Surgical Resection of the Primary Tumor in Stage IV Colorectal Cancer Without Metastasectomy is Associated With Improved Overall Survival Compared With Chemotherapy/Radiation Therapy Alone

Survival Benefit of Primary Tumor Resection Combined With Chemotherapy in Patients With Unresectable Colorectal Mucinous Adenocarcinoma With Liver Metastasis

OBJECTIVE

To evaluate the survival benefit of combining primary tumor resection (PTR) and chemotherapy in patients with unresectable colorectal mucinous adenocarcinoma with liver metastasis (UCR-MAC-LM).

METHODS

We obtained data from the surveillance, epidemiology, and end results database for patients with UCR-MAC-LM from 2010 to 2017. Clinicopathological characteristics were analyzed using the χ2 test. Propensity score matching was performed to balance baseline characteristics. Kaplan-Meier analysis and log-rank tests were used to estimate and compare survival outcomes. Univariate and multivariate Cox regression analyses were conducted to identify the prognostic factors.

RESULTS

A total of 10,178 patients with unresectable colorectal adenocarcinoma with liver metastasis were included, of whom 6.01% (n=612) had UCR-MAC-LM. The UCR-MAC-LM group had a higher proportion of female patients, a greater number of elderly patients, an increased incidence of right colon localization, larger tumor size, and higher T and N staging than the unresectable colorectal non-mucinous adenocarcinoma with liver metastasis group (P<0.05). Multivariate analysis identified several independent prognostic factors (P<0.05). Patients with unresectable colorectal adenocarcinoma with liver metastasis who underwent PTR+C had superior survival rates compared with those who received PTR/C alone or no treatment (cancer-specific survival, P<0.05; overall survival, P<0.05). Subgroup analysis revealed that 17 of 22 groups of patients with UCR-MAC-LM who received PTR+C had significantly prolonged long-term survival compared with those who received PTR/C alone.

CONCLUSIONS

This surveillance, epidemiology, and end results-based study indicates that PTR+C may offer a survival advantage for a specific subgroup of patients with UCR-MAC-LM compared with PTR/C alone. Nonetheless, additional clinical trials are necessary to validate these findings.

Palliative resection of the primary tumour improves survival in incurable metastatic colorectal cancer

BACKGROUND

Studies show conflicting results on whether primary tumour resection (PTR) in metastatic colorectal cancer (mCRC) prolongs survival. The aim of this study was to analyse prognostic factors and the effects of PTR on overall survival (OS) in mCRC patients.

METHODS

In this population-based cohort study, factors associated with PTR and OS were assessed in 188 mCRC patients with mCRC treated with palliative chemotherapy between 2008 and 2019. The Chi-square test and Mann-Whitney U-test were used to assess factors associated with PTR. The log-rank test was used to compare Kaplan-Meier estimates for OS. Cox regression was used to identify factors predicting OS.

RESULTS

Patients undergoing PTR had significantly better performance status, fewer metastatic sites, lower CEA levels, and more often had left-sided CRC than patients not undergoing PTR. OS was longer in palliative mCRC patients undergoing PTR (P < 0.01) and PTR was an independent variable in the Cox regression analysis (P < 0.05). Median OS was 22.9 ± 1.9 months for the PTR group and 14.5 ± 1.5 months for the non-operated group. Poor performance status and liver metastases were significantly associated with poor prognosis.

CONCLUSION

This study shows that PTR had a positive effect on OS and may be considered in patients suitable for surgery. PTR was offered to palliative mCRC patients with prognostic factors associated with better prognosis.

Clinical Outcomes of Upfront Primary Tumor Resection in Synchronous Unresectable Metastatic Colorectal Cancer

The role of upfront primary tumor resection (PTR) in patients with unresectable metastatic colorectal cancer without severe symptoms remains controversial. We retrospectively analyzed the role of PTR in overall survival (OS) in this population. Among the 205 patients who enrolled, the PTR group (n = 42) showed better performance (p = 0.061), had higher frequencies of right-sided origin (p = 0.058), the T4 stage (p = 0.003), the M1a stage (p = 0.012), and <2 organ metastases (p = 0.002), and received fewer targeted agents (p = 0.011) than the chemotherapy group (n = 163). The PTR group showed a trend for longer OS (20.5 versus 16.0 months, p = 0.064) but was not related to OS in Cox regression multivariate analysis (p = 0.220). The male sex (p = 0.061), a good performance status (p = 0.078), the T3 stage (p = 0.060), the M1a stage (p = 0.042), <2 organ metastases (p = 0.035), an RAS wild tumor (p = 0.054), and the administration of targeted agents (p = 0.037), especially bevacizumab (p = 0.067), seemed to be related to PTR benefits. Upfront PTR could be considered beneficial in some subgroups, but these findings require larger studies to verify.

Engineered Plant-Derived Nanovesicles Facilitate Tumor Therapy: Natural Bioactivity Plus Drug Controlled Release Platform

Tumors are the second-most common disease in the world, killing people at an alarming rate. As issues with drug resistance, lack of targeting, and severe side effects are revealed, there is a growing demand for precision-targeted drug delivery systems. Plant-derived nanovesicles (PDNVs), which arecomposed of proteins, lipids, RNA, and metabolites, are widely distributed and readily accessible. The potential for anti-proliferative, pro-apoptotic, and drug-resistant-reversing effects on tumor cells, as well as the ability to alter the tumor microenvironment (TME) by modulating tumor-specific immune cells, make PDNVs promising anti-tumor therapeutics. With a lipid bilayer structure that allows drug loading and a transmembrane capacity readily endocytosed by cells, PDNVs are also expected to become a new drug delivery platform. Exogenous modifications of PDNVs enhance their circulating stability, tumor targeting ability, high cell endocytosis rate, and controlled-release capacity. In this review, we summarize PDNVs' natural antitumor activity, as well as engineered PDNVs as efficient precision-targeted drug delivery tools that enhance therapeutic effects. Additionally, we discuss critical considerations related to the issues raised in this area, which will encourage researchers to improve PDNVs as better anti-tumor therapeutics for clinic applications.

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.

Development and validation of a clinical survival model for young-onset colorectal cancer with synchronous liver-only metastases: a SEER population-based study and external validation

Background

The morbidity and mortality of young-onset colorectal cancer (YO-CRC) patients have been increasing in recent years. Moreover, YO-CRC patients with synchronous liver-only metastases (YO-CRCSLM) have various survival outcomes. Therefore, the purpose of this study was to construct and validate a prognostic nomogram for patients with YO-CRCSLM.

Methods

The YO-CRCSLM patients were rigorously screened from the Surveillance, Epidemiology, and End Results (SEER) database in January 2010 and December 2018 and then assigned to a training and validation cohort randomly (1488 and 639 patients, respectively). Moreover, the 122 YO-CRCSLM patients who were enrolled in The First Affiliated Hospital of Nanchang University were served as a testing cohort. The variables were selected using the multivariable Cox model based on the training cohort and then developed a nomogram. The validation and testing cohort were used to validate the model's predictive accuracy. The calibration plots were used to determine the Nomogram's discriminative capabilities and precision, and the decision analysis (DCA) was performed to evaluate the Nomogram's net benefit. Finally, the Kaplan-Meier survival analyses were performed for the stratified patients based on total nomogram scores classified by the X-tile software.

