The prognostic factors of stage IV colorectal cancer and assessment of proper treatment according to the patient's status

The value of machine learning based on CT radiomics in the preoperative identification of peripheral nerve invasion in colorectal cancer: a two-center study

BACKGROUND

We aimed to explore the application value of various machine learning (ML) algorithms based on multicenter CT radiomics in identifying peripheral nerve invasion (PNI) of colorectal cancer (CRC).

METHODS

A total of 268 patients with colorectal cancer who underwent CT examination in two hospitals from January 2016 to December 2022 were considered. Imaging and clinicopathological data were collected through the Picture Archiving and Communication System (PACS). The Feature Explorer software (FAE) was used to identify the peripheral nerve invasion of colorectal patients in center 1, and the best feature selection and classification channels were selected. Finally, the best feature selection and classifier pipeline were verified in center 2.

RESULTS

The six-feature models using RFE feature selection and GP classifier had the highest AUC values, which were 0.610, 0.699, and 0.640, respectively. FAE generated a more concise model based on one feature (wavelet-HLL-glszm-LargeAreaHighGrayLevelEmphasis) and achieved AUC values of 0.614 and 0.663 on the validation and test sets, respectively, using the "one standard error" rule. Using ANOVA feature selection, the GP classifier had the best AUC value in a one-feature model, with AUC values of 0.611, 0.663, and 0.643 on the validation, internal test, and external test sets, respectively. Similarly, when using the "one standard error" rule, the model based on one feature (wave-let-HLL-glszm-LargeAreaHighGrayLevelEmphasis) achieved AUC values of 0.614 and 0.663 on the validation and test sets, respectively.

CONCLUSIONS

Combining artificial intelligence and radiomics features is a promising approach for identifying peripheral nerve invasion in colorectal cancer. This innovative technique holds significant potential for clinical medicine, offering broader application prospects in the field.

CRITICAL RELEVANCE STATEMENT

The multi-channel ML method based on CT radiomics has a simple operation process and can be used to assist in the clinical screening of patients with CRC accompanied by PNI.

KEY POINTS

• Multi-channel ML in the identification of peripheral nerve invasion in CRC. • Multi-channel ML method based on CT-radiomics can detect the PNI of CRC. • Early preoperative identification of PNI in CRC is helpful to improve the formulation of treatment strategies and the prognosis of patients.

Immune-related genes STIM1, ITPKC and PELI1 polymorphisms are associated with risk of colorectal cancer

OBJECTIVES

STIM1, ITPKC and PELI1 are all immune-related genes that take part in the T cell activation, toll-like receptor and IL1 receptor pathways. The goal of this study was to evaluate the associations between STIM1, ITPKC and PELI1 polymorphisms and colorectal cancer (CRC) risk.

METHODS

Six single nucleotide polymorphisms (SNPs) in STIM1, ITPKC and PELI1 were genotyped using a MassARRAY platform in a discovery cohort including 480 CRC cases and 480 healthy individuals and validated in a replication cohort including 505 CRC cases and 510 controls.

RESULTS

The minor alleles of rs3794050, rs3750996 and rs2607420 were associated with an increased CRC risk (P < 0.05). In contrast, the minor allele of rs329497 was correlated with reduced disease risk (P = 0.025). Genetic model analysis showed that rs3794050 was related to an increased risk of disease in recessive and log-additive models (P < 0.05); rs3750996 had a strong correlation with CRC risk under all genetic models (P < 0.02); rs2607420 was correlated with an increased risk of disease in dominant and log-additive models (P < 0.01); whereas the protective effect of rs329497 on CRC risk was observed in dominant and log-additive models (P < 0.05). Finally, the association between the above SNPs and CRC risk was validated in a replication cohort (P < 0.05).

CONCLUSIONS

Our results could be helpful for the early screening of individuals with high CRC risk.

Mesothelin Expression is Correlated with Chemoresistance in Stage IV Colorectal Cancer

BACKGROUND

Mesothelin (MSLN) is a cell-surface glycoprotein present on mesothelial cells; its expression in several epithelial cancers generally portends an unfavorable prognosis. We investigated MSLN as a surrogate chemopredictive biomarker and examined the impact of MSLN expression in stage IV colorectal cancer (CRC).

METHODS

We recruited 254 patients with CRC who received systemic chemotherapy following primary tumor resection between 2000 and 2019. Resected specimens were immunostained for MSLN and stratified by MSLN expression. The associations of tumor MSLN expression with tumor response in metastatic lesions and survival were evaluated.

RESULTS

Of the 247 patients with stage IV CRC, 41 (16.1%) and 213 (83.9%) had high and low MSLN expression, respectively. Based on the Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 criteria, the investigator-assessed objective response rate was 22.0% in the high MSLN expression group and 45.5% in the low MSLN expression group (p = 0.0050). The disease control rates in these groups were 65.9% and 85.9%, respectively (p = 0.00019). In the patients with high MSLN expression, the conversion rate among those with initially unresectable metastases was 0% versus 14% in the patients with low MSLN expression (p = 0.0053). The median overall survival (OS) was 1.5 years (95% confidence interval [CI] 1.1-2.8) in the high MSLN expression group versus 2.6 years (95% CI 2.2-3.0) in the low MSLN expression group. The 3-year OS rates in these groups were 23.5 and 41.5%, respectively (p = 0.0120).

CONCLUSIONS

High MSLN expression is correlated with chemoresistance and poor prognoses in stage IV CRC.

Zip Code-Related Income Disparities in Patients with Colorectal Cancer

INTRODUCTION

Screening and early detection reduce morbidity and mortality in colorectal cancer. Our aim is to study the effect of income disparities on the clinical characteristics of patients with colorectal cancer in Massachusetts.

METHODS

Patients were extracted from a database containing all surgically treated colorectal cancers between 2004 and 2015 at a tertiary hospital in Massachusetts. We split patients into 2 groups: "above-median income" and "below-median income" according to the median income of Massachusetts ($74,167).

RESULTS

The analysis included 817 patients. The above-median income group consisted of 528 patients (65%) and the below-median income group consisted of 289 patients (35%). The mean age of presentation was 64 ± 15 years for the above-median income group and 67 ± 15 years for the below-median income group (P = .04). Patients with below-median income were screened less often (P < .001) and presented more frequently with metastatic disease (P = .02). Patients with above-median income survived an estimated 15 months longer than those with below-median income (P < .001). The survival distribution was statistically significantly different between the groups for stage III disease (P = .004), but not stages I, II, or IV (P = 1, 1, and .2, respectively). For stage III disease, a lower proportion of below-median income patients received chemotherapy (61% vs. 79%, P = .002) and a higher proportion underwent nonelective surgery (5% vs. 2%, P = .007).

CONCLUSIONS

In Massachusetts, patients with colorectal cancer residing in lower income areas are screened less, received adjuvant chemotherapy less, and have worse outcomes, especially when analyzing those who present with stage III disease.

Effective dissection for rectal cancer with lateral lymph node metastasis based on prognostic factors and recurrence type

PURPOSE

There are no reports showing the significance and effective range of dissection for patients with lateral lymph node metastasis (LLNM). This study aimed to investigate the indications for lateral lymph node dissection (LLND) in patients with LLNM based on prognostic factors and recurrence types.

METHODS

We reviewed 379 patients with advanced rectal cancer who were treated with total mesorectal excision plus LLND. We analyzed background factors and survival times of patients who had LLNM to determine prognostic factors and recurrence types.

RESULTS

Pathological LLNM occurred in 44 (11.6%). Among patients with LLNM, the predictors of poor prognoses, according to univariate analysis, were > 3 node metastases, the presence of node metastasis on both sides, and spreading beyond the internal iliac lymph nodes. Moreover, LLNM beyond the internal iliac region was found to be an independent prognostic risk factor. Twenty-eight of the 44 patients with lateral lymph node metastasis (64%) relapsed, 22 of whom had distant metastases and 11 of whom experienced local recurrences. Among the latter group, nine (20%) and two (5%) had recurrences in the central and lateral pelvis, respectively.

