Is primary sidedness a prognostic factor in patients with resected colon cancer liver metastases (CLM)?

The survival outcome differs between left-sided colon cancer and middle/low rectal cancer after colorectal hepatic metastasectomy

BACKGROUND

The clinical outcomes between left-sided colon cancer and middle/low rectal cancer seem to be different. This study aimed to examine the effect of primary tumor location regarding the left-sided colon and middle/low rectum on the overall survival (OS) of patients who underwent colorectal hepatic metastasectomy.

METHODS

Patients who underwent colorectal hepatic metastasectomy were retrospectively enrolled. Patients were classified into 2 groups according to the primary tumor location (left-sided colon and middle/low rectum). Categorical variables were compared using the chi-square test or Fisher exact test, and continuous variables were analyzed using the Student t test. Survival was analyzed using the Kaplan-Meier method and log-rank test. The prognostic factors were analyzed by univariate and multivariate analyses using Cox proportional hazards regression models.

RESULTS

Overall, 365 patients were enrolled. Patients with left-sided colon cancer had significantly better OS than those with middle/low rectal cancer (hazard ratio [HR], 0.725; P = .018), with median OS estimates of 48 and 38 months, respectively. In the subgroup analysis of RAS mutations, patients with left-sided colon cancer had significantly prolonged OS compared with those with middle/low rectum cancer (HR, 0.608; P = .034), with median OS estimates of 49 and 26 months, respectively. This observation was limited to patients with RAS mutations.

CONCLUSION

According to our findings, patients with middle/low rectal cancer had poorer survival outcome and should not be categorized together with patients with left-sided colon cancer in terms of OS after colorectal hepatic metastasectomy.

Prognostic Role for Primary Tumor Location in Patients With Colorectal Liver Metastases: A Comparison of Right-Sided Colon, Left-Sided Colon, and Rectum

BACKGROUND

Although right-sided colon cancer is increasingly recognized as having a worse prognosis than left-sided colorectal cancer for colorectal liver metastases, little is known about the differences between the left-sided colon and rectum.

OBJECTIVE

This study evaluated the prognostic value of primary tumor location in patients with colorectal liver metastases by examining the left-sided colon and rectum separately.

DESIGN

This was a retrospective study from 2003 to 2017.

SETTINGS

The study was conducted in a National Cancer Center Hospital.

PATIENTS

The study cohort included 489 patients with colorectal liver metastases from right-sided colon cancer ( n = 119, 24%), left-sided colon cancer ( n = 251, 51%), or rectal cancer ( n = 119, 24%) who underwent hepatic resection.

MAIN OUTCOME MEASURES

Primary outcomes were relapse-free survival and overall survival.

RESULTS

Five-year relapse-free survival rates for patients with right-sided colon cancer, left-sided colon cancer, and rectal cancer were 28.6%, 34.1%, and 26.4%, and 5-year overall survival rates were 53.9%, 70.3%, and 60.8%. Multivariable analysis revealed significant differences in relapse-free survival and overall survival between left-sided colon cancer and rectal cancer (relapse-free survival: HR = 1.37, p = 0.03; overall survival: HR = 1.49, p = 0.03) and between left-sided colon cancer and right-sided colon cancer (relapse-free survival: HR = 1.39, p = 0.02; overall survival: HR = 1.60, p = 0.01), but not between right-sided colon cancer and rectal cancer. In patients with recurrence ( n = 325), left-sided colon cancer had the lowest multiple-site recurrence rate and the highest surgical resection rate for recurrence (left-sided colon cancer, 20%/46%; right-sided colon cancer, 32%/30%; rectal cancer, 26%/39%).

LIMITATIONS

This study was retrospective in design.

CONCLUSIONS

Rectal cancer was associated with worse relapse-free survival and overall survival compared with left-sided colon cancer in patients with colorectal liver metastases who underwent hepatic resection. Our findings suggest that the left-sided colon and rectum should be considered distinct entities in colorectal liver metastases. See Video Abstract at http://links.lww.com/DCR/B882 .

