Adjuvant chemotherapy for isolated resectable colorectal lung metastasis: A retrospective study using inverse probability treatment weighting propensity analysis.

It remains controversial whether patients benefit from adjuvant chemotherapy (ACT) after resection of pulmonary metastasis (PM) from colorectal cancer (CRC). This meta-analysis was intended to evaluate the efficacy of ACT in patients after resection of PM from CRC. We systematically retrieved articles from PMC, PubMed, Cochrane Library, and Embase (up to March 5, 2019). Survival data, including overall survival (OS) and disease-free survival (DFS), were tested by hazard ratios (HRs) and 95% confidence intervals (CIs). We included 18 cohort studies with a total of 3885 patients. The meta-analysis showed that ACT had no significant effect on OS (HR = 0.78; 95% CI = 0.60-1.03; P = 0.077) and DFS (HR = 0.91; 95% CI = 0.74-1.11; P = 0.339) in patients after resection of PM from CRC. There was no significant difference in OS (HR = 0.79; 95% CI = 0.42-1.50; P = 0.474) in patients after resection of PM from CRC treated with bevacizumab (BV). Subgroup analysis showed that ACT did not improve OS (HR = 0.86; 95% CI = 0.57-1.29; P = 0.461) in patients who had undergone previous resection of extra PM. ACT did not improve OS in patients who had positive hilar/mediastinal lymph node metastasis (HR = 0.80; 95% CI = 0.57-1.14; P = 0.22). In conclusion, ACT does not provide survival benefits for patients after resection of PM from CRC. ACT and targeted agents (BV) are not suggested for these patients.

Radical cystectomy versus trimodality therapy for muscle-invasive bladder cancer: a multi-institutional propensity score matched and weighted analysis.

BackgroundThe correlation between cirrhosis and the long‐term oncological outcome in intrahepatic cholangiocarcinoma (ICC) is debatable, and this study aimed to explore the impact of cirrhosis on the long‐term prognosis of patients with ICC.MethodsA total of 398 ICC patients were identified in the Surveillance, Epidemiology, and End Results (SEER) database from 2000 to 2018. The diagnosis of cirrhosis was based on the Ishak fibrosis score provided by the SEER database. Propensity score matching (PSM) and inverse probability of treatment weighting (IPTW) analysis were performed to minimize the potential confounders. Overall survival (OS) and cancer‐specific survival (CSS) were observed, and the Cox regression model was used to select potential factors that affect the prognosis of the patients with ICC.ResultsOf the included patients, there were 142 patients and 256 patients in the cirrhotic and noncirrhotic groups, respectively. Additionally, 299 of 398 patients (75.1%) died following a median follow‐up of 19 months (interquartile range [IQR], 7, 43). The OS and CSS indicated advantage trend in the noncirrhotic group than the cirrhotic group in either the original cohort (OS: 17 vs 12 months, p = 0.023; CSS: 26 vs 15 months, p = 0.004) or the PSM (OS: 17 vs 12 months, p = 0.52; CSS: 22 vs 14 months, p = 0.15) or IPTW (OS: 20 vs 13 months, p = 0.163; CSS: 22 vs 15 months, p = 0.059) cohorts. Subgroup analyses displayed that the prognosis of patients who experienced surgery for ICC in the noncirrhotic group was better than that of the cirrhotic group with regard to OS and CSS.ConclusionsCollectively, it seems that the noncirrhotic patients have similar relative OS but better CSS compared with that of the cirrhotic patients.

