Clinical Outcomes of Neoadjuvant Chemotherapy in Colorectal Cancer Patients With Synchronous Resectable Liver Metastasis: A Propensity Score Matching Analysis

Colon cancer: the 2023 Korean clinical practice guidelines for diagnosis and treatment

Colorectal cancer is the third most common cancer in Korea and the third leading cause of death from cancer. Treatment outcomes for colon cancer are steadily improving due to national health screening programs with advances in diagnostic methods, surgical techniques, and therapeutic agents.. The Korea Colon Cancer Multidisciplinary (KCCM) Committee intends to provide professionals who treat colon cancer with the most up-to-date, evidence-based practice guidelines to improve outcomes and help them make decisions that reflect their patients' values and preferences. These guidelines have been established by consensus reached by the KCCM Guideline Committee based on a systematic literature review and evidence synthesis and by considering the national health insurance system in real clinical practice settings. Each recommendation is presented with a recommendation strength and level of evidence based on the consensus of the committee.

Recurrence Patterns and Risk Factors after Curative Resection for Colorectal Cancer: Insights for Postoperative Surveillance Strategies

This study aimed to assess recurrence patterns and related risk factors following curative resection of colorectal cancer (CRC). This retrospective observational study was conducted at a tertiary care center, including 2622 patients with stage I-III CRC who underwent curative resection between 2008 and 2018. Hazard rates of recurrence were calculated using a hazard function. The primary outcome was the peak recurrence time after curative resection and secondary outcomes were prognostic factors associated with recurrence. Over a median follow-up period of 53 months, the overall, locoregional and systemic recurrence rates were 8.9%, 0.7%, and 8.5%, respectively. Recurrence rates were significantly higher for rectal cancer (14.9% overall, 4.4% locoregionally, and 12.3% systemically) than for colon cancer (all p < 0.001). The peak recurrence time was 11 months, with variations in hazard rates and curves depending on the tumor location, stage, and risk factors. Patients with AL or CRM involvement exhibited a distinct pattern, with a high hazard rate in the early postoperative period. Understanding these recurrence patterns and risk factors is crucial for establishing effective postoperative surveillance strategies. Our findings suggested that short-interval surveillance should be considered during the first 2 years post-surgery, particularly for high-risk patients who should receive early attention.

Fluorescence-guided colorectal surgery: applications, clinical results, and protocols

In recent years, the rise of minimally invasive surgery has driven the development of surgical devices. Indocyanine green (ICG) fluorescence imaging is receiving increased attention in colorectal surgery for improved intraoperative visualization and decision-making. ICG, approved by the U.S. Food and Drug Administration in 1959, rapidly binds to plasma proteins and is primarily intravascular. ICG absorption of near-infrared light (750-800 nm) and emission as fluorescence (830 nm) when bound to tissue proteins enhances deep tissue visualization. Applications include assessing anastomotic perfusion, identifying sentinel lymph nodes, and detecting colorectal cancer metastasis. However, standardized protocols and research on clinical outcomes remain limited. This study explores ICG's role, advantages, disadvantages, and potential clinical impact in colorectal surgery.

Survival of patients with colorectal liver metastases treated with and without preoperative chemotherapy: Nationwide propensity score-matched study

INTRODUCTION

Routine treatment with preoperative systemic chemotherapy (CTx) in patients with colorectal liver metastases (CRLM) remains controversial due to lack of consistent evidence demonstrating associated survival benefits. This study aimed to determine the effect of preoperative CTx on overall survival (OS) compared to surgery alone and to assess hospital and oncological network variation in 5-year OS.

METHODS

This was a population-based study of all patients who underwent liver resection for CRLM between 2014 and 2017 in the Netherlands. After 1:1 propensity score matching (PSM), OS was compared between patients treated with and without preoperative CTx. Hospital and oncological network variation in 5-year OS corrected for case-mix factors was calculated using an observed/expected ratio.

RESULTS

Of 2820 patients included, 852 (30.2%) and 1968 (69.8%) patients were treated with preoperative CTx and surgery alone, respectively. After PSM, 537 patients remained in each group, median number of CRLM; 3 [IQR 2-4], median size of CRLM; 28 mm [IQR 18-44], synchronous CLRM (71.1%). Median follow-up was 80.8 months. Five-year OS rates after PSM for patients treated with and without preoperative chemotherapy were 40.2% versus 38.3% (log-rank P = 0.734). After stratification for low, medium, and high tumour burden based on the tumour burden score (TBS) OS was similar for preoperative chemotherapy vs. surgery alone (log-rank P = 0.486, P = 0.914, and P = 0.744, respectively). After correction for non-modifiable patient and tumour characteristics, no relevant hospital or oncological network variation in five-year OS was observed.

CONCLUSION

In patients eligible for surgical resection, preoperative chemotherapy does not provide an overall survival benefit compared to surgery alone.