PAPEL PRONSTICO DE LA UBICACIN DEL TUMOR PRIMARIO EN PACIENTES CON METSTASIS HEPTICAS COLORRECTALES UNA COMPARACIN ENTRE COLON DERECHO, COLON IZQUIERDO Y RECTO

ANTECEDENTES:Aunque se reconoce cada vez más que el cáncer de colon del lado derecho tiene un peor pronóstico que el cáncer colorrectal del lado izquierdo para las metástasis hepáticas colorrectales, se sabe poco acerca de las diferencias entre el recto y el colon del lado izquierdo.OBJETIVO:Este estudio evaluó el valor pronóstico de la ubicación del tumor primario en pacientes con metástasis hepáticas colorrectales examinando el recto y el colon del lado izquierdo por separado.DISEÑO:Este fue un estudio retrospectivo de 2003 a 2017.ENTORNO CLÍNICO:El estudio se llevó a cabo en un Hospital del Centro Nacional de Cáncer.PACIENTES:La cohorte del estudio incluyó a 489 pacientes con metástasis hepáticas colorrectales de cáncer de colon del lado derecho (n = 119, 24%), cáncer de colon del lado izquierdo (n = 251, 51%) o cáncer de recto (n = 119, 24%). %) que fueron sometidos a resección hepática.PRINCIPALES MEDIDAS DE VALORACIÓN:Los resultados primarios fueron la supervivencia sin recaídas y la supervivencia general.RESULTADOS:Las tasas de supervivencia sin recaída a cinco años para los pacientes con cáncer de colon derecho, cáncer de colon izquierdo y cáncer de recto fueron del 28,6%, 34,1%, y 26,4%, respectivamente, y las tasas de supervivencia general a los 5 años fueron del 53,9%, 70,3%, y 60,8%, respectivamente. El análisis multivariable reveló diferencias significativas en la supervivencia sin recaída y la supervivencia general entre el cáncer de colon izquierdo y el cáncer de recto (supervivencia sin recaída: HR = 1,37, p = 0,03; supervivencia general: HR = 1,49, p = 0,03) y entre el cáncer de colon izquierdo y el cáncer de colon del lado derecho (supervivencia libre de recaídas: HR = 1,39, p = 0,02; supervivencia global: HR = 1,60, p = 0,01), pero no entre el cáncer de colon del lado derecho y el cáncer de recto. En pacientes con recurrencia (n = 325), el cáncer de colon izquierdo tuvo la tasa de recurrencia en sitios múltiples más baja y la tasa de resección quirúrgica más alta por recurrencia (cáncer de colon izquierdo, 20%/46%; cáncer de colon derecho, 32%/30%; cáncer de recto, 26%/39%).LIMITACIONES:Este estudio fue de diseño retrospectivo.CONCLUSIONES:El cáncer de recto se asoció con una peor supervivencia sin recaída y una supervivencia general peor en comparación con el cáncer de colon izquierdo en pacientes con metástasis hepáticas colorrectales que se sometieron a resección hepática. Nuestros hallazgos sugieren que el colon y el recto del lado izquierdo deben considerarse entidades distintas en las metástasis hepáticas colorrectales. Consulte Video Resumen en http://links.lww.com/DCR/B882 . (Tradducción-Dr. Ingrid Melo ).

Embryologic Origin of the Primary Tumor and RAS Status Predict Survival after Resection of Colorectal Liver Metastases

Background and objectives. In colorectal cancers, the embryologic origin of the primary tumor determines important molecular dissimilarities between right-sided (RS) and left-sided (LS) carcinomas. Although important prognostic differences have been revealed between RS- and LS-patients with resected colorectal liver metastases (CLMs), it is still unclear if this observation depends on the RAS mutational status. To refine the impact of primary tumor location (PTL) on the long-term outcomes of patients with resected CLMs, the rates of overall survival (OS), relapse-free survival (RFS) and survival after recurrence (SAR) were compared between RS- vs. LS-patients, according to their RAS status. Material and Methods. All patients with known RAS status, operated until December 2019, were selected from a prospectively maintained database, including all patients who underwent hepatectomy for histologically-proven CLMs. A log-rank test was used to compare survival rates between the RS- vs. LS-group, in RAS-mut and RAS-wt patients, respectively. A multivariate analysis was performed to assess if PTL was independently associated with OS, RFS or SAR. Results. In 53 patients with RAS-mut CLMs, the OS, RFS and SAR rates were not significantly different (p = 0.753, 0.945 and 0.973, respectively) between the RS and LS group. In 89 patients with RAS-wt CLMs, the OS and SAR rates were significantly higher (p = 0.007 and 0.001, respectively) in the LS group vs. RS group, while RFS rates were similar (p = 0.438). The multivariate analysis performed in RAS-wt patients revealed that RS primary (p = 0.009), extrahepatic metastases (p = 0.001), N-positive (p = 0.014), age higher than 65 (p = 0.002) and preoperative chemotherapy (p = 0.004) were independently associated with worse OS, while RS location (p < 0.001) and N-positive (p = 0.007) were independent prognostic factors for poor SAR. Conclusions. After resection of CLMs, PTL had no impact on long-term outcomes in RAS-mut patients, while in RAS-wt patients, the RS primary was independently associated with worse OS and SAR.

