Risk of metachronous peritoneal metastases in patients with pT4a versus pT4b colon cancer: An international multicentre cohort study

Clinical and Pathological Risk Factors for Peritoneal Metastases in a Surgical Series of T4 Colorectal Cancers

Background: T4 colorectal cancer (CRC) is associated with an increased risk of peritoneal metastases (PM), but it is currently not possible to accurately predict which patients with T4 CRC develop PM. We investigated the occurrence and risk factors for PM in these patients. Methods: A mono-institutional prospective database of 352 patients undergoing T4 primary CRC resection from 2012 to 2021 was reviewed. Clinico-pathological variables potentially associated with synchronous or metachronous PM were tested by univariate and multivariate analyses. Results: The prevalence of synchronous PM was 73/352 (20.7%) and was significantly associated with age (p = 0.037), primary site (p = 0.002), positive nodes (p = 0.005), elevated CA19.9 (p = 0.001), and non-intestinal histology (p = 0.001). After a median follow-up of 35.9 months (95% confidence interval [CI] = 29.5-44.9), metachronous CRC-PM occurred in 36/164 patients (22.0%) with available data, accounting for a three-year cumulative incidence of 21.5% (95% CI = 14.3-28.1). Metachronous CRC-PM occurred in 3/48 patients (6.2%) with negative nodes and normal CEA, as compared with 33/116 patients (28.4%) with positive nodes and/or elevated CEA (p < 0.001). Combined nodal and CEA status (hazard ratio [HR] = 1.27; 95% CI = 1.02-1.59; p = 0.033), postoperative chemotherapy (HR= 0.51; 95% CI = 0.33-0.77; p = 0.001), and positive resection margins (HR = 2.01; 95% CI = 1.20-3.39; p = 0.008) were significantly associated with PM. Conclusions: The peritoneum is a major site for treatment failure in T4 CRC. Patients with normal CEA and negative lymph nodes are associated with a significantly lower risk for metachronous CRC-PM. These findings may help in refining patient selection for integrated approaches aiming at the prevention or early treatment of CRC-PM, which are pending validation in prospective studies.

Development and validation of cancer-specific survival prediction nomogram for patients with T4 stage colon cancer after surgical resection: a population-based study

PURPOSE

The increasing incidence of colorectal cancer has coincided with a rise in T4 stage colon cancer (CC), yet research on its prognosis remains limited. This study aimed to identify risk factors and develop a nomogram to predict cancer-specific survival (CSS), optimizing treatment strategies for different subgroups.

METHODS

Using data from the from the Surveillance, Epidemiology, and End Results (SEER) database, we identified risk factors in T4 stage CC patients and created a nomogram to predict CSS. Patients were divided into low- and high-risk groups, and the nomogram was validated. Propensity score matching was used to evaluate the benefits of various therapies across subgroups.

RESULTS

Independent risk factors, including T stage, N stage, tumor grade, age, and therapy sequence, were identified through Cox regression analyses and incorporated into the nomogram. The nomogram outperformed the American Joint Committee on Cancer (AJCC) 7th staging system, with a Concordance-index of 0.77 in both training and validation sets. The receiver operating characteristic curves showed area under the curve values of 0.81, 0.77, and 0.75 for 1-, 3-, and 5-year CSS, respectively. Calibration plots confirmed strong alignment between predicted and actual outcomes, and decision curve analysis highlighted the nomogram's superior clinical utility. Chemotherapy significantly improved CSS, while radiation did not. Adjuvant therapy was particularly beneficial in high-risk groups.

CONCLUSION

This study offered a thorough prognostic analysis of T4 stage colon cancer patients and developed nomograms for predicting CSS. Subgroup analyses highlight the potential benefits of various treatment options.

Risk of metachronous peritoneal metastases after surgery for obstructive colon cancer: Multivariate analysis from a series of 1,085 patients

BACKGROUND

Data in the literature suggest that obstruction is an independent predictor of poor prognosis in colon cancer. Of all possible sites of recurrence, peritoneal metastases are associated with worse survival. Our aim was to report the incidence of metachronous peritoneal metastases from a cohort of patients undergoing resection of obstructive colon cancer with curative intent and to identify predictive factors for metachronous peritoneal metastases.

