Increased Survival of Patients with Synchronous Colorectal Peritoneal Metastases Receiving Preoperative Chemotherapy Before Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy

Is cytoreductive surgery and hyperthermic intraperitoneal chemotherapy still beneficial in patients diagnosed with colorectal peritoneal metastasis who underwent palliative chemotherapy?

BACKGROUND

With a 5-year overall survival of less than 5%, colorectal peritoneal metastasis (CPM) patients are often managed with palliative chemotherapy (CTx). In the past few decades, cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) has been introduced as a possible curative treatment for highly selective CPM patients. We share our experience of CRS and HIPEC given the unique characteristics of the medical system and the benefit of CRS and HIPEC in palliative setting.

METHODS

From April 2017 to October 2021, CPM patients who underwent CRS and HIPEC were analyzed. Patients were allocated into perioperative and palliative CTx arm based on the duration between initial diagnosis of CPM to undergoing CRS and HIPEC of 6 months. Data including perioperative parameters, postoperative outcomes, and survival were analyzed with a median follow-up of 28.5 months.

RESULTS

Twenty-six CPM patients underwent CRS and HIPEC. Mean time from diagnosis of CPM to CRS and HIPEC was 5.5 months with 14 patients in the perioperative arm and 12 patients in the palliative arm. Perioperative group showed a longer RFS of 13.5 months compared to 8 months in the palliative group. Median overall survival of palliative group was 41.50 months, and 18 patients among all groups are alive at the time of this report.

CONCLUSION

CRS and HIPEC could be a treatment option for a carefully selected CPM patients performed by experienced surgeons. Overall survival of 41.50 months in palliative group compared to 16.8 months from conventional systemic CTx supports CRS and HIPEC even in palliative patients.

Is Systemic Chemotherapy Useful in Patients Treated with Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy (HIPEC) for Colorectal Peritoneal Metastases? A Propensity-Score Analysis

PURPOSE

Multimodal treatment of colorectal (CRC) peritoneal metastases (PM) includes systemic chemotherapy (SC) and surgical cytoreduction (CRS), eventually with hyperthermic intraperitoneal chemotherapy (HIPEC), in select patients. Considering lack of clear guidelines, this study was designed to analyze the role of chemotherapy and its timing in patients treated with CRS-HIPEC.

METHODS

Data from 13 Italian centers with PM expertise were collected by a collaborative group of the Italian Society of Surgical Oncology (SICO). Clinicopathological variables, SC use, and timing of administration were correlated with overall survival (OS), disease-free survival (DFS), and local (peritoneal) DFS (LDFS) after propensity-score (PS) weighting to reduce confounding factors.

RESULTS

A total of 367 patients treated with CRS-HIPEC were included in the propensity-score weighting. Of the total patients, 19.9% did not receive chemotherapy within 6 months of surgery, 32.4% received chemotherapy before surgery (pregroup), 28.9% after (post), and 18.8% received both pre- and post-CRS-HIPEC treatment (peri). SC was preferentially administered to younger (p = 0.02) and node-positive (p = 0.010) patients. Preoperative SC is associated with increased rate of major complications (26.9 vs. 11.3%, p = 0.0009). After PS weighting, there were no differences in OS, DFS, or LDFS (p = 0.56, 0.50, and 0.17) between chemotherapy-treated and untreated patients. Considering SC timing, the post CRS-HIPEC group had a longer DFS and LDFS than the pre-group (median DFS 15.4 vs. 9.8 m, p = 0.003; median LDFS 26.3 vs. 15.8 m, p = 0.026).

CONCLUSIONS

In patients with CRC-PM treated with CRS-HIPEC, systemic chemotherapy was not associated with overall survival benefit. The adjuvant schedule was related to prolonged disease-free intervals. Additional, randomized studies are required to clarify the role and timing of systemic chemotherapy in this patient subset.

Effect of Intraperitoneal Chemotherapy with Regorafenib on IL-6 and TNF-α Levels and Peritoneal Cytology: Experimental Study in Rats with Colorectal Peritoneal Carcinomatosis

Cytoreductive surgery (CRS), combined with hyperthermic intraperitoneal chemotherapy, has significantly improved survival outcomes in patients with peritoneal carcinomatosis from colorectal cancer (CRC). Regorafenib is an oral agent administered in patients with refractory metastatic CRC. Our aim was to investigate the outcomes of intraperitoneal administration of regorafenib for intraperitoneal chemotherapy (IPEC) or/and CRS in a rat model of colorectal peritoneal metastases regarding immunology and peritoneal cytology. A total of 24 rats were included. Twenty-eight days after carcinogenesis induction, rats were randomized into following groups: group A: control group; group B: CRS only; group C: IPEC only; and group D: CRS + IPEC. On day 56 after carcinogenesis, euthanasia and laparotomy were performed. Serum levels of interleukin-6 (IL-6) and tumor necrosis factor α (TNF-α) as well as peritoneal cytology were investigated. Groups B and D had statistically significant lower mean levels of IL-6 and TNF-α compared to groups A and C, but there was no significant difference between them. Both B and D groups presented a statistically significant difference regarding the rate of negative peritoneal cytology, when compared to the control group, but not to group C. In conclusion, regorafenib-based IPEC, combined with CRS, may constitute a promising tool against peritoneal carcinomatosis by altering the tumor microenvironment.

Delaying Surgery After Neoadjuvant Chemotherapy Affects Survival in Patients with Colorectal Peritoneal Metastases: A BIG-RENAPE Network Multicentric Study

BACKGROUND

Multimodal treatment for patients with peritoneal metastases (PM) from colorectal cancer (CRC), including perioperative chemotherapy (CT) plus complete resection, is associated with prolonged survival. The oncologic impact of therapeutic delays is unknown.

OBJECTIVE

The aim of this study was to assess the survival impact of delaying surgery and CT.

METHODS

Medical records from the national BIG RENAPE network database of patients with complete cytoreductive (CC0-1) surgery of synchronous PM from CRC who received at least one neoadjuvant CT cycle plus one adjuvant CT cycle were retrospectively reviewed. The optimal interval between the end of neoadjuvant CT to surgery, surgery to adjuvant CT, and total interval without systemic CT were estimated using Contal and O'Quigley's method plus restricted cubic spline methods.