Association of primary tumor laterality with surgical outcomes for colorectal liver metastases: results from the Colorectal Liver Operative Metastasis International Collaborative (COLOMIC)

BACKGROUND

Primary laterality of colorectal cancer is thought to be associated with differences in outcomes. Liver metastasis is the most common site of solitary colorectal cancer spread. However, how primary colorectal cancer laterality affects outcomes in colorectal liver metastasis remains unclear.

METHODS

The Colorectal Liver Operative Metastasis International Collaborative (COLOMIC) of operative hepatectomy cases for colorectal liver metastasis was compiled from five participating institutions. This included consecutive cases from 2000 to 2018 at all sites. A total of 884 patients were included in this study. Univariate, multivariate, and Kaplan-Meier analyses were performed.

RESULTS

Patients with left-sided versus right-sided cancers had significantly better overall survival: 49.4 vs. 41.8 months (p < 0.05). Patients with KRAS mutations had significantly worse median overall survival compared to KRAS wild-type (43.6 vs 56.1 months; p < 0.001). In left-sided cancers, KRAS mutations were associated with significantly worse median overall survival compared to KRAS wild-type cancers (43.6 vs 56.6 months; p < 0.01). This association was absent in patients with right-sided primary tumors. Multivariate Cox regression analysis revealed different variable sets (non-overlapping) were associated with overall survival, when comparing left-sided and right-sided cancers.

CONCLUSION

Understanding how primary tumor laterality and related biological aspects affect long-term outcomes can potentially inform treatment decisions for patients with colorectal liver metastases.

Indications for conversion hepatectomy for initially unresectable colorectal cancer with liver metastasis

PURPOSE

Selected patients with initially unresectable colorectal cancer (CRC) and liver metastases undergo conversion surgery after appropriate chemotherapy. The prognosis of these patients is good, with some even cured of the disease. This retrospective, single-institution study analyzes the clinical importance of patient characteristics on the outcomes of conversion hepatectomy.

METHODS

We evaluated 229 consecutive patients with initially unresectable CRC and liver metastasis, who underwent systemic chemotherapy. The patients were assigned to groups depending on conversion hepatectomy.

RESULTS

Conversion hepatectomy was performed in 30 patients (13.1%). The proportion of patients with extrahepatic metastasis was significantly lower in the conversion group than in the unresectable group (30.0 vs. 66.8%; P < 0.01). The rate of left-sided primary colorectal tumors was significantly higher in the conversion group than in the unresectable group (96.7 vs. 65.8%; P < 0.01). Multivariate analyses identified that left-sided tumors, no extrahepatic metastasis, H1 or H2 grade CLM, and treatment with molecular-targeted agents were associated with conversion hepatectomy (odds ratios: 16.314, 4.216, 7.631, and 4.070; P < 0.01). Overall survival was significantly longer in the conversion group than in the unresectable group (MST: 50.0 versus 14.7 months; P < 0.01).

CONCLUSION

Left-sided primary tumors, absence of extrahepatic metastases, H1 or H2 grade, and use of molecular-targeted agents were associated with successful conversion hepatectomy; thus, patients with these characteristics may be candidates for conversion therapy.

Assessing the Impact of Primary Tumour Location on Survival After Resection of Colorectal Liver Metastases: A Propensity Weighted Retrospective Cohort Study

BACKGROUND

Right-sided colonic tumours appear to have poorer survival after resection of colorectal liver metastases, although this may be confounded by various factors including advanced stage and emergency presentation.