CONCLUSION

The therapeutic benefit of resection was high, especially in patients with ≤ 3 positive lateral lymph nodes, one-sided bilateral lymph node areas, and positive nodes localized near the internal iliac artery.

Prognostic value of regional lymph node involvement in patients with metastatic colorectal cancer: palliative versus curative resection

Background

Approximately 20% of patients with colorectal cancer are initially diagnosed with stage IV disease. This study aims to examine the role of regional lymph node (LN) status in metastatic colorectal cancer (mCRC) with respect to clinicopathologic features and survival outcomes.

Methods

We investigated 1147 patients diagnosed with mCRC and had undergone surgical resection of the primary CRC. A total of 167 patients were placed in the LN-negative (LN−) group and another 980 in the LN-positive (LN+) group.

Results

LN+ patients exhibited a significantly higher rate of T4 tumors (p = 0.008), poorly differentiated adenocarcinoma (p < 0.001), lymphovascular invasion (p < 0.001), and perineural invasion (p < 0.001) than those in the LN− group. LN− patients had a significantly higher rate of lung metastasis (p < 0.001), whereas the rate of peritoneal seeding (p < 0.001) and systemic node metastasis (p < 0.001) was both significantly higher in the LN+ group. The 5-year overall survival (OS) in the LN+ group was significantly poorer than that in the LN− group (LN− vs. LN+ 23.2% vs. 18.1%; p = 0.040). In patients with curative resection, the 5-year OS rate has no significant difference between the two groups (LN− vs. LN+ 19.5% vs. 24.3%; p = 0.890).

Conclusions

Metastatic CRC patients with LN+ who underwent primary tumor resection may present with more high-risk pathological features, more peritoneal seeding, and systemic node metastasis, but less lung metastasis than LN− patients. LN+ patients had poorer long-term outcomes compared with that in LN− patients. Nevertheless, with curative resection, LN+ patients could have similar survival outcomes as LN− patients.

Survival and prognostic association in stage IV colorectal cancer patients treated with chemotherapy in Bangladesh

OBJECTIVE

Prognostic factors in colorectal cancer have lesser been evaluated in developing countries. This study aims to determine overall survival and prognostic factors for metastatic colorectal cancer patients who were non-operable and received chemotherapy.

METHODS

The study retrospectively investigated 67 inoperable metastatic colorectal cancer patients at Square Hospital, Bangladesh. The primary endpoint was overall survival, and the secondary endpoints were prognostic association with factors. Survival probabilities were calculated by non-parametric Kaplan-Meier method and compared by log-rank test. Univariate and multivariable Cox proportional hazard models were implemented to assess the prognostic association.

RESULTS

Median survival of the entire cohort was 14 months (95% confidence interval: 11-25). In multivariable analysis, two prognostic factors were independently associated with survival: Karnofsky performance status and carcinoembryonic antigen. Patients with Karnofsky performance status <70 had significant higher risk of death than those with Karnofsky performance status ≥70 (adjusted hazard ratio 4.25, 95% confidence interval: 2.15-8.39). Higher risk of death was found to be associated with higher carcinoembryonic antigen: adjusted hazard ratio was 1.72 (95% confidence interval: 0.81-3.68) and 2.96 (95% confidence interval: 1.25-7.01) for patients with carcinoembryonic antigen 10-100 and >100 ng/ml, respectively, while comparing with carcinoembryonic antigen <10 ng/ml. The presence of peritoneal metastasis and grade-III tumour significantly worsened the survival in univariate analysis (hazard ratio 2.46, 95% confidence interval: 1.32-4.57 and hazard ratio 1.74, 95% confidence interval: 1.01-3.03, respectively) but not in multivariable analysis (adjusted hazard ratio 1.92, 95% confidence interval: 0.88-4.18 and adjusted hazard ratio 1.25, 95% confidence interval: 0.66-2.36, respectively).

CONCLUSION

The study reported survival of stage IV colorectal cancer patients undergo chemotherapy and identified that Karnofsky performance status and carcinoembryonic antigen are the poor prognostic factors to this cohort adjusting for other factors.

Prognostic and predictive values of tumour budding in stage IV colorectal cancer

BACKGROUND

Tumour budding is an important prognostic feature in early-stage colorectal cancer, but its prognostic significance in metastatic disease has not been fully investigated.

METHODS

Patients with stage IV disease who had primary colorectal tumour resection without previous chemotherapy or radiotherapy from January 2000 to December 2018 were reviewed retrospectively. Budding was evaluated at the primary site and graded according to the criteria of the International Tumor Budding Consensus Conference (ITBCC) (BD1, low; BD2, intermediate; BD3, high). Patients were categorized by metastatic (M1a, M1b) and resectional (R0/R1, R2/unresected) status. Subgroups were compared for overall (OS) and recurrence-free (RFS) survival in R0/R1 subgroups; R2/unresected patients were evaluated for the rate of tumour progression, based on change in tumour size from baseline.

RESULTS

Of 371 patients observed during the study, 362 were analysed. Patients with BD3 had a lower 5-year OS rate than those with BD1 + BD2 (18·4 versus 40·5 per cent; P < 0·001). Survival analyses according to metastatic and resection status also showed that BD3 was associated with shorter OS than BD1 + BD2. In multivariable analysis, BD3 (hazard ratio (HR) 1·51, 95 per cent c.i. 1·11 to 2·10; P = 0·009), T4 status (HR 1·39) and R2/unresected status (HR 3·50) were associated with decreased OS. In the R0/R1 subgroup, the 2-year RFS rate was similar for BD3 and BD1 + BD2 according to metastatic status. There was no significant difference between BD3 and BD1 + BD2 for change in tumour size in the R2/unresected subgroup (P = 0·094). Of 141 patients with initially unresectable metastases who had chemotherapy, 35 achieved conversion from unresectable to resectable status. The conversion rate was significantly higher for BD1 + BD2 than for BD3 (36 versus 18 per cent; P = 0·016).

CONCLUSION

Stage IV colorectal cancer with high-grade tumour budding according to ITBCC criteria correlates with poor prognosis.

Prognostic accuracy of different lymph node staging system in predicting overall survival in stage IV colon cancer

PURPOSE

With emphasis of surgical management, the lymph node (LN) status has been advocated to predict prognosis in colon cancer with distant metastatic. Therefore, we tend to compare the prognostic performance of American Joint Committee on Cancer (AJCC) N-staging relative to lymph node ratio (LNR), log odds of metastatic lymph nodes (LODDS), and N-score in stage IV colon cancer.

METHODS

About 20,961 patients who underwent primary surgical resection for stage IV colon cancer were extracted from Surveillance, Epidemiology, and End Results (SEER) Program database. Harrell's C statistic (C-index) and Akaike's Information Criterion (AIC) were used to distinguish the prognostic performance of the different LN-staging schemes.

RESULTS

Of the 20,961 patients, 17,043 (81.3%) had been with lymph node metastasis, and the median number of examined lymph nodes (ELNs) was 15. When assessed as continuous values, the LODDS shown as the best system with greatest discriminatory power (C-index, 0.6241; AIC, 29114.29) generally and each subgroups divided by ELNs. When modeled as categorical cutoff variables for further clinical usage, the 8th AJCC N-stage outperformed the other three schemes with either ELNs less than 12 (C-index, 0.5770; AIC, 8992.638), between 12 and 25 (C-index, 0.6084; AIC, 13905.72), or more than 25(C-index, 0.6192; AIC, 3138.018) with increasing C-index and less AIC value.

CONCLUSIONS

When assessed as categorical variables, N-stage performed superiorly regardless of ELNs. When assessed as a continuous variable, LODDS exhibited good discriminative ability and goodness of fit in predicting survival for colon cancer patients regardless of ELNs.