Results

The Nomogram was constructed including ten variables: marital status, primary site, grade, metastatic lymph nodes ratio (LNR), T stage, N stage, carcinoembryonic antigen (CEA), Surgery, and chemotherapy. The Nomogram performed admirably in the validation and testing group according to the calibration curves. The DCA analyses showed good clinical utility values. Low-risk patients (score<234) had significantly better survival outcomes than middle-risk (234-318) and high-risk (>318) patients (P < 0.001).

Conclusion

A nomogram predicting the survival outcomes for patients with YO-CRCSLM was developed. In addition to facilitating personalized survival prediction, this nomogram may assist in developing clinical treatment strategies for patients with YO-CRCSLM who are undergoing treatment.

Impact of primary tumor resection on the survival of patients with unresectable colon cancer liver metastasis at different colonic subsites: a propensity score matching analysis

OBJECTIVE

To investigate the effect of primary tumor resection (PTR) on the prognosis of patients with unresectable colon cancer liver metastasis (UCCLM) at seven colonic subsites using the Surveillance, Epidemiology, and End Results (SEER) database.

METHODS

Propensity score matching (PSM) was performed to balance selection bias using all available variables that could be of potential relevance. After matching, the groups were redefined in a 1:1 ratio using the nearest method. Cancer-specific survival (CSS) was compared among the patients of PTR and non-PTR groups. Cox regression models were used to identify the prognostic factors for CSS.

RESULTS

CSS was significantly different between all groups. Cox regression analysis showed that PTR was an independent prognostic factor for all groups. After PSM, PTR significantly prolonged CSS for all groups. Subgroup analysis showed that PTR did not improve the prognosis of N2 stage patients in the cecum, ascending colon, and descending colon groups; T1 + T2 stage patients in the hepatic flexure group; and patients with a tumor size ≤5 cm in the splenic flexure group. Segmental colectomy could prolong CSS of patients in the cecum, ascending colon, transverse colon, splenic flexure, and sigmoid colon groups, while extended colectomy could prolong CSS of patients in the hepatic flexure and descending colon groups.

CONCLUSION

At different colonic subsites, UCCLM patients had different CSS. PTR could improve their prognosis, however, N stage, T stage, and tumor size are important reference indicators. In addition to patients in the hepatic flexure and descending colon groups, we suggested that patients in other groups should choose segmental colectomy.

Primary Tumor Resection for Metastatic Colorectal, Gastric and Pancreatic Cancer Patients: In Search of Scientific Evidence to Inform Clinical Practice

The management of the primary tumor in metastatic colorectal, gastric and pancreatic cancer patients may be challenging. Indeed, primary tumor progression could be associated with severe symptoms, compromising the quality of life and the feasibility of effective systemic therapy, and might result in life-threatening complications. While retrospective series have suggested that surgery on the primary tumor may confer a survival advantage even in asymptomatic patients, randomized trials seem not to definitively support this hypothesis. We discuss the evidence for and against primary tumor resection for patients with metastatic gastrointestinal (colorectal, gastric and pancreatic) cancers treated with systemic therapies and put in context the pros and cons of the onco-surgical approach in the time of precision oncology. We also evaluate current ongoing trials on this topic, anticipating how these will influence both research and everyday practice.

Short-course radiotherapy and chemotherapy for conversion surgery in patients with unresectable metastatic rectal cancer: a preliminary case series study

Purpose

Curative treatment is challenging in patients with locally advanced rectal cancer and unresectable metastases. The aim of this study was to evaluate the clinical outcomes of short-course radiotherapy (RT) followed by systemic chemotherapy for patients with rectal cancer with mesorectal fascia (MRF) involvement and unresectable distant metastases.

Methods

The study included consecutive patients diagnosed as having metastatic mid-to-low rectal cancer treated with short-course RT followed by systemic chemotherapy for conversion radical or palliative surgery between 2014 and 2019 at Gil Medical Center. The patients had primary rectal tumors involving the MRF and unresectable distant metastases. The treatment strategies were determined in a multidisciplinary team discussion.

Results

Seven patients (five men and two women) underwent short-course RT (5×5 Gy) and preoperative systemic chemotherapy. The median age was 68 years (range, 46-84 years), and the median distance from the anal verge to the primary tumor was 6.0 cm (range, 2.0-9.0 cm). During the median follow-up period of 29.4 months, three patients underwent conversion radical surgery with R0 resection, two underwent palliative surgery, and two could not undergo surgery. No postoperative major morbidity or mortality occurred. The patients who underwent conversion complete radical surgery showed good long-term survival outcomes, with an overall survival time of 29.4-48.8 months and progression-free survival time of 14.7-41.1 months.

Conclusion

Short-course RT followed by systemic chemotherapy could provide patients with unresectable stage IV rectal cancer a chance to undergo to conversion radical surgery with good long-term survival outcomes.

Is There a Role for Perioperative Pelvic Radiotherapy in Surgically Resected Stage IV Rectal Cancer?: A Propensity Score-matched Analysis

OBJECTIVES

This study aimed to determine whether perioperative pelvic radiotherapy (RT) improves outcomes in stage IV rectal cancer patients treated with primary surgical resection and systemic chemotherapy and to identify predictive factors for selection of patients for these approaches.

MATERIALS AND METHODS

We searched the Surveillance, Epidemiology, and End Results (SEER) database for patients diagnosed between 2010 and 2015 with stage IV rectal cancer, but without brain or bone metastases. After applying the exclusion criteria, a total of 26,132 patients were included in the analysis; propensity score matching was used to balance their individual characteristics.

RESULTS

Overall, 3283 (12.6%) patients received perioperative RT; the 3-year overall survival (OS) rates were 43.6% in the surgery group and 50.5% in the surgery with RT group (P<0.001). The survival benefit of RT was maintained after propensity score matching and multivariate adjustment (hazard ratio: 0.70; 95% confidence interval: 0.66-0.81; P<0.001). Interaction testing of the prognostic variables showed a significant interaction between RT and the presence of lung metastasis (P<0.001): the benefit of RT was observed only in patients without lung metastases (3 y OS 52.1% vs. 44.1%, P<0.001), but it was observed regardless of liver metastases. In addition, we developed a web-based calculator (http://bit.do/mRC_surv) to provide individualized estimates of OS benefit based on the receipt of perioperative pelvic RT.

CONCLUSIONS

Perioperative pelvic RT significantly improved OS rates, especially in patients without lung metastases. We successfully developed a nomogram and web-based calculator that could predict survival benefit with the addition of RT for these patients.

Predictors of curative-intent oncologic management among patients with stage IV rectal cancer

BACKGROUND

Management of stage IV rectal adenocarcinoma is categorized into curative and palliative-intent strategies. The aim of this study is to determine the incidence of and associations with curative-intent treatment in stage IV rectal cancer.

METHODS

The National Cancer Database from 2010 to 2016 was queried for patients with stage IV rectal adenocarcinoma and were grouped into curative-intent and non-curative management. Multivariable logistic regression was used to predict use of curative-intent management.

RESULTS

16,862 patients were included in this study: 4886 (30.0%) curative-intent and 11,975 (71.0%) non-curative. Multivariable regression demonstrated curative intent was associated with young age, female gender, white race, private insurance, mucinous histology and anaplastic grade.

CONCLUSION

Use of curative intent oncologic management among patients with stage IV rectal adenocarcinoma is influenced by age, tumor biology and location of metastatic disease. Association with gender and insurance imply the presence of disparity in the delivery of cancer care among this patient population.

Surgical resection and survival outcomes in metastatic young adult colorectal cancer patients

Background

The incidence of colorectal cancer in adults younger than age 50 has increased with rates expected to continue to increase over the next decade. The objective of this study is to examine the survival benefit of surgical resection (primary and/or metastatic) versus palliative therapy in this patient population.