METHODS

Medical records of consecutive patients undergoing resection of colorectal liver metastases at a single centre from 2008 to 2015 were retrospectively reviewed. Cases were categorised by primary tumour location (right colon, left colon, rectum). Each primary location was weighted using propensity scores to balance covariates, including staging and mode of presentation. Cox regression was then applied to derive multivariable hazard ratios (HR) of survival after liver resection. Primary outcomes were 10-year overall survival (OS) and 5-year disease-free survival (DFS) after liver resection based on PTL.

RESULTS

414 patients were included in the analysis. Left colonic tumours were significantly associated with higher rates of bilobar liver metastasis (36.2% vs. 20.1% and 30.1%) and larger maximum size of liver metastases compared with rectal and right-sided tumours, respectively. There was no difference in rates of extra-hepatic metastases, recurrence in the liver after resection or RAS, BRAF or p53 mutational status. After propensity weighting and Cox-regression, right-sided tumours were independently associated with significantly reduced 10 year OS (HR 1.56, 95% CI 1.03-2.36, p = 0.04) but not 5 year DFS (HR 1.36, 95% CI 0.89-2.08, p = 0.15).

CONCLUSIONS

Compared with left colonic and rectal tumours, right-sided colonic tumours are independently associated with inferior OS after resection of CRLM. This is despite higher rates of bilobar liver metastases and larger metastases with left-sided tumours.

Prognostic value of the combination of primary tumor location and RAS mutational status on patients with colorectal liver metastasis undergoing hepatectomy

OBJECTIVE

To assess prognostic influences of RAS mutational status and primary tumor site on cases with colorectal liver metastasis (CRLM) who underwent hepatectomy.

METHODS

Clinicopathological data of 762 patients with CRLM who underwent hepatectomy between January 2000 and November 2018 were retrospectively analyzed. The left-sided tumors (LST) included tumors located in the splenic flexure, descending colon, sigmoid colon, and rectum; while right-sided tumors (RST) included those located in the cecum, ascending colon, and transverse colon. RAS mutational status was determined using Sanger sequencing or next-generation sequencing, including KRAS (Codons 12, 13, and 61) and NRAS (Codons 12, 13, and 61), which were defined as wild-type (RASwt) and mutant-type (RASmut), respectively. Survival curves were plotted using the Kaplan-Meier plotter and compared by the log rank test. The clinicopathological data were analyzed using univariate and multivariate analyses.

RESULTS

The 5-year overall survival (OS) in the LST group was longer than that in the RST group (OS: 47.1% vs. 31.0%, p = 0.000, respectively), and the OS in the RASwt group was longer compared with that in the RASmut group (OS: 53.6% vs. 24.0%, p = 0.000). Besides, overall survival of the patients after hepatectomy was alternative, which was stratified by primary tumor site, with the 1-, 3-, and 5-year survival rates of 93.1%, 62.1%, and 47.1% for patients with LST, and 91.1%, 42.8%, and 31.0% for patients with RST, respectively. OS and disease-free survival (DFS) were significantly different stratified by RAS mutational status, with the 1-, 3-, and 5-year rates of 96.9%, 67.9%, and 53.6% for patients with RASwt tumors, and 85.7%, 41.5%, and 24.0% for patients with RASmut tumors, respectively. The 1-, 3-, and 5-year DFS rates were 51.9%, 30.0%, and 26.7% for patients with RASwt tumors, and 35.8%, 18.2%, and 14.9% for patients with RASmut tumors, respectively. The results of multivariate analysis showed that RAS mutational status and primary tumor site were both independent influencing factors of OS.

CONCLUSION

RAS mutational status and primary tumor site affect OS independently in CRLM patients undergoing hepatectomy. The worse prognosis of RST cannot be simply attributed to the imbalance of RAS mutational status in different primary tumor sites.

The Prognostic Impact of Primary Tumor Site Differs According to the KRAS Mutational Status: A Study By the International Genetic Consortium for Colorectal Liver Metastasis

OBJECTIVE

To examine the prognostic impact of tumor laterality in colon cancer liver metastases (CLM) after stratifying by Kirsten rat sarcoma 2 viral oncogene homolog (KRAS) mutational status.

BACKGROUND

Although some studies have demonstrated that patients with CLM from a right sided (RS) primary cancer fare worse, others have found equivocal outcomes of patients with CLM with RS versus left-sided (LS) primary tumors. Importantly, recent evidence from unresectable metastatic CRC suggests that tumor laterality impacts prognosis only in those with wild-type tumors.