Comparison of four lymph node staging systems for predicting prognosis for stage IV rectum cancer

Background

With recommendation of surgical management in primary site, both the positive and negative lymph nodes (LNs) retrieved have been emphasized to predict prognosis in stage IV rectum cancer. Therefore, we attempt to compare the prognostic performance of American Joint Committee on Cancer (AJCC) N-stage relative to lymph node ratio (LNR), log odds of metastatic lymph nodes (LODDS), and N-score in stage IV rectal cancer.

Methods

Total 5,090 patients taken surgical resection of primary site in rectum cancer with distant metastasis were extracted from Surveillance, Epidemiology, and End Results Program (SEER) database. Harrell's C statistic (C-index) and Akaike's Information Criterion (AIC) were used to evaluate the discriminative ability of the different LN staging systems.

Results

Of the 3,243 patients without radiotherapy, 82.46% (n=2,675) had been found with lymph nodes metastasis with median number of 16 lymph nodes collected (IQR: 11-22). Modeled as categorical cutoff variables for further clinical usage, when number of LNs was between 12 and 25 (C-index: 0.5997, AIC: 1,698.015), 8^th AJCC N-stage outperformed other three schemas with increasing C-index and less AIC value. Assessed as continuous values, the LODDS shown as the best schemas with greatest discriminatory power (C-index: 0.5971, AIC: 3,680.017), generally. On the other hand, in the cohorts of other 1274 patients taken radiation, the median number of lymph nodes retrieved was 13 (IQR: 9-18). LODDS still remained remarkable performance as continuous (C-index: 0.5912; AIC: 1,058.765) and categorical variables (C-index: 0.5700; AIC: 1,061.703), while N-staging outperformed with less than 25 lymph nodes retrieved (LNs <12 C-index: 0.5678, AIC: 481.94; 12< LNs <25 C-index: 0.5933, AIC: 390.395).

Conclusions

When assessed as categorical variables, N-stage performed superiorly with adequate lymph nodes examined, whether the patients have got radiotherapy prior to surgery or not. LODDS showed, when assessed as a continuous variable, good discriminative ability and goodness of fit in predicting survival for stage IV rectum cancer patients regardless of radiation therapy status.

Metastatic lymph node ratio as a prognostic indicator in patients with stage IV colon cancer undergoing resection

Background: It has been shown that the metastatic lymph node ratio (LNR, metastatic LNs divided by the total number of retrieved LNs) significantly affects the prognosis of patients with non-stage IV and some curative stage IV colon cancer undergoing curative resection. In this study, we aimed to evaluate the role of the LNR as a predictor of prognosis in patients with stage IV colon cancer undergoing curative or palliative resection. Patients and Methods: We conducted a retrospective study of 424 patients who were initially diagnosed with stage IV colon cancer at the Sun Yat-Sen University Cancer Center from 2003 to 2014. The patients were divided into the curative and palliative primary tumor resection groups with regional lymph nodes harvest. The median value was used as the cutoff for the LNR. Overall survival (OS) was assessed with the Kaplan-Meier method and log-rank test. Multivariate analysis was performed to identify the prognostic factors for OS. Results: The cutoff value for the LNR was 0.2. A total of 71 and 353 patients were classified as being in the curative and palliative resection groups, respectively. Patients in the palliative resection group showed higher pretreatment levels of carbohydrate antigen 19-9 (CA199; P = 0.014), a deeper infiltration of the primary tumor (P = 0.049), a lower regional lymph node harvest (i.e., total lymph node yield [TLN] ≤ 11; P = 0.001), and more extensive metastasis (P = 0.006). Among all patients, initial elevated CA199 levels, a TLN≤11, a negative lymph nodes (NLN) ≤7, and a LNR ≤0.2 were significantly associated with an unfavorable prognosis. OS was significantly longer in patients with a low LNR in both groups (P = 0.008 and P = 0.001, respectively). The LNR was an independent prognostic indicator in patients with stage IV colon cancer, with a hazard ratio (HR) of 1.47 (95% confidence interval [CI] 1.14-1.91; P = 0.003) in total population, and an HR of 1.43 (95% CI 1.09-1.86; P = 0.009) in patients with palliative resection. Conclusion: The LNR can be used as an independent prognostic factor in patients with stage IV colon cancer patients undergoing resection.

The Use of Circulating Tumor DNA for Prognosis of Gastrointestinal Cancers

Gastrointestinal cancers, including oesophageal, gastric and colorectal cancers (CRC) have high rates of disease recurrence despite curative resection. There are a number of recent studies that have investigated the use of circulating tumor DNA (ctDNA) for prognostic value in these cancers. We reviewed studies that had been published prior to March 2018 that assessed the prognostic values of ctDNA in patients with oesophageal and gastric cancers, gastrointestinal stromal tumors (GIST) and CRC. We identified 63 eligible clinical studies that focussed on recurrence and survival. Studies assessed investigated various ctDNA biomarkers in patients with different stages of cancer undergoing surgical resection, chemotherapy and no treatment. For oesophageal squamous cell carcinoma and oesophageal adenocarcinoma, methylation of certain genes such as APC and DAPK have been highlighted as promising biomarkers for prognostication, but these studies are limited and more comprehensive research is needed. Studies focusing on gastric cancer patients showed that methylation of ctDNA in SOX17 and APC were independently associated with poor survival. Two studies demonstrated an association between ctDNA and recurrence and survival in GIST patients, but more studies are needed for this type of gastrointestinal cancer. A large proportion of the literature was on CRC which identified both somatic mutations and DNA methylation biomarkers to determine prognosis. ctDNA biomarkers that identified somatic mutations were more effective if they were personalized based on mutations found in the primary tumor tissue, but ctDNA methylation studies identified various biomarkers that predicted increased risk of recurrence, poor disease free survival and overall survival. While the use of non-invasive ctDNA biomarkers for prognosis is promising, larger studies are needed to validate the clinical utility for optimizing treatment and surveillance strategies to reduce mortality from gastrointestinal cancers.

Outcomes of stage IV patients with colorectal cancer treated in a single institution: What is the key to the long-term survival?

OBJECTIVES

The purpose of this study is to summarize our short- and long-term treatment results for stage IV colorectal cancer (CRC) and to clarify the factors predicting the favorable long-term survival.

METHODS

Between January 2008 and December 2015, 149 consecutive patients with stage IV CRC underwent initial treatment at Nagoya University Hospital. Their clinical and pathological characteristics, the treatment methods used, and the outcomes were retrospectively analyzed.

RESULTS

The median observation period was 23 months. All of the primary and metastatic lesions were technically resectable in 74 patients; however, the remaining 75 were judged as initially unresectable. R0/1 resection during the treatment course was achieved in 74 patients (50%). For the cohort as a whole, the 5-year overall survival (OS) rate was 35%. The 5-year OS rate in the R0/1 resection group was 57%, which was significantly better than that of the non-R0/1 resection group (6%, p < 0.001). In the R0/1 resection group, perioperative chemotherapy significantly improved the outcome (5-year OS; 62% vs. 0%, p = 0.03). In the non-R0/1 resection group, primary tumor resection was associated with a significantly higher favorable prognosis (3-year OS; 20.4% vs. 0%, p = 0.026). Moreover, the additional use of molecular targeted drugs significantly improved the survival. In multivariate analysis, the differentiated histologic type, R0/1 resection, and parallel use of molecular targeted drugs remained independent factors of a favorable outcome.

CONCLUSIONS

The present study suggested that aggressive curative resection with perioperative chemotherapy might improve survival and that primary tumor resection might improve the outcome in the non-R0/1 group.

Individualized prediction of perineural invasion in colorectal cancer: development and validation of a radiomics prediction model

Objective

To develop and validate a radiomics prediction model for individualized prediction of perineural invasion (PNI) in colorectal cancer (CRC).

Methods

After computed tomography (CT) radiomics features extraction, a radiomics signature was constructed in derivation cohort (346 CRC patients). A prediction model was developed to integrate the radiomics signature and clinical candidate predictors [age, sex, tumor location, and carcinoembryonic antigen (CEA) level]. Apparent prediction performance was assessed. After internal validation, independent temporal validation (separate from the cohort used to build the model) was then conducted in 217 CRC patients. The final model was converted to an easy-to-use nomogram.