METHODS

From 2000 to 2015, a total of 2,325 patients were treated for obstructive colon cancer in French surgical centers, members of the French National Surgical Association (AFC). Patients with palliative management, synchronous metastatic disease, and with postoperative mortality were excluded. A multivariate analysis was performed to determine independent predictive factors of metachronous peritoneal metastases.

RESULTS

The cohort included 1,085 patients. The median follow-up was 21.5 months. Metachronous peritoneal metastases occurred in 12% of patients and were diagnosed after a median interval of 13.5 months. The cumulative 3-year metachronous peritoneal metastasis rate was 10.9%. Three-year overall survival was 85% for patients who did not develop recurrence, 71% for those who develop recurrence without peritoneal metastases, and 56% for those with metachronous peritoneal metastases (P < .0001). In multivariate analysis, 3 variables were identified as independent risk factors for metachronous peritoneal metastases: pT4 stage (odds ratio: 1.98; 95% confidence interval: 1.17-3.36; P = .011), pN2 stage (odds ratio: 2.57; 95% confidence interval: 1.89-4.45; P = .0007), and fewer than 12 lymph nodes examined (odds ratio: 2.01; 95% confidence interval: 1.08-3.74; P = .028).

CONCLUSION

This study showed a significant risk of metachronous peritoneal metastases after curative-intent resection of obstructive colon cancer. The awareness of factors predisposing to metachronous peritoneal metastases could improve the treatment strategy of these patients.

Laparoscopic surgery is associated with increased risk of postoperative peritoneal metastases in T4 colon cancer: a propensity score analysis

BACKGROUND

This study aims to evaluate the postoperative safety, long-term survival, and postoperative peritoneal metastases (PPM) rate associated with laparoscopic surgery (LS) for T4 colon cancer.

MATERIALS AND METHODS

After propensity score matching, there were 68 patients in each of the LS and Open surgery groups. The primary outcomes were the 3-year OS, DFS, and PPM rates.

RESULTS

After matching, 68 patients in each of the groups. The LS group had a higher cumulative 3-year peritoneal metastasis rate (19.8% vs. 6.7%, P = .036), while the 3-year OS (82.3% vs. 83.8%, P = .750) and 2-year DFS (69.0% vs. 75.7%, P = .310) showed no significant difference, compared to the open surgery group. The LS group had a significantly longer operation time (201 ± 85.7 min vs. 164 ± 65.9 min, P = .008) but less postoperative complications (P = .036). Additionally, patients in the LS group removed gastric tube more quickly (1.91 ± 1.18 days vs. 2.69 ± 2.41 days, P = .048). The multivariate analysis revealed that LS (HR = 3.496, 95% CI = 1.108-11.030, P = .033), underweight (HR = 11.650, 95% CI = 2.155-62.990, P = .004), and lymphovascular invasion (HR = 3.123, 95% CI = 1.010-9.664, P = .048) were all predictive factors of PPM. For the pN + subgroup, the 3-year cumulative PPM rate was 29.6% in the LS group, significantly higher than 15.3% in the open group (P = .029), but there was no significant difference after PSM (P = .100).

CONCLUSION

LS offers faster postoperative recovery and comparable long-term survival outcomes. Therefore, it should remain a viable option for locally advanced T4 colon cancer. However, it is crucial to fully recognize the potential risk of increased PPM associated with LS, especially in patients with preoperative suspicion of positive lymph nodes. Further multicenter prospective studies are necessary to validate the potential risks of LS and gain insight into treatment efficacy in different patient populations. In addition, future studies should assess prognosis based on the grade and extent of peritoneal dissemination to provide a more nuanced understanding.

Staging Paradox and recurrence pattern among stage IIB, IIC, and IIIA Colon cancers: a retrospective cohort study

PURPOSE

The survival rates of patients with stage IIB and IIC colon cancer are paradoxically inferior to that of patients with stage IIIA colon cancer. This study aimed to examine the oncological outcomes and investigate the factors that could affect the staging paradox among stage IIB, IIC, and IIIA colon cancers based on a 9-year cancer database.