METHODS

Patients with rectal or transverse colon tumors and those with unknown KRAS mutational status were excluded from analysis. The prognostic impact of RS versus LS primary CRC was determined after stratifying by KRAS mutational status.

RESULTS

277 patients had a RS (38.6%) and 441 (61.4%) had a LS tumor. Approximately one-third of tumors (28.1%) harbored KRAS mutations. In the entire cohort, RS was associated with worse 5-year overall survival (OS) compared with LS (39.4% vs 50.8%, P = 0.03) and remained significantly associated with worse OS in the multivariable analysis (hazard ratio 1.45, P = 0.04). In wild-type patients, a worse 5-year OS associated with a RS tumor was evident in univariable analysis (43.7% vs 55.5%, P = 0.02) and persisted in multivariable analysis (hazard ratio 1.49, P = 0.01). In contrast, among patients with KRAS mutated tumors, tumor laterality had no impact on 5-year OS, even in the univariable analysis (32.8% vs 34.0%, P = 0.38).

CONCLUSIONS

This study demonstrated, for the first time, that the prognostic impact of primary tumor side differs according to KRAS mutational status. RS tumors were associated with worse survival only in patients with wild-type tumors.

Long-term outcome for colorectal liver metastases: combining hepatectomy with intraoperative ultrasound guided open microwave ablation versus hepatectomy alone

OBJECTIVE

To compare the long-term outcome of combining hepatectomy with intraoperative ultrasound (IOUS)-guided open microwave ablation (MWA) versus hepatectomy alone in patients with colorectal cancer liver metastases (CRLM).

METHOD

A retrospective analysis of patients with CRLM who underwent hepatectomy alone (HT group; 380 patients) or hepatectomy combined with IOUS-guided open MWA (HT + MWA group; 57 patients) from April 2002 to September 2018 was conducted at our center. A propensity score-matched (PSM) analysis was used to reduce data bias between the two groups.

RESULTS

The overall survival (OS) and disease-free survival (DFS) were not significantly different between the two groups after matching. Although intrahepatic recurrence was more frequent in the HT + MWA group in both the whole and matched cohort, the two groups exhibited similar rates of extrahepatic recurrence as well as concomitant intra- and extrahepatic recurrence. A higher number of CRLM (>3), larger maximum-size and absence of response to induction chemotherapy were independent risk factors for OS.

CONCLUSION

The oncological outcomes of hepatectomy combined with intraoperative open ablation was not significantly different to hepatectomy alone and should be considered as a safe and fair option for patients with difficultly resectable CRLM.

Effect of Primary Tumor Location on Postmetastasectomy Survival in Patients with Colorectal Cancer Liver Metastasis

BACKGROUND

The effects of primary tumor location on colorectal liver metastasis (CRLM) and post-hepatic-metastasectomy overall survival (OS) are controversial. This study evaluated the difference in post-hepatic-metastasectomy OS among right-sided colon, left-sided colon, and rectal cancer groups.

METHODS

In total, 381 patients who underwent curative-intent CRLM resection were enrolled. Patients were grouped based on the primary tumor location (right-sided, left-sided, and rectum). The Kaplan-Meier analysis and log-rank test were performed for survival analysis. The univariate and multivariate analyses of clinical and pathological factors were performed using the Cox proportional hazards model.

RESULTS

Significant OS difference was noted among the three groups (log-rank, p = 0.014). The multivariate analysis revealed a 32% lower death risk in left-sided colon cancer compared with right-sided colon cancer (hazard ratio [HR] 0.68, p = 0.042), whereas no OS difference was noted between the rectal cancer and right-sided colon cancer groups. The left- versus right-sided OS advantage was noted only in the KRAS wild-type subgroup (HR 0.46, p = 0.002), and a rectal versus right-sided OS disadvantage was noted in the KRAS mutant subgroup (HR 1.78, p = 0.03).

CONCLUSIONS

The CRLM post-hepatic-metastasectomy OS was superior in left-sided colon cancer than in right-sided colon cancer and was similar in rectal and right-sided colon cancer. The OS difference in different primary tumor locations is dependent on KRAS mutation status, with a decreased left- versus right-sided death risk noted only in KRAS wild-type colon cancer and an increased rectal versus right-sided death risk noted only in KRAS mutant colon cancer.