Applications of propensity score matching: a case series of articles published in Annals of Coloproctology

Propensity score matching (PSM) is an increasingly applied method of ensuring comparability between groups of interest. However, PSM is often applied unconditionally, without precise considerations. The purpose of this study is to provide a nonmathematical guide for clinicians at the stage of designing a PSM-based study. We provide a seed of thought for considering whether applying PSM would be appropriate and, if so, the scope of the list of variables. Although PSM may be simple, its results could vary substantially according to how the propensity score is constructed. Misleading results can be avoided through a critical review of the process of PSM.

Molecular Analyses in Peritoneal Metastasis from Colorectal Cancer: A Review-An English Version

Despite a trend showing continued improvement in survival by combing targeted agents in colorectal cancer, the improvement was limited, and clinically meaningful benefits were not achieved in peritoneal metastasis. The role of cytoreductive surgery (CRS) and proportion of the benefit from hyperthermic intraperitoneal chemotherapy (HIPEC) have been questioned. The PRODIGE 7 study aimed to assess the specific contribution of HIPEC to the survival benefit of peritoneal metastasis from colorectal cancer (CRC-PM) by grouping CRS alone versus CRS with oxaliplatin-based HIPEC, but failed to show any survival improvement. Of these criticisms, oxaliplatin resistance was suggested as the main cause of the negative result. In this regard, the relative resistance to oxaliplatin in consensus molecular subtype 4 colorectal cancer (CRC) is of great interest. Recent treatments for metastatic CRC have gradually moved to precision medicine based on individual biological information through high-throughput technology such as next generation sequencing. This review aimed to provide an overview of the current status of studies reporting the molecular knowledge of CRC-PM.

Recent Advance in the Surgical Treatment of Metastatic Colorectal Cancer-An English Version

Stage IV colorectal cancer (CRC) has heterogeneous characteristics in tumor extent and biology. The overall survival of patients with metastatic CRC has improved with the development of multimodal treatments and new chemotherapeutic drugs. Resection of metastatic CRC is performed for liver, lung, or peritoneal metastases. Conversion surgeries to resect oligometastatic lesions have been developed with tumor regression using chemotherapeutic agents. Two-stage hepatectomy has extended the surgical indications for patients with metastatic CRC. Synchronous liver and primary tumor resection can be considered in patients with adequate conditions. Local ablation with radiotherapy can be used to treat lung metastasis. In the treatment of patients with CRC with peritoneal metastasis, cytoreductive surgery with hyperthermic intraperitoneal chemotherapy can be considered. Surgical treatments should be performed in patients with symptomatic primary tumors with unresectable metastasis. However, primary tumor resection in patients with asymptomatic CRC with synchronous, unresectable metastases did not show overall survival benefits in recent studies. Therefore, the treatment of metastatic CRC is challenging due to the variable tumor extent and heterogenous characteristics. Tailored surgical treatments and multidisciplinary approaches may improve survival and the quality of life in patients with metastatic CRC.

Oncological outcomes of neoadjuvant chemotherapy in patients with resectable synchronous colorectal liver metastasis: A result from a propensity score matching study

Background

The efficacy and safety of neoadjuvant chemotherapy (NAC) in treating resectable synchronous colorectal liver metastases (CRLM) remain controversial.

Methods

Data from CRLM patients who underwent simultaneous liver resection between January 2015 and December 2019 were collected from the Surveillance, Epidemiology, and End Results (SEER) database (SEER cohort, n=305) and a single Chinese Cancer Center (NCC cohort, n=268). Using a 1:2 ratio of propensity score matching (PSM), the prognostic impact of NAC for patients who underwent NAC before surgical treatment and patients who underwent surgical treatment alone was evaluated.

Results

After PSM, there was no significant difference in overall survival (OS) between patients receiving NAC prior to CRLM resection and those undergoing surgery only, in both the NCC and SEER cohorts (each P &gt; 0.05). Age was an independent predictor of OS only in the SEER cohort (P = 0.040), while the pN stage was an independent predictor for OS only in the NCC cohort (P = 0.002). Furthermore, Disease-free survival (DFS) was comparable between the two groups in the NCC cohort. In a subgroup analysis, the DFS and OS in the NAC- group were significantly worse than those in the NAC+ group for patients with more than two liver metastases in the NCC cohort (P &lt; 0.05 for both).

Conclusion

NAC did not have a significant prognostic impact in patients with resectable synchronous CRLM. However, patients with more than two liver metastases could be good candidates for receiving NAC.