METHODS

Patients with stage IIB (pT4aN0M0), IIC (pT4bN0M0), or IIIA (pT1-2N1M0) colon cancer were retrospectively selected from a prospectively maintained medical database from January 2011 to December 2019. Factors that might influence the staging paradox, including radicality, harvested lymph nodes, and chemotherapy administration, were examined.

RESULTS

A total of 282 patients (stage IIB, n = 59; stage IIC, n = 46; and stage IIIA, n = 177) were enrolled. Patients with stage IIB/C cancer demonstrated higher carcinoembryonic antigen levels, larger tumor size, more frequent tumor obstruction, and higher locoregional recurrence than those with stage IIIA cancer. With respect to 10-year locoregional recurrence-free survival and cancer-specific survival, patients with stage IIB and IIC cancers had significantly lower survival rates than did those with stage IIIA cancer (73.7% vs. 66.3% vs. 91.2%, P = 0.0003; 5.4% vs. 10.9% vs. 11.2%, P = 0.0023). The staging paradox persisted in patients who underwent R0 resection, had harvested lymph nodes ≥ 12, and received chemotherapy, as confirmed by multivariate regression analysis.

CONCLUSIONS

Based on the inferior oncological outcomes and higher locoregional recurrence rate, this study highlighted the need for intensified cytotoxic chemotherapy specific to this recurrence pattern for patients with stage IIB/C colon cancer.

Prospective observational non-randomized trial protocol for surgical planner 3D image processing & reconstruction for locally advanced colon cancer

INTRODUCTION

Colon cancer presents significant surgical challenges that necessitate the development of precise strategies. Standardization with complete mesocolic excision (CME) is common, but some cases require extended resections. This study investigates the use of 3D Image Processing and Reconstruction (3D-IPR) to improve diagnostic accuracy in locally advanced colon cancer (LACC) with suspected infiltration and achieve R0 surgery.

METHODS

Single-center, prospective, observational, comparative, non-randomized study. •Participants: Patients aged > 18 years undergoing LACC surgery, as indicated by CT scans, confirmed via colonoscopy. Exclusion criteria include neoadjuvant therapy, suspected carcinomatosis on CT, and unresectable tumors. •Interventions: 3D-IPR models are used for surgical planning, providing detailed tumor and surrounding structure metrics. Surgical procedures are guided by CT scans and intraoperative findings, categorized by surgical margins as R0, R1, or R2. •Objective: The primary goal is to evaluate 3D-IPR's utility in achieving R0 resection in LACC with suspected infiltration. Secondary objectives include assessing preoperative surgical strategy, comparing CT reports, detecting adenopathy, and identifying vascularization and anatomical variants. • Outcome: The main outcome is the diagnostic accuracy of 3D-IPR in determining tumor infiltration of neighboring structures compared to conventional CT scans, using definitive pathological reports as the gold standard.

RESULTS

•Recruitment and Number Analyzed: The study aims to recruit about 20 patients annually over two years, focusing on preoperative 3D-IPR analysis and subsequent surgical procedures. •Outcome Parameters: These include loco-regional and distant recurrence rates, peritoneal carcinomatosis, disease-free and overall survival, and mortality due to oncologic progression. •Harms: No additional risks from CT scans, as they are mandatory for staging colon tumors. 3D-IPR is derived from these CT scans.

DISCUSSION

If successful, this study could provide an objective tool for precise tumor extension delimitation, aiding decision-making for radiologists, surgeons, and multidisciplinary teams. Enhanced staging through 3D-IPR may influence therapeutic strategies, reduce postsurgical complications, and improve the quality of life of patients with LACC.

TRIAL REGISTRATION

Trial is registered at ISRCTN registry as ISRCTN81005215. Protocol version I (Date 29/06/2023).

Does Adjuvant Chemotherapy Benefit Patients with T4 N0 Colon Cancer?