Impact of primary tumour location on colorectal liver metastases: A systematic review

BACKGROUND

Colorectal cancer (CRC) is the third most common cause of cancer-related death worldwide. Despite significant advances in screening, surgical management and adjuvant therapies, average 5-year survival seldom exceeds 60% in most developed nations. Metastatic disease represents the primary cause of mortality in patients with CRC, and the liver is the most common location for distant tumour spread. Up to 25% of patients are found to have synchronous liver metastases at the time of diagnosis and a further 30%-40% will develop metachronous disease in the course of follow-up. It has been suggested that primary tumour location [right side versus left side, primary tumour location (PTL)] can influence oncological outcomes in this patient group and that this should be considered in prognostic models and therapeutic decision-making algorithms. This suggestion is not universally accepted and there have been conflicting reports in the literature to date.

AIM

To provide a comprehensive summary of the available evidence regarding the impact of PTL on oncological outcomes in patients with colorectal cancer liver metastases (CRCLM).

METHODS

MEDLINE, EMBASE and COCHRANE were searched for relevant publications using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses methodology. Data on oncological outcomes was then extracted from full text articles that met the predefined inclusion criteria.

RESULTS

A total of 41 studies were identified that met predefined inclusion criteria for this review. In 21 out of 38 studies that provided data on overall survival, a statistically significant improvement in overall survival was reported in patients with left sided primary tumours. These studies included a total of 13897 patients compared with 4306 patients in the studies that did not show a significant difference. Eight studies noted a similar trend towards improved disease-free or progression-free survival. Several authors observed distinct patterns of relapse after treatment of hepatic metastases according to PTL; for example hepatic recurrence after treatment of CRCLM appears to occur more aggressively with right-sided CRC.

CONCLUSION

Taken together, the findings of the present review indicate that PTL may have a role as an independent prognostic factor when determining treatment and disease surveillance strategies in CRC. The mechanisms responsible for this variation remain poorly understood, but are likely to relate to molecular, histological and embryological differences, as well as inherent differences in therapeutic sensitivity.

Primary tumor location and the prognosis of patients after local treatment of colorectal liver metastases: a systematic review and meta-analysis

BACKGROUND

Recently numerous studies have reported primary tumor location as a potential prognostic factor after surgery for colorectal liver metastases (CRLM). The aim of this study was to comprehensively review and analyze all the available literature on the impact of primary tumor location in patients after local treatment of CRLM.

METHODS

Studies examining the association of right- and left-sided colorectal cancer and overall survival (OS) and recurrence free survival (RFS) after local treatment (resection and/or ablation) of CRLM were identified. Random-effects models were used for both clinicopathological and outcome variables. Pooled hazard ratios (HR) with 95% confidence intervals (95% CI) were shown for both OS and RFS.

RESULTS

Ten studies (including 11 patient cohorts) were eligible for inclusion, representing 3962 patients. Right-sided tumors (i.e. proximal to the splenic flexure) were observed in 1340 patients (33.8%). Median follow-up ranged from 25 to 137 months. Patients with right-sided tumors had a significantly decreased OS (HR 1.60, 95% CI 1.30-1.98, p < 0.001) and RFS (HR 1.35, 95% CI 1.04-1.77, p = 0.03), when compared to patients with left-sided tumors.

CONCLUSION

This meta-analysis suggests that patients with right-sided primaries suffer from a worse prognosis, compared to patients with left-sided primaries in patients after local treatment of CRLM.

Tumor Sidedness Is Associated with Survival in Patients with Synchronous Colorectal Peritoneal Carcinomatosis

BACKGROUND

Synchronous colorectal peritoneal carcinomatosis (SCPC) is not a rare entity, and the prognosis is extremely poor compared to other metastatic sites such as the liver and lung. Therefore, optimal treatment based on tumor characteristics is needed. Recently, the tumor sidedness of colorectal cancer has been reported as one of the prognostic factors and also as a key factor for the treatment strategy. The purpose of this study was to assess the clinical impact of tumor sidedness in patients with SCPC.

METHODS

A total of 189 cases of SCPC were identified in a retrospective database at Wakayama Medical University Hospital (WMUH) between 1998 and 2014, and were analyzed with a special focus on tumor location.