Pulmonary resection is the best therapeutic option for lung metastases from colorectal cancer (CRC) today. However, recurrences are frequent following pulmonary resection. We aimed to evaluate the recurrence pattern and treatment of initial pulmonary resection for metastases from CRC. Data from 76 patients with recurrence after curative resection of primary CRC and lung metastases were reviewed. The primary outcome measure was overall survival (OS), defined as the interval between the date of recurrence after pulmonary resection and the date of death or last follow-up. Cox regression analyses were performed to identify the factors associated with OS. Recurrence sites after initial pulmonary resection were lung (n = 37), liver (n = 12), others (n = 11), and multiple (n = 16). Treatments for recurrence included surgery (n = 35), chemotherapy (n = 37), and palliative care (n = 4). Of 35 patients who underwent surgery, 22 had pulmonary resection, and 11 had hepatic resection, and 2 had other resection. The 3-year OS was 84.1 % for surgery, 38.9 % for chemotherapy, and 0 % for palliative care, respectively (p < 0.001). In the surgery group, there was no difference in survival between surgical treatments for pulmonary and hepatic recurrences (p = 0.503). Cox regression analyses identified three factors: disease-free interval (DFI) (HR 1.99, 95 % CI 1.03-3.83), surgery (HR 0.30, 95 % CI 0.12-0.72), and recurrence site (lung: HR 0.10, 95 % CI 0.04-0.28, liver: HR 0.08, 95 % CI 0.02-0.31). The most common recurrence site after resection of lung metastases was the lung. Although the relapse rate is high, surgery for isolated recurrences is a promising strategy, especially for patients with long DFI.

Approximately 20% of patients with resectable non-small cell lung cancer (NSCLC) are treated nonsurgically. To compare the clinical outcomes between nonsurgical patients receiving radiofrequency ablation (RFA) alone and those receiving no treatment (NT), we assessed RFA effectiveness in terms of survival using the surveillance, epidemiology, and end-results (SEER) database. Using the SEER registry process, we identified 5268 patients who were ineligible for the surgical treatment between 2004 and 2015. Overall survival (OS) and cancer-specific survival (CSS) were compared between the groups using propensity score matching (PSM), inverse probability of treatment weight (IPTW), and overlap weight analysis. In addition, an exploratory analysis was conducted to determine RFA treatment effectiveness based on clinically relevant patient subsets. Of the 5268 patients, 189 (3.6%) received RFA. The OS and CSS in these patients were significantly better than those in the NT group (P < 0.0001). RFA was associated with a 16-month median OS improvement. Both OS and CSS improved in the nonsurgical patients (hazard ratio [HR], 0.695, 95% confidence interval [CI], 0.585-0.826, P < 0.0001; HR, 0.636; 95% CI, 0.505-0.800, P < 0.0001). The 1-, 3-, and 5-year OS in the unmatched RFA and NT groups were 84.2%, 49.0%, and 29.4% vs. 62.8%, 31.1%, and 17.1%, respectively (P < 0.001). PSM, IPTW, and overlap weight analysis showed comparable results. The odds of receiving RFA decreased with larger tumor size (>1, ≤2 cm, odds ratio [OR], 0.623, 95% CI, 0.402-0.966; >2, ≤3 cm, OR, 0.300, 95% CI, 0.186-0.483) compared to tumor size s1 cm (P < 0.05). RFA improves unresected stage IA NSCLC patient survival. Our results are limited by the retrospective nature of the study; however, we believe that our findings are noteworthy for recommending local ablative therapy.

Background and aimsPostoperative adjuvant chemotherapy in older adults aged ≥ 80 years with locally advanced gastric cancer (LAGC) remains debated owing to concerns over treatment tolerance and limited data. We aimed to assess the effectiveness of postoperative adjuvant chemotherapy in adults aged ≥ 80 years with LAGC using data from the Surveillance, Epidemiology, and End Results database.Methods and resultsA total of 2395 patients with LAGC aged ≥ 80 years who underwent radical surgery between 2004 and 2015 were identified. Propensity score matching (1:1) was applied to pair 422 patients receiving adjuvant chemotherapy with 1973 patients who underwent surgery alone. Multivariate logistic regression identified independent predictors of adjuvant chemotherapy, including the period from 2012–2015, pN1–2 and pN3 stages, and radiation therapy. Conversely, age ≥ 85 years predicted decreased chemotherapy use. Cancer-specific survival (CSS) and overall survival (OS) were compared using multivariate Cox analysis, showing significantly longer OS and CSS in the adjuvant chemotherapy group, before and after matching. Subgroup analysis revealed that patients aged 80–84 years and those with N + stages benefited most from adjuvant chemotherapy, whereas patients aged ≥ 90 years did not show significant benefit.ConclusionPostoperative adjuvant chemotherapy should be considered for patients aged ≥ 80 years with LAGC, especially those with lymph node involvement, as it offers significant survival benefits. However, as age approaches 90 years, the benefits of adjuvant chemotherapy may diminish, warranting more cautious application.