Background and Objectives: Colorectal cancer (CRC) poses a major global health challenge, with high incidence rates and ongoing treatment debates. Adjuvant chemotherapy benefits for high-risk subgroups, particularly stage II disease, remain controversial. This study seeks to clarify this issue by specifically examining the impact of adjuvant chemotherapy on disease-free survival (DFS) and overall survival (OS) in patients diagnosed with T4 colon cancer. Materials and Methods: This retrospective study analyzed patients undergoing radical surgery for T4 colon cancer between 2002 and 2023. Results: Our study of 184 pT4 pN0 colon cancer patients revealed that 79.3% received adjuvant chemotherapy. Multivariate analysis demonstrated significant DFS improvement: a 60% reduction in risk for those who received adjuvant therapy (0.40 95% CI: 0.25-0.62, p < 0.001). Lymphovascular invasion (LVI) and adjuvant treatment were also significantly associated with OS. Adjuvant treatment reduced mortality by 60% (HR: 0.40, 95% CI: 0.23-0.68, p = 0.001). Patients with LVI had a 1.9-fold increase in mortality (HR: 1.94, 95% CI: 1.17-3.20, p = 0.011). These findings underscore the potential value of adjuvant chemotherapy and highlight the importance of treatment completion in managing T4 colon cancer. Conclusions: Our study identifies LVI and adjuvant chemotherapy as key prognostic factors in T4 colon cancer patients. These results support the consideration of adjuvant chemotherapy in this patient population.

Prophylactic hyperthermic intraperitoneal chemotherapy in T4 colorectal cancer: Can it improve the oncologic prognosis? - A propensity score matching study

BACKGROUND

Some studies show that cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (HIPEC) may improve overall survival and is a possible curative treatment for selected colorectal cancer (CRC) patients with restricted peritoneal metastasis (PM). The value of HIPEC in preventing PM of CRC is still controversial.

MATERIALS AND METHODS

In this retrospective propensity score matching (PSM) cohort study, all patients with cT4N0-2M0 undergoing treatment at a single institution in China (2014-2018) were reviewed. The 3-year disease-free survival (DFS) was set as the primary outcome, and the 3-year PM rate was also analyzed.

RESULTS

220 patients were included in this study for analysis. After 1:3 PSM: HIPEC (n = 45) and No HIPEC (n = 135). Through analysis, it was found that prophylactic HIPEC correlated to better DFS [hazard ratio (HR) 0.43, 95 % confidence interval (CI) 0.19-0.95; p = 0.037], and N2 stage correlated to worse DFS [HR 1.97, 95 % CI 1.09-3.56; p = 0.025]. For laparoscopic surgery subgroup analyses, 3-year PM rate of patients with laparoscopic surgery was 13.8 % in No HIPEC group, and 2.6 % in HIPEC group (p = 0.070). Besides, no post-operative death occurred, the anastomotic leakage rate was 2.2 % in HIPEC group and 0.7 % in the control group (p = 0.439).

CONCLUSIONS

Prophylactic HIPEC may improve the prognosis in patients with cT4N0-1M0 CRC, but not in cT4N2M0 CRC, and it does not significantly increase surgery-related complications. Laparoscopic surgery followed by HIPEC for T4 stage CRC may not increase risk of PM.

Recommendations for the optimal management of peritoneal metastases in patients with colorectal cancer: a TTD and GECOP-SEOQ expert consensus statement

Peritoneal metastases (PM) occur when cancer cells spread inside the abdominal cavity and entail an advanced stage of colorectal cancer (CRC). Prognosis, which is poor, correlates highly with tumour burden, as measured by the peritoneal cancer index (PCI). Cytoreductive surgery (CRS) in specialized centres should be offered especially to patients with a low to moderate PCI when complete resection is expected. The presence of resectable metastatic disease in other organs is not a contraindication in well-selected patients. Although several retrospective and small prospective studies have suggested a survival benefit of adding hyperthermic intraperitoneal chemotherapy (HIPEC) to CRS, the recently published phase III studies PRODIGE-7 in CRC patients with PM, and COLOPEC and PROPHYLOCHIP in resected CRC with high-risk of PM, failed to show any survival advantage of this strategy using oxaliplatin in a 30-min perfusion. Final results from ongoing randomized phase III trials testing CRS plus HIPEC based on mitomycin C (MMC) are awaited with interest. In this article, a group of experts selected by the Spanish Group for the Treatment of Digestive Tumours (TTD) and the Spanish Group of Peritoneal Oncologic Surgery (GECOP), which is part of the Spanish Society of Surgical Oncology (SEOQ), reviewed the role of HIPEC plus CRS in CRC patients with PM. As a result, a series of recommendations to optimize the management of these patients is proposed.