RESULTS

In multivariate analysis, a right-sided location (p = 0.02) and the presence of liver metastases (p < 0.001) were found to be the worst prognostic factors. The median survival time (MST) with right-sided and with left-sided SCPC was 10 and 16 months, respectively. The right-sided SCPC group included more aged patients (p = 0.045) and fewer patients who received postoperative chemotherapy (p = 0.034). When we focused on patients with macroscopically complete resection (n = 39), the MST and disease-free survival in the right-sided SCPC group was significantly shorter than in the left-sided SCPC group (p = 0.030 and p = 0.043, respectively). The MST of the right-sided and the left-sided SCPC patients among the completely resected patients was 24 and 73 months, respectively.

CONCLUSION

Tumor sidedness may be a potent prognostic indicator for patients with SCPC. The survival time with right-sided SCPC is dramatically reduced compared to that with left-sided SCPC, especially among completely resected cases. We should change the treatment strategy according to the location of SCPC.

Synchronous and metachronous liver metastases in patients with colorectal cancer-towards a clinically relevant definition

Background

Approximately 25% of patients with colorectal cancer (CRC) will have liver metastases classified as synchronous or metachronous. There is no consensus on the defining time point for synchronous/metachronous, and the prognostic implications thereof remain unclear. The aim of the study was to assess the prognostic value of differential detection at various defining time points in a population-based patient cohort and conduct a literature review of the topic.

Methods

All patients diagnosed with CRC in the counties of Stockholm and Gotland, Sweden, during 2008 were included in the study and followed for 5 years or until death to identify patients diagnosed with liver metastases. Patients with liver metastases were followed from time of diagnosis of liver metastases for at least 5 years or until death. Different time points defining synchronous/metachronous detection, as reported in the literature and identified in a literature search of databases (PubMed, Embase, Cochrane library), were applied to the cohort, and overall survival was calculated using Kaplan-Meier curves and compared with log-rank test. The influence of synchronously or metachronously detected liver metastases on disease-free and overall survival as reported in articles forthcoming from the literature search was also assessed.

Results

Liver metastases were diagnosed in 272/1026 patients with CRC (26.5%). No statistically significant difference in overall survival for synchronous vs. metachronous detection at any of the defining time points (CRC diagnosis/surgery and 3, 6 and 12 months post-diagnosis/surgery) was demonstrated for operated or non-operated patients. In the literature search, 41 publications met the inclusion criteria. No clear pattern emerged regarding the prognostic significance of synchronous vs. metachronous detection.

Conclusion

Synchronous vs. metachronous detection of CRC liver metastases lacks prognostic value. Using primary tumour diagnosis/operation as standardized cut-off point to define synchronous/metachronous detection is semantically correct. In synchronous detection, it defines a clinically relevant group of patients where individualized multimodality treatment protocols will apply.

Prognostic significance of primary tumor sidedness in patients undergoing liver resection for metastatic colorectal cancer

BACKGROUND

Approximately 38% of patients with colorectal cancer will develop isolated liver metastases. Sidedness of colon tumor is identified in non-metastatic and unresected metastatic cancers as predictive of survival, yet its dedicated analysis in resected liver metastases is minimal. Our primary aim was to assess whether left-sided primary tumors improve prognosis in stage IV cancer patients undergoing curative-intent liver metastasectomy; it was hypothesized that it would.

METHODS

This is a retrospective, observational cohort study from 1996 to 2016 in a single tertiary-care facility. Survival from diagnosis was calculated via Kaplan-Meier method and compared between the right and left sides via log-rank analysis.

RESULTS

Median survival differs significantly between colorectal tumors of the right and left origins after hepatic metastasectomy in 612 patients. In patients with right-sided tumors, median survival from diagnosis was 4.5 years (IQR 4.1-5.3), and 6.3 years (IQR 5.6-6.9) in those with left tumors (HR 1.5, 95% CI 1.38-1.60, p < 0.001).

CONCLUSION

As in studies on earlier-stage or unresected metastatic disease, tumor sidedness is an important prognostic factor in patient survival with liver metastasectomy. Clinical risk scores should include side of primary tumor. Further work is needed to determine the molecular basis for this difference.