Results

The developed radiomics nomogram that integrated the radiomics signature and CEA level showed good calibration and discrimination performance [Harrell's concordance index (c-index): 0.817; 95% confidence interval (95% CI): 0.811-0.823]. Application of the nomogram in validation cohort gave a comparable calibration and discrimination (c-index: 0.803; 95% CI: 0.794-0.812).

Conclusions

Integrating the radiomics signature and CEA level into a radiomics prediction model enables easy and effective risk assessment of PNI in CRC. This stratification of patients according to their PNI status may provide a basis for individualized auxiliary treatment.

Palliative surgery for colorectal cancer with peritoneal metastasis: a propensity-score matching analysis

PURPOSE

Peritoneal metastasis (PM) in patients with colorectal cancer (CRC) is associated with poor prognosis. We conducted this study to assess whether palliative resection (PR) of the primary tumor improved the overall survival (OS) of patients with PM-CRC.

METHODS

We analyzed retrospectively, data collected prospectively from patients with CRC. PM was categorized into three subgroups according to the Japanese classification of PM. A propensity-score model was used to compare the outcomes of patients who underwent PR (PR group) and those who did not [non-resection (NR) group].

RESULTS

Among 1909 patients with metastatic CRC, 309 (16 %) had only peritoneal metastases and 255 of these patients who underwent palliative surgery (R2) were the subjects of our analysis: 161 in the PR group and 94 in the NR group. Median OS was significantly longer in the PR group than in the NR group (23 vs. 11 months, P < 0.001). Patients in the PR group had less extensive PM and a higher rate of receiving palliative chemotherapy than those in the NR group (P < 0.001). In a Cox multivariate analysis of 69 propensity-score matched pairs, PR resulted in significantly longer OS than NR (hazard ratio 0.496, 95 % confidence interval 0.268-0.919, P = 0.025).

CONCLUSIONS

Our results show that PR resulted in better OS than NR for patients with PM-CRC, when their overall condition permitted a more aggressive approach.

Adverse Effects of Anastomotic Leakage on Local Recurrence and Survival After Curative Anterior Resection for Rectal Cancer: A Systematic Review and Meta-analysis

BACKGROUND

Anastomotic leakage is a serious complication associated with anterior resection for rectal cancer, the long-term effects of which are unclear. Therefore, a systematic review and meta-analysis were conducted to evaluate the impact of anastomotic leakage on disease recurrence and survival.

METHODS

We searched PubMed, Embase, and the Cochrane Library databases from their inception to January 2016. Studies evaluating the oncologic impact of anastomotic leakage were included in the meta-analysis. Outcome measures were local recurrence, overall survival, cancer-specific survival, and distant recurrence. Pooled hazard ratio (HR) with 95 % confidence interval (CI) was calculated using random effects models.

RESULTS

Fourteen studies containing 11,353 patients met inclusion criteria. Anastomotic leakage was associated with a greater local recurrence (HR 1.71; 95 % CI 1.22-2.38) and decreased in both overall survival (HR 1.67; 95 % CI 1.19-2.35) and cancer-specific survival (HR 1.30; 95 % CI 1.08-1.56); anastomotic leakage did not increase distant recurrence (HR 1.03; 95 % CI 0.76-1.40).

CONCLUSIONS

Anastomotic leakage was associated with high local recurrence and poor survival (both overall and cancer-specific), but not with distant recurrence.

Palliative resection of a primary tumor in patients with unresectable colorectal cancer: could resection type improve survival?

PURPOSE

The aim of this study was to evaluate the impact of extended resection of primary tumor on survival outcome in unresectable colorectal cancer (UCRC).

METHODS

A retrospective analysis was conducted for 190 patients undergoing palliative surgery for UCRC between 1998 and 2007 at a single institution. Variables including demographics, histopathological characteristics of tumors, surgical procedures, and course of the disease were examined.

RESULTS

Kaplan-Meier survival curve indicated a significant increase in survival times in patients undergoing extended resection of the primary tumor (P < 0.001). Multivariate analysis showed that extra-abdominal metastasis (P = 0.03), minimal resection of the primary tumor (P = 0.034), and the absence of multimodality adjuvant therapy (P < 0.001) were significantly associated poor survival outcome. The histological characteristics were significantly associated with survival times. Patients with well to moderate differentiation tumors that were extensively resected had significantly increased survival time (P < 0.001), while those with poor differentiation tumors that were extensively resected did not have increase survival time (P = 0.786).

CONCLUSION

Extended resection of primary tumors significantly improved overall survival compared to minimal resection, especially in well to moderately differentiated tumors (survival time: extended resection, 27.8 ± 2.80 months; minimal resection, 16.5 ± 2.19 months; P = 0.002).

Prognostic impact of carcinoembryonic antigen and carbohydrate antigen 19-9 in stage IV colorectal cancer patients after R0 resection

BACKGROUND

Although preoperative carcinoembryonic antigen (pre-CEA) and carbohydrate antigen 19-9 (pre-CA 19-9) are reportedly prognostic indicators for colorectal cancer (CRC), the prognostic roles of postoperative CEA (post-CEA) and CA 19-9 (post-CA 19-9) shortly after surgery have not been clarified in patients with curatively resected stage IV CRC. The aim of this study was to evaluate the predictive abilities of post-CEA and post-CA 19-9.

METHODS

A total of 129 consecutive patients who had stage IV CRC and underwent R0 resection were retrospectively analyzed. Pre-CEA and post-CEA and CA 19-9 levels were measured within 1 mo before and 3 mo after surgery, respectively. Relapse-free survival (RFS) and overall survival were estimated using the Kaplan-Meier method, and multivariate analysis was performed using the Cox proportional hazards model.

RESULTS

Pre-CEA was elevated (≥5.0 ng/mL) in 73.6% of the patients and remained elevated after surgery in 32.7% of the patients. Elevated post-CA 19-9 (≥50 U/mL) was observed in 9.5% of the patients. Neither elevated pre-CEA nor elevated pre-CA 19-9 was significantly associated with RFS but both elevated post-CEA and elevated post-CA 19-9 were associated with markedly reduced RFS (P = 0.0002 and P = 0.0004, respectively). When considered in combination, post-CEA and post-CA 19-9 significantly stratified RFS and was an independent predictive factor for recurrence (P = 0.0035), as was lymphatic invasion (P = 0.0015). Post-CA 19-9 was the only evident independent predictive factor for overall survival (P = 0.0336).

CONCLUSIONS

In patients with stage IV CRC who underwent curative resection, the combination of post-CEA and post-CA 19-9 at 3 mo after surgery was a potent prognostic indicator for recurrence.

Prognostic Significance of Preoperative Serum Carbohydrate Antigen 19-9 in Patients With Stage IV Colorectal Cancer

INTRODUCTION

Carbohydrate antigen (CA) 19-9 is a widely used tumor marker in colorectal cancer (CRC). However, its prognostic impact in patients with stage IV CRC who have undergone curative resection is not clear. We evaluated the prognostic power of preoperative serum CA 19-9 in these patients.

PATIENTS AND METHODS

We performed a retrospective review of 173 patients with stage IV CRC who had undergone curative resection at our institution. Patients were categorized into normal and high CA 19-9 groups, and relapse-free survival and overall survival were compared using Kaplan-Meier curves. Multivariate analyses were performed using a Cox proportional hazard model.

RESULTS

The preoperative serum CA 19-9 level was elevated in 80 patients (46%). The 3-year relapse-free survival of the high CA 19-9 group was significantly worse than that of the normal CA 19-9 group (18% vs. 28%, respectively; P = .026). The 3-year overall survival of the high CA 19-9 group was significantly lower than that of the normal CA 19-9 group (75% vs. 82%; P = .047). Multivariate analyses indicated that elevated preoperative serum CA 19-9 level was an independent prognostic factor for poor relapse-free survival and overall survival, with a hazard ratio of 1.46 (95% confidence interval, 1.03-2.06; P = .035) and 1.90 (95% confidence interval, 1.10-3.29; P = .023), respectively.