Epidemiology, oncologic results and risk stratification model for metachronous peritoneal metastases after surgery for pT4 colon cancers: results from an observational retrospective multicentre long-term follow-up study

PURPOSE

Metachronous peritoneal metastases (MPM) following a curative surgery procedure for pT4 colon cancer is a challenging condition. Current epidemiological studies on this topic are scarce.

METHODS

A retrospective multicentre trial was designed. All consecutive patients who underwent operations to treat pT4 cancers between 2015 and 2017 were reviewed. Demographic, clinical, operative, pathological and oncological follow-up variables were included. MPM were described as any oncological disease at the peritoneum, clearly different from a local recurrence. Univariate and multivariate Cox regression models were constructed. A risk stratification model was created on a cumulative factor basis. According to the calculated hazard ratio (HR), a scoring system was designed (HR < 3, 1 point; HR > 3, 2 points) and a scale from 0 to 6 was calculated for peritoneal disease-free rate (PDF-R). A risk stratification model was also created on the basis of these calculations.

RESULTS

Fifty different hospitals were involved, which included a total of 1356 patients. Incidence of MPM was 13.6% at 50 months median follow-up. The strongest independent risk factors for MPM were positive pN stage [HR 3.72 (95% CI 2.56-5.41; p < 0.01) for stage III disease], tumour perforation [HR 1.91 (95% CI 1.26-2.87; p < 0.01)], mucinous or signet ring cell histology [HR 1.68 (95% CI 1.1-2.58; p = 0.02)], poorly differentiated tumours [HR 1.54 (95% CI 1.1-2.2; p = 0.02)] and emergency surgery [HR 1.42 (95% CI 1.01-2.01; p = 0.049)]. In the absence of additional risk factors, pT4 tumours showed 98% and 96% PDF-R in 1-year and 5-year periods based on Kaplan-Meier curves.

CONCLUSIONS

Cumulative MPM incidence was 13.6% at 5-year follow-up. The sole presence of a pT4 tumour resulted in high rates of PDF-R at 1-year and 5-year follow-up (98% and 96% respectively). Five additional risk factors different from pT4 status itself were identified as possible MPM indicators during follow-up.

Development of a Nomogram to Predict Postoperative Peritoneal Metastasis of Colon Cancer

OBJECTIVE

The aim of this study was to determine the clinicopathological and radiological risk factors for postoperative peritoneal metastasis and develop a prediction model for the early detection of peritoneal metastasis in patients with colon cancer.

METHODS

We included 174 patients with colon cancer. The clinicopathological and radiological data were retrospectively analyzed. A Cox proportional hazards regression model was used to identify risk factors for postoperative peritoneal metastasis. Based on these risk factors, a nomogram was developed.

RESULTS

At a median follow-up of 63 months, 43 (24.7%) patients developed peritoneal metastasis. Six independent risk factors (hazards ratio [95% confidence interval]) were identified for postoperative peritoneal metastasis: abdominopelvic fluid (2.12 [1.02-4.40]; P = 0.04), longer maximum tumor length (1.02 [1.00-1.03]; P = 0.02), pN1 (2.50 [1.13-5.56]; P = 0.02), pN2 (4.45 [1.77-11.17]; P = 0.02), nonadenocarcinoma (2.75 [1.18-6.38]; P = 0.02), and preoperative carcinoembryonic antigen levels ≥5 ng/mL (3.08 [1.50-6.30]; P < 0.01). A clinicopathological-radiological model was developed based on these factors. The model showed good discrimination (concordance index, 0.798 [0.723-0.876]; P < 0.001) and was well-calibrated.

CONCLUSIONS

The developed clinicopathological-radiological nomogram may assist clinicians in identifying patients at high risk of postoperative peritoneal metastasis.

Laparoscopic cytoreductive surgery and hyperthermic intraperitoneal chemotherapy: Long term oncologic outcomes from the international PSOGI registry

The laparoscopic approach for cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (L-CRS + HIPEC) in highly selected patients was previously reported from the PSOGI registry with a demonstrable reduction in length of stay and post-operative morbidity. This study aims to update this international PSOGI registry with a larger cohort of patients and a longer follow-up period.