Methods

We identified 6708 young adults aged 18–45 years diagnosed with metastatic colorectal cancer (mCRC) from 2004 to 2015 from the SEER database. Overall survival (OS) was analyzed using Kaplan–Meier estimation, log rank test, and multivariate Cox proportional hazards model.

Results

Sixty‐three percent of patients in our study underwent primary tumor resection (PTR), with 40% undergoing PTR alone and 23% undergoing both resection of primary disease and metastasectomy. The median OS for patients who underwent both PTR and metastasectomy was 36 months, compared to 13 months for those who did not receive any surgical intervention. The multivariate analysis showed significant OS benefit of receiving both PTR and metastasectomy (HR 0.34, 95% CI: 0.31–0.37, p < 0.001) compared to palliative therapy. Undergoing PTR only and metastasectomy only were also associated with improved OS (HR 0.46, 95% CI: 0.43–0.49, p < 0.001 and HR 0.64, 95% CI: 0.55–0.76, p < 0.001, respectively).

Conclusion

This is the largest observational study to evaluate survival outcomes in young‐onset mCRC patients and the role of surgical intervention of the primary and/or metastatic site. Our study provides evidence of statistically significant increase in OS for young mCRC patients who undergo surgical intervention of the primary and/or metastatic site.

A novel risk stratification for predicting prognosis of colorectal cancer patients with bone metastasis

Background

Our understanding in prognosis of bone metastasis (BM) from colorectal cancer (CRC) is limited. We aimed to establish a clinical risk stratification for individually predicting the survival of CRC patients with BM.

Methods

A total of 200 CRC patients with BM were included in this study. Survival time from BM diagnosis was estimated using the Kaplan-Meier method. The multivariable COX regression model identified the risk factors on cancer specific survival (CSS). Based on weighted scoring system, the stratification model was constructed to classify patients with BM according to prognostic risk. Discrimination power and calibration ability of risk stratification were measured.

Results

The median CSS time was 11 months after BM diagnosis. Lymph node metastasis, Carbohydrate antigen 199 (CA199) levels, bone involvement, Karnofsky Performance Status (KPS) scores, primary tumor resection, bisphosphonates therapy and radiotherapy were identified as predictors of CSS. Four risk groups were stratified according to weighted scoring system, including low risk, medium risk, medium-high risk and high risk group, with 35, 16, 9 and 5 months of median CSS, respectively (P=0.000). The risk stratification displayed good accuracy in predicting CSS, with acceptable discrimination and calibration.

Conclusions

This novel risk stratification predicts CSS in CRC patient with BM using easily accessible clinicopathologic factors, which is recommended for use in individualized clinical decision making in patient with BM.

Primary tumor resection improves prognosis of unresectable carcinomas of the transverse colon including flexures with liver metastasis: a preliminary population-based analysis

Purpose

Studies on unresectable colorectal cancer liver metastasis(CRLM) rarely analyze the prognosis of the patients from the point of colonic subsites. We aimed to evaluate the effect of primary tumor resection (PTR) and different scope of colectomy on the prognosis of patients with unresectable transverse colon cancer liver metastasis (UTCLM), hepatic flexure cancer liver metastasis (UHFLM), and splenic flexure cancer liver metastasis (USFLM).

Patients and methods

The patients were identified from the Surveillance, Epidemiology, and End Results (SEER) database from 2010 to 2015. Cox proportional hazards regression models were used to identify prognostic factors of overall survival (OS) and cause-specific survival (CSS). Kaplan-Meier analyses and log-rank tests were conducted to assess the effectiveness of PTR on survival.

Results

In total, this study included a cohort of 1960 patients: 556 cases of UHFLM, 1008 cases of UTCLM, and 396 cases of USFLM. The median survival time of whole patients was 11.0 months, ranging from 7.0 months for UHFLM patients to 15.0 months for USFLM patients. USFLM patients had the best OS and CSS, followed by UTCLM patients. UHFLM patients had the worst OS and CSS (All P < 0.001). PTR could improve the OS and CSS of UTCLM, UHFLM, and USFLM (All P < 0.001). Subgroups analysis revealed that USFLM patients with tumor size≤5 cm and negative CEA had not demonstrated an improved OS and CSS after PTR. Multivariate analysis showed that PTR and perioperative chemotherapy were common independent prognostic factors for UHFLM, UTCLM, and USFLM patients. There was no difference between segmental colon resection and larger colon resection on CSS of UHFLM, UTCLM, and USFLM patients.

Conclusions

We confirmed the different survival of patients with UTCLM, UHFLM, and USFLM, and for the first time, we proved that PTR could provide survival benefits for patients with unresectable CRLM from the perspective of colonic subsites of transverse colon, hepatic flexure, and splenic flexure. Besides, PTR may not improve the prognosis of USFLM patients with CEA- negative or tumor size≤5 cm. For oncologic outcomes, we concluded that segmental colon resection seemed an effective surgical procedure for UTCLM, UHFLM, and USFLM.

The association of the neutrophil-lymphocyte ratio with the presence of minimal residual disease and outcome in patients with Stage II colon cancer treated with surgery alone

AIM

Despite curative surgery, 25% of patients with Stage II colorectal cancer will relapse due to minimal residual disease (MRD). Markers of immune function, such as the neutrophil to lymphocyte ratio (NLR), may be associated with MRD defined by bone marrow micro-metastasis (mM) and circulating tumour cells (CTCs).

METHOD

A prospective cohort study of consecutive patients with Stage II colon cancer patients attended at a single centre between 2007 and 2014. Blood and bone marrow samples were taken to detect CTCs and mM using immunocytochemistry with anti-carcinoembryonic antigen 1 month after surgery. The NLR and absolute neutrophil and lymphocyte counts were determined immediately pre-surgery and 1 month post-surgery. These were compared with the sub-types of MRD: group I MRD(-); group II mM positive and group III CTC positive. Cut-off values of the NLR of >3.0 and >5.0 were used. Follow-up was for up to 5 years or relapse and disease-free survival (DFS) was calculated using Kaplan-Meier analysis.

RESULTS

In all, 181 patients (99 women) participated. Mean age was 68 years. Median follow-up was 4.04 years: I, N = 105; II, N = 36; III, N = 40. The NLR significantly decreased post-surgery only in group I patients. The frequency of NLR >3.0 and >5.0 was significantly higher in group III; between groups I and II there was no significant difference. 5-year DFS was 98% in group I, 68% in group II and 7% in group III.

CONCLUSIONS

Patients with a significantly higher immune dysfunction had a shorter time to disease progression, a worse DFS and the presence of CTCs.

Outcomes of Simultaneous Resections and Classical Strategy for Synchronous Colorectal Liver Metastases in Sweden: A Nationwide Study with Special Reference to Major Liver Resections

Background

About 20% of patients with colorectal cancer have liver metastases at the time of diagnosis, and surgical resection offers a chance for cure. The aim of the present study was to compare outcomes for patients that underwent simultaneous resection to those that underwent a staged procedure with the bowel-first (classical) strategy by using information from two national registries in Sweden.

Methods

In this prospectively registered cohort study, we analyzed clinical, pathological, and survival outcomes for patients operated in the period 2008–2015 and compared the two strategies.

