Interaction Between Primary Tumor Resection, Primary Tumor Location, and Survival in Synchronous Metastatic Colorectal Cancer: A Population-Based Study

Upfront resection versus no resection of the primary tumor in patients with synchronous metastatic colorectal cancer: the randomized phase III CAIRO4 study conducted by the Dutch Colorectal Cancer Group and the Danish Colorectal Cancer Group

BACKGROUND

Upfront primary tumor resection (PTR) has been associated with longer overall survival (OS) in patients with synchronous unresectable metastatic colorectal cancer (mCRC) in retrospective analyses. The aim of the CAIRO4 study was to investigate whether the addition of upfront PTR to systemic therapy resulted in a survival benefit in patients with synchronous mCRC without severe symptoms of their primary tumor.

PATIENTS AND METHODS

This randomized phase III trial was conducted in 45 hospitals in The Netherlands and Denmark. Eligibility criteria included previously untreated mCRC, unresectable metastases, and no severe symptoms of the primary tumor. Patients were randomized (1 : 1) to upfront PTR followed by systemic therapy or systemic therapy without upfront PTR. Systemic therapy consisted of first-line fluoropyrimidine-based chemotherapy with bevacizumab in both arms. Primary endpoint was OS in the intention-to-treat population. The study was registered at ClinicalTrials.gov, NCT01606098.

RESULTS

Between August 2012 and February 2021, 206 patients were randomized. In the intention-to-treat analysis, 204 patients were included (n = 103 without upfront PTR, n = 101 with upfront PTR) of whom 116 were men (57%) with median age of 65 years (interquartile range 59-71 years). Median follow-up was 69.4 months. Median OS in the arm without upfront PTR was 18.3 months (95% confidence interval 16.0-22.2 months) compared with 20.1 months (95% confidence interval 17.0-25.1 months) in the upfront PTR arm (P = 0.32). The number of grade 3-4 events was 71 (72%) in the arm without upfront PTR and 61 (65%) in the upfront PTR arm (P = 0.33). Three deaths (3%) possibly related to treatment were reported in the arm without upfront PTR and four (4%) in the upfront PTR arm.

CONCLUSIONS

Addition of upfront PTR to palliative systemic therapy in patients with synchronous mCRC without severe symptoms of the primary tumor does not result in a survival benefit. This practice should no longer be considered standard of care.

Primary tumor resection for asymptomatic colorectal cancer patients with synchronous unresectable metastases: a meta-analysis of randomized controlled trials and case-matched studies

PURPOSE

The value of upfront primary tumor resection (PTR) for asymptomatic unresectable metastatic colorectal cancer (mCRC) patients remains contentious. This meta-analysis aimed to assess the prognostic significance of upfront PTR for asymptomatic unresectable mCRC.

METHODS

A systematic literature search was performed on June 21st, 2024. To minimize the bias and ensure robust evidence, only randomized controlled trials (RCTs) and case-matched studies (CMS) that compared PTR followed by chemotherapy to chemotherapy alone were included. The primary outcome was overall survival (OS), while cancer-specific survival (CSS) served as the secondary outcome.

RESULTS

Eight studies (three RCTs and five CMS) involving 1221 patients were included. Compared to chemotherapy alone, upfront PTR followed by chemotherapy did not improve OS (hazard ratios [HR] 0.91, 95% confidence interval [CI] 0.79-1.04, P = 0.17), but was associated with slightly better CSS (HR 0.59, 95% CI 0.40-0.88, P = 0.009).

CONCLUSIONS

The current limited evidence indicates that upfront PTR does not improve OS but may enhance CSS in asymptomatic unresectable mCRC patients. Ongoing trials are expected to provide more reliable evidence on this issue.

Primary Tumor Resection Before Systemic Therapy in Patients With Colon Cancer and Unresectable Metastases: Combined Results of the SYNCHRONOUS and CCRe-IV Trials

PURPOSE

Chemotherapy is established as primary treatment in patients with stage IV colorectal cancer and unresectable metastases. Data from nonrandomized clinical trials have fueled persistent uncertainty if primary tumor resection (PTR) before chemotherapy prolongs survival. We investigated the prognostic value of PTR in patients with newly diagnosed stage IV colon cancer who were not amenable to curative treatment.

PATIENTS AND METHODS

Patients enrolled in the multicenter, randomized SYNCHRONOUS and CCRe-IV trials were included in the analysis. Patients with colon cancer with synchronous unresectable metastases were randomly assigned at 100 sites in Austria, Germany, and Spain to undergo PTR or up-front chemotherapy (No PTR group). The chemotherapy regimen was left at discretion of the local team. Patients with tumor-related symptoms, inability to tolerate surgery and/or systemic chemotherapy, and history of another cancer were excluded. The primary end point was overall survival (OS), and the analyses were performed with intention-to-treat.