METHODS

An international registry was designed through a networking database (REDCAP®). All centers performing L-CRS + HIPEC were invited through PSOGI to submit data on their cases. Variables such as demographics, clinical outcomes, and survival were analyzed.

RESULTS

A total of 315 L-CRS + HIPEC cases were provided by 14 worldwide centers. A total of 215 patients were included in the L-CRS + HIPEC group. The median peritoneal cancer index (PCI) was 3 (3-5). The median length of stay was 7 days (5-10) and the major morbidity (Clavien-Dindo ≥3) was 6.1% after 30 days. The 5-year disease-free survival (DFS) per tumor origin was: 94% for PMP-LG, 85% for PMP-HG, 100% for benign multicyst peritoneal mesothelioma (MPM), 37.4% for colonic origin, and 54%(at 3 years) for ovarian origin. The 5 years overall survival (OS) per tumor origin was: 100% for PMP-LG, PMP-HG and MPM; 61% for colonic origin, and 74% (at 3 years) for ovarian origin. In addition, a total of 85 patients were analyzed in the laparoscopic risk-reducing HIPEC (L-RR + HIPEC). The median length of stay was 5 days (4-6) and the major morbidity was 6% after 30 days. The 5-year DFS per tumor origin was: 96% for perforated low grade appendiceal mucinous neoplasm (LAMN II) and 68.1% for colon origin. The 5 years OS per tumor origin was: 98% for LAMN II and 83.5% for colonic origin.

CONCLUSIONS

Minimally invasive CRS + HIPEC is a safe procedure for selected patients with peritoneal carcinomatosis in specialized centers. It improves perioperative results while providing satisfactory oncologic outcomes. L-RR + HIPEC represents a promising strategy that could be evaluated in patients with high risk of developing peritoneal carcinomatosis into prospective randomized trials.

Efficacy and Safety of Intraoperative Hyperthermic Intraperitoneal Chemotherapy for Locally Advanced Colon Cancer: A Phase 3 Randomized Clinical Trial

IMPORTANCE

Peritoneal metastasis in patients with locally advanced colon cancer (T4 stage) is estimated to recur at a rate of approximately 25% at 3 years from surgical resection and is associated with poor prognosis. There is controversy regarding the clinical benefit of prophylactic hyperthermic intraperitoneal chemotherapy (HIPEC) in these patients.

OBJECTIVE

To assess the efficacy and safety of intraoperative HIPEC in patients with locally advanced colon cancer.

DESIGN, SETTING, AND PARTICIPANTS

This open-label, phase 3 randomized clinical trial was conducted in 17 Spanish centers from November 15, 2015, to March 9, 2021. Enrolled patients were aged 18 to 75 years with locally advanced primary colon cancer diagnosed preoperatively (cT4N02M0).

INTERVENTIONS

Patients were randomly assigned 1:1 to receive cytoreduction plus HIPEC with mitomycin C (30 mg/m2 over 60 minutes; investigational group) or cytoreduction alone (comparator group), both followed by systemic adjuvant chemotherapy. Randomization of the intention-to-treat population was done via a web-based system, with stratification by treatment center and sex.

MAIN OUTCOMES AND MEASURES

The primary outcome was 3-year locoregional control (LC) rate, defined as the proportion of patients without peritoneal disease recurrence analyzed by intention to treat. Secondary end points were disease-free survival, overall survival, morbidity, and rate of toxic effects.

RESULTS

A total of 184 patients were recruited and randomized (investigational group, n = 89; comparator group, n = 95). The mean (SD) age was 61.5 (9.2) years, and 111 (60.3%) were male. Median duration of follow-up was 36 months (IQR, 27-36 months). Demographic and clinical characteristics were similar between groups. The 3-year LC rate was higher in the investigational group (97.6%) than in the comparator group (87.6%) (log-rank P = .03; hazard ratio [HR], 0.21; 95% CI, 0.05-0.95). No differences were observed in disease-free survival (investigational, 81.2%; comparator, 78.0%; log-rank P = .22; HR, 0.71; 95% CI, 0.41-1.22) or overall survival (investigational, 91.7%; comparator, 92.9%; log-rank P = .68; HR, 0.79; 95% CI, 0.26-2.37). The definitive subgroup with pT4 disease showed a pronounced benefit in 3-year LC rate after investigational treatment (investigational: 98.3%; comparator: 82.1%; log-rank P = .003; HR, 0.09; 95% CI, 0.01-0.70). No differences in morbidity or toxic effects between groups were observed.