Results

In total, 537 patients constituted the study cohort, where 160 were treated with the simultaneous strategy and 377 with the classical strategy. Patients managed with the simultaneous strategy had less often rectal primary tumors (22% vs. 31%, p = 0.046) and underwent to a lesser extent a major liver resection (16% vs. 41%, p < 0.001), but had a shorter total length of stay (11 vs. 15 days, p < 0.001) and more complications (52% vs. 36%, p < 0.001). No significant 5-year overall survival (p = 0.110) difference was detected. Twenty-five patients had a major liver resection in the simultaneous strategy group and 155 in the classical strategy group without difference in 5-year overall survival (p = 0.198).

Conclusion

Simultaneous resection of the colorectal primary cancer and liver metastases can possibly have more complications, with no difference in overall survival compared to the classical strategy.

Perioperative therapy in metastatic colorectal cancer: Pattern of use and survival outcomes

BACKGROUND

Multimodality therapy of metastatic colorectal cancer (mCRC) is currently considered the standard of care. The aim of this study was to evaluate the impact of perioperative therapy on surgical resection in mCRC.

METHODS

The National Cancer Database was analyzed for affected patients between 2004 and 2013. Univariate and multivariate analyses were done to identify factors associated with patient outcomes. Kaplan-Meier analysis and Cox proportional hazards models were used for the association between patient characteristics and survival.

RESULTS

About 61,940 patients with mCRC were identified. Mean age = 63.4 years (SD ± 14). About 69% had a colon primary and 32% had only one metastatic site. Only 49% of those who underwent surgery for both primary and metastatic sites received postoperative chemotherapy (p < .001). Negative prognostic factors included no chemotherapy received (hazard ratio [HR], 2.32; 2.27-2.37; p < .001), more than three metastatic sites (HR, 2.28; 2.09-2.48; p < .001), year of diagnosis between 2004 and 2008 (HR, 1.71; 1.15-1.20; p < .001) and colon tumor location with right worse than left-sided (HR, 1.21; 1.19-1.24; p < .001). Five-year overall survival for resection of the primary and metastatic site (28.2%) was higher than for no surgical treatment (4.7%).

CONCLUSION

Perioperative therapy was associated with improved survival, following resection of metastatic sites or primary tumor.

Nomograms predicting Overall Survival and Cancer-specific Survival for Synchronous Colorectal Liver-limited Metastasis

Background: Colorectal cancer (CRC) ranks as the third most frequent cancer type and the second leading cause of cancer-related death worldwide. The liver is the most common metastatic site of CRC with 20%-34% of patients suffering synchronous liver metastasis. Patients with colorectal liver-limited metastasis account for one-third of deaths from colorectal cancer. Moreover, some evidence indicated that CRC patients with synchronous liver disease encounter a worse prognosis and more disseminated disease state comparing with metastatic liver disease that develops metachronously.

Methods: Data in this retrospective analysis were extracted from the Surveillance, Epidemiology, and End Results (SEER) database. Nomograms were constructed with basis from a multivariate Cox regression analysis. The prognostic nomograms were validated by C-index, time-dependent receiver operating characteristic (ROC) curve, decision curve analysis (DCA) and calibration curves.

Results: A total of 9,958 CRC patients with synchronous liver-limited metastasis were extracted from the SEER database during 2010-2016. Both overall survival (OS) and cancer-specific survival (CSS) were significantly correlated with age, marital status, race, tumor location, pathological grade, histologic type, T stage, N stage, surgery for primary tumor, surgery for liver metastasis, chemotherapy and CEA. All of the significant variables were used to create the nomograms predicting OS and CSS. C-index values, time-dependent ROC curves, DCA curves and calibration curves, proved the superiority of the nomograms.

Conclusions: Our research investigated a national cohort of almost 10,000 patients to create and verify nomograms based on pathological, therapeutic and demographic features to predict OS and CSS for synchronous colorectal liver-limited metastasis (SCLLM). The nomograms may act as an excellent tool to integrate clinical characteristics to guide the therapeutic choice for SCLLM patients.

Colonic stent vs surgical resection of the primary tumor. Effect on survival from stage-IV obstructive colorectal cancer

BACKGROUND AND OBJECTIVES

the impact of surgical primary tumor resection on survival of obstructive metastatic colorectal cancer remains controversial. The primary goal of this study was to analyze survival in patients with obstructive metastatic colorectal cancer after treatment with either resection surgery or a colonic stent.

MATERIAL AND METHODS

a prospective study was performed of all patients with stage-IV colorectal cancer and obstructive manifestations, diagnosed from 2005 to 2012 and managed with either resection surgery or a colonic stent. Cases with a perforation, abscess, right colon or distal rectal malignancy, multiple colorectal cancer or derivative surgery were excluded.

RESULTS

a total of 95 patients were included, 49 were managed with resection surgery and 46 with a colonic stent. The colonic stent group had a higher Charlson index (9.5 ± 2.1 vs 8.6 ± 1.5, p = 0.01), a shorter time to oral intake (0.9 ± 1.1 vs 16.4 ± 53.5 days, p = 0.05), a shorter hospital stay (4 ± 4.8 vs 16.7 ± 15.5 days, p = 0.0001), less need for stomata (11.1 % vs 32.7 %, p = 0.01), fewer early complications (4.3 % vs 46.9 %, p = 0.0001) and more late complications (33.3 % vs 6.4 %, p = 0.001). Undergoing chemotherapy (p = 0.008) was the only independent factor related to increased survival. In the subgroup of patients managed with chemotherapy, surgical primary tumor resection was an independent factor associated with increased survival.

CONCLUSION

both treatments are effective for resolving obstructive manifestations in patients diagnosed with stage-IV obstructive colorectal cancer. Resection surgery has no positive impact on survival and thus cannot be recommended as a therapy of choice.

Individualized prediction of survival benefit from primary tumor resection for patients with unresectable metastatic colorectal cancer

Background

The impact of primary tumor resection (PTR) on the prognosis of unresectable metastatic colorectal cancer (mCRC) patients remains debatable. We aimed to develop several prognostic nomograms which could be useful in predicting whether patients might benefit from PTR or not.

Methods

Patients diagnosed as mCRC without resected metastasis were identified from the Surveillance Epidemiology and End Results database and randomly assigned into two groups: a training cohort (6369 patients) and a validation cohort (2774 patients). Univariate and multivariable Cox analyses were performed to identify the independent predictors and construct nomograms that could independently predict the overall survival (OS) of unresectable mCRC patients in PTR and non-PTR groups, respectively. The performance of these nomograms was assessed by the concordance index (C-index), calibration curves, and decision curve analysis (DCA).

Results

Based on the result of univariate and multivariable Cox analyses, two nomograms were respectively constructed to predict the 1-year OS rates of unresectable mCRC patients when receiving PTR and not. The first one included age, gender, tumor grade, proximal colon, N stage, CEA, chemotherapy, radiotherapy, histology type, brain metastasis, liver metastasis, lung metastasis, and bone metastasis. The second nomogram included age, race, tumor grade, primary site, CEA, chemotherapy, brain metastasis, and bone metastasis. These nomograms showed favorable sensitivity with the C-index range of 0.700–0.725. The calibration curves and DCAs also exhibited adequate fit and ideal net benefits in prognosis prediction and clinical application.

Conclusions

These practical prognosis nomograms could assist clinicians in making appropriate treatment decisions to effectively manage the disease.

Lnc HAGLR Promotes Colon Cancer Progression Through Sponging miR-185-5p and Activating CDK4 and CDK6 in vitro and in vivo

BACKGROUND/AIM

LncRNA plays a key role in tumor progression. HAGLR functions as an oncogene in many cancers. However, the molecular mechanism of HAGLR in colon cancer is still unclear.

