Patients who undergo primary tumor resection (PTR) reportedly have significantly higher overall survival (OS) than those who do not undergo this procedure. However, this result is only evident in past retrospective studies, and clinical trial results did not show the same trend. Thus, it remains unclear whether primary tumor resection effectively increases survival in patients with metastatic colorectal cancer (mCRC) across different study designs. We compared the OS of patients with asymptomatic unresectable mCRC who underwent PTR with that of those who did not. This retrospective cohort study was designed to be a target trial emulation of a randomized controlled trial (RCT) that would have compared the effectiveness of PTR versus non-PTR in patients with asymptomatic unresectable mCRC from 2009 to 2017. A systematic review and meta-analysis were conducted to compare the efficacy of PTR and non-PTR in patients with mCRC, and corresponding results were compared. This cohort included 1,132 patients for a per-protocol analysis. The PTR group had non-significantly longer survival (adjusted hazard ratio: 0.70, 95% confidence interval: 0.62-1.01) than the non-PTR group in our cohort. A meta-analysis including five RCTs (1,016 patients) and our cohort found that the PTR group did not have a significantly lower mortality rate than the non-PTR group. The results of this cohort study and previous RCTs suggest that PTR is not associated with improved survival compared to systemic chemotherapy combined with targeted therapy among asymptomatic unresectable mCRC patients. Therefore, routine PTR is not recommended in these patients.

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.
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.

Neuroendocrine neoplasms of the small intestine (SI-NENs) are one of the most commonly recognized gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs). Carcinoid heart disease (CHD) is the primary cause of death in patients with the carcinoid syndrome (CS). The aim of this retrospective study was to evaluate possible factors impacting upon overall survival (OS) in subjects with both neuroendocrine tumors (NETs) G1/G2 of the small intestine (SI-NET) and CHD. Enrolled in our study of 275 patients with confirmed G1/G2 SI-NET, were 28 (10%) individuals with CHD. Overall survival was assessed using the Kaplan-Meier method. The Cox-Mantel test was used to determine how OS varied between groups. A Cox proportional hazards model was used to conduct univariate analyses of predictive factors for OS and estimate hazard ratios (HRs). Of the 28 individuals with confirmed carcinoid heart disease, 12 (43%) were found to have NET G1 and 16 (57%) were found to have NET G2. Univariate analysis revealed that subjects with CHD and without resection of the primary tumor had a lower OS. Our retrospective study observed that patients who presented with CHD and without resection of primary tumor had worse prognosis of survival. These results suggest that primary tumors may need to be removed when feasible, but further research is needed. However, no solid recommendations can be issued on the basis of our single retrospective study.

UNASSIGNED: Gastric cancer with liver metastasis (GCLM) is highly aggressive and has a poor prognosis. This study aims to evaluate the survival benefit of primary tumor resection (PTR) for gastric cancer with liver metastasis.
UNASSIGNED: Data on patients with GCLM was extracted from the Surveillance, Epidemiology, and End Results (SEER) database from 2010 to 2015. A 1:1 propensity score matching (PSM) analysis was performed to minimize the heterogeneity between the PTR and no-PTR groups. The Kaplan-Meier method and Cox regression analysis were used to assess the impact of primary tumor resection (PTR) on overall survival (OS) and cause-specific survival (CSS).
UNASSIGNED: A total of 3,001 patients with GCLM were included, with 328 patients treated with primary tumor resection (PTR), whereas the other 2,673 patients were not. Patients with PTR had a significantly higher OS and CSS rate than those without PTR in unmatched and PSM cohorts. In an unmatched cohort, the median OS was 12.0 months (95% CI, 10 months to 14 months) for those who underwent PTR and 4 months (95% CI, 4 months to 5 months) for those without PTR; the median CSS for those who underwent PTR was 12.0 months (95% CI, 10 months to14 months) and 4 months (95% CI, 4 months to 5 months) for those without PTR, respectively. After PMS, the median OS was 12.0 months (95% CI, 10 months to 17 months) for those who underwent PTR and 7 months (95% CI, 5 months to 10 months) for those without PTR, respectively; the median CSS for those who underwent PTR was 12.0 months (95% CI, 11 months to 17 months) and 7 months (95% CI, 5 months to 8 months) for those without PTR, respectively. In addition, multivariate Cox analysis in the PSM cohort showed that PTR, age, degree of tumor differentiation, and chemotherapy were independent prognostic factors for OS and CSS in GCLM. Specifically, PTR was a significant protective factor for OS (HR: 0.427; 95% CI, 0.325 to 0.561, P <0.001) and CSS (HR: 0.419; 95% CI, 0.313 to 0.561, P <0.001).
UNASSIGNED: Primary tumor resection improves the survival of gastric cancer patients with liver metastasis.