RESULTS

From 2007 to 2019, 227 patients were identified. After a median follow-up of 45.7 months, the median overall survival (OS) and progression-free survival (PFS) was 47.6 and 10.9 months, respectively. The best cut-off period was 42 days in the preoperative interval, no cut-off period was optimal in the postoperative interval, and the best cut-off period in the total interval without CT was 102 days. In multivariate analysis, age, biologic agent use, high peritoneal cancer index, primary T4 or N2 staging, and delay to surgery of more than 42 days (median OS 63 vs. 32.9 months; p = 0.032) were significantly associated with worse OS. Preoperative delay of surgery was also significantly associated with PFS, but only in univariate analysis.

CONCLUSION

In selected patients undergoing complete resection plus perioperative CT, a period of more than 6 weeks from completion of neoadjuvant CT to cytoreductive surgery was independently associated with worse OS.

External validation of COMPASS and BIOSCOPE prognostic scores in colorectal peritoneal metastases treated with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (HIPEC)

INTRODUCTION

The selection of patients undergoing cytoreductive- surgery (CRS) followed by hyperthermic intraperitoneal chemotherapy (HIPEC) is crucial. BIOSCOPE and COMPASS are prognostic scores designed to stratify survival into four classes according to clinical and pathological features. The purpose of this study is to analyze the prognostic role of these scores using a large cohort of patients as an external reference.

METHODS

Overall survival analysis was performed using Log-Rank and Kaplan-Meier curves for each score. The probability of survival at 12, 36, and 60 months was tested using receiver operating characteristic (ROC) curves to determine sensitivity and specificity.

RESULTS

From the validation cohort of 437 patients, the analysis included 410 patients in the COMPASS group and 364 patients in the BIOSCOPE group (100% data completeness). We observed a different patient distribution between classes (high-risk for BIOSCOPE compared to COMPASS, p = 0.0001). Nevertheless, both COMPASS and BIOSCOPE effectively stratified overall survival (Log-Rank, p = 0.0001 in both cases), with a lack of discrimination between COMPASS classes II and III (p = n.s.). COMPASS at 12 m and BIOSCOPE at 60 m showed the best performance in terms of survival prediction (AUC of 0.82 and 0.81). The specificity of the two tests is good (median 81.3%), whereas sensibility is quite low (median 64.2%).

CONCLUSION

Following external validation in a large population of patients with CRC-PM who are eligible for surgery, the COMPASS and BIOSCOPE scores exhibit high inter-test variability but effectively stratify cancer-related mortality risk. While the quality of the scores is similar, BIOSCOPE shows better inter-tier differentiation, suggesting that tumor molecular classification could improve test discrimination capability. More powerful stratification scores with the inclusion of novel predictors are needed.

A total neoadjuvant chemotherapy approach is associated with improved recurrence-free survival in patients with colorectal peritoneal metastases undergoing cytoreductive surgery and HIPEC

BACKGROUND

The primary aim of this study is to evaluate the oncologic outcomes of two popular systemic chemotherapy approaches in patients with colorectal peritoneal metastases (CPM) undergoing cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS-HIPEC).

METHODS

We performed a dual-center retrospective review of consecutive patients who underwent CRS-HIPEC for CPM due to high or intermediate-grade colorectal cancer. Patients in the total neoadjuvant therapy (TNT) group received 6 months of preoperative chemotherapy. Patients in the "sandwich" (SAND) chemotherapy group received 3 months of preoperative chemotherapy with a maximum of 3 months of postoperative chemotherapy.

RESULTS

A total of 34 (43%) patients were included in the TNT group and 45 (57%) patients in the SAND group. The median overall survival (OS) in the TNT and SAND groups were 77 and 61 months, respectively (p = 0.8). Patients in the TNT group had significantly longer recurrence-free survival (RFS) than the SAND group (29 vs. 12 months, p = 0.02). In a multivariable analysis, the TNT approach was independently associated with improved RFS.

CONCLUSION

In this retrospective study, a TNT approach was associated with improved RFS, but not OS when compared with a SAND approach. Further prospective studies are needed to examine these systemic chemotherapeutic approaches in patients with CPM undergoing CRS-HIPEC.

Perioperative chemotherapy in colorectal cancer with peritoneal metastases: A global propensity score matched study

BACKGROUND

There is a paucity of studies evaluating perioperative systemic chemotherapy in conjunction with cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) in patients with colorectal cancer peritoneal metastases (CRCPM). The aim was to evaluate neoadjuvant and/or adjuvant systemic therapy in CRCPM.

METHODS

Patients with CRCPM from 39 treatment centres globally from January 1, 1991, to December 31, 2018, who underwent CRS+HIPEC were identified and stratified according to neoadjuvant/adjuvant use. Crude data analysis, propensity score matching (PSM) and Cox-proportional hazard modelling was performed.

FINDINGS

Of 2093 patients, 1613 were included in neoadjuvant crude evaluation with 708 in the PSM cohort (354 patients/arm). In the adjuvant evaluation, 1176 patients were included in the crude cohort with 778 in the PSM cohort (389 patients/arm). The median overall survival (OS) in the PSM cohort receiving no neoadjuvant vs neoadjuvant therapy was 37.0 months (95% CI: 32.6-42.7) vs 34.7 months (95% CI: 31.2-38.8, HR 1.08 95% CI: 0.88-1.32, p = 0.46). The median OS in the PSM cohort receiving no adjuvant therapy vs adjuvant therapy was 37.0 months (95% CI: 32.9-41.8) vs 45.7 months (95% CI: 38.8-56.2, HR 0.79 95% CI: 0.64-0.97, p = 0.022). Recurrence-free survival did not differ in the neoadjuvant evaluation but differed in the adjuvant evaluation - HR 1.04 (95% CI: 0.87-1.25, p = 0.66) and 0.83 (95% CI: 0.70-0.98, p = 0.03), respectively. Multivariable Cox-proportional hazard modelling in the crude cohorts showed hazard ratio 1.08 (95% CI: 0.92-1.26, p = 0.37) for administering neoadjuvant therapy and 0.86 (95% CI: 0.72-1.03, p = 0.095) for administering adjuvant therapy.

INTERPRETATION

Neoadjuvant therapy did not confer a benefit to patients undergoing CRS+HIPEC for CRCPM, whereas adjuvant therapy was associated with a benefit in this retrospective setting.

FUNDING

None.

