BACKGROUND: Whether patients with asymptomatic primary tumors and unresectable metastases of colorectal cancer (CRC) should undergo primary tumor resection (PTR) remains controversial. This study aims to determine the appropriateness of PTR for these individuals by evaluating a number of outcome measures.
METHODS: A systematic literature search was performed. Outcome measures included overall survival, emergency surgery rates, incidence of postoperative complications, time to initiate chemotherapy, conversion rates, and chemotherapy-related toxicities.
RESULTS: Patients who received PTR in addition to chemotherapy had a better overall survival rate than those who only received chemotherapy (HR = 0.62, 95%CI, 0.50-0.78, I2 = 84%, p < 0.00001). In the RCT subgroup, there were no significant differences with a HR of 0.72 (95%CI, 0.45-1.13, I2 = 17%, p = 0.15). More patients in the chemotherapy alone group could be converted to resectable status (OR = 0.47, 95%CI, 0.27-0.82, I2 = 0%, p = 0.008), but the incidence of emergency surgery was 23% (95%CI, 17-29%, I2 = 14%). The risk of chemotherapy-related toxicity was not significantly higher in the PTR group (OR = 1.5, 95%CI, 0.94-2.43, p = 0.09, I2 = 0%), with a 7% incidence of postoperative complications (95%CI, 0-14%, p = 0.05, I2 = 0%). The time to initiate chemotherapy after PTR was approximately 33.06 days (95%CI, 25.55-40.58, I2 = 0%).
CONCLUSIONS: PTR plus chemotherapy may be associated with improved survival in asymptomatic CRC patients with unresectable metastases. However, PTR did not provide a significant survival benefit in the subgroup of RCTs. Additionally, PTR did not result in a significantly increased risk of chemotherapy-related toxicity, with a postoperative complication rate of approximately 7%, and chemotherapy could be initiated at approximately 33.06 days after PTR. Compared with the PTR plus chemotherapy, chemotherapy alone could result in a significantly higher conversion rate. However, about 23% of patients receiving chemotherapy alone required emergency surgery for primary tumor-related symptoms. The above results needed to be validated in future larger prospective randomized trials.

OBJECTIVE: 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.

UNASSIGNED: Controversy exists over the role of upfront primary tumor resection (PTR) in asymptomatic patients with unresectable stage IV colorectal cancer (CRC). The purpose of this study was to evaluate the effect of upfront PTR on survival outcomes and adverse outcomes.
UNASSIGNED: Searches were conducted on PubMed, EMBASE, Web of Science, and Cochrane Library from inception to August 2021. Studies comparing survival outcomes with or without adverse outcomes between PTR and non-PTR treatments were included. Review Manager 5.3 was applied for meta-analyses with a random-effects model whenever possible.
UNASSIGNED: Overall, 20 studies with 3,088 patients were finally included in this systematic review. Compared with non-PTR, upfront PTR was associated with better 3-year (HR: 0.69, 95% CI, 0.57-0.83, P = 0.0001) and 5-year overall survival (OS) (HR: 0.77, 95% CI, 0.62-0.95, P = 0.01), while subgroup analysis indicated that there was no significant difference between upfront PTR and upfront chemotherapy (CT) group. In addition, grade 3 or higher adverse effects due to CT were more frequent in the PTR group with marginal significance (OR: 1.74, 95% CI, 0.99-3.06, P = 0.05), and other adverse outcomes were comparable.
UNASSIGNED: PTR might be related to improved OS for asymptomatic patients with unresectable stage IV CRC, whereas receiving upfront CT is a rational alternative without detrimental influence on survival or adverse outcomes compared with upfront PTR.
UNASSIGNED: https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=272675.

UNASSIGNED: It remains controversial whether primary tumor resection (PTR) improves survival in patients with asymptomatic, unresectable metastatic colorectal cancer (mCRC). Therefore, we conducted a meta-analysis to assess the latest evidence on clinical outcomes.
UNASSIGNED: We systematically searched PubMed, Web of Science, Cochrane Library, and Embase databases for eligible studies published between database inception and May 2022. RevMan 5.4 and Stata 16.0 were used for the meta-analysis.
UNASSIGNED: A total of nine studies were included, including four randomized controlled trials (RCTs) and five retrospective cohort studies. Meta-analysis showed that overall survival (OS) [HR = 0.89, 95%CI (0.74, 1.06), P = 0.19] and progression-free survival (PFS) [HR = 0.87, 95%CI (0.71, 1.06), P = 0.17] were not significantly different between the PTR and non-PTR groups. In the subgroup analysis, all subgroups showed no significant difference in OS between the two groups.
UNASSIGNED: PTR may not provide additional survival benefits over chemotherapy in asymptomatic, unresectable mCRC patients. However, in view of the limitations of this study, more well-designed RCTs are needed to validate our conclusions.

The impact of primary tumor resection (PTR) on survival is still controversial in stage IV breast cancer. This systematic review and meta-analysis aimed to evaluate the impact of PTR on overall survival (OS) in stage IV breast cancer.
Comprehensive literature search was conducted to identify studies comparing PTR with no PTR for stage IV breast cancer. The quality of the studies was assessed using Cochrane risk of bias tool and Newcastle-Ottawa Scale. We used subgroup and meta-regression analysis to assess the contribution of demographic and clinical factors to heterogeneity.
Data on 714 patients in 3 randomized controlled trials (RCTs) and 67,272 patients in 30 observational studies were included. One RCT was terminated early due to poor recruitment, and the remaining two RCTs\' design were different, thus RCTs were only performed systematic review without meta-analysis. The pooled outcomes of 30 observational studies showed PTR significantly improved OS (HR = 0.65; 95%CI, 0.61 to 0.70, P < 0.001, I2 = 80%). Additionally, PTR was associated with better distant progression-free survival (HR = 0.42; 95%CI, 0.29 to 0.60) but did not impact progression-free survival. Subgroup analysis showed PTR benefit in patients who had only one metastatic site (HR = 0.62, 95%CI. 0.48 to 0.81), bone-only metastasis (HR = 0.61, 95%CI. 0.37 to 1.00), with negative margin (HR = 0.61, 95%CI. 0.58 to 0.65).
PTR should not be part of routine clinical practice in stage IV breast cancer but might be performed in selected patients. Our findings highlight PTR might be valuable in patients with limited disease burden or attaining clear margin.

BACKGROUND: Treatment for midgut neuroendocrine tumor patients with unresectable liver metastasis has long been a controversial issue. This system review aims to summarize existing evidence concerning the value of primary tumor resection in this group of patients.
RESULTS: 8 cohort studies were identified for qualitative analysis. None of them strictly met with the inclusion criteria and meta-analysis was impossible. There was a tendency towards better overall survival for the primary tumor resected group in all 8 studies, in which 6 demonstrated significant difference. Progression free survival to liver disease was prolonged and less patients died of liver failure in the resected group.
METHODS: MEDLINE, EMBASE and CENTRAL were searched until 2016/7/4 for relevant studies, with primary outcome being overall survival, and secondary outcome being progression free survival, cause of death and symptom relief.
CONCLUSIONS: Current evidence supports resection of primary tumor for midgut neuroendocrine tumor patients with liver metastases, but randomized controlled trials are required to reach a final conclusion.