CONCLUSIONS AND RELEVANCE

In this randomized clinical trial, the addition of HIPEC to complete surgical resection for locally advanced colon cancer improved the 3-year LC rate compared with surgery alone. This approach should be considered for patients with locally advanced colorectal cancer.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02614534.

Recurrence After Colectomy for Locally Advanced Colon Cancer: Experience from a Developing Country

Risk factors for disease recurrence following curative resection for locally advanced colon cancer (LACC) remain unclear as conflicting results have been reported in the literature. The aim of this study was to examine these factors in the setting of developing country's health care system affected by limited accessibility to the multimodal cancer treatment. Patients who had undergone curative colon resection for LACC between 2004 and 2018 were included. Data were obtained from a prospectively maintained database. Factors associated with disease recurrence, types of recurrence and recurrence-free survival were studied. A total of 118 patients with LACC were operated within the study period. Median follow-up was 36 (2-147) months. Adjuvant therapy was used in 41 (34.7%) patients and 62 (52.5%) were diagnosed with recurrence. In the multivariable analysis, disease recurrence was associated with tumor and nodal stages, as well as with the lymph node yield. Local recurrence, distant metastases, and peritoneal carcinomatosis were observed in 8 (6.8%), 30 (25.4%), and 24 (20.3%) patients, respectively. Early recurrence was diagnosed in 27 (22.9%) cases with peritoneal carcinomatosis being its most common type. Preoperative serum CA 19-9 levels, tumor, and nodal stages were linked to recurrence-free survival in the univariable analysis. Only tumor stage remained such in the multivariable model. Our findings suggest that lymph node yield, tumor, and nodal stages are associated with recurrence following curative resection for LACC.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13193-022-01672-x.

Development and validation of a nomogram for predicting metachronous peritoneal metastasis in colorectal cancer: A retrospective study

BACKGROUND

Peritoneal metastasis (PM) after primary surgery for colorectal cancer (CRC) has the worst prognosis. Prediction and early detection of metachronous PM (m-PM) have an important role in improving postoperative prognosis of CRC. However, commonly used imaging methods have limited sensitivity to detect PM early. We aimed to establish a nomogram model to evaluate the individual probability of m-PM to facilitate early interventions for high-risk patients.

AIM

To establish and validate a nomogram model for predicting the occurrence of m-PM in CRC within 3 years after surgery.

METHODS

We used the clinical data of 878 patients at the Second Hospital of Jilin University, between January 1, 2014 and January 31, 2019. The patients were randomly divided into training and validation cohorts at a ratio of 2:1. The least absolute shrinkage and selection operator (LASSO) regression was performed to identify the variables with nonzero coefficients to predict the risk of m-PM. Multivariate logistic regression was used to verify the selected variables and to develop the predictive nomogram model. Harrell’s concordance index, receiver operating characteristic curve, Brier score, and decision curve analysis (DCA) were used to evaluate discrimination, distinctiveness, validity, and clinical utility of this nomogram model. The model was verified internally using bootstrapping method and verified externally using validation cohort.

RESULTS

LASSO regression analysis identified six potential risk factors with nonzero coefficients. Multivariate logistic regression confirmed the risk factors to be independent. Based on the results of two regression analyses, a nomogram model was established. The nomogram included six predictors: Tumor site, histological type, pathological T stage, carbohydrate antigen 125, v-raf murine sarcoma viral oncogene homolog B mutation and microsatellite instability status. The model achieved good predictive accuracy on both the training and validation datasets. The C-index, area under the curve, and Brier scores were 0.796, 0.796 [95% confidence interval (CI) 0.735-0.856], and 0.081 for the training cohort and 0.782, 0.782 (95%CI 0.690-0.874), and 0.089 for the validation cohort, respectively. DCA showed that when the threshold probability was between 0.01 and 0.90, using this model to predict m-PM achieved a net clinical benefit.