Lymph node positive pseudomyxoma peritonei

BACKGROUND

Appendiceal mucinous neoplasms are routinely accompanied by peritoneal metastases at the time of diagnosis of the primary appendiceal tumor. In contrast, liver metastases and lymph node metastases are unusual.

METHODS

From an extensive database, patients with lymph node metastases identified at the time of primary appendiceal cancer resection were selected for special study. The clinical, treatment-related and histologic variables of this group of patients were statistically analyzed for their impact on overall survival.

RESULTS

From a prospectively maintained database of 685 patients with a complete cytoreduction of a mucinous appendiceal neoplasm with peritoneal dissemination, 39 patients (5.6%) had lymph node metastases at the time of primary diagnosis. The median follow-up was 5.0 years and overall median survival was 6.0 years. Histologically, 6 of these patients (15.4%) had an appendiceal mucinous neoplasm - Intermediate type (MACA-Int). In 5 patients, the involved lymph nodes were not within the ileocolic lymph node group. The 7 patients (17.9%) who had a complete or near complete response to neoadjuvant chemotherapy prior to definite cytoreductive surgery (CRS) plus hyperthermic intraperitoneal chemotherapy (HIPEC) showed prolonged survival (HR 4.8 (1.1, 20.5) p = 0.0323). A prior right colon resection required repeat resection in 87% of patients.

CONCLUSION

Long-term survival is unusual but occasionally seen in this group of patients. Response to neoadjuvant chemotherapy is an important determinant of a favorable outcome.

The Impact of Neoadjuvant Chemotherapy on the Surgical Management of Colorectal Peritoneal Metastases: A Systematic Review and Meta-Analysis

Background

Cytoreductive surgery (CRS) with or without hyperthermic intraperitoneal chemotherapy (HIPEC) is a well-recognised treatment option for the management of colorectal peritoneal metastases (CRPM). However, incorporating the routine use of neoadjuvant chemotherapy (NAC) into this management plan is controversial.

Methods

A systematic review and meta-analysis were conducted to evaluate the impact of neoadjuvant chemotherapy on perioperative morbidity and mortality, and long-term survival of patients with CRPM undergoing CRS and HIPEC.

Results

Twelve studies met the inclusion criteria (n = 2,463 patients). Ten were retrospective cohort, one was prospective cohort, and one was a prospective randomised by design. Patients who received NAC followed by CRS and HIPEC experienced no difference in major perioperative morbidity and mortality compared with patients who underwent surgery first (SF). There was no difference in overall survival at 3 years, but at 5 years NAC patients had superior survival (relative risk [RR] 1.31; 95% confidence interval [CI] 1.11–1.54, P < 0.001). There were no differences in 1- and 3-year, disease-free survival (DFS) between groups. Study heterogeneity was generally high across all outcome measures.

Conclusions

Patients who received neoadjuvant chemotherapy did not experience any increase in perioperative morbidity or mortality. The potential improvement in 5-year overall survival in patients receiving NAC is based on limited confidence due to several limitations in the data, but not sufficiently enough to curtail its use. The practice of NAC in this setting will remain heterogeneous and guided by retrospective evidence until prospective, randomised data are reported.

Revised prognostic indicators for treatment of lymph node positive colorectal peritoneal metastases

BACKGROUND

Peritoneal metastases from colon and rectal cancer presents a new target for a regional approach to treatment. Proper patient selection requires an understanding of the natural history of the disease progression.

METHODS

Data from colorectal cancer patients treated for peritoneal metastases by cytoreductive surgery (CRS) plus hyperthermic intraperitoneal chemotherapy and early postoperative intraperitoneal chemotherapy and the records from the primary colon or rectal cancer surgery were analyzed to assess their impact on survival. Data regarding the anatomic sites of colorectal peritoneal metastases was gathered at the time of a complete CRS.

RESULTS

A cohort of 73 patients with peritoneal metastases and lymph node metastases but no liver metastases provided the information. All patients had a complete cytoreduction. Left-sided primary cancer and a complete or near complete response to neoadjuvant chemotherapy (NAC) indicated improved survival. Tumor progression within the abdominal incision, carcinoembryonic antigen (CEA) >10, peritoneal cancer index >9 and peritoneal metastases present in the abdominopelvic regions 6 and 11 carried an especially guarded prognosis.

CONCLUSIONS

Reduced survival occurred with a right-sided or rectal primary cancer, a CEA >10, tumor cell entrapment, and involvement of abdominopelvic regions 6 and 11. Effective NAC showed a favorable outcome.

Quality Standards for Surgery of Colorectal Peritoneal Metastasis After Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy

BACKGROUND

The standardization of surgical outcomes throughout surgical procedures is mandatory. Cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS + HIPEC) should provide proficient oncological and surgical outcomes.

STUDY DESIGN

The aim of this study was to identify clinically relevant quality indicators and their quality standard, and to determine their acceptable quality limit. A systematic review on cytoreductive results from 2000 to 2018 was performed focusing on clinical guidelines, consensus conferences, and publications. After the selection of quality indicators, a systematic review of indexed references was performed in order to calculate the quality standard for each indicator.

STUDY SELECTION

Unicentric/multicentric series, comparative studies, and clinical trials. Studies were to include outcomes after cytoreduction of colorectal origin and series with more than 50 patients. Quality indicators with at least 10 series were mandatory and objective measurements were also mandatory for inclusion.

MAIN OUTCOME MEASUREMENTS

Quality indicators selected were 1- to 5-year survival, overall disease-free survival, 1- to 5-year disease-free survival, complete surgical resection, duration of surgery, length of stay, overall morbimortality, major morbidity, re-intervention, postoperative hemorrhage, intestinal fistula, anastomotic leakage, wound infection, postoperative medical complications, overall recurrence, and failure to rescue.

RESULTS

The most relevant quality indicators and critical quality limits were overall disease-free survival and 5-year overall disease-free survival (14 months and <10 months, and 14% and <4%, respectively), completeness of surgical resection (89% and <80%, respectively), overall mortality (3% and >8%, respectively), overall morbidity (47% and >63%, respectively), failure to rescue (12% and <30%, respectively), reintervention (13 and <22%, respectively), anastomotic leakage (6% and <13%, respectively), and overall recurrence (60% and <74%, respectively).

