentration IP/IV ratio. The relationship between tumour load and IP/IV ratios and the correlation between the IP/IV ratios of different treatments were assessed statistically. Results: A total of 438 5-FU samples and 578 oxaliplatin samples were analysed in plasma and peritoneal fluid. Bevacizumab was quantified with 17 measurements in plasma and 15 measurements IP. Median IP/IV ratios were 0.143, 0.352 and 0.085 for 5-FU, oxaliplatin and bevacizumab, respectively. Oxaliplatin exhibited a longer IP half-life than 5-FU. A correlation was found between oxaliplatin and bevacizumab IP/IV ratios (R=0.69, p=0.01). No statistical correlations were found between the other investigated drugs. Conclusions: Our findings indicate that only a small percentage of systemically administered anti-cancer treatment reaches the IP cavity, questioning their efficacy against PM. This strengthens the hypothesis for repeated intraperitoneal chemotherapy to reach adequate anti-cancer drug levels.</p

Towards Equal Access to Cytoreductive Surgery with Hyperthermic Intraperitoneal Chemotherapy and Survival in Patients with Isolated Colorectal Peritoneal Metastases:A Nationwide Population-Based Study

Background: Before 2016, patients with isolated synchronous colorectal peritoneal metastases (PMCRC) diagnosed in expert centers had a higher odds of undergoing cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) and better overall survival (OS) than those diagnosed in referring centers. Nationwide efforts were initiated to increase awareness and improve referral networks. Methods: This nationwide study aimed to evaluate whether the between-center differences in odds of undergoing CRS-HIPEC and OS have reduced since these national efforts were initiated. All patients with isolated synchronous PMCRC diagnosed between 2009 and 2021 were identified from the Netherlands Cancer Registry. Associations between hospital of diagnosis and the odds of undergoing CRS-HIPEC, as well as OS, were assessed using multilevel multivariable regression analyses for two periods (2009–2015 and 2016–2021). Results: In total, 3948 patients were included. The percentage of patients undergoing CRS-HIPEC increased from 17.2% in 2009–2015 (25.4% in expert centers, 16.5% in referring centers), to 23.4% in 2016–2021 (30.2% in expert centers, 22.6% in referring centers). In 2009–2015, compared with diagnosis in a referring center, diagnosis in a HIPEC center showed a higher odds of undergoing CRS-HIPEC (odds ratio [OR] 1.64, 95% confidence interval [CI] 1.02–2.67) and better survival (hazard ratio [HR] 0.80, 95% CI 0.66–0.96). In 2016–2021, there were no differences in the odds of undergoing CRS-HIPEC between patients diagnosed in HIPEC centers versus referring centers (OR 1.27, 95% CI 0.76–2.13) and survival (HR 1.00, 95% CI 0.76–1.32). Conclusion: Previously observed differences in odds of undergoing CRS-HIPEC were no longer present. Increased awareness and the harmonization of treatment for PMCRC may have contributed to equal access to care and a similar chance of survival at a national level.</p

Towards Equal Access to Cytoreductive Surgery with Hyperthermic Intraperitoneal Chemotherapy and Survival in Patients with Isolated Colorectal Peritoneal Metastases:A Nationwide Population-Based Study

Background: Before 2016, patients with isolated synchronous colorectal peritoneal metastases (PMCRC) diagnosed in expert centers had a higher odds of undergoing cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) and better overall survival (OS) than those diagnosed in referring centers. Nationwide efforts were initiated to increase awareness and improve referral networks. Methods: This nationwide study aimed to evaluate whether the between-center differences in odds of undergoing CRS-HIPEC and OS have reduced since these national efforts were initiated. All patients with isolated synchronous PMCRC diagnosed between 2009 and 2021 were identified from the Netherlands Cancer Registry. Associations between hospital of diagnosis and the odds of undergoing CRS-HIPEC, as well as OS, were assessed using multilevel multivariable regression analyses for two periods (2009–2015 and 2016–2021). Results: In total, 3948 patients were included. The percentage of patients undergoing CRS-HIPEC increased from 17.2% in 2009–2015 (25.4% in expert centers, 16.5% in referring centers), to 23.4% in 2016–2021 (30.2% in expert centers, 22.6% in referring centers). In 2009–2015, compared with diagnosis in a referring center, diagnosis in a HIPEC center showed a higher odds of undergoing CRS-HIPEC (odds ratio [OR] 1.64, 95% confidence interval [CI] 1.02–2.67) and better survival (hazard ratio [HR] 0.80, 95% CI 0.66–0.96). In 2016–2021, there were no differences in the odds of undergoing CRS-HIPEC between patients diagnosed in HIPEC centers versus referring centers (OR 1.27, 95% CI 0.76–2.13) and survival (HR 1.00, 95% CI 0.76–1.32). Conclusion: Previously observed differences in odds of undergoing CRS-HIPEC were no longer present. Increased awareness and the harmonization of treatment for PMCRC may have contributed to equal access to care and a similar chance of survival at a national level.</p