CONCLUSION

The preoperative serum CA 19-9 level is a good predictive marker of tumor recurrence and prognosis in patients with stage IV CRC who have undergone curative resection.

Perineural Invasion is a Strong Prognostic Factor in Colorectal Cancer: A Systematic Review

Perineural invasion (PNI) is a possible route for metastatic spread in various cancer types, including colorectal cancer (CRC). PNI is linked to poor prognosis, but systematic analyses are lacking. This study systematically reviews the frequency and impact of PNI in CRC. A literature search was performed using PubMed database from inception to January 1, 2014. Data were analyzed using Review Manager 5.3. A quality assessment was performed on the basis of modified REMARK criteria. Endpoints were local recurrence (LR), 5-year disease-free survival (5yDFS), 5-year cancer-specific survival (5yCSS), and 5-year overall survival (5yOS). Meta-analysis was performed in terms of risk ratios (RR) and hazard ratios (HR) with 95% confidence interval (95% CI). In this meta-analysis, 58 articles with 22,900 patients were included. PNI was present in 18.2% of tumors. PNI is correlated with increased LR (RR 3.22, 95% CI, 2.33-4.44) and decreased 5yDFS (RR 2.35, 95% CI, 1.66-3.31), 5yCSS (RR 3.61, 95% CI, 2.76-4.72), and 5yOS (RR 2.09, 95% CI, 1.68-2.61). In multivariate analysis PNI remains an independent prognostic factor for 5yDFS, 5yCSS, and 5yOS (HR 2.35, 95% CI, 1.97-3.08; HR 1.91, 95% CI, 1.50-2.42; and HR 1.85, 95% CI, 1.63-2.12, respectively). We confirmed the strong impact of PNI for LR and survival in CRC. The prognostic value of PNI is similar to that of well-established prognostic factors as depth of invasion, differentiation grade, lymph node metastases, and lymphatic and extramural vascular invasion. Therefore, PNI should be one of the factors in the standardized reporting of CRC and might be considered a high-risk feature.

Prognostic value of perineural invasion in colorectal cancer: a meta-analysis

BACKGROUND

The prognostic value of perineural invasion (PNI) in colorectal cancer (CRC) does not reach a consensus.

METHODS

A comprehensive literature search for relevant reports published up to October 2014 was performed using the electronic databases: PubMed, Embase, and Web of Science. The pooled hazard ratio (HR) with 95 % confidence intervals (CI) was used to estimate the prognostic effects.

RESULT

Thirty-eight studies comprising 12,661 CRC patients were analyzed. Our results showed that PNI is significantly associated with poor prognosis in OS (overall survival) (HR = 2.07, 95 % CI = 1.87-2.29, P < 0.01) and DFS (disease-free survival) (HR = 2.23, 95 % CI = 1.79-2.78, P < 0.01). There was no significant prognostic difference in DFS between stage II CRC patients with PNI(+) and stage III patients (HR = 1.67, 95 % CI = 0.53-5.25, P = 0.38). Further subgroup analysis revealed that the significance of the association between PNI and worse prognosis in CRC patients is not affected by many factors, including geographic setting, PNI positive rate, treatment, TNM stage, tumor site, and quality of the study.

CONCLUSIONS

The meta-analysis indicates that PNI is a poor prognostic factor in CRC patients. The postoperative survival of stage II CRC patients with PNI(+) is probably more similar to that of stage III patients. Currently available adjuvant therapy should be considered in stage II CRC patients with PNI(+).

Log odds of positive lymph nodes as a prognostic indicator in stage IV colorectal cancer patients undergoing curative resection

BACKGROUND

Recent studies have proposed the use of log odds of positive lymph nodes (LODDS) as a prognostic indicator in colorectal cancer (CRC) patients without distant synchronous metastasis. In the present study, we aimed to evaluate the prognostic impact of the LODDS in Stage IV CRC patients who have undergone curative resection.

METHODS

We performed a retrospective review of 117 Stage IV CRC patients who underwent curative resection at our institute from 1998 to 2011. Patients were categorized into 3 groups (LODDS1-3) according to the ratio of their LODDS. The relationship between the LODDS and disease-free survival (DFS) and overall survival (OS) rates were assessed.

RESULTS

DFS was not significantly different between patients in each LODDS group. The association between the LODDS classification and OS was statistically significant (P = 0.021). Multivariate analysis indicated that LODDS classification was an independent prognostic factor for OS, with a hazard ratio of 2.95 for LODDS2 (95% confidence interval [CI]: 1.18-8.35; P = 0.021), and 2.98 for LODDS3 (95% CI: 1.20-8.37; P = 0.017).

CONCLUSIONS

The LODDS is a good prognostic indicator in Stage IV CRC patients who have undergone curative resection.

GRECCAR 8: impact on survival of the primary tumor resection in rectal cancer with unresectable synchronous metastasis: a randomized multicentre study

BACKGROUND

A majority of patients with rectal cancer and metastasis are not eligible to curative treatment because of an extensive and unresectable metastatic disease. Primary tumor resection is still debated in this situation. Rectal surgery treats or prevents the symptoms and avoids the risk of acute complications related to the primary tumor. Several studies on colorectal cancers seem to show interesting results in terms of survival in favor to the resection of the primary tumor. To date, no randomized trial or even a prospective study has assessed the impact of primary tumor resection on overall survival in patients with colorectal cancer with unresectable metastasis. All published studies were retrospective and included colon and rectal cancers. Rectal cancer is associated with specific problems related to the rectal surgery. Surgery is more complex, and may be source of more morbidity and postoperative functional dysfunctions (stoma, digestive, sexual, urinary) than colic surgery. On the other hand, symptoms related to the progression of rectal tumor are often very disabling: pain, rectal syndrome.

METHODS/DESIGN

GRECCAR 8 is a multicentre randomized open-label controlled trial aimed to evaluate the impact on survival of the primary tumor resection in rectal cancer with unresectable synchronous metastasis. Patients must undergo upfront systemic chemotherapy for at least 4 courses before inclusion. Patients with progressive metastatic disease during upfront chemotherapy will be excluded from the study. Patients will be randomly assigned in a 1:1 ratio to Arm A: primary tumor resection followed by systemic chemotherapy versus Arm B: systemic chemotherapy alone. Primary endpoint will be overall survival measured from the date of randomization to the date of death or to the end of follow-up (2 years). Secondary endpoints will include progression-free survival, quality of life, toxicity of chemotherapy, response of the primary tumor and metastatic disease to chemotherapy, postoperative morbidity and mortality, rate of patient not eligible for postoperative chemotherapy (arm A), primary tumor related complications and rate of emergency surgery (arm B). The number of patients needed is 290.

TRIAL REGISTRATION

ClinicalTrial.gov: NCT02314182.

Nomograms for predicting the prognosis of stage IV colorectal cancer after curative resection: a multicenter retrospective study

PURPOSE

Although stage IV colorectal cancer (CRC) encompasses a wide variety of clinical conditions with diverse prognoses, no statistical model for predicting the postoperative prognosis of stage IV CRC has been established. Thus, we here aimed to construct a predictive model for disease-free survival (DFS) and overall survival (OS) after curative surgery for stage IV CRC using nomograms.

METHODS

The study included 1133 stage IV CRC patients who underwent curative surgical resection in 19 institutions. Patients were divided into derivation (n = 586) and validation (n = 547) groups. Nomograms to predict the 1- and 3-year DFS rates and the 3- and 5-year OS rates were constructed using the derivation set. Calibration plots were constructed, and concordance indices (c-indices) were calculated. The predictive utility of the nomogram was validated in the validation set.

RESULTS

The postoperative carcinoembryonic antigen (CEA) level, depth of tumor invasion (T factor), lymph node metastasis (N factor), and number of metastatic organs were adopted as variables for the DFS-predicting nomogram, whereas the postoperative CEA level, T factor, N factor, and peritoneal dissemination were adopted for the nomogram to predict OS. The nomograms showed moderate calibration, with c-indices of 0.629 and 0.640 in the derivation set and 0.604 and 0.637 in the validation set for DFS and OS, respectively.