CONCLUSION

This is the first study to assess quality standards in CRS + HIPEC for colorectal peritoneal metastases. The current data are of particular relevance for future studies to control the variability of this surgery.

Definition and Prediction of Early Recurrence and Mortality Following Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy for Colorectal Peritoneal Metastases: Towards Predicting Oncologic Futility Preoperatively

INTRODUCTION

Early recurrence (ER) is a significant challenge for patients with colorectal peritoneal metastases (CRPM) following cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS HIPEC). Preoperative risk stratification for ER would improve preoperative decision making.

METHODS

We conducted a retrospective study examining patients who underwent CRS HIPEC for CRPM from 2000 to 2018. Optimal definition of ER was determined via minimum p-value approach based on differentiation of post-recurrence survival. Risk factors for ER were assessed in a derivation cohort by uni- and multivariate logistic regression. A predictive score for ER was generated using preoperative variables and validated in an independent cohort.

RESULTS

384 patients were analyzed, 316 (82%) had documented recurrence. Optimal length of post-operative RFS to distinguish ER (n = 144, 46%) vs. late recurrence (LR) (n = 172, 63%) was 8 mos (p<0.01). ER patients had shorter median OS post-CRS-HIPEC (13.6 vs. 39.4 mos, p<0.01). Preoperative BMI (OR 1.88), liver lesions (OR 1.89), progression on chemotherapy (OR 2.14), positive lymph nodes (OR 2.47) and PCI score (16-20: OR 1.7; >20: OR 4.37) were significant predictors of ER (all p<0.05). Using this model, patients were assigned risk scores from 0 to 9. Intermediate (scores 4-6) and high-risk patients (score 7-9) had observed rates of ER of 56% and 79% and overall 2-year survival rates of 27% and 0% respectively. The model showed fair discrimination (AUC 0.72) and good calibration (Hosmer-Lemeshow GOF p = 0.68).

CONCLUSIONS

ER predicts markedly worse OS following surgery. Preoperative factors can accurately stratify risk for ER and identify patients in whom CRS-HIPEC for CPRM is futile.

Effective Strategies to Predict Survival of Colorectal Peritoneal Metastases Patients Eligible for Cytoreductive Surgery and HIPEC

Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC), often combined with systemic therapy, can be offered to selected colorectal peritoneal metastases (PM) patients. However, clinical heterogeneity and the lack of high-level evidence challenges determination of the correct treatment strategy. This review aims to provide an overview of current strategies to predict survival of colorectal PM patients treated with CRS and HIPEC, guiding clinicians to select a suitable treatment-strategy and to inform patients about their prognosis. First, the prognostic relevance of several clinicopathological prognostic factors, such as extent of PM, location of primary tumor, histology type, and the presence of lymph node or liver metastases will be discussed. Subsequently, special attention will be given to recent developments in several aspects of tumor biology such as RAF/RAS mutations, circulating tumor DNA, immunoprofiling, and consensus molecular subtypes. Finally, currently available prognostic models to predict survival will be evaluated, concluding these models perform moderate to good, but most of them partly rely on intra-operative data. New insights in tumor biology, as well as the reliable assessment of extent of peritoneal disease by diffusion weighted MRI pose promising opportunities to establish an adequate and clinically meaningful preoperative prognostic model in the near future.

Direct surgery with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for patients with colorectal peritoneal metastases

INTRODUCTION

Neoadjuvant chemotherapy is widely used in treatment of peritoneal metastases from colorectal cancer, but there is little scientific evidence for this approach. This study aimed to study survival in patients treated with direct surgery with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC), i.e. without neoadjuvant chemotherapy.

MATERIAL AND METHODS

Patients with histopathologically confirmed peritoneal metastases from colorectal cancer that underwent first-time CRS-HIPEC with complete cytoreduction (CC0 or 1) at Karolinska University Hospital 2012-2019 were included. Patients with synchronous extraperitoneal metastases were excluded if not treated before end of follow-up. Factors associated with overall survival (OS) and disease-free survival (DFS) were evaluated using the Kaplan-Meier method and Cox regression models. The multivariable models were adjusted for sex, age, synchronous/metachronous peritoneal metastases, peritoneal carcinomatosis index (PCI), extraperitoneal metastases and the pathological tumor (T) and lymph node (N) stage of the primary tumor.

RESULTS

In all, 131 patients underwent complete CRS-HIPEC for peritoneal metastases without neoadjuvant chemotherapy. The median OS and DFS were 40.3 months and 12.5 months, respectively, in patients treated with direct surgery. In the multivariable model, PCI≥16 was the only variable associated with decreased OS, whereas elevated PCI, metachronous development of peritoneal metastases and synchronous extraperitoneal metastases were associated with decreased DFS. Age was not associated with an impaired prognosis.

CONCLUSION

Patients who underwent direct surgery with CRS-HIPEC had a good prognosis, with a median OS of more than 3 years. The results from this study question the need of neoadjuvant chemotherapy in all patients eligible for CRS-HIPEC.

Neoadjuvant chemotherapy followed by hyperthermic intraperitoneal chemotherapy for patients with colorectal peritoneal metastasis: a retrospective study of its safety and efficacy

Background

Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) are effective routine treatments for colorectal peritoneal metastasis (PM). However, the safety and efficacy of neoadjuvant chemotherapy (NAC) before CRS+HIPEC are poorly understood. Therefore, this study aimed to assess the perioperative safety and long-term efficacy of NAC prior to CRS+HIPEC for patients with synchronous colorectal PM.

Methods

Patients with synchronous colorectal PM who received NAC prior to CRS+HIPEC were systematically reviewed at the China National Cancer Center and Huanxing Cancer Hospital from June 2017 to June 2019. The clinicopathologic characteristics, perioperative parameters, and survival rates of patients who underwent CRS+HIPEC with NAC (NAC group) and patients who underwent CRS+HIPEC without NAC (non-NAC group) were compared.