RESULTS

A total of 393 patients were randomly assigned to undergo PTR (n = 187) or no PTR (n = 206) between November 2011 and March 2017. Chemotherapy was not administered to 6.4% in the No PTR group and 24.1% in the PTR group. The median follow-up time was 36.7 months (95% CI, 36.6 to 37.3). The median OS was 16.7 months (95% CI, 13.2 to 19.2) in the PTR group and 18.6 months (95% CI, 16.2 to 22.3) in the No PTR group (P = .191). Comparable OS between the study groups was further confirmed on multivariate analysis (hazard ratio, 0.944 [95% CI, 0.738 to 1.209], P = .65) and across all subgroups. Patients with serious adverse events were more common in the No PTR group (10.2% v 18.0%; P = .027).

CONCLUSION

Among patients with colon cancer and synchronous unresectable metastases, PTR before systemic chemotherapy was not associated with prolonged OS.

Multimodal Therapy Versus Primary Surgery for Gastric and Gastroesophageal Junction Diffuse Type Carcinoma, with a Focus on Signet Ring Cell Carcinoma: A Nationwide Study

BACKGROUND

Diffuse type adenocarcinoma and, more specifically, signet ring cell carcinoma (SRCC) of the stomach and gastroesophageal junction (GEJ) have a poor prognosis and the value of neoadjuvant chemo(radio)therapy (nCRT) is unclear.

METHODS

All patients who underwent surgery for diffuse type gastric and GEJ carcinoma between 2004 and 2015 were retrospectively included from the Netherlands Cancer Registry. The primary outcome was overall survival after surgery. Kaplan-Meier curves were plotted. Furthermore, multivariable Poisson and Cox regressions were performed, correcting for confounders. To comply with the Cox regression proportional hazard assumption, gastric cancer survival was split into two groups, i.e. <90 days and >90 days, postoperatively by adding an interaction variable.

RESULTS

Analyses included 2046 patients with diffuse type cancer: 1728 gastric cancers (50% SRCC) and 318 GEJ cancers (39% SRCC). In the gastric cancer group, 49% received neoadjuvant chemotherapy (nCT) and 51% received primary surgery (PS). All-cause mortality within 90 days postoperatively was lower after nCT (hazard ratio [HR] 0.29, 95% confidence interval [CI] 0.20-0.44; p < 0.001). Also after 90 days, mortality was lower in the nCT group (HR for the interaction variable 2.84, 95% CI 1.87-4.30, p < 0.001; total HR 0.29*2.84 = 0.84). In the GEJ group, 38% received nCT, 22% received nCRT, and 39% received PS. All-cause mortality was lower after nCT (HR 0.63, 95% CI 0.43-0.93; p = 0.020) compared with PS. The nCRT group was removed from the Cox regression analysis since the Kaplan-Meier curves of nCRT and PS intersected. The results for gastric and GEJ carcinomas were similar between the SRCC and non-SRCC subgroups.

CONCLUSION

For gastric and GEJ diffuse type cancer, including SRCC, nCT was associated with increased survival.

Upfront primary tumor resection versus upfront systemic therapy for metastatic colorectal cancer: a systematic review and meta-analysis

PURPOSE

The standard initial treatment for metastatic colorectal cancer (mCRC) remains debated. This study investigated whether upfront primary tumor resection (PTR) or upfront systemic therapy (ST) provides better survival outcomes for patients with mCRC.

METHODS

The PubMed, Embase, Cochrane Library, and ClinicalTrials.gov databases were searched for studies published at any time from January 1, 2004, to December 31, 2022. Randomized controlled trials (RCTs) and prospective or retrospective cohort studies (RCSs) utilizing propensity score matching (PSM) or inverse probability treatment weighting (IPTW) were included. We evaluated overall survival (OS) and short-term (60-day) mortality in these studies.

RESULTS

After reviewing 3,626 articles, we identified 10 studies including a total of 48,696 patients. OS differed significantly between the upfront PTR and upfront ST arms (hazard ratio [HR] 0.62; 95% CI: 0.57-0.68; p < 0.001). However, a subgroup analysis identified no significant difference in OS in RCTs (HR 0.97; 95% CI: 0.7-1.34; p = 0.83), whereas significant difference in OS occurred between the treatment arms in RCSs with PSM or IPTW (HR 0.59; 95% CI: 0.54-0.64; p < 0.001). Short-term mortality was analyzed in three RCTs, and 60-day mortality differed significantly between the treatment arms (risk ratio [RR] 3.52; 95% CI: 1.23-10.10; p = 0.02).