CONCLUSIONS

The nomograms developed were capable of estimating the probability of DFS and OS on the basis of only 4 variables, and may represent useful tools for postoperative surveillance of stage IV CRC patients in routine practice.

The role of palliative resection for asymptomatic primary tumor in patients with unresectable stage IV colorectal cancer

BACKGROUND

The prognostic role of surgical resection of primary tumors is not well established in patients with asymptomatic unresectable stage IV colorectal cancer.

OBJECTIVE

The aims of this study were to reveal the prognostic role of surgical resection of primary tumors and to define prognostic factors affecting long-term oncological outcomes in patients with asymptomatic unresectable synchronous metastases.

DESIGN

This study was a retrospective analysis of prospectively collected data.

PATIENTS

Between 2000 and 2008, a total of 416 patients with asymptomatic unresectable stage IV colorectal cancer were analyzed with propensity score matching.

MAIN OUTCOME MEASURES

Prematching baseline characteristics were compared by bivariate analysis, and 113 pairs were selected after 1:1 matching with propensity scores estimated from logistic regression. The primary end point was overall survival.

RESULTS

Among 416 patients, 218 (52.4%) underwent palliative resection of the primary tumor. Before propensity score matching, palliative resection resulted in a better survival rate than nonresection in univariate analysis (p < 0.001), but not in multivariate analysis (p = 0.08). After matching, the 5-year overall survival rate was significantly lower for patients with peritoneal metastasis and clinical M1b stage tumors in univariate analysis (p = 0.004 and p = 0.02). However, neither peritoneal metastasis nor clinical M1b stage showed any prognostic significance in multivariate analysis. The overall 5-year survival rate of the postmatching group was 4.9% and 3.5% in the palliative resection and nonresection groups. Consequently, palliative resection was not associated with a significant increase in survival compared with nonresection (p = 0.27). A subgroup analysis performed according to the site of metastasis also did not show any significant survival benefit of palliative resection after matching.

LIMITATIONS

Selection bias and potential confounders were limitations of this study.

CONCLUSIONS

Resection of the primary tumor in patients with asymptomatic unresectable stage IV colorectal cancer was not associated with an improvement in overall survival after propensity score matching.

Evaluation of four comorbidity indices and Charlson comorbidity index adjustment for colorectal cancer patients

INTRODUCTION

Cancer survival is related not only to primary malignancy but also to concomitant nonmalignant diseases. The aim of this study was to investigate the prognostic capacity of four comorbidity indices [the Charlson comorbidity index (CCI), the Elixhauser method, the National Institute on Aging (NIA) and National Cancer Institute (NCI) comorbidity index, and the Adult Comorbidity Evaluation-27 (ACE-27)] for both cancer-related and all-cause mortality among colorectal cancer patients. A modified version of the CCI adapted for colorectal cancer patients was also built.

METHODS

The study population comprised 468 cases of colorectal cancer diagnosed between 1 January 2000 and 31 December 2010 at a community hospital. Data were prospectively collected and abstracted from patients' clinical records. Kaplan-Meier method and multivariate logistic regression models were performed for survival and risk of death analysis.

RESULTS

Only moderate or severe renal disease [hazard ratio (HR) 2.71, 95% confidence interval (CI) 1.11-6.63] and AIDS (HR 3.27, 95% CI 1.23-8.68) were independently associated with cancer-specific mortality, with a population attributable risk of 5.18 and 4.36%, respectively. For each index, the highest comorbidity burden was significantly associated with poorer overall survival (NIA/NCI: HR 2.14, 95% CI 1.14-4.01; Elixhauser: HR 1.98, 95% CI 1.09-1.42; ACE-27: HR 1.78, 95% CI 1.07-1.23; CCI: HR 1.68, 95% CI 1.05-1.42) and cancer-specific survival. The modified version of the CCI resulted in a higher predictive power compared with other indices studied (cancer-specific mortality HR = 2.37, 95% CI 1.37-4.08).

CONCLUSIONS

The comorbidity assessment tools provided better prognostic prevision of prospective outcome of colorectal cancer patients than single comorbid conditions.

Prognostic Implications of Primary Tumor Resection in Stage IVB Colorectal Cancer in Elderly Patients

PURPOSE

The aim of this study was to identify prognostic factors in stage IVB colorectal cancer in elderly patients, focusing on the influence of treatment modalities, including palliative chemotherapy and primary tumor resection.

METHODS

A cohort of 64 patients aged over 65 years who presented with stage IVB colorectal cancer at the Gangneung Asan Hospital between July 1, 2001, and December 31, 2009, was analyzed. Demographics, tumor location, tumor grade, performance status, levels of carcinoembryonic antigen (CEA), level of aspartate aminotransferase (AST), and distant metastatic site at diagnosis were analyzed. Using the treatment histories, we analyzed the prognostic implications of palliative chemotherapy and surgical resection of the primary tumor retrospectively.

RESULTS

The cohort consisted of 30 male (46.9%) and 34 female patients (53.1%); the median age was 76.5 years. Primary tumor resection was done on 28 patients (43.8%); 36 patients (56.2%) were categorized in the nonresection group. The median survival times were 12.43 months in the resection group and 3.58 months in the nonresection group (P < 0.001). Gender, level of CEA, level of AST, Eastern Cooperative Oncology Group performance status, tumor location, and presence of liver metastasis also showed significant differences in overall survival. On multivariate analysis, male gender, higher level of CEA, higher AST level, and no primary tumor resection were independent poor prognostic factors. In particular, nonresection of the primary tumor was the most potent/poor prognostic factor in the elderly-patient study group (P = 0.001; 95% confidence interval, 2.33 to 21.99; hazard ratio, 7.16).

CONCLUSION

In stage IVB colorectal cancer in elderly patients, resection of the primary tumor may enhance survival.

Prognostic and predictive value of liver volume in colorectal cancer patients with unresectable liver metastases

PURPOSE

To determine the prognostic and predictive value of liver volume in colorectal cancer patients with unresectable liver metastases.

MATERIALS AND METHODS

Sixteen patients received whole liver radiotherapy (WLRT) between January 1997 and June 2013. A total dose of 21 Gy was delivered in 7 fractions.

RESULTS

The median survival time after WLRT was 9 weeks. In univariate analysis, performance status, serum albumin and total bilirubin level, liver volume and extrahepatic metastases were associated with survival. The mean liver volume was significantly different between subgroups with and without pain relief (3,097 and 4,739 mL, respectively; p = 0.002).

CONCLUSION

A larger liver volume is a poor prognostic factor for survival and also a negative predictive factor for response to WLRT. If patients who are referred for WLRT have large liver volume, they should be informed of the poor prognosis and should be closely observed during and after WLRT.

Primary tumor resection in colorectal cancer with unresectable synchronous metastases: A review

At the time of diagnosis, 25% of patients with colorectal cancer (CRC) present with synchronous metastases, which are unresectable in the majority of patients. Whether primary tumor resection (PTR) followed by chemotherapy or immediate chemotherapy without PTR is the best therapeutic option in patients with asymptomatic CRC and unresectable metastases is a major issue, although unanswered to date. The aim of this study was to review all published data on whether PTR should be performed in patients with CRC and unresectable synchronous metastases. All aspects of the management of CRC were taken into account, especially prognostic factors in patients with CRC and unresectable metastases. The impact of PTR on survival and quality of life were reviewed, in addition to the characteristics of patients that could benefit from PTR and the possible underlying mechanisms. The risks of both approaches are reported. As no randomized study has been performed to date, we finally discussed how a therapeutic strategy's trial should be designed to provide answer to this issue.

Prognostic factors associated with primary cancer in curatively resected stage IV colorectal cancer

PURPOSE

The aim of this study is to evaluate the prognostic factors associated with primary cancer in patients with curatively resected stage IV colorectal cancer, based on lymph node status.