Results

The study enrolled 52 patients, with 20 patients in the NAC group and 32 in the non-NAC group. In the NAC group, the proportion of patients with a peritoneal carcinomatosis index (PCI) score < 12 was significantly higher than that in the non-NAC group (80.0% vs 50.0%, P = 0.031), and more patients achieved complete cytoreduction (80.0% vs 46.9%, P = 0.018). The two groups had comparable grade III/IV complications and similar reoperation and mortality rates (P > 0.05). However, patients who received NAC had lower platelet counts (151.9 vs 197.7 × 10⁹/L, P = 0.036) and neutrophil counts (4.7 vs 7.2 × 10⁹/L, P = 0.030) on postoperative day 1. More patients survived for 2 years in the NAC group than in the non-NAC group (67.4% vs 32.2%, respectively, P = 0.044). However, the completeness of cytoreduction score (HR, 2.99; 95% CI, 1.14–7.84; P = 0.026), rather than NAC, was independently associated with overall survival (OS) in the multivariate analysis after controlling for confounding factors.

Conclusion

NAC administration before CRS+HIPEC can be regarded as safe and feasible for patients with colorectal PM with comparably low mortality rates and acceptable morbidity rates. Nevertheless, large-sample randomized controlled studies are needed to confirm whether the administration of NAC before CRS+HIPEC confers a survival benefit to patients.

Peritoneal cytology as an indicator of peritoneal metastases in colorectal cancer

BACKGROUND

In the management of peritoneal metastases from colon and rectal cancer, the most favorable results are reported with an aggressive combined treatment on patients who have a small extent of the disease. A test to detect occult peritoneal metastases would greatly facilitate the management of this component of colorectal dissemination.

METHODS

Currently, the standard test by which to confirm the diagnosis of the peritoneal spread of colorectal cancer is peritoneal cytology. To study the utility of this test, we gathered information from patients with biopsy-proven peritoneal metastases. The clinical, histologic, and treatment-related features of these patients at the time of a cytoreductive surgery were statistically correlated with the results of the peritoneal cytology test.

RESULTS

Forty-nine patients with colorectal cancer peritoneal metastases and a peritoneal cytology determination at the time of a cytoreductive surgery were available for analysis. Twenty-eight patients (55.1%) had a positive test. Patients with a high peritoneal cancer index and mucinous histology were most likely to have positive peritoneal cytology.

CONCLUSION

Peritoneal cytology identified patients with mucinous histology and a large extent of disease but was consistently negative in patients who had a small extent of disease compatible with a favorable response to treatment.

Systemic therapy in addition to cytoreduction and hyperthermic intraperitoneal chemotherapy for colorectal peritoneal metastases: recent insights from clinical studies and translational research

There is a lack of randomized or high-quality intention-to-treat cohort studies addressing the role of systemic therapy in addition to cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) as part of the treatment of colorectal peritoneal metastases (PM). Therefore, the choice whether or not to treat patients with systemic therapy is currently mainly based on expert opinion. As a result, treatment with neoadjuvant and/or adjuvant systemic therapy is implemented in various ways around the world. The aim of this review was to provide an overview of recent insights with regard to the systemic treatment of PM of colorectal origin obtained from clinical studies and translational research.

Cytoreductive surgery with hyperthermic intraperitoneal chemotherapy for resectable peritoneal metastases is feasible in elderly patients

The aim is to evaluate the feasibility and the prognosis of cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) for resectable peritoneal metastases (RPM) in elderly patients. Patients who underwent CRS with HIPEC for RPM between 2012 and 2018 in one tertiary reference center were retrospectively included and divided according to the age: Group A (< 65 years) and Group B (≥ 65 years). Postoperative outcomes and survivals were compared. Ninety-five patients were included in Groups A (n = 65) and B (n = 30). The incidence of comorbidities was significantly higher in elderly patients (65 vs 90%, p = 0.01), but RPM characteristics were similar between groups. There was no difference between groups in terms of postoperative results: 30-day major morbidity (33 vs 23%, p = 0.4), 30-day mortality (0 vs 3%, p = 0.3), mean length of stay (26.7 ± 19.4 vs 22.4 ± 10.3 days, p = 0.3) and readmission's rate (15 vs 33%, p = 0.06). The only one significant difference was the 90-day mortality which never occurred before 65 years but in 10% of elderly patients (p = 0.03). There was no difference regarding recurrence's rate (56 vs 37%, p = 0.1), neither 1-, 3- and 5-year overall survival rates (86, 64 and 52% vs 85, 74% and not reached, p = 0.8) and disease-free survival rates (61, 28 and 28% vs 56, 45% and not reached, p = 0.6). CRS with HIPEC is feasible in elderly patients. Since the 90-day mortality appeared to be higher in elderly patients, additional criteria are necessary to improve the selection of elderly patients for this major surgery.

The absence of benefit of perioperative chemotherapy in initially resectable peritoneal metastases of colorectal cancer origin treated with complete cytoreductive surgery and hyperthermic intraperitoneal chemotherapy: A retrospective analysis

INTRODUCTION

The aim of this study was to compare the outcome of patients with peritoneal metastasis (PM) of colorectal origin treated with complete cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) with or without perioperative systemic chemotherapy (PCT+/PCT-).

PATIENTS AND METHODS

Retrospective analysis of 125 patients treated with complete CRS (R0/R1) and HIPEC for PM from colorectal origin in two Belgian academic centers between 2008 and 2017. Disease-free survival (DFS) and overall survival (OS) were assessed with regard to PCT. Statistical analyses were adjusted for non-balanced survival risk factors.

RESULTS

The PCT+ group (n = 67) received at least 5 cycles of PCT and the PCT-group (n = 56) did not receive PCT. The groups were well balanced for all prognostic factors except presentation of synchronous disease (more in PCT+). Survival analysis was adjusted to peritoneal cancer index and presentation of synchronous disease. After a median follow-up of 54±5-months, the 1, 3, 5-years OS in the PCT+ group were 98%, 59% and 35% compared to 97%, 77% and 56% in the PCT-group (HR = 1.46; 95% CI:0.87-2.47; p = 0.155). The 1,3 and 5 years DFS in the PCT+ group were 47%, 13% and 6% compared to 58%, 29% and 26% respectively in the PCT- (HR = 1.22; 95% CI:0.78-1.92; p = 0.376).

CONCLUSION

This study does not show any clear benefit of PCT in carefully selected patients undergoing R0/R1 CRS and HIPEC for colorectal PM. The ongoing CAIRO6 trial randomizing CRS/HIPEC versus CRS/HIPEC and PCT will probably clarify the role of PCT in patients with resectable PM.