Towards Equal Access to Cytoreductive Surgery with Hyperthermic Intraperitoneal Chemotherapy and Survival in Patients with Isolated Colorectal Peritoneal Metastases: A Nationwide Population-Based Study

Background: Before 2016, patients with isolated synchronous colorectal peritoneal metastases (PMCRC) diagnosed in expert centers had a higher odds of undergoing cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) and better overall survival (OS) than those diagnosed in referring centers. Nationwide efforts were initiated to increase awareness and improve referral networks. Methods: This nationwide study aimed to evaluate whether the between-center differences in odds of undergoing CRS-HIPEC and OS have reduced since these national efforts were initiated. All patients with isolated synchronous PMCRC diagnosed between 2009 and 2021 were identified from the Netherlands Cancer Registry. Associations between hospital of diagnosis and the odds of undergoing CRS-HIPEC, as well as OS, were assessed using multilevel multivariable regression analyses for two periods (2009–2015 and 2016–2021). Results: In total, 3948 patients were included. The percentage of patients undergoing CRS-HIPEC increased from 17.2% in 2009–2015 (25.4% in expert centers, 16.5% in referring centers), to 23.4% in 2016–2021 (30.2% in expert centers, 22.6% in referring centers). In 2009–2015, compared with diagnosis in a referring center, diagnosis in a HIPEC center showed a higher odds of undergoing CRS-HIPEC (odds ratio [OR] 1.64, 95% confidence interval [CI] 1.02–2.67) and better survival (hazard ratio [HR] 0.80, 95% CI 0.66–0.96). In 2016–2021, there were no differences in the odds of undergoing CRS-HIPEC between patients diagnosed in HIPEC centers versus referring centers (OR 1.27, 95% CI 0.76–2.13) and survival (HR 1.00, 95% CI 0.76–1.32). Conclusion: Previously observed differences in odds of undergoing CRS-HIPEC were no longer present. Increased awareness and the harmonization of treatment for PMCRC may have contributed to equal access to care and a similar chance of survival at a national level

Intraperitoneal irinotecan with concomitant FOLFOX and bevacizumab for patients with unresectable colorectal peritoneal metastases: Protocol of the multicentre, open-label, phase II, INTERACT-II trial

Introduction The peritoneum is the second most affected organ for the dissemination of colorectal cancer (CRC). Patients with colorectal peritoneal metastases (CPM) face a poor prognosis, despite the majority of patients being treated with palliative systemic therapy. The efficacy of palliative systemic therapy is limited due to the plasma-peritoneum barrier. The poor prognosis of unresectable CPM patients has resulted in the development of new treatment strategies where systemic therapy is combined with local, intraperitoneal chemotherapy. In the recently published phase I study, the maximum tolerated dose and thus the recommended phase II dose of intraperitoneal irinotecan was investigated and determined to be 75 mg. In the present study, the overall survival after treatment with 75 mg irinotecan with concomitant mFOLFOX4 and bevacizumab will be investigated. Materials and methods In this single-arm phase II study in two Dutch tertiary referral centres, 85 patients are enrolled. Eligibility criteria are an adequate performance status and organ function, histologically confirmed microsatellite stable and unresectable CPM, no previous palliative therapy for CRC, no systemic therapy20, too extensive small bowel involvement), a peritoneal access port and a port-a-cath are placed for administration of intraperitoneal and intravenous chemotherapy, respectively. Patients may undergo up to 12 cycles of study treatment. Each cycle consists of intravenous mFOLFOX4 with bevacizumab and concomitant intraperitoneal irinotecan (75 mg), which is repeated every 2 weeks, with a maximum of 12 cycles. Modified FOLFOX-4 regimen consists of 85 mg/m 2 oxaliplatin plus 200 mg/m 2 LV and 5-FU 400 mg/m 2 bolus on day 1 followed by 1600 mg/m 2 5-FU as a 46 hours infusion. Study treatment ends after the 12th cycle, or earlier in case of disease progression or unacceptable toxicity. The primary outcome is overall survival and key secondary outcomes are progression-free survival, safety (measured by the amount of grade ≥3 adverse events (Common Terminology Criteria for Adverse Events V.5.0)), patient-reported outcomes and pharmacokinetics of irinotecan. It is hypothesised that the trial treatment will lead to a 4 month increase in overall survival; from a median of 12.2 to 16.2 months. Ethics and dissemination This study is approved by the Dutch Authority (CCMO, the Hague, the Netherlands), by a central medical ethics committee (MEC-U, Nieuwegein, the Netherlands) and by the institutional research boards of both research centres. Results will be submitted for publication in peer-reviewed medical journals and presented to patients and healthcare professionals. Trial registration number NCT06003998