METHODS

A total of 468 consecutive patients with curatively resected stage IV colorectal cancer from October 1994 to December 2010 were prospectively enrolled. Survival curves were constructed using the Kaplan-Meier method, and multivariate analysis assessed independent prognostic factors.

RESULTS

During the median follow-up period of this study, which was 37 months (range 1-177), the 3- and 5-year overall survival rates were 66.5 and 52.1%, respectively, and the 3- and 5-year disease-free survival rates were 43.0 and 38.2%, respectively. According to multivariate analysis, adjuvant chemotherapy and the preoperative serum carcinoembryonic antigen (CEA) level were independent prognostic factors for overall survival, and primary tumor location and preoperative serum CEA level were independent variables for disease-free survival. For the patients with N0 and N1 tumors, the overall survival curves in the preoperative CEA groups differed significantly (P = 0.046 and P < 0.013, respectively). However, for patients with pN2 tumors, the overall survival did not differ significantly according to the preoperative CEA (P = 0.948).

CONCLUSION

The preoperative serum CEA level is a reliable predictor of recurrence and survival after curative surgery in patients with metastatic colorectal cancer. A multidisciplinary approach that combines both complete resection and adjuvant chemotherapy may achieve improved overall survival in these patients.

Palliative surgery in patients with unresectable colorectal liver metastases: a propensity score matching analysis

BACKGROUND AND OBJECTIVES

The current study was primarily intended to determine the best surgical treatment for patients with unresectable liver metastatic colorectal cancer (CRC). In addition, we assessed whether the improvement in survival resulting from palliative resection (PR) of the primary tumor was a function of the extent of liver metastasis.

METHODS

The demographics, tumor characteristics, and survival outcomes of 261 patients who underwent palliative surgery for unresectable liver metastatic CRC were analyzed. A propensity-score model was used to compare the group of patients receiving PR and non-resection (NR).

RESULTS

There were 195 PR patients and 66 NR. The median survival of PR and NR patients was 21 months and 10 months, respectively (P < 0.001). In a Cox multivariate analysis of 51 propensity-score matched pairs, PR resulted in longer survival than NR (Hazard Ratio for NR 1.481; 95% confidence interval: 1.003-2.185; P = 0.048). The extent of liver metastasis only led to better survival of PR than NR patients among patients with limited liver metastasis not among those with extensive liver metastasis (P = 0.001).

CONCLUSIONS

PR appears to result in better survival than NR when the patient's overall condition permits an aggressive approach, especially in patients with limited liver metastases.

Should noncurative resection of the primary tumour be performed in patients with stage iv colorectal cancer? A systematic review and meta-analysis

PURPOSE

Surgical resection of the primary tumour in patients with advanced colorectal cancer (crc) remains controversial. This review compares survival in patients with advanced crc who underwent surgical resection of the primary tumour with that in patients not undergoing resection, and determines rates of post-operative mortality and nonfatal complications, the primary tumour complication rate, the non-resection surgical procedures rate, and quality of life (qol).

METHODS

Reports in the central, medline, and embase databases were searched for relevant studies, which were selected using pre-specified eligibility criteria. The search was also restricted to publication dates from 1980 onward, the English language, and studies involving human subjects. Screening, evaluation of relevant articles, and data abstraction were performed in duplicate, and agreement between the abstractors was assessed. Articles that met the inclusion criteria were assessed for quality using the Newcastle-Ottawa Scale. Data were collected and synthesized per protocol.

RESULTS

From among the 3379 reports located, fifteen retrospective observational studies were selected. Of the 12,416 patients in the selected studies, 8620 (69%) underwent surgery. Median survival was 15.2 months (range: 10-30.7 months) in the resection group and 11.4 months (range: 3-22 months) in the non-resection group. Hazard ratio for survival was 0.69 [95% confidence interval (ci): 0.61 to 0.79] favouring surgical resection. Mean rates of postoperative mortality and nonfatal complications were 4.9% (95% ci: 0% to 9.7%) and 25.9% (95%ci: 20.1% to 31.6%) respectively. The mean primary tumour complication rate was 29.7% (95% ci: 18.5% to 41.0%), and the non-resection surgical procedures rate in the non-resection group was 27.6% (95 ci: 15.4% to 39.9%). No study provided qol data.

CONCLUSIONS

Although this review supports primary tumour resection in advanced crc, the results have significant biases. Randomized trials are warranted to confirm the findings.

Palliative excisional surgery for primary colorectal cancer in patients with incurable metastatic disease. Is there a survival benefit? A systematic review

AIM

Patients with stage IV colorectal cancer with unresectable metastases can either receive chemotherapy or palliative resection of the primary lesion. In the absence of any randomized data the choice of initial treatment in stage IV colorectal cancer is not based on firm evidence.

METHOD

A search of MEDLINE, Pubmed, Embase and the Cochrane Library database was performed from 1980 to 2010 for studies comparing palliative resection in stage IV colorectal cancer with other treatment modalities. Audits and observational studies were excluded. Median survival was the primary outcome measure. The morbidity and mortality of surgical and nonsurgical treatments were compared.

RESULTS

Twenty-one studies (no randomized controlled trials) were identified. Most demonstrated a survival benefit for patients who underwent palliative resection. Multivariate analysis indicates that tumour burden and performance status are both major independent prognostic variables. Selection bias, incomplete follow up and nonstandardized reporting of complications make the data difficult to interpret.

CONCLUSION

The studies indicate that there may be a survival benefit for primary resection of colorectal cancer in stage IV disease. The findings suggest that resection of the primary tumour should be based on tumour burden and performance status rather than on the presence or absence of symptoms alone.

Assessment of prognostic factors after primary tumor resection in metastatic colon cancer patients: a Veteran's Affairs Central Cancer Registry (VACCR) analysis, 1995-2008

BACKGROUND

Resection of the primary tumor in metastatic colon cancer may occur for palliation of bleeding or obstruction despite distant metastases. This study evaluates clinicopathologic features that serve as prognostic markers in those patients with stage IV colon cancer who undergo resection of their primary tumor.

METHODS

Retrospective analysis of stage IV colon cancer patients who underwent surgical resection of the primary tumor from 1995 to 2008 was done via the Veteran's Affairs Central Cancer Registry. Age, Charlson co-morbidity index score, extent of metastases, sex, number of lymph nodes examined, lymph node ratio (LNR), type of surgery, use of adjuvant chemotherapy, primary tumor site, and grade were studied with respect to overall survival by using log-rank and Kaplan-Meier analysis.

RESULTS

There were 2,625 patients with stage IV colon cancer who had primary tumor resection. Age at diagnosis, Charlson co-morbidity index score, lymph node ratio, and use of chemotherapy were found to be independent predictors of survival by multivariate analysis.

CONCLUSION

Clinicopathologic factors such as LNR, use of chemotherapy, age, co-morbidities, site of primary colon tumor, and number of sites of metastasis are all independent predictors of overall survival in patients who undergo primary colon tumor resection in the metastatic setting.

Stage IV colorectal cancers: an analysis of factors predicting outcome and survival in 728 cases

INTRODUCTION

Stage IV colorectal cancer (CRC) is a heterogeneous disease with many treatment options. The optimum management algorithm is yet to be established. The aim of this study was to evaluate the prognostic factors of survival and to determine the operative benefit of resection of the primary tumour followed by chemotherapy.

METHODS

Seven hundred twenty-eight consecutive patients who presented with stage IV CRC from 1999 to 2007 were identified. The demographics and clinicopathological characteristics of these patients were reviewed. Survival curves were constructed using the Kaplan-Meier method. Multivariate analysis assessed independent prognostic factors.