METHODS

qRT-PCR was used to measure the expression of HAGLR, miR-185-5p in colon cancer. The expression of CDK4 and CDK6 was detected by Western blot. CCK-8 assay, EdU staining, transwell and Annexin V-FITC/PI assay were used to analyze the effect of HAGLR and miR-185-5p on cell proliferation, invasion, migration and apoptosis. Bioinformatic analysis and luciferase were used to analyze the target genes of HAGLR and miR-185-5p. Nude mice were used to detect mouse tumor changes.

RESULTS

Compared with normal colon cancer tissues and cells, the expression of HAGLR was increased in colon cancer tissues and cells. In addition, the expression of HAGLR down-regulation inhibited the growth, migration, and invasion of colon cancer cells. MiR-185-5p was reduced in colon cancer, and CDK4 and CDK6 acted as target genes of miR-185-5p to regulate the progress of colon cancer. And CDK4 and CDK6 were predicted as downstream targets of miR-185-5p. Finally, it was demonstrated that HAGLR regulated tumor progression in vivo.

CONCLUSION

Lnc HAGLR promoted the development of colon cancer by miR-185-5p/CDK4/CDK6 axis, and lnc HAGLR might be potential target for colon cancer.

The effect of primary tumor radiotherapy in patients with Unresectable stage IV Rectal or Rectosigmoid Cancer: a propensity score matching analysis for survival

BACKGROUND

To evaluate the impact of primary tumor radiotherapy on survival in patients with unresectable metastatic rectal or rectosigmoid cancer.

METHODS

From September 2008 to September 2017, 350 patients with unresectable metastatic rectal or rectosigmoid cancer were retrospectively reviewed in our center. All patients received at least 4 cycles of chemotherapy and were divided into two groups according to whether they received primary tumor radiotherapy. A total of 163 patients received primary tumor radiotherapy, and the median radiation dose was 56.69 Gy (50.4-60). Survival curves were estimated with the Kaplan-Meier method to roughly compare survival between the two groups. Subsequently, the 18-month survival rate was used as the outcome variable for this study. This study mainly evaluated the impact of primary tumor radiotherapy on the survival of these patients through a series of multivariate Cox regression analyses after propensity score matching (PSM).

RESULTS

The median follow-up time was 21 months. All 350 patients received a median of 7 cycles of chemotherapy (range 4-12), and 163 (46.67%) patients received primary tumor radiotherapy for local symptoms. The Kaplan-Meier survival curves showed that the primary tumor radiotherapy group had a significant overall survival (OS) advantage compared to the group without radiotherapy (20.07 vs 17.33 months; P = 0.002). In this study, the multivariate Cox regression analysis after adjusting for covariates, multivariate Cox regression analysis after PSM, inverse probability of treatment weighting (IPTW) analysis and propensity score (PS)-adjusted model analysis consistently showed that primary tumor radiotherapy could effectively reduce the risk of death for these patients at 18 months (HR: 0.62, 95% CI 0.40-0.98; HR: 0.79, 95% CI: 0.93-1.45; HR: 0.70, 95% CI 0.55-0.99 and HR: 0.74, 95% CI: 0.59-0.94).

CONCLUSION

Compared with patients with stage IV rectal or rectosigmoid cancer who did not receive primary tumor radiotherapy, those who received primary tumor radiotherapy had a lower risk of death. The prescription dose (59.4 Gy/33 fractions or 60 Gy/30 fractions) of radiation for primary tumors might be considered not only to relieve symptoms improve the survival of patients with inoperable metastatic rectal or rectosigmoid cancer.

A prognostic index model to individually predict clinical outcomes for colorectal cancer with synchronous bone metastasis

Background: The prognosis of synchronous bone metastasis (BM) in colorectal cancer (CRC) is poor and rarely concerned. A clinical tool to evaluate the prognosis and clinical outcomes for BM would be attractive in current clinical practice. Methods: A total of 342 CRC patients with synchronous BM were identified from Surveillance, Epidemiology, and End Results (SEER) database. The cancer specific survival (CSS) was estimated with the Kaplan-Meier method. Prognostic factors were identified from multivariate Cox model, and the final clinical nomogram was developed to predict the CSS. The concordance index (C-index) was used to assess the discriminative ability. Calibration curves were provided to internally validate the performance of the nomogram. Results: The nomogram finally consisted of 6 prognostic factors including age, tumor grade, AJCC N stage, carcinoembryonic antigen (CEA) levels, primary tumor resection and chemotherapy, which translated the effects of prognostic factors into certain scores to predict the 1-, 2- and 3-year CSS for the synchronous BM in CRC patients. The nomogram presented a good accuracy for predicting the CSS with the C-index of 0.742. The calibration of the nomogram predictions was also accurate. Conclusions: This nomogram was accurate enough to predict the CSS of CRC patients with synchronous BM using readily available clinicopathologic factors and could provide individualized clinical decisions for both physicians and patients.

Predicting Overall Survival in Patients with Metastatic Rectal Cancer: a Machine Learning Approach

BACKGROUND

A significant proportion of patients with rectal cancer will present with synchronous metastasis at the time of diagnosis. Overall survival (OS) for these patients are highly variable and previous attempts to build predictive models often have low predictive power, with concordance indexes (c-index) less than 0.70.

METHODS

Using the National Cancer Database (2010-2014), we identified patients with synchronous metastatic rectal cancer. The data was split into a training dataset (diagnosis years 2010-2012), which was used to build the machine learning model, and a testing dataset (diagnosis years 2013-2014), which was used to externally validate the model. A nomogram predicting 3-year OS was created using Cox proportional hazard regression with lasso penalization. Predictors were selected based on clinical significance and availability in NCDB. Performance of the machine learning model was assessed by c-index.

RESULTS

A total of 4098 and 3107 patients were used to construct and validate the nomogram, respectively. Internally validated c-indexes at 1, 2, and 3 years were 0.816 (95% CI 0.813-0.818), 0.789 (95% CI 0.786-0.790), and 0.778 (95% CI 0.775-0.780), respectively. External validated c-indexes at 1, 2, and 3 years were 0.811, 0.779, and 0.778, respectively.

CONCLUSIONS

There is wide variability in the OS for patients with metastatic rectal cancer, making accurate predictions difficult. However, using machine learning techniques, more accurate models can be built. This will aid patients and clinicians in setting expectations and making clinical decisions in this group of challenging patients.

Surgery on primary tumor shows survival benefit in selected stage IV colon cancer patients: A real-world study based on SEER database

Objectives: Most patients with stage IV colon cancer did not have the opportunity for curative surgery, only selected patients could benefit from surgery. This study aimed to determine whether surgery on the primary tumor (SPT) should be performed in patients with stage IV colon cancer and how to select patients for SPT.

Methods: This study included 48,933 patients with stage IV colon cancer who were identified in the Surveillance, Epidemiology and End Results (SEER) database between 1998 and 2015. Propensity score matching (PSM) analysis was adopted to balance baseline differences between SPT and non-surgery groups. Kaplan-Meier (K-M) curves were utilized to compare the overall survival (OS). Prognostic nomograms were generated to predict survival based on pre- and post-operative risk factors. Patients were divided into low, middle, and high mortality risk subsets for OS by X-tile analyses based on scores derived from above nomograms.

Results: Patients with SPT had a significantly longer OS than those without surgery, regardless of the metastatic sites and diagnostic years. Nomograms, according to the pre- and post-operative risk factors, showed moderate discrimination (all C-indexes above 0.7). Based on X-tile analyses, low mortality risk subset (post-operative score ≤ 22.3, preoperative score ≤ 9.7) recommended for SPT, and high mortality risk was not.