Canadian guidelines on the management of colorectal peritoneal metastases

Modern management of colorectal cancer (crc) with peritoneal metastasis (pm) is based on a combination of cytoreductive surgery (crs), systemic chemotherapy, and hyperthermic intraperitoneal chemotherapy (hipec). Although the role of hipec has recently been questioned with respect to results from the prodige 7 trial, the role and benefit of a complete crs were confirmed, as observed with a 41-month gain in median survival in that study, and 15% of patients remaining disease-free at 5 years. Still, crc with pm is associated with a poor prognosis, and good patient selection is essential. Many questions about the optimal management approach for such patients remain, but all patients with pm from crc should be referred to, or discussed with, a pm surgical oncologist, because cure is possible. The objective of the present guideline is to offer a practical approach to the management of pm from crc and to reflect on the new practice standards set by recent publications on the topic.

The role of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy in the treatment of peritoneal carcinomatosis: a systematic review including evidence from Japan

The prognosis of peritoneal carcinomatosis is poor. However, the emergence of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS + HIPEC) as a treatment option has prolonged survival and it can even potentially cure patients with peritoneal carcinomatosis. Randomized controlled studies and other observational studies indicated that this combined therapy potentially improved the prognosis of patients with colon, gastric, and ovarian cancers with acceptable morbidity and mortality rates. Even in rarer diseases, such as pseudomyxoma peritonei and malignant peritoneal mesothelioma, CRS + HIPEC markedly improved the prognoses over those with conventional treatment. Based on the accumulated evidence, clinical guidelines recommend CRS + HIPEC for selected patients with peritoneal carcinomatosis. However, several issues still need to be overcome. A standard method for HIPEC has not yet been established. Furthermore, the criteria employed for patient selection need to be clarified to achieve real benefits. The peritoneal cancer index, chemo-sensitivity and several biological markers are considered to be key factors.

Adjuvant Systemic Chemotherapy vs Active Surveillance Following Up-front Resection of Isolated Synchronous Colorectal Peritoneal Metastases

Importance

To date, there are no data on the value of adjuvant systemic chemotherapy following up-front resection of isolated synchronous colorectal peritoneal metastases.

Objective

To assess the association between adjuvant systemic chemotherapy and overall survival following up-front resection of isolated synchronous colorectal peritoneal metastases.

Design, Setting, and Participants

In this population-based, observational cohort study using nationwide data from the Netherlands Cancer Registry (diagnoses between January 1, 2005, and December 31, 2017; follow-up until January 31, 2019), 393 patients with isolated synchronous colorectal peritoneal metastases who were alive 3 months after up-front complete cytoreductive surgery with hyperthermic intraperitoneal chemotherapy were included. Patients allocated to the adjuvant systemic chemotherapy group were matched (1:1) with those allocated to the active surveillance group by propensity scores based on patient-, tumor-, and treatment-level covariates.

Exposures

Adjuvant systemic chemotherapy, defined as systemic chemotherapy without targeted therapy, starting within 3 months postoperatively.

Main Outcomes and Measures

Overall survival was compared between matched groups using Cox proportional hazards regression analysis adjusted for residual imbalance. A landmark analysis was performed by excluding patients who died within 6 months postoperatively. A sensitivity analysis was performed to adjust for unmeasured confounding by major postoperative morbidity.

Results

Of 393 patients (mean [SD] age, 61 [10] years; 181 [46%] men), 172 patients (44%) were allocated to the adjuvant systemic chemotherapy group. After propensity score matching of 142 patients in the adjuvant systemic chemotherapy group with 142 patients in the active surveillance group, adjuvant systemic chemotherapy was associated with improved overall survival compared with active surveillance (median, 39.2 [interquartile range, 21.1-111.1] months vs 24.8 [interquartile range, 15.0-58.4] months; adjusted hazard ratio [aHR], 0.66; 95% CI, 0.49-0.88; P = .006), which remained consistent after excluding patients who died within 6 months postoperatively (aHR, 0.68; 95% CI, 0.50-0.93; P = .02) and after adjustment for major postoperative morbidity (aHR, 0.71; 95% CI, 0.53-0.95).

Conclusions and Relevance

Findings of this study suggest that in patients undergoing up-front resection of isolated synchronous colorectal peritoneal metastases, adjuvant systemic chemotherapy appeared to be associated with improved overall survival. Although randomized trials are needed to address the influence of potential residual confounding and allocation bias on this association, results of this study may be used for clinical decision-making in this patient group for whom no data are available.

Optimal perfusion chemotherapy: A prospective comparison of mitomycin C and oxaliplatin for hyperthermic intraperitoneal chemotherapy in metastatic colon cancer

BACKGROUND

Peritoneal carcinomatosis of colorectal adenocarcinoma (CRC) origin is common and is the second-most frequent cause of death in colorectal cancer. There is survival benefit to surgical resection plus hyperthermic intraperitoneal chemotherapy (HIPEC) for patients with metastatic CRC. However, there remains controversy between oxaliplatin (Oxali) and mitomycin C (MMC), as the agent of choice.

METHODS

A review of our 285 patients prospective HIPEC database from July 2007 to May 2018 identified 48 patients who underwent cytoreductive surgery plus HIPEC with MMC or Oxali. Patients were stratified based on preoperative and postoperative peritoneal cancer indices (PCI). The primary outcomes of survival and progression-free survival were compared.

RESULTS

Type of HIPEC chemotherapy was not found to be predictive of overall survival. Preoperative PCI (P = .04), preoperative response to chemotherapy (P = .0001), and postoperative PCI (P = .05) were predictive for overall survival.

CONCLUSIONS

MMC or Oxali based HIPEC chemotherapy are both safe and effective for the management of peritoneal only metastatic CRC. Both perfusion therapies should be considered with all patients receiving modern induction chemotherapy.