Purpose: To comparing the survival in different strategies, preoperative systemic treatment (PST) versus upfront surgery (US) in patients of HER2-positive early breast cancer in real-world.Methods: Eligible patients from 2012 to 2015 were classified as PST or US group prospectively, according to the real upfront treatment. The primary endpoint is disease-free survival (DFS), the second endpoint is overall survival (OS). All the outcomes were examined in unadjusted model, propensity score matching (PSM) model, and inverse probability of treatment weighting (IPTW) model. Results: Finally, 1067 eligible patients (215 in PST group, 852 in US group) were included into analysis (Table 1). In unweighted analysis, the cumulative DFS of PST group was significantly lower than US group (78.1% vs 87.7%, P&amp;lt;0.001), especially for those did not reach pathological complete response after PST. After adjusting the parameters, in PSM model (matching at 1:1 ratio), the DFS of PST group was significantly higher than the DFS of US group (HR, 0.57s2, 95%CI, 0.371~0.881, P, 0.012). In IPTW model, there was no significant difference of DFS between two groups (HR, 0.946, 95%CI, 0.763~1.172, P, 0.609). For OS, there were no significant difference between two groups in all three models. Conclusions: The patients in PST group have worse DFS than those in US group, mainly because of the unbalancing stage and biological risk. By real-world statistic method, after adjusting and making parameters comparable, the DFS of PST group is non-inferiority to the DFS of US group in IPTW model and even superior to US group in PSM model. *Proportions and medians are weighted using IPTW, all covariates included in the propensity analysis. Abbreviations: PSM, propensity score matching, IPTW, inverse probability of treatment weighting, PST, preoperative systemic treatment, US, upfront surgery, SMD, standardized mean difference, ER, estrogen receptor, PR, progesterone receptor.In IPTW model, the DFS rate of the PST group was 81.3% versus 80.8% of the US group, and the OS rate of the PST group was 92.1% versus 90.3% (Figure 2E, 2F), both having no significantly differences (Table 4). In further stratified analysis (Figure 3E, 3F), as in PSM model, the DFS and OS rate of the patients without pCR after PST (73.1%, 88.4%) were worse than those with pCR (96.6%, 99.3%) and US group (80.8%, 90.3%), respectively. Table 1. The clinicopathologic characteristics of two groups in PSM and IPTW modelsCharacteristicsNumber of casesUnweighted primary samplePSM modelIPTW model*PST group (215)US group (852)SMDPST group (145)US group (145)SMDPST group (765)US group (1021)SMDN (%)N (%)N (%)N (%)N (%)N (%)Age (years, medium, 95%CI)50, 39~6150, 33~640.0550, 40~6549, 34~620.1049, 39~6750, 31~640.03Stage T14588 (3.7)450 (52.8)0.7018(3.7)10 (6.9)0.03280 (10.5)450 (44.1)0.4672529157 (73.0)372 (43.7)118 (81.4)116 (80.0)635 (83.0)458 (44.9)38050 (23.3)30 (3.5)19 (13.1)19 (13.1)50 (6.5)113 (11.1)Stage N057137 (17.2)534 (62.7)1.04837 (17.2)32 (22.1)0.081310 (40.5)538 (52.7)0.2461596178 (82.8)318 (37.3)108 (81.4)113 (77.9)455 (59.5)483 (47.3)Grade1 and 252292 (42.8)430 (50.5)0.15477 (53.1)89 (61.4)0.168345 (45.1)493 (48.3)0.0643545123 (57.2)422 (49.5)68 (46.9)56 (38.6)420 (54.9)528 (51.7)ERNegative536142 (66.0)394 (46.2)0.40787 (60.0)68 (46.9)0.265386 (50.5)513 (50.2)0.004Positive53173 (34.0)458 (53.8)58 (40.0)77 (53.1)379 (49.5)508 (49.8)PRNegative649171 (79.5)478 (56.1)0.418108 (74.5)113 (77.9)0.081499 (65.2)625 (61.2)0.083Positive41844 (20.5)374 (43.9)37 (25.5)32 (22.1)266 (34.8)396 (38.8) Citation Format: Yang Hongjian, Xingfei Yu, Chen Wang, Zheng Yabing, Hu Jiejie, Xiying Shao, Liming Sheng, Juan Lin, Yuqin Ding, Haojun Xuan, Lijie Gong, Weiliang Feng, Chengdong Qin, Daobao Chen, Yang Yu. Preoperative systemic therapy versus upfront surgery in HER2-positive early breast cancer: A prospective nested case-control study in the real world [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS13-52.