Conclusions: SPT led to prolonged survival in stage IV colon cancer. Our nomograms would help to select suitable patients for SPT.

Locoregional therapy of the primary tumour in de novo stage IV breast cancer in 216 066 patients: A meta-analysis

Patients presenting with de novo stage IV metastatic breast cancer have a complex disease which is normally treated with palliative intent and systemic therapy. However, there is mounting evidence that resection of the primary tumour and/or localised radiotherapy (locoregional therapy; LRT) could be associated with overall survival improvements. We aimed to conduct a meta-analysis to inform decision making. Using the PubMed, Cochrane and Ovid SP databases, a literature review and meta-analysis were conducted to assess the effect of LRT on overall survival. Studies were analysed for the impact of LRT on survival. All forms of LRT resulted in a significant 31.8% reduction in mortality (N = 42; HR = 0.6823 (95% CI 0.6365; 0.7314)). Surgical resection resulted in a significant 36.2% reduction in mortality (N = 37; HR = 0.6379 (95% CI 0.5974; 0.6811)). The prospective trials reported a 19.23% reduction in mortality which was not statistically significant (N = 3, HR = 0.8077 (95% CI 0.5704; 1.1438). 216 066 patients were included. This is the largest meta-analysis regarding this question to date. Our meta-analysis shows that LRT of the primary tumour seems to improve overall survival in de novo stage IV disease. Therefore, this therapeutic option should be considered in selected patients after a careful multidisciplinary discussion.

National statistics about resection of the primary tumor in asymptomatic patients with Stage IV colorectal cancer and unresectable metastases. Need for improvement in data collection. A systematic review with meta-analysis

BACKGROUND

Patients with asymptomatic Stage IV colorectal cancer represent a significant heterogeneous group. National statistics represent an effective method to follow in real time the clinical outcomes of patients, and they may represent an important tool to analyze and to compare different therapeutic approaches. The aim of our study was to analyze the reviews of national data and single institutions reports, which compared the clinical outcomes of patients with asymptomatic Stage IV colorectal cancer and un-resectable metastases who had resection of the primary tumor with those who did not have resection. We gave special attention to the number of missing established relevant variables, to determine the appropriateness of the results of the published studies.

MATERIAL

We performed a systematic review of papers comparing patients who had and who had not primary tumor resection. Screened reports included the time of publication from June 2012 to June 2018; 2556 papers were identified and 27 were included into the review. The primary outcome was observed survival. We analyzed the number of major missing variables in National Data Bases and Single Institution Reports, to assess the overall validity of the conclusions of the analyzed reports.

RESULTS

In the majority of the reports and in the meta-analysis of studies with propensity score matching, resection of the primary tumor was correlated to improved survival and to the possibility for a better response to postoperative chemotherapy.

CONCLUSIONS

The high number of missing significant variables, and a clear clinical selection in single center reports make any analysis error-prone. National statistics might represent a valid method to follow in real time the clinical outcomes of these patients, comparing different therapeutic approaches. There is the need for improvement in national data collection, to make descriptive national statistics the ground for future progress in treatment. (PROSPERO) CRD 42018089691.

An increase in the peripheral lymphocyte-to-monocyte ratio after primary site resection is associated with a prolonged survival in unresectable colorectal carcinoma

PURPOSE

The prognostic benefits of primary tumor resection in patients with unresectable distant metastatic colorectal cancer remain unclear. A high pre-treatment lymphocyte-to-monocyte ratio (LMR) was previously shown to be associated with a better prognosis. We assessed whether or not primary tumor resection was associated with an improved survival if the peripheral lymphocyte-to-monocyte ratio increased after primary site resection.

METHODS

The survival in 64 and 59 patients with and without primary tumor resection, respectively, was retrospectively compared. After resection, the survival in 39 patients with a postoperatively increased LMR (LMR-increase) and 25 patients with a decreased LMR (LMR-decrease) was compared.

RESULTS

Primary tumor resection prolonged the median survival more frequently in cases of non-differentiated adenocarcinoma, obstructive symptoms, high serum albumin levels, and no lymph-node metastasis than in others. Cox regression showed that the potential independent prognostic variable was non-resection of the primary lesion. After resection, the median survival in the LMR-increase vs. LMR-decrease groups was significantly different (27.3 vs. 20.8 months). There were no marked differences in patient background characteristics between the groups, except for in the number of pre-operative peripheral blood lymphocytes. The resected specimens showed significantly lower CD8⁺:CD163⁺ invading leukocyte ratios in the LMR-increase group than in the LMR-decrease group.

CONCLUSIONS

Primary tumor resection in patients with unresectable metastatic colorectal cancer may be associated with an improved survival, especially when the LMR is increased after primary tumor resection.

Primary tumor resection for initially staged IV breast cancer: An emphasis on programmed death-ligand 1 expression, promoter methylation status, and survival

Conventional therapy modalities for advanced breast cancer are problematic, whereas checkpoint blockade immunotherapy has been considered as a promising approach. This study aims to determine programmed death-ligand 1 (PD-L1) expression and methylation status of PD-L1 promoter in primary tumor tissue and metastatic foci of patients with stage IV breast cancer.Clinicopathological data and survival rates of 57 breast cancer patients, who were initially staged IV, and operated for intact tumors, were retrospectively analyzed. Immunohistochemical analysis of PD-L1 using 57 primary tumors, 33 paired metastatic lymph nodes, and 14 paired distant metastases was performed. Additionally, the methylation rate of the PD-L1 gene promoter region was determined with real-time polymerase chain reaction (PCR) analysis in 38 samples.Overall PD-L1 expression in primary tumors was 23.1% (12/52). PD-L1 positivity was reduced in lymph nodes by 15.2% (5/33) and in distant metastases by 21.4% (3/14). PD-L1 expression diverged between primary and metastatic foci in a subset of cases (18.2% for lymph node and 33.3% for distant metastasis). In general, the PD-L1 promoter was not methylated, and mean methylation rates were low (min. 0%-max. 21%). We observed no correlation between PD-L1 expression, promoter methylation, and survival.Neither the expression nor the methylation status of PD-L1 in patients, who were presented with stage IV breast cancer and operated for an intact primary tumor, had a statistically significant relation with survival. Discordance in PD-L1 expression between primary tumor and metastasis should be considered during pathological and clinical management of patients who would undergo checkpoint blockade therapy.

Treatments for Stage IV Colon Cancer and Overall Survival

BACKGROUND

The role of primary tumor resection (PTR) for asymptomatic stage IV colon cancer with unresectable metastases remains unclear. Increasingly there has been a trend away from resection. The aim of this study was to examine trends in the treatment of stage IV colon cancers, impact of different treatments on long-term mortality, and factors associated with receipt of postoperative chemotherapy.

METHODS

The 2006-2012 National Cancer Data Base was queried for stage IV colon cancer patients. Treatments were grouped into PTR and chemotherapy, PTR only, chemotherapy only, and no treatment. A descriptive analysis was performed examining patient and hospital characteristics associated with different treatments. A Cox regression analysis was used to assess the adjusted effect of different treatments on long-term survival. A multivariable logistic regression was used to examine factors associated with postoperative chemotherapy.

RESULTS

Of 31,310 patients, who met inclusion criteria, 22% of the patients underwent PTR and chemotherapy, 37.5% received chemotherapy only, 11.9% underwent PTR, and 28.6% received no treatment. Patients who received no treatment had the highest hazard of death at 1, 3, and 5 y, followed by PTR only, and chemotherapy only compared with PTR combined with chemotherapy. Patients who were older and had more comorbidities were less likely to receive postoperative chemotherapy.