BACKGROUND: Primary tumor resection (PTR) in patients with metastatic unresectable colorectal cancer is less and less used to prevent local complications. Although its therapeutic effect is debated, poor data are available about the activity of chemotherapy (CHT) after PTR. The study aims to evaluate trials that compared PTR followed by CHT vs. CHT alone.
METHODS: After a literature search on two databases by predefined criteria, studies published from 2011 to 2021 were selected. All studies evaluating the progression-free survival (PFS) of patients receiving CHT after PTR or not were included in a meta-analysis. Finally, 18 possible moderating variables were extracted from each study and examined.
RESULTS: Eleven trials reported a reduced risk of progression after first-line CHT among patients receiving PTR (HR 0.72, CI 0.66-0.79). The heterogeneity was moderate (Q = 17.52; p-value = 0.093) and the grade of inconsistence intermediate (I2 = 37.21%). Among moderating variables, female sex and low percentage of patients with liver metastases were related with a stronger effect size of PTR on PFS, whereas a longer OS and a trend to better PFS was evident after poly-chemotherapy regimens.
CONCLUSIONS: PTR could improve the results of first-line CHT in patients with unresectable colorectal cancer with low tumor burden only in the subgroup receiving more aggressive chemotherapy.

UNASSIGNED: The impact of the preoperative carbohydrate antigen 125 (CA125) level on the survival of metastatic colorectal cancer (CRC) patients undergoing primary tumor resection (PTR) remains uncertain. The aim of this study was to assess the prognostic value in overall survival (OS) and cancer-specific survival (CSS) between patients with and without an elevated preoperative CA125 level.
UNASSIGNED: All metastatic CRC patients receiving PTR between 2007 and 2017 at the Sixth Affiliated Hospital of Sun Yat-sen University (Guangzhou, China) were retrospectively included. OS and CSS rates were compared between patients with and without elevated preoperative CA125 levels.
UNASSIGNED: Among 326 patients examined, 46 (14.1%) exhibited elevated preoperative CA125 levels and the remaining 280 (85.9%) had normal preoperative CA125 levels. Patients with elevated preoperative CA125 levels had lower body mass index, lower preoperative albumin level, lower proportion of preoperative chemotherapy, higher carcinoembryonic antigen and carbohydrate antigen 19-9 (CA19-9) levels, poorer differentiation, and more malignant histopathological type than patients with normal preoperative CA125 levels. In addition, patients with elevated preoperative CA125 levels exhibited more advanced pathological T and N stages, more peritoneal metastasis, and more vessel invasion than patients with normal preoperative CA125 levels. Moreover, the primary tumor was more likely to be located at the colon rather than at the rectum in patients with elevated CA125 levels. Both OS and CSS rates in patients with elevated preoperative CA125 levels were significantly lower than those in patients with normal preoperative CA125 levels. Multivariate Cox regression analysis revealed that an elevated preoperative CA125 level was significantly associated with poor prognosis in metastatic CRC patients undergoing PTR. The hazard ratio (HR) in OS was 2.36 (95% confidence interval [CI], 1.67-3.33, P < 0.001) and the HR in CSS was 2.50 (95% CI, 1.77-3.55, P < 0.001). The survival analysis stratified by peritoneal metastasis also demonstrated that patients with elevated preoperative CA125 levels had lower OS and CSS rates regardless of peritoneal metastasis.
UNASSIGNED: Based on an analysis of metastatic CRC patients undergoing PTR, an elevated preoperative CA125 level was associated with poor prognosis, which should be taken into consideration in clinical practice.

UNASSIGNED: Selected patients with stage IV non-small cell lung cancer (NSCLC) who underwent primary tumor resection have witnessed a survival benefit. Whether additional lymph node dissection (LND) would result in a better effect remain unknown. We investigated the prognostic impact of LND on patients with stage IV NSCLC who received primary tumor resection (PTR).
UNASSIGNED: Patients with stage IV NSCLC who underwent PTR were identified from the Surveillance, Epidemiology, and End Results database from 2004 to 2016. Propensity-score matching was performed to minimize the confounding effect, and lung cancer-specific survival (CSS) and overall survival (OS) were compared after matching. Multivariable Cox regression was used to identify prognostic factors and to adjust for covariates in subgroup analysis. The effect of the number of lymph nodes examined on the CSS was evaluated by repeating the Cox analysis in a binary method.
UNASSIGNED: A total of 4,114 patients with stage IV NSCLC who receive surgery met our criteria, of which 2,622 (63.73%) underwent LND and 628 patients were identified 1:1 in LND and non-LND groups after matching. Compared with the non-LND group, the LND group had a longer CSS (median: 23 vs. 16 months, p < 0.001) and OS (median: 21 vs. 15 months, p < 0.001). Multivariable regression showed that LND was independently associated with favorable CCS [hazard ratio (HR) = 0.78, 95% confidence interval (CI) 0.69-0.89, P < 0.001] and OS (HR = 0.79, 95% CI 0.70-0.89, P < 0.001). Subgroup analysis suggested that LND is an independent favorable predictor to survival in the surgical patients who were older age (>60 years old), female, T3-4, N0, and M1a stage and those who underwent sublobar resection. In addition, a statistically significant CCS benefit was associated with an increasing number of lymph nodes examined through 25 lymph nodes.
UNASSIGNED: LND with a certain range of lymph nodes number examined was associated with improved survival for patients with stage IV NSCLC who received primary tumor resection. The results may have implications for guidelines on lymph nodes management in selective advanced NSCLC for surgery.