Impact of Neoadjuvant Chemotherapy on the Outcomes of Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy for Colorectal Peritoneal Metastases: A Multi-Institutional Retrospective Review

Cytoreductive surgery (CRS) with or without hyperthermic intraperitoneal chemotherapy (HIPEC) is associated with improved survival for patients with colorectal peritoneal metastases (CR-PM). However, the role of neoadjuvant chemotherapy (NAC) prior to CRS-HIPEC is poorly understood. A retrospective review of adult patients with CR-PM who underwent CRS+/-HIPEC from 2000–2017 was performed. Among 298 patients who underwent CRS+/-HIPEC, 196 (65.8%) received NAC while 102 (34.2%) underwent surgery first (SF). Patients who received NAC had lower peritoneal cancer index score (12.1 + 7.9 vs. 14.3 + 8.5, p = 0.034). There was no significant difference in grade III/IV complications (22.4% vs. 16.7%, p = 0.650), readmission (32.3% vs. 23.5%, p = 0.114), or 30-day mortality (1.5% vs. 2.9%, p = 0.411) between groups. NAC patients experienced longer overall survival (OS) (median 32.7 vs. 22.0 months, p = 0.044) but similar recurrence-free survival (RFS) (median 13.8 vs. 13.0 months, p = 0.456). After controlling for confounding factors, NAC was not independently associated with improved OS (OR 0.80) or RFS (OR 1.04). Among patients who underwent CRS+/-HIPEC for CR-PM, the use of NAC was associated with improved OS that did not persist on multivariable analysis. However, NAC prior to CRS+/-HIPEC was a safe and feasible strategy for CR-PM, which may aid in the appropriate selection of patients for aggressive cytoreductive surgery.

Perioperative systemic therapy and cytoreductive surgery with HIPEC versus upfront cytoreductive surgery with HIPEC alone for isolated resectable colorectal peritoneal metastases: protocol of a multicentre, open-label, parallel-group, phase II-III, randomised, superiority study (CAIRO6)

Background

Upfront cytoreductive surgery with HIPEC (CRS-HIPEC) is the standard treatment for isolated resectable colorectal peritoneal metastases (PM) in the Netherlands. This study investigates whether addition of perioperative systemic therapy to CRS-HIPEC improves oncological outcomes.

Methods

This open-label, parallel-group, phase II-III, randomised, superiority study is performed in nine Dutch tertiary referral centres. Eligible patients are adults who have a good performance status, histologically or cytologically proven resectable PM of a colorectal adenocarcinoma, no systemic colorectal metastases, no systemic therapy for colorectal cancer within six months prior to enrolment, and no previous CRS-HIPEC. Eligible patients are randomised (1:1) to perioperative systemic therapy and CRS-HIPEC (experimental arm) or upfront CRS-HIPEC alone (control arm) by using central randomisation software with minimisation stratified by a peritoneal cancer index of 0–10 or 11–20, metachronous or synchronous PM, previous systemic therapy for colorectal cancer, and HIPEC with oxaliplatin or mitomycin C. At the treating physician’s discretion, perioperative systemic therapy consists of either four 3-weekly neoadjuvant and adjuvant cycles of capecitabine with oxaliplatin (CAPOX), six 2-weekly neoadjuvant and adjuvant cycles of 5-fluorouracil/leucovorin with oxaliplatin (FOLFOX), or six 2-weekly neoadjuvant cycles of 5-fluorouracil/leucovorin with irinotecan (FOLFIRI) followed by four 3-weekly (capecitabine) or six 2-weekly (5-fluorouracil/leucovorin) adjuvant cycles of fluoropyrimidine monotherapy. Bevacizumab is added to the first three (CAPOX) or four (FOLFOX/FOLFIRI) neoadjuvant cycles. The first 80 patients are enrolled in a phase II study to explore the feasibility of accrual and the feasibility, safety, and tolerance of perioperative systemic therapy. If predefined criteria of feasibility and safety are met, the study continues as a phase III study with 3-year overall survival as primary endpoint. A total of 358 patients is needed to detect the hypothesised 15% increase in 3-year overall survival (control arm 50%; experimental arm 65%). Secondary endpoints are surgical characteristics, major postoperative morbidity, progression-free survival, disease-free survival, health-related quality of life, costs, major systemic therapy related toxicity, and objective radiological and histopathological response rates.

Discussion

This is the first randomised study that prospectively compares oncological outcomes of perioperative systemic therapy and CRS-HIPEC with upfront CRS-HIPEC alone for isolated resectable colorectal PM.

Trial registration

Clinicaltrials.gov/NCT02758951, NTR/NTR6301, ISRCTN/ISRCTN15977568, EudraCT/2016–001865-99.

Perioperative Systemic Chemotherapy, Cytoreductive Surgery, and Hyperthermic Intraperitoneal Chemotherapy in Patients With Colorectal Peritoneal Metastasis: Results of the Prospective Multicenter Phase 2 COMBATAC Trial

BACKGROUND

Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) as parts of an interdisciplinary treatment concept including systemic chemotherapy can improve survival of selected patients with peritoneal metastatic colorectal cancer (pmCRC). Nevertheless, the sequence of the therapeutic options is still a matter of debate. Thus, the COMBATAC (COMBined Anticancer Treatment of Advanced Colorectal cancer) trial was conducted to evaluate a combined treatment regimen consisting of preoperative systemic polychemotherapy + cetuximab followed by CRS + HIPEC and postoperative systemic polychemotherapy + cetuximab.

PATIENTS AND METHODS

The COMBATAC trial is a prospective, multicenter, open-label, single-arm, single-stage phase 2 trial. Twenty-six patients with synchronous or metachronous colorectal or appendiceal peritoneal carcinomatosis were included. Enrollment was terminated prematurely by the sponsor because of slow recruitment. Progression-free survival as primary end point and overall survival were estimated by the Kaplan-Meier method. Also evaluated were morbidity according to Common Terminology Criteria for Adverse Events v4.0 and feasibility of the combined treatment concept.

RESULTS

Median progression-free survival for the intention-to-treat population (n = 25) was 14.9 months. Median overall survival was not reached during the study duration. Ninety-two adverse events were documented in 16 patients, including 14 serious adverse events in 9 patients. The overall morbidity rate was 64%, and the grade 3/4 morbidity rate was 44%. Of all grade 3/4 morbidity events, 36.4% were related to systemic chemotherapy and 22.7% to surgery, whereas 40.9% were not directly related. There was no treatment-related mortality.

CONCLUSION

The results of the COMBATAC trial show that the multimodal treatment concept consisting of perioperative systemic chemotherapy and CRS + HIPEC is safe and feasible. Progression-free survival in selected patients with colorectal or appendiceal peritoneal metastasis might be improved.