CONCLUSIONS

Primary tumor resection in conjunction with postoperative chemotherapy among stage IV colon cancer patients with unresectable metastases was associated with a long-term survival benefit compared with other treatment options. Efforts should be made to increase the use of postoperative chemotherapy where feasible.

Review of Colorectal Studies Using the National Cancer Database

The National Cancer Database (NCDB) is a large clinical oncology database developed with data collected from Commission on Cancer (CoC)-accredited facilities. The CoC is managed under the American College of Surgeons, and is a multidisciplinary team that maintains standards in cancer care delivery in health care settings. This database has been used in multiple cancer-focused studies and reports on cancer diagnosis, hospital-level, and patient-related demographics. The focus of this review is to explore and discuss the use of NCDB in colorectal surgery research. Furthermore, our aim for this review is to formulate a guide for researchers who are interested in using the NCDB to complete colorectal research.

The impact of primary tumor location in patients with metastatic colorectal cancer: a Korean Cancer Study Group CO12-04 study

BACKGROUND/AIMS

Colorectal cancer is associated with different anatomical, biological, and clinical characteristics. We determined the impact of the primary tumor location in patients with metastatic colorectal cancer (mCRC).

METHODS

Demographic data and clinical information were collected from 1,115 patients from the Republic of Korea, who presented with mCRC between January 2009 and December 2011, using web-based electronic case report forms. Associations between the primary tumor location and the patient's clinical characteristics were assessed, and factors inf luencing overall survival were analyzed using Cox proportional hazards regression models.

RESULTS

Of the 1,115 patients recruited to the study, 244 (21.9%) had right colon cancer, 483 (43.3%) had left colon cancer, and 388 (34.8%) had rectal cancer. Liver and lung metastases occurred more frequently in patients with left colon and rectal cancer (p = 0.005 and p = 0.006, respectively), while peritoneal and ovarian metastases occurred more frequently in patients with right and left colon cancer (p < 0.001 and p = 0.031, respectively). The median overall survival of patients with tumors originating in the right colon was significantly shorter than that of patients whose tumors had originated in the left colon or rectum (13.7 months [95% confidence interval (CI), 12.0 to 15.5] vs. 18.0 months [95% CI, 16.3 to 19.7] or 19.9 months [95% CI, 18.5 to 21.3], respectively; p = 0.003). Tumor resection, the number of metastatic sites, and primary tumor location correlated with overall survival in the univariate and multivariate analyses.

CONCLUSION

Primary tumor location influences the metastatic sites and prognosis of patients with mCRC.

A systematic analysis highlighting deficiencies in reported outcomes for patients with stage IV colorectal cancer undergoing palliative resection of the primary tumour

BACKGROUND

Management of the primary tumour in the presence of unresectable metastatic colorectal cancer (mCRC) is controversial. The role of primary tumour resection (PTR) has been investigated by a number of retrospective cohort studies, with a number on going randomised controlled trials. The aim of this study was to identify the clinical and patient-reported outcomes currently reported in studies that evaluate the role of PTR in mCRC.

METHODS

Literature searches were performed in MEDLINE (via OvidSP) (1966-June 2017), EMBASE (via OvidSP) and the Cochrane Library using terms related to colorectal cancer and primary tumour resection. All studies documenting outcomes following palliative PTR were included. Eligible articles were assessed using the Risk of Bias In Non-Randomised Studies of Intervention (ROBINS-I) tool.

RESULTS

Of 11,209 studies screened, 59 non-randomised studies reporting outcomes on 331,157 patients were included. Patient characteristics regarding performance status and co-morbidity were recorded in 26 (44.1%) and 17 (28.8%) studies. The chemotherapy regime used was reported in 27 (45.8%) studies. The operative setting and the operative approach was reported in 42 (71%) and 14 (23.7%) studies. Post-operative mortality and morbidity were reported in 33 (55.9%) and 35 (59.3%) studies. Overall survival was reported in 49 (83.1%) studies, with 5 different definitions identified. Quality of life was only reported in 1 (1.7%) study.

CONCLUSION

This study demonstrates significant heterogeneity in the selection and definition of outcomes reported following PTR in mCRC. There is significant heterogeneity with a significant under-reporting of important outcomes such as treatment related adverse events and patient reported outcomes.

Survival outcomes following primary tumor resection for patients with incurable metastatic colorectal carcinoma: Experience from a single institution

OBJECTIVE

Palliative primary tumor resection (PTR) has been used for preventing and treating tumor-related complications. We aimed to determine whether PTR can increase overall survival (OS) in patients with unresectable metastatic colorectal cancer (CRC).

METHODS

A retrospective review of a prospectively collected database in a single center was performed. Patients diagnosed with metastatic CRC from January 2004 to December 2014 were included. Patients who had attained curative resection or had disease recurrence were excluded. All patients were discussed at a multidisciplinary tumor board where subsequent treatment decisions were made.

RESULTS

Altogether 408 patients were analyzed. Of these 145 received PTR with palliative chemotherapy (PC; group A), 110 received PC only (group B), 52 received PTR only (group C), while 101 received neither PTR nor PC (group D). Undergoing PTR led to statistically significant improvement in OS (22.7 months vs 12.1 months vs 6.9 months vs 2.7 months, P < 0.001). We performed subgroup analyses to control for potential confounders and found that the influence of PTR on OS persisted. With multivariate analysis, the predictors of poor OS were no PTR (hazards ratio [HR] 2.32, 95% confidence interval [CI] 1.82-2.96, P < 0.001), no PC (HR 4.25, 95% CI 3.27-5.33, P < 0.001) and the presence of peritoneal metastases (HR 1.37, 95% CI 1.06-1.78, P = 0.018). Diversion surgery did not lead to a statistical difference in OS.

CONCLUSIONS

The absences of PTR and PC, and peritoneal metastases are independently associated with decreased OS in patients with unresectable metastatic CRC. Randomized controlled trials are needed to verify this observation.

Benefit of Surgical Resection of the Primary Tumor in Patients Undergoing Chemotherapy for Stage IV Colorectal Cancer with Unresected Metastasis

PURPOSE

Resection of the primary tumor in patients with unresected metastatic colorectal cancer is controversial, and often performed only for palliation of symptoms. Our goal was to determine if resection of the primary tumor in this patient population is associated with improved survival.

METHODS

This is a retrospective cohort study of the National Cancer Data Base from 2004 to 2012. The study population included all patients with synchronous metastatic colorectal adenocarcinoma who were treated with systemic chemotherapy. The study groups were patients who underwent definitive surgery for the primary tumor and those who did not. Patients were excluded if they had surgical intervention on the sites of metastasis or pathology other than adenocarcinoma. Primary outcome was overall survival.

RESULTS

Of the 65,543 patients with unresected stage IV colorectal adenocarcinoma undergoing chemotherapy, 55% underwent surgical resection of the primary site. Patients who underwent surgical resection of the primary tumor had improved median survival compared to patients treated with chemotherapy alone (22 vs 13 months, p < .0001). The surgical survival benefit was present for patients who were treated with either multi-agent or single-agent chemotherapy (23 vs 14 months, p < 0.001; 19 vs 9 months, p < 0.001). Surgical resection of the primary tumor was also associated with improved survival when using multivariate analysis with propensity score matching (OR = 0.863; 95% CI [0.805-.924]; HR = 0.914; 95% CI [0.888-0.942]).