The present study used inverse probability of treatment weighting (IPTW) and propensity score matching (PSM) to compare survival benefits among 112 patients with resectable, stage II–IV esophageal squamous cell carcinoma (SCC) treated between 1996 and 2016 with neoadjuvant chemoradiotherapy (NAC) plus surgery (Group A, n=55) or with surgery alone (Group B, n=57). Their propensity scores (PS) were calculated using a multivariable logistic regression model in which age, sex, cancer site, primary tumor length, cTNM stage, lymph node metastasis and depth of tumor invasion were the independent variables, and used to match Groups A and B according to the IPTW and matching method. After IPTW and PSM, univariate analysis was used to assess overall survival (OS) and disease-free survival (DFS), followed by Cox proportional hazard models for OS using IPTW between the two groups and the subgroups. After PSM, 5-year OS and DFS were significantly higher in Group A (OS: 65.2%, DFS: 65.2%) compared with Group B (OS: 31.2%, DFS: 20.87%). Similarly, after IPTW, OS and DFS were significantly higher in Group A compared with Group B patients. Five-year OS was 73.18% for Group A and 37.69% for Group B (hazard ratio: 0.2899, 95% confidence interval: 0.1167–0.7205). To conclude, treatment was more effective in Group A patients with clinical stage II, N0 and T3 disease involving the mid-esophagus. It was concluded that for patients with esophageal SCC, NAC plus esophagectomy exhibited improved survival compared with surgery alone, as demonstrated by use of IPTW and PSM methods.

Substantial uncertainties remain regarding the establishment of an optimal examined lymph node (ELN) count for the comprehensive management of resectable colorectal cancer (CRC). The correlation of the ELN count with cancer-specific survival (CSS) and benefit from adjuvant chemotherapy (AC) in CRC was investigated using a large database, and the minimal threshold for ELN count in LN-negative patients was determined. The data on stage I to III CRC available in the SEER database (2010-2015) were analyzed to determine the correlation of ELN count with CSS and the benefit of AC using multivariable models. The series of odds ratios (ORs) and hazard ratios (HRs) were fitted using the join-point regression analysis. External validation was performed using the data of patients with stage I to III CRC (2004 to 2009) available in the SEER database. Among LN-negative patients, both cohorts indicated that an increase in the ELN count (≤ 18) led to incremental enhancements in CSS, while no additional improvement in CSS was noted beyond an ELN count of 18. Notably, the efficacy of AC diminished gradually as the ELN count increased. Moreover, post-AC CSS was impaired when the ELN count exceeded 18 (serial HRs > 1), a trend that was accentuated with a higher ELN count. Among the LN-positive patients, two cohorts exhibited proportional increases in ELNs, from one positive LN (PLN) to 20 PLN disease, and incremental benefit from AC, as the ELN count increased (serial HRs < 1). The present study recommends an ELN threshold of 18 when evaluating the quality of prognostic stratification and guiding AC for LN-negative cases. A higher ELN count would be associated with further accurate PLN detection and incremental benefit from AC in LN-positive diseases.