Przerzuty do otrzewnej raka jelita grubego

Częstość przerzutów do otrzewnej w raku jelita grubego wynosi 5%-15% w przypadku przerzutów synchronicznych i aż 40% w przypadku wystąpienia wznowy miejscowej. Najlepsze wyniki leczenia uzyskuje się poprzez skojarzone wykonanie zabiegu cytoredukcyjnego w połączeniu z dootrzewnową chemioterapią perfuzyjną w hipertermii (HIPEC). Wyniki takiego leczenia są zdecydowanie lepsze i pozwalają na osiągnięcie przeżyć 5-letnich na poziomie 30%-50%. Zabiegi te wymagają dużego doświadczenia w chirurgii jamy brzusznej, są czasochłonne (średni czas procedury chirurgicznej wynosi 6-8 godzin) i obarczone powikłaniami związanymi nie tylko z zabiegiem operacyjnym, ale także podaniem cytostatyku do jamy otrzewnej w podwyższonej temperaturze (41,5 st. C). Chorzy po zabiegu wymagają pobytu na oddziale intensywnej terapii, co jest związane z wystąpieniem potencjalnych powikłań spowodowanych rozległością zabiegu, długością procedury chirurgicznej, zastosowaniu chemioterapii w połączeniu z hipertermią. Prowadzenie pooperacyjne tych chorych wymaga doświadczenia całego zespołu lekarskiego i pielęgniarskiego. Zabiegi cytoredukcyjne w połączeniu z HIPEC jako wysoce specjalistyczne procedury medyczne powinny być merytorycznie ocenione pod kątem korzyści długoterminowych dla chorych i odpowiednio skalkulowane pod względem realnej wysokości refundacji. Jako procedura zalecana w wytycznych Kionsultanta Krajowego d.s. Chirurgii Onkologicznej oraz wytycznych ESMO, niezbędna jest jej realna wycena i refundacja pokrywająca jej całkowite średnie koszty.

Applications of hyperthermic intraperitoneal chemotherapy for metastatic colorectal cancer

INTRODUCTION

Cytoreductive surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC) plays a pivotal role in the current treatment of peritoneal carcinomatosis (PC) from colorectal cancer (CRC). Since the first demonstration, benefits for patients and especially an increase in survival have been described. In recent years, feasibility, efficacy and safety of HIPEC have been improved and progress has been made in understanding its oncological mechanism. Areas covered: In this article, leading publications have been reviewed including clinical trials to describe the clinical presentation of PC due to CRC and present recent evidence of the CRS/HIPEC procedure. The surgical approach including evaluation of the extent of PC is described and, in addition, the article reports about different HIPEC techniques as well as several protocols. Furthermore, the development and prognostic benefit of the combination of intraperitoneal and intravenous chemotherapy are outlined. Consideration has been given in particular to patient selection and the use of HIPEC if complete cytoreduction is not feasible. Expert commentary: The CRS/HIPEC procedure represents a curative approach to treat patients with PC from CRC. However, surgical skills and the HIPEC technique still require specialized oncological centers.

Patient selection for cytoreductive surgery and HIPEC for the treatment of peritoneal metastases from colorectal cancer

Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) is a viable option for selected patients with peritoneal metastases (PM) from colorectal origin, resulting in long-term survival and even cure in some cases. However, adequate patient selection for this treatment is currently one of the major challenges. The aim of this review is to provide a comprehensive overview of clinically relevant factors associated with overall survival. This may help to guide clinicians through the complex interplay of patient, tumor, and treatment characteristics to adequately select patients who benefit the most from this extensive surgical treatment. First, basic principles of colorectal PM and the CRS and HIPEC treatment will be discussed. According to available literature, especially extent of peritoneal disease, completeness of cytoreduction, and signet ring cell histology have great influence on the outcome after CRS and HIPEC. Other factors that seem to have a negative prognostic value are the presence of liver metastases and the absence of treatment with neo-adjuvant systemic therapy. Prognostic models combining the above-mentioned factors, such as the Colorectal Peritoneal Metastases Prognostic Surgical Score nomogram, may provide clinically relevant tools to use in everyday practice.

Perioperative systemic therapy for resectable colorectal peritoneal metastases: Sufficient evidence for its widespread use? A critical systematic review

BACKGROUND/PURPOSE

Despite its widespread use, no randomised studies have investigated the value of perioperative systemic therapy as adjunct to cytoreduction and HIPEC for colorectal peritoneal metastases. This systematic review evaluated the available evidence, which consists of non-randomised studies only.

METHODS

A systematic search identified studies that investigated the influence of neoadjuvant, adjuvant, or perioperative systemic therapy on overall survival (OS).

RESULTS

The 11 included studies (n=1708) were clinically heterogeneous and subject to selection bias. Studies on neoadjuvant systemic therapy revealed OS benefit (n=3), no OS benefit (n=1), and superiority of chemotherapy with bevacizumab vs. chemotherapy (n=2). Studies on adjuvant systemic therapy showed no OS benefit (n=3). Studies on perioperative systemic therapy demonstrated OS benefit (n=1), and superiority of modern vs. conventional systemic therapy(n=1).

CONCLUSION

Significant limitations of available evidence question the widespread use of perioperative systemic therapy in this setting, stress the need for randomised studies, and impede conclusions regarding optimal timing and regimens. Included studies may suggest a survival benefit of neoadjuvant systemic therapy.

Therapeutic options for peritoneal metastasis arising from colorectal cancer

Peritoneal metastasis is a common sign of advanced tumor stage, tumor progression or tumor recurrence in patients with colorectal cancer. Due to the improvement of systemic chemotherapy, the development of targeted therapy and the introduction of additive treatment options such as cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC), the therapeutic approach to peritoneal metastatic colorectal cancer (pmCRC) has changed over recent decades, and patient survival has improved. Moreover, in contrast to palliative systemic chemotherapy or best supportive care, the inclusion of CRS and HIPEC as inherent components of a multidisciplinary treatment regimen provides a therapeutic approach with curative intent. Although CRS and HIPEC are increasingly accepted as the standard of care for selected patients and have become part of numerous national and international guidelines, the individual role, optimal timing and ideal sequence of the different systemic, local and surgical treatment options remains a matter of debate. Ongoing and future randomized controlled clinical trials may help clarify the impact of the different components, allow for further improvement of patient selection and support the standardization of oncologic treatment regimens for pmCRC. The addition of further therapeutic options such as neoadjuvant intraperitoneal chemotherapy or pressurized intraperitoneal aerosol chemotherapy, should be investigated to optimize therapeutic regimens and further improve the oncological outcome.