CONCLUSION

We have established and validated a nomogram model to predict m-PM in patients undergoing curative surgery, which shows good discrimination and high accuracy.

Metachronous peritoneal metastases in patients with pT4b colon cancer: An international multicenter analysis of intraperitoneal versus retroperitoneal tumor invasion

BACKGROUND

It was hypothesized that colon cancer with only retroperitoneal invasion is associated with a low risk of peritoneal dissemination. This study aimed to compare the risk of metachronous peritoneal metastases (mPM) between intraperitoneal and retroperitoneal invasion.

METHODS

In this international, multicenter cohort study, patients with pT4bN0-2M0 colon cancer who underwent curative surgery were categorized as having intraperitoneal invasion (e.g. bladder, small bowel, stomach, omentum, liver, abdominal wall) or retroperitoneal invasion only (e.g. ureter, pancreas, psoas muscle, Gerota's fascia). Primary outcome was 5-year mPM cumulative rate, assessed by Kaplan-Meier analysis.

RESULTS

Out of 907 patients with pT4N0-2M0 colon cancer, 198 had a documented pT4b category, comprising 170 patients with intraperitoneal invasion only, 12 with combined intra- and retroperitoneal invasion, and 16 patients with retroperitoneal invasion only. At baseline, only R1 resection rate significantly differed: 4/16 for retroperitoneal invasion only versus 8/172 for intra- +/- retroperitoneal invasion (p = 0.010). Overall, 22 patients developed mPM during a median follow-up of 45 months. Two patients with only retroperitoneal invasion developed mPM, both following R1 resection. The overall 5-year mPM cumulative rate was 13% for any intraperitoneal invasion and 14% for retroperitoneal invasion only (Log Rank, p = 0.878), which was 13% and 0%, respectively, in patients who had an R0 resection (Log Rank, p = 0.235).

CONCLUSION

This study suggests that pT4b colon cancer patients with only retroperitoneal invasion who undergo an R0 resection have a negligible risk of mPM, but this is difficult to prove because of its rarity. This observation might have implications regarding individualized follow-up.

Risk factors for metachronous peritoneal carcinomatosis after radical resection for patients with nonmetastatic pT3-4 colon cancer

BACKGROUND

Patients with nonmetastatic pT3-4 colon cancers are prone to develop metachronous peritoneal carcinomatosis (mPC). Risk factors for mPC and the influence of mutant kirsten rat sarcoma viral oncogene (KRAS)/neuroblastoma rat sarcoma (NRAS)/v-raf murine sarcoma viral oncogene homolog B1 (BRAF) and DNA mismatch repair (MMR) status on mPC remain to be described in these patients.

METHOD

All enrolled patients were identified from the prospectively collected colorectal cancer database of a tertiary referral hospital between 2013 and 2018. Multivariate analysis was used to identify risk factors associated with mPC.

RESULTS

Of the 1689 patients with nonmetastatic pT3-4 colon carcinoma, 8.4% (142/1689) progressed to mPC. Endoscopic obstruction (HR = 3.044, p < 0.001), elevated CA125 (HR = 1.795, p = 0.009), pT (T4a vs. T3, HR = 2.745, p < 0.001; T4b vs. T3, HR = 3.167, p = 0.001), pN (N1 vs. N0, HR = 2.592, p < 0.001; N2 vs. N0, HR = 4.049, p < 0.001), less than 12 lymph nodes harvested (HR = 2.588, p < 0.001), mucinous or signet ring cell carcinoma (HR = 1.648, p = 0.038), perineural invasion (HR = 1.984, p < 0.001), and adjuvant chemotherapy (HR = 1.522, p = 0.039) were strongly related to mPC but that mutant KRAS/NRAS/BRAF and MMR status was not associated with mPC.

CONCLUSION

This study identified the high-risk factors for mPC in patients with nonmetastatic pT3-4 colon carcinoma, and these factors should be considered in selective preventive therapy and close follow-up for patients subsequently deemed to have high risk for mPC.

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.