8503 Background: Stage III-N2 non-small cell lung cancer (NSCLC) is a heterogeneous disease with controversial management options. Induction therapy as part of multimodal treatment is the standard of care for Stage III-N2 NSCLC. We aim to investigate the effect of adding radiotherapy to neoadjuvant chemotherapy on survival outcomes. Methods: All adult NSCLC patients diagnosed between 2004 and 2015 were identified in the Surveillance, Epidemiology, and End Results (SEER) database using ICD-O-3 histologic type coding. Inclusion criteria involved stage III NSCLC patients with ipsilateral lymph node involvement (N2), of any T stage, and with no known distant metastasis (M0). Our main sub-cohorts were patients who either underwent chemoradiotherapy (CRT) or chemotherapy (CT) in neoadjuvant settings. Our primary outcomes were overall survival (OS) and cancer-specific survival (CSS) in months. Cox proportional hazards model was used to analyze the effect of each treatment modality on OS and CSS in univariate and multivariate fashions. Multivariate analysis was adjusted for age, sex, marital status, T stage, resected lymph node status, tumor histology, primary site, laterality, and surgical procedure. Inverse probability treatment weighting (IPTW) was applied to create weighted samples based on study covariates. Results: Our analysis included 1175 patients; 799 (68.0%) underwent neoadjuvant CRT and 376 (32.0%) underwent neoadjuvant CT. Sample median age was 63 (IQR:56-69) years. T2 stage was the most prevalent (N =561, 47.7%), followed by T4 (N=243, 20.7%), T1 (N=228, 19.4%), and T3 (N=143, 12.2%). The main tumor histology was non-squamous cell carcinoma in 773 (65.8%) patients. The upper lobe was the most common primary tumor site (N =788, 67.1%). Patients underwent lobectomy (N=917, 78.0%), pneumonectomy (N=184, 15.7%), or sub-lobar resection (N=69, 5.9%). Adding radiotherapy to chemotherapy showed a slightly higher median OS than chemotherapy alone in neoadjuvant settings (51 vs. 47 months, respectively), and a higher median CSS (75 vs. 59 months, respectively). However, these differences were not statistically significant for OS or CSS (HR = 1.08, 95% CI: 0.91-1.28 and HR = 1.04, 95% CI: 0.89-1.21, respectively). After adjustment, age, T3-T4 stage, non-squamous histology, lower lobe primary site, positive resected lymph nodes, and pneumonectomy were all significant independent predictors for worse OS and CSS. IPTW analysis showed no remarkable survival advantage for CRT patients (HR = 1.15, 95% CI: 0.95-1.40 and HR= 1.12, 95% CI: 0.90-1.39) for OS and CSS, respectively. Conclusions: Adding radiotherapy to neoadjuvant CT did not result in significant survival benefits. Multiple prognostic factors should be taken into consideration when identifying the optimal choice and sequence of multimodal treatment for stage III-N2M0 NSCLC patients.

This retrospective cohort study aimed to explore the surgical outcomes and prognostic factors of resection of pulmonary metastases (PM) from colorectal cancer (CRC). Overall, 60 patients who underwent resection of PM from CRC between 2015 and 2021 at two institutions were reviewed. The primary outcome were overall survival (OS) and early recurrence after PM resection. The association between OS and right-sided colon cancer (RCC) was investigated. Early recurrence after PM resection was defined as recurrence within one year. The 5-year OS after CRC resection was 83.8% (95% confidence interval [CI] 67.5-92.4) and after PM resection was 69.4% (95% CI 47.5-83.6). In total, 25 patients had recurrence after PM resection (16 within 1year and 9 after 1year). In multivariable analysis for OS, RCC (hazard ratio [HR] 4.370, 95% CI 1.020-18.73; p = 0.047) and early recurrence after resection of PM (HR 17.23, 95% CI 2.685-110.6; p = 0.003) were risk factors for poor OS. In multivariable analysis for early recurrence after PM resection, higher value of carcinoembryonic antigen (CEA) (> 5.0mg/dL) before PM resection was a risk factor for early recurrence (HR 3.275, 95% CI 1.092-9.821; p = 0.034). The RCC and early recurrence after PM resection were poor prognosis factors of OS. Higher value of CEA before PM resection was an independent risk factor for early recurrence after resection of PM. Comparitive study between surgery and nonsurgery is necessary in patients with higher CEA values.