UNASSIGNED: The liver is the most common site for rectal cancer metastasis, and liver resection combined with chemotherapy is the only treatment offering the possibility of long-term survival in patients with metastatic rectal cancer. However, a significant proportion of liver metastases cannot be surgically removed, and very limited data are available regarding the survival outcomes of these patients. This study aimed to investigate the survival pattern of rectal cancer patients with unresectable liver metastases after both chemoradiotherapy and primary tumor resection.
UNASSIGNED: A total of 51,178 rectal cancer patients were identified from the Surveillance, Epidemiology, and End Results (SEER) database, of whom 448 had synchronous liver metastases and underwent both chemoradiotherapy and primary tumor resection. According to different treatment modalities, patients were divided into a hepatic resectable group and an unresectable group. The Kaplan-Meier method was used to estimate patient survival, and differences between the hepatic resectable and unresectable groups were compared using the log-rank test. Univariate and multivariate Cox regression models were used to analyze independent prognostic factors for unresectable tumors.
UNASSIGNED: Among the 448 metastatic rectal cancer patients, 60.3% (270) had unresectable liver metastasis. The median survival period, 2-year overall survival (OS) rate, and 5-year OS rate of the unresectable group were 37.0 months, 68.5%, and 32.9%, respectively, compared with 56.0 months, 87.4%, and 48.0%, respectively, in the hepatic resectable group (P<0.001). Multivariate Cox regression analysis suggested that a poor or undifferentiated histological type was independently associated with poor CSS in patients with unresectable liver metastases (P=0.001).
UNASSIGNED: Primary tumor resection combined with chemoradiotherapy might be able to yield a satisfactory survival outcome in unresectable metastatic rectal cancer patients. Resection of liver metastases remains the primary treatment for prolonging the OS and CSS time in stage IV patients.

OBJECTIVE: Primary tumor resection for patients with incurable stage IV colorectal cancer can prevent tumor-related complications but may cause postoperative complications. Postoperative complications delay the administration of chemotherapy and can lead to the spread of malignancy. However, the impact of postoperative complications after primary tumor resection on survival in patients with incurable stage IV colorectal cancer remains unclear. Therefore, this study aimed to investigate how postoperative complications after primary tumor resection affect survival in this patient group.
METHODS: We reviewed data on 966 patients with stage IV colorectal cancer who underwent palliative primary tumor resection between January 2006 and December 2007. We examined the association between major complications (National Cancer Institute Common Terminology Criteria for Adverse Events v3.0 grade 3 or more) and overall survival using Cox proportional hazard model and explored risk factors associated with major complications using multivariable logistic regression analysis.
RESULTS: Ninety-three patients (9.6%) had major complications. The 2-year overall survival rate was 32.7% in the group with major complications and 50.3% in the group with no major complications. Patients with major complications had a significantly poorer prognosis than those without major complications (hazard ratio: 1.62; 95% confidence interval: 1.21-2.18; P < .01). Male, rectal tumor, and open surgery were identified to be risk factors for major complications.
CONCLUSIONS: Postoperative complications after primary tumor resection was associated with decreased long-term survival in patients with incurable stage IV colorectal cancer.

OBJECTIVE: To clarify the role of primary tumor resection in stage 4S neuroblastoma.
METHODS: We investigated a cohort of 172 infants diagnosed with stage 4S neuroblastoma between 1994 and 2013. Of 160 evaluable patients, 62 underwent upfront resection of the primary tumor and 98 did not.
RESULTS: Five-year progression-free and overall survival were significantly better in those who had undergone upfront surgery (83.6% vs 64.2% and 96.8% vs 85.7%, respectively). One post-operative death and four non-fatal complications occurred in the resection group. Three patients who had not undergone resection died of chemotherapy-related toxicity. Thirteen patients underwent late surgery to remove a residual tumor, without complications: all but one alive. Outcomes were better in patients diagnosed from 2000 onwards.
CONCLUSIONS: Infants diagnosed with stage 4S neuroblastoma who underwent upfront tumor resection had a better outcome. However, this result cannot be definitely attributed to surgery, since these patients were selected on the basis of their favorable presenting features. Although the question of whether to operate or not at disease onset is still unsolved, this study confirms the importance of obtaining enough adequate tumor tissue to enable histological and biological studies to properly address treatment, to achieve the best possible outcome.