CONCLUSIONS

Our results show that in patients with synchronous unresected stage IV colorectal adenocarcinoma undergoing single- or multi-agent chemotherapy, after adjusting for confounding variables, definitive resection of the primary site was associated with improved overall survival. Large randomized controlled trials are needed to determine if there is a causal relationship between surgery and increased overall survival in this patient population.

Recent updates in the surgical treatment of colorectal cancer

Because of recent advances in medical technology and new findings of clinical trials, treatment options for colorectal cancer are evolutionally changing, even in the last few years. Therefore, we need to update the treatment options and strategies so that patients can receive optimal and tailored treatment. The present review aimed to elucidate the recent global trends and update the surgical treatment strategies in colorectal cancer by citing the literature published in the last 2 years, namely 2016 and 2017. Although laparoscopic surgery is still considered the most common approach for the treatment of colorectal cancer, new surgical technologies such as transanal total mesorectal excision, robotic surgery, and laparoscopic lateral pelvic lymph node dissection are emerging. However, with the recent evidence, superiority of the laparoscopic approach to the open approach for rectal cancer seems to be controversial. Surgeons should notice the risk of adverse outcomes associated with unfounded and uncontrolled use of these novel techniques. Many promising results are accumulating in preoperative and postoperative treatment including chemotherapy, chemoradiotherapy, and targeted therapy. Development of new biomarkers seems to be essential for further improvement in the treatment outcomes of colorectal cancer patients.

Integrated analysis of gene expression signatures associated with colon cancer from three datasets

PURPOSE

The present study aimed to elucidate the pathogenesis of colon cancer and identify genes associated with tumor development.

METHODS

Three datasets, two (GSE74602 and GSE44861) from the Gene Expression Omnibus database and RNA-Seq colon cancer data from The Cancer Genome Atlas data portal, were downloaded. These three datasets were grouped using a meta-analysis approach, and differentially expressed genes (DEGs) were identified between colon tumor samples and adjacent normal samples. Functional enrichment analysis and regulatory factor predication were performed for significant genes. Additionally, small-molecule drugs associated with colon cancer were predicted, and a prognostic risk model was constructed.

RESULTS

There were 251 overlapping DEGs (135 up- and 116 downregulated) between cancer samples and control samples in the three datasets. The DEGs were mainly involved in protein transport and apoptotic and neurotrophin signaling pathways. A total of 70 small-molecule drugs were predicated to be associated with colon cancer. Additionally, in the miRNA-target regulatory network, we found that SLC44A1 can be targeted by hsa-miR-183, hsa-miR-206, and hsa-miR-147, while KLF13 can be regulated by hsa-miR-182, hsa-miR-206, and hsa-miR-153. Moreover, the results of the prognostic risk model showed that four genes (VAMP1, P2RX5, CACNB1, and CRY2) could divide the samples into high and low risk groups.

CONCLUSION

SLC44A1 and KLF13 may be involved in tumorigenesis and the metastasis of colon cancer by miRNA regulation. In addition, a four-gene (VAMP1, P2RX5, CACNB1, and CRY2) expression signature may have prognostic and predictive value in colon cancer.

Meta-analysis of outcomes following resection of the primary tumour in patients presenting with metastatic colorectal cancer

BACKGROUND

It is not clear whether resection of the primary tumour (when there are metastases) alters survival and/or whether resection is associated with increased morbidity. This systematic review and meta-analysis assessed the prognostic value of primary tumour resection in patients presenting with metastatic colorectal cancer.

METHODS

A systematic review of MEDLINE/PubMed was performed on 12 March 2016, with no language or date restrictions, for studies comparing primary tumour resection versus conservative treatment without primary tumour resection for metastatic colorectal cancer. The quality of the studies was assessed using the MINORS and STROBE criteria. Differences in survival, morbidity and mortality between groups were estimated using random-effects meta-analysis.

RESULTS

Of 37 412 initially screened articles, 56 retrospective studies with 148 151 patients met the inclusion criteria. Primary tumour resection led to an improvement in overall survival of 7·76 (95 per cent c.i. 5·96 to 9·56) months (risk ratio (RR) for overall survival 0·50, 95 per cent c.i. 0·47 to 0·53), but did not significantly reduce the risk of obstruction (RR 0·50, 95 per cent c.i. 0·16 to 1·53) or bleeding (RR 1·19, 0·48 to 2·97). Neither was the morbidity risk altered (RR 1·14, 0·77 to 1·68). Heterogeneity between the studies was high, with a calculated I² of more than 50 per cent for most outcomes.

CONCLUSION

Primary tumour resection may provide a modest survival advantage in patients presenting with metastatic colorectal cancer.

Meta-analysis of oncologic effect of primary tumor resection in patients with unresectable stage IV colorectal cancer in the era of modern systemic chemotherapy

Purpose

The management of primary tumors in patients with stage IV colorectal cancer remains unclear. This meta-analysis evaluated the survival benefits of primary tumor resection (PTR) in patients with unresectable stage IV colorectal cancer in the era of modern chemotherapy.

Methods

Multiple comprehensive databases were searched for studies comparing survival outcomes in patients with metastatic colorectal cancer who did and did not undergo PTR. Outcome data were pooled, and overall effect size was calculated using random effect models.

Results

Seventeen nonrandomized studies involving 18,863 patients met the inclusion criteria. Meta-analysis showed that PTR significantly improved overall survival (hazard ratio [HR], 0.63; 95% confidence interval [CI], 0.56–0.71; P < 0.001) and progression free survival (HR, 0.76; 95% CI, 0.67–0.87; P < 0.001). Subgroup analyses and sensitivity analyses, performed by predefined methods, also indicated that PTR improved overall patient survival.

Conclusion

Palliative resection of the primary tumor may have survival benefits in patients with unresectable stage IV colorectal cancer. Randomized controlled trials are needed to determine the optimal treatment for these patients.

The influence of local therapy on the survival of patients with metastatic rectal cancer: a population-based, propensity-matched study

PURPOSE

This study was aimed to determine the effect of the local tumor therapy on patients' prognosis in the management of metastatic rectal cancer.

METHODS

Patients diagnosed with metastatic rectal cancer from 2004 to 2013 were selected from the SEER (Surveillance, Epidemiology, and End Results) database. Overall survival and cancer-specific survival were compared between the local treatment group and the nonlocal treatment group using Kaplan-Meier methods. Uni- and multivariate analyses were further performed to confirm or deny the results. The statistical approach of propensity score matching was conducted to avoid potential confounding factors.

RESULTS

Of 6867 patients included in this analysis, 3971 (57.8%) received local therapy to the primary tumor and 2896 (42.2%) did not receive. Both univariable and multivariable analysis showed local therapy continued to be associated with an improvement in OS (HR 0.532; 95% CI 0.503-0.563, p < 0.001 and HR 0.532; 95% CI 0.498-0.568, p < 0.001, respectively) and CSS (HR 0.527; 95% CI 0.497-0.559, p < 0.001 and HR 0.521; 95% CI 0.487-0.557, p < 0.001, respectively) in the unmatched cohorts. Further analysis showed patients underwent local tumor destruction or surgical resection had a better overall survival compared with those who did not undergo (p < 0.001). In the matched population, patients receiving local therapy had a better OS (HR 0.427; 95% CI 0.428-0.519, p < 0.001) and CSS (HR 0.462; 95% CI 0.418-0.511, p < 0.001) compared with those who did not receive.

CONCLUSIONS

Local therapy to the primary tumor may be associated with a better survival in patients with metastatic rectal cancer.