RESULTS

In the surgical management of the primary, 79% (n = 572) were performed electively, 18% (n = 134) as an emergency procedure and 3% (n = 22) did not have any surgery. Twelve percent (n = 78) had a permanent stoma. Major morbidity was 4.3% (n = 31), and 30-day mortality was low at 6% (n = 46). Ten percent (n = 71) had a subsequent metasectomy. Patients who underwent curative resections tended to be female (p = 0.05), of a younger age group (age, ≤ 50; p = 0.005), as well as had better haemoglobin (p = 0.0001) and albumin levels (p = 0.0001). For the study cohort, the cancer-specific survival (CSS) at 1 year was 47.9% [95% confidence interval (CI), 44.2-51.6%], 3-year CSS was 10.8% (95% CI, 3.3-13.3%) and 5-year CSS was 7.0% (95% CI, 4.8-9.2%). CSS was significantly higher in patients that underwent colonic resection. In cases where resection of the primary was possible, multivariate analysis revealed that CEA value >40 ng/ml, low albumin levels ≤ 34 g/l, poorly differentiated tumours, advanced tumour stage (T3/T4), nodal disease (N1/N2) and presence of diffuse metastasis were all significant factors associated with poorer cancer-specific survival.

CONCLUSION

This study has shown a good survival benefit in stage IV CRC when an aggressive policy of primary resection is adopted. Resection of metastases with curative intent should be performed whenever possible.

Surgery of the primary in stage IV colorectal cancer with unresectable metastases

Surgery plays an important role in the treatment of patients with limited metastatic disease of colorectal cancer (CRC). Long term survival and cure is reported in 20-50% of highly selected patients with oligometastatic disease who underwent surgery. This paper describes the role of surgery of the primary tumour in patients with unresectable stage IV colorectal cancer. Owing to the increased efficacy of chemotherapeutic regimens in stage IV colorectal cancer, complications from unresected primary tumours are relatively infrequent. The risk of emergency surgical intervention is less than 15% in patients with synchronous metastatic disease who are treated with chemotherapy. Therefore, there is a tendency among surgeons not to resect the primary tumour in case of unresectable metastases. However, it is suggested that resection of the primary tumour in case of unresectable metastatic disease might influence overall survival. All studies described in the literature (n = 24) are non-randomised and the majority is single-centre and retrospective of nature. Most studies are in favour of resection of the primary tumour in patients with symptomatic lesions. In asymptomatic patients the results are less clear, although median overall survival seems to be improved in resected patients in the majority of studies. The major drawback of all these studies is that primarily patients with a better performance status and better prognosis (less metastatic sites involved) are being operated on. Another limitation of these studies is that few if any data on the use of systemic therapy are presented, which makes it difficult to assess the relative contribution of resection on outcome. Prospective studies on this topic are warranted, and are currently being planned.

CONCLUSION

Surgery of the primary tumour in patients with synchronous metastasised CRC is controversial, although data from the literature suggest that resection might be a positive prognostic factor for survival. Therefore prospective studies on the value of resection in this setting are required.

Prognostic value of resection of primary tumor in patients with stage IV colorectal cancer: retrospective analysis of two randomized studies and a review of the literature

Background

In patients with metastatic colorectal cancer (mCRC) with an asymptomatic primary tumor, there is no consensus on the indication for resection of the primary tumor.

Methods

A retrospective analysis was performed on the outcome of stage IV colorectal cancer (CRC) patients with or without resection of the primary tumor treated in the phase III CAIRO and CAIRO2 studies. A review of the literature was performed.

Results

In the CAIRO and CAIRO2 studies, 258 and 289 patients had undergone a primary tumor resection and 141 and 159 patients had not, respectively. In the CAIRO study, a significantly better median overall survival and progression-free survival was observed for the resection compared to the nonresection group, with 16.7 vs. 11.4 months [P < 0.0001, hazard ratio (HR) 0.61], and 6.7 vs. 5.9 months (P = 0.004; HR 0.74), respectively. In the CAIRO2 study, median overall survival and progression-free survival were also significantly better for the resection compared to the nonresection group, with 20.7 vs. 13.4 months (P < 0.0001; HR 0.65) and 10.5 vs. 7.8 months (P = 0.014; HR 0.78), respectively. These differences remained significant in multivariate analyses. Our review identified 22 nonrandomized studies, most of which showed improved survival for mCRC patients who underwent resection of the primary tumor.

Conclusions

Our results as well as data from literature indicate that resection of the primary tumor is a prognostic factor for survival in stage IV CRC patients. The potential bias of these results warrants prospective studies on the value of resection of primary tumor in this setting; such studies are currently being planned.

Systematic review of prognostic factors related to overall survival in patients with stage IV colorectal cancer and unresectable metastases

BACKGROUND

With the improvements in newer chemotherapeutic agents, the role of primary tumour resection in patients with stage IV colorectal cancer is controversial. In many cases primary tumour resection is still favoured as first-line management. However, a detailed understanding of independent prognostic factors related to survival is necessary before making this decision.

METHOD

A literature search was conducted using Medline and Embase. Studies that performed multivariate analysis on overall survival of patients with incurable stage IV colorectal cancer were included in this review.

RESULTS

Fourteen retrospective studies involving 3209 patients were included. Clinical variables analysed to consistently have independent prognostic significance for long-term survival included the patients' performance status (<2), volume of liver metastases (<50%), nodal stage (N0), disease-free resection margins, and treatment with chemotherapy and/or primary tumour resection. Cancer antigen (CA) 19-9, low albumin, elevated ALP levels, apical lymph node involvement, presence of ascites, and postoperative transfusion were each assessed by only one study and found to be independently associated with survival. Factors inconsistently reported to have independent prognostic significance were age, ASA score, preoperative CEA levels, primary tumour location, tumour size and differentiation, peritoneal dissemination, and extrahepatic metastases.

CONCLUSION

Each patient should be reviewed individually on the basis of the above independent prognostic factors before deciding to resect the primary tumour. Patients with a poor performance status, extensive hepatic metastases, and extensive nodal disease detected preoperatively are less likely to have a survival benefit. Nonsurgical approaches to manage these patients should be given careful consideration.

Predictors of postoperative mortality, morbidity, and long-term survival after palliative resection in patients with colorectal cancer

BACKGROUND

Limited information is available on predictors of postoperative mortality, morbidity, and long-term survival in patients with stage IV colorectal cancer.

OBJECTIVE

This study aimed to identify independent predictors of postoperative mortality and morbidity as well as independent predictors of long-term survival.

DESIGN

This study was planned as a retrospective single-institution review.

SETTING

This study took place at the Department of Surgery, The Royal Brisbane and Women's Hospital, Australia, between 1984 and 2004.

PARTICIPANTS

Prospectively collected data were extracted from the records of 1867 patients undergoing treatment for colorectal cancer. The outcomes for 379 patients undergoing surgical resection of their primary colon or rectal tumor in the presence of unresectable synchronous metastases were analyzed.

MAIN OUTCOME MEASURES

Independent predictive factors for postoperative mortality and morbidity as well as long-term survival were assessed by use of logistic regression and Cox regression analysis.

RESULTS

Thirty-five (9.2%) patients died in the postoperative period and morbidity was 48.3%. Median survival was 11 months. Thirty-day postoperative mortality was independently associated with medical complications (P < .001), emergency operations (P = .001), female sex (P = .002), and age (≥ 70; P = .007) on regression analysis. Elderly (≥ 70) patients with either advanced local disease or extrahepatic metastases were at a particularly high risk. Preoperative predictors of surgical morbidity included male sex (P = .028) and advanced local disease (P = .036). Preoperative predictors of medical complications included repeat operations (P < .001), elevated urea levels (P = .017), and emergency operations (P = .003). Independent factors associated with poor overall survival included medical complications (P < .001), nodal stage (N2) (P = .004), poor tumor differentiation (P = .006), and apical lymph node involvement (P = .042). A subgroup of patients with advanced nodal disease (N2) and a poor tumor differentiation had a significantly poorer prognosis.

LIMITATIONS

This study was limited by its retrospective nature.

CONCLUSION

Elderly patients with advanced local disease or extrahepatic metastases are at high risk of 30-day postoperative mortality. Significant nodal disease and poor tumor differentiation are important predictors of long-term survival.