This research evaluates how surgical intervention affects survival rates in individuals with stage IV thymic epithelial tumors (TET) based on data from the SEER database, offering essential information for clinical decision making. The SEER database (2004-2020) provided data on stage IV TET patients, classified into surgical and non-surgical groups. Analytical techniques, including propensity score matching (PSM) and inverse probability treatment weighting (IPTW), were employed. The primary and secondary outcomes evaluated were cancer-specific survival (CSS) and overall survival (OS), respectively. Of 634 patients (394 diagnosed with thymoma and 240 with thymic carcinoma), 335 underwent surgery, while 299 did not. In univariate analysis, those who had surgery demonstrated significantly improved CSS and OS, with 5-year survival rates of 74.6% for CSS and 62.3% for OS, compared to 41.4% and 26.0%, respectively, in the non-surgical group. Multivariate analysis identified surgery as an independent factor for better CSS and OS. After applying PSM with 194 patients in each group, surgery continued to be associated with significantly improved CSS (HR = 0.417, 95% CI: 0.297-0.587, p < 0.001) and OS (HR = 0.457, 95% CI: 0.350-0.596, p < 0.001). Inverse probability of treatment weighting (IPTW) analysis confirmed these findings, showing better CSS (HR = 0.361, 95% CI: 0.265-0.492, p < 0.001) and OS (HR = 0.423, 95% CI: 0.335-0.535, p < 0.001). Subgroup analyses underscored the survival benefit of surgery for patients with stage IV thymoma and thymic carcinoma, including those with lymph node or distant metastasis. For stage IV thymic epithelial tumors, the inclusion of surgery in multimodal treatment can improve patient survival.

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. 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. 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). 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.

Currently, the benefits of the administration of adjuvant chemotherapy (AT) in pathological low-risk rectal mucinous adenocarcinoma (RM) with T1-3N0M0 are unclear. The objective of this study is to retrospectively investigate the clinical significance of AT in terms of survival outcomes for patients with pathological T1-3N0M0 RM using data from a large population. The patient data were collected from the Surveillance, Epidemiology, and End Results (SEER) Program. The Chi-squared test was used to analyze categorical variables. The survival curves were compared using the log-rank test and the Kaplan-Meier method. A multivariate proportional hazards regression (Cox) model was applied to identify the independent prognostic factors of survival outcomes. Propensity score matching (PSM) was utilized to eliminate the differences between groups and estimate AT's effect. The median follow-up duration for the rectal cancer (RC) cohort was 116 months. Multivariate analyses revealed that RM was a significant adverse prognostic factor, correlating with poorer overall survival (OS) and cancer-specific survival (CSS) for RC [hazard ratio (HR): 1.226, 95% confidence interval (CI): 1.094-1.375, P<0.001; HR: 1.446, 95% CI: 1.242-1.683, P<0.001]. Among patients with RM, the rates of 5-year OS and CSS were 68.6% and 79.3% in the AT (-) group, respectively. Additionally, the AT (+) group exhibited similar rates of 65.6% for 5-year OS and 74% for CSS (P=0.80, P=0.26). Subtype analysis according to preoperative therapy status showed that AT also did not significantly affect survival outcomes (P=0.65, P=0.34; P=0.90, P=0.76). Our study found that RM is a poor prognostic factor in pathological T1-3N0M0 RC. However, AT does not appear necessary to improve survival outcomes of pathological T1-3N0M0 RM.

Background:Adjuvant chemotherapy (AC) is known to be beneficial for stage III colorectal cancer (CRC). In contrast, only a few studies have reported the survival benefits of AC for stage IV CRC after curative surgery.Methods:We identified 155 CRC patients with various organ metastases who underwent curative surgery in our hospital between 2003 and 2017. Clinicopathological parameters and postoperative AC were reviewed. Multivariate analyses were performed to identify prognostic factors. Moreover, the effects of AC on recurrence-free survival (RFS) and overall survival (OS) were analyzed using inverse probability of treatment weighting.Results:The cohort comprised 94 males and 61 females, with a mean age of 63 years. AC was administered to 57% of patients who underwent surgery between 2003 and 2010 and 76% between 2011 and 2017 (p = 0.015). AC was more likely administered to patients with a good performance status, high preoperative albumin level, regional node and peritoneal metastases, and no intraoperative blood transfusion. Multivariate analyses identified AC as a significant prognostic factors for RFS and OS [hazard ratio (HR): 1.86, p = 0.003, and 2.66, p = 0.002, respectively]. After adjusting for different backgrounds, 5-year RFS and OS rates were higher in patients receiving AC (27% and 67%) than in those without AC (14% and 46%, p < 0.0001 and p = 0.0005). Subgroup analyses showed that AC significantly improved RFS in node-negative patients (HR: 2.16, p = 0.029), and RFS and OS in node-positive patients (HR: 2.03, p < 0.0001, and 2.02, p = 0.001, respectively).Conclusion:AC can be discussed with resectable stage IV CRC patients because of its significant survival-improving effects.