CONCLUSIONS

In RCTs, upfront PTR for mCRC did not improve OS and enhanced the risk of 60-day mortality. However, upfront PTR seemed to increase OS in RCSs with PSM or IPTW. Therefore, whether upfront PTR should be used for mCRC remains unclear. Further large RCTs are required.

Primary tumor resection or systemic treatment as palliative treatment for patients with isolated synchronous colorectal cancer peritoneal metastases in a nationwide cohort study

Limited data are available to guide the decision-making process for clinicians and their patients regarding palliative treatment options for patients with isolated synchronous colorectal cancer peritoneal metastases (CRC-PM). Therefore, the aim of this study is to analyze the outcome of the different palliative treatments for these patients. All patients diagnosed with isolated synchronous CRC-PM between 2009 and 2020 (Netherlands Cancer Registry) who underwent palliative treatment were included. Patients who underwent emergency surgery or curative intent treatment were excluded. Patients were categorized into upfront palliative primary tumor resection (with or without additional systemic treatment) or palliative systemic treatment only. Overall survival (OS) was compared between both groups and multivariable cox regression analysis was performed. Of 1031 included patients, 364 (35%) patients underwent primary tumor resection and 667 (65%) patients received systemic treatment only. Sixty-day mortality was 9% in the primary tumor resection group and 5% in the systemic treatment group (P = 0.007). OS was 13.8 months in the primary tumor resection group and 10.3 months in the systemic treatment group (P < 0.001). Multivariable analysis showed that primary tumor resection was associated with improved OS (HR 0.68; 95%CI 0.57-0.81; P < 0.001). Palliative primary tumor resection appeared to be associated with improved survival compared to palliative systemic treatment alone in patients with isolated synchronous CRC-PM despite a higher 60-day mortality. This finding must be interpreted with care as residual bias probably played a significant role. Nevertheless, this option may be considered in the decision-making process by clinicians and their patients.

Sixty-Day Mortality of Patients With Metastatic Colorectal Cancer Randomized to Systemic Treatment vs Primary Tumor Resection Followed by Systemic Treatment: The CAIRO4 Phase 3 Randomized Clinical Trial

Importance

The role of primary tumor resection (PTR) in synchronous patients with metastatic colorectal cancer (mCRC) who had unresectable metastases and few or absent symptoms of their primary tumor is unclear. Studying subgroups with low postoperative mortality may identify patients who potentially benefit from PTR.

Objective

To determine the difference in 60-day mortality between patients randomized to systemic treatment only vs PTR followed by systemic treatment, and to explore risk factors associated with 60-day mortality.

Design, Setting, and Participants

CAIRO4 is a randomized phase 3 trial initiated in 2012 in which patients with mCRC were randomized to systemic treatment only or PTR followed by systemic treatment with palliative intent. This multicenter study was conducted by the Danish and Dutch Colorectal Cancer Group in general and academic hospitals in Denmark and the Netherlands. Patients included between August 2012 and December 2019 with histologically proven colorectal cancer, unresectable metastases, and a primary tumor with few or absent symptoms were eligible.

Interventions

Systemic treatment, consisting of fluoropyrimidine-based chemotherapy with bevacizumab vs PTR followed by fluoropyrimidine-based chemotherapy with bevacizumab.

Main Outcomes and Measures

The aim of the current analysis was to compare 60-day mortality rates in both treatment arms. A secondary aim was the identification of risk factors for 60-day mortality in the treatment arms. These aims were not predefined in the study protocol.

Results

A total of 196 patients were included in the intention-to-treat analysis (112 [57%] men; median [IQR] age, 65 [59-70] years). Sixty-day mortality was 3% (95% CI, 1%-9%) in the systemic treatment arm and 11% (95% CI, 6%-19%) in the PTR arm (P = .03). In a per-protocol analysis, 60-day mortality was 2% (95% CI, 1%-7%) vs 10% (95% CI, 5%-18%; P = .048). Patients with elevated serum levels of lactate dehydrogenase, aspartate aminotransferase, alanine aminotransferase, and/or neutrophils who were randomized to PTR had a significantly higher 60-day mortality than patients without these characteristics.

Conclusions and Relevance

Patients with mCRC who were randomized to PTR followed by systemic treatment had a higher 60-day mortality than patients randomized to systemic treatment. Especially patients randomized to the PTR arm with elevated serum levels of lactate dehydrogenase, neutrophils, aspartate aminotransferase, and/or alanine aminotransferase were at high risk of postoperative mortality. Final study results on overall survival have to be awaited.

Trial Registration

ClinicalTrials.gov Identifier: NCT01606098.