Surgical treatment for metastatic colorectal cancer

Background: Stage IV colorectal cancer (CRC) exhibits heterogeneous characteristics in tumor extent and biology. The overall survival of patients with metastatic CRC has improved with the development of multimodal treatments and new chemotherapeutic drugs.Current Concepts: Resection of metastatic CRC is performed for liver, lung, or peritoneal metastases. Conversion surgeries to resect oligometastatic lesions have been developed with tumor regression using chemotherapeutic agents. Two-stage hepatectomy has extended the surgical indications for patients with metastatic CRC. Synchronous liver and primary tumor resection can be considered in patients with adequate conditions. Local ablation with radiotherapy can be used to treat lung metastasis. Meanwhile, for treating patients with CRC with peritoneal metastasis, cytoreductive surgery with hyperthermic intraperitoneal chemotherapy can be considered. Surgical treatments should be performed in patients with symptomatic primary tumors with unresectable metastasis. However, in recent studies, primary tumor resection in patients with asymptomatic CRC with synchronous, unresectable metastases did not show overall survival benefits.Discussion and Conclusion: The treatment of metastatic CRC is challenging because of the variable tumor extent and heterogenous characteristics. Tailored surgical treatments and multidisciplinary approaches may improve the survival and quality of life of patients with metastatic CRC.

Direction of diagnosis and treatment improvement in colorectal cancer

Background: Cancer is a major public health problem and the leading cause of death in Korea since 2000. Colorectal cancer is the third leading cause of cancer-related death. Therefore, early detection through screening, surgical techniques improvement, anticancer drugs, adjuvant treatment, and medical resources advancement is important to reduce colorectal cancer-related mortality.Current Concepts: In Korea, the 5-year relative survival rate of patients with colorectal cancer is approximately mid-70%, which is superior to other developed countries, such as the United States, United Kingdom, and Japan, with 60% to 68% because of the well performed screening program and technical improvement. Efforts are underway to conduct active endoscopic treatment for early colorectal cancer and identify cases requiring surgery. Minimally invasive surgery has evolved beyond conventional applications into disease-specific methods, and the robotic system has an important role for evolvement. Performing metastatic colorectal cancer efforts is necessary to improve the survival rate through active surgical treatment and gene therapy.Discussion and Conclusion: Eventually, the role of the patient’s genetic information in diagnosing and treating colorectal cancer is expected to increase. In some cases, diagnosing colorectal cancer using a non-invasive method is already realized. Active surgical treatment based on personal characteristics contributes in improving the treatment outcomes for difficult-to-treat metastatic colorectal cancer. After the period of overall colorectal cancer treatment results improvement, we will undertake the precision treatment era.

Molecular analyses of peritoneal metastasis from colorectal cancer

Background: Despite a trend showing continued improvement in survival by combing targeted agents for colorectal cancer (CRC), the improvement observed is limited. Moreover, clinically relevant benefits were not achieved in peritoneal metastasis cases. The role of cytoreductive surgery (CRS) and the benefits of hyperthermic intraperitoneal chemotherapy (HIPEC) have been questioned. This review aimed to provide an overview of the current status of the studies reporting on the molecular knowledge of peritoneal metastasis from CRC (CRC-PM).Current Concepts: The PRODIGE 7 study was performed to assess the specific contributions of HIPEC to the survival benefit in CRC-PM cases by comparing CRS treatment alone and CRS with oxaliplatin-based HIPEC. However, this study did not reveal any survival improvement, and oxaliplatin resistance was suggested as the main cause of this negative outcome. Hence, the relative resistance to oxaliplatin in consensus molecular subtype (CMS) 4 CRC is of great interest.Discussion and Conclusion: Recent treatments for metastatic CRC have gradually moved to precision medicine based on individual biological information through high-throughput technology, such as next-generation sequencing. In the transcriptome study, CRC-PM was identified as an almost homogeneous CMS4 classification, which is known to have strong resistance to oxaliplatin-based chemotherapy. These results suggest the need to clarify complex sub-signal transmission pathways derived from transcriptome or proteome studies of CRC-PM. Finally, to compare two studies, it is necessary to establish a representative patient group and consider standardized sample collection, treatment, and analysis.

Surgical safety in the COVID-19 era: present and future considerations

The impacts of coronavirus disease 2019 (COVID-19) have been globally paradigm shifting in all aspects. Surgeons have experienced unprecedented changes regarding operation schedules, preparations before surgery, and the precautions needed both during and after surgery. Many medical centers simultaneously reported a decrease in their numbers of surgeries, whether they were elective or emergent, or for cancerous or benign resections. However, accumulated surgical outcomes from the last 2 years of experience presented postoperative morbidity and mortality data that were comparable to the pre-pandemic era, whether in elective or urgent settings. Although COVID-19 showed a significant association with postoperative morbidity and mortality, the majority of noninfected patients could be treated successfully with stringent mitigation protocols. Initially recommended to be avoided at the start of the pandemic, minimally invasive surgery seems to be safe and feasible according to reported surgical outcomes. Numerous sets of guidelines have now been produced from medical societies and adhering to the basic precautions has been found to be practicable. It is crucial that health care systems and surgical staff remain vigilant and attentive to the ever-changing situation in this pandemic in order to provide optimal medical support to their patients.