Meta-analysis of the association between primary tumour location and prognosis after surgical resection of colorectal liver metastases

BACKGROUND

Primary tumour location is emerging as an important prognostic factor in localized and metastatic colorectal cancers. However, its prognostic role in colorectal liver metastasis (CRLM) after hepatectomy remains controversial. A systematic review and meta-analysis was undertaken to evaluate its prognostic value.

METHODS

References were identified through searches of PubMed, Embase, Web of Science and the Cochrane Library comparing overall or disease-free survival after hepatic resection between patients with CRLM originating from right- or left-sided colorectal cancers. Data were pooled using hazard ratios (HRs) and 95 per cent confidence intervals according to a random-effects model. Meta-regression and subgroup analyses were conducted to assess the effect of underlying confounding factors on HR estimates and to adjust for this.

RESULTS

The final analysis included 21 953 patients from 45 study cohorts. Compared with left-sided primary tumour location, right-sided location was associated with worse overall survival (HR 1·39, 95 per cent c.i. 1·28 to 1·51; P < 0·001; prediction interval 1·00 to 1·93), and also tended to have a negative impact on disease-free survival (HR 1·18, 1·06 to 1·32; P = 0·004; prediction interval 0·79 to 1·75). Subgroup analysis showed that the negative effect of right-sided primary tumour location on overall survival was more prominent in the non-Asian population (HR 1·47, 1·33 to 1·62) than the Asian population (HR 1·18, 1·05 to 1·32) (P for interaction <0·01).

CONCLUSION

This study demonstrated a prognostic role for primary tumour location in patients with CRLM receiving hepatectomy, especially regarding overall survival. Adding primary tumour location may provide important optimization of prognosis prediction models for CRLM in current use.

Primary tumour location affects survival after resection of colorectal liver metastases: A two-institutional cohort study with international validation, systematic meta-analysis and a clinical risk score

BACKGROUND

Colorectal cancer (CRC) represents a major cause for cancer death and every third patient develops liver metastases (CRLM). Several factors including number and size of metastases and primary tumour lymph-node status have been linked to survival. The primary tumour location along the colo-rectum continuum (sidedness) was analysed in first-line chemotherapy trials, where right-sided CRCs showed decreased survival. This association has not yet been clearly established in patients undergoing resection for CRLM.

METHODS

Clinicopathological differences in CRLM resections according to sidedness in two Austrian centres (2003-2016) are described and survival is compared through Kaplan-Meier and multivariable analysis. A risk-score is presented with time-dependent receiver operating curve analysis and international validation in two major hepatobiliary centres. Furthermore, a systematic meta-analysis of studies on primary tumour location and survival after CRLM resection was performed.

RESULTS

259 patients underwent hepatectomy. Right-sided CRC patients (n = 59) more often had positive primary tumour lymph-nodes (76.3%/61.3%;p = 0.043) and RAS-mutations (60%/34.9%;p = 0.036). The median overall and disease-free survival was 33.5 and 9.1 months in right-sided versus 55.5 (p = 0.051) and 12.1 months (p = 0.078) in left-sided patients. In multivariable analysis nodal-status (HR 1.52), right-sidedness (HR 1.53), extrahepatic disease (HR 1.71) and bilobar hepatic involvement (HR 1.41) were significantly associated with overall survival. Sidedness was not independently associated with disease-free survival (HR 1.33; p = 0.099). A clinical risk score including right-sidedness, nodal-positivity and extrahepatic involvement significantly predicted overall (p = 0.005) and disease-free survival (p = 0.027), which was confirmed by international validation in 527 patients (p = 0.001 and p = 0.011). Meta-analysis including 10 studies (n = 4312) showed a significant association of right-sidedness with overall survival after resection (HR 1.55;p<0.001). There was no significant association with disease-free survival (HR 1.22;p = 0.077), except when rectal-cancers were excluded (HR 1.39;p = 0.006).

CONCLUSIONS

Patients with liver metastases from right-sided CRC experience worse survival after hepatic resection. Sidedness is a simple yet effective factor to predict outcome.

The primary tumor location impacts survival outcome of colorectal liver metastases after hepatic resection: A systematic review and meta-analysis

OBJECTIVE

Location of the primary tumor side has become an increasingly prognostic factor for colorectal liver metastasis. The present study was to perform a meta-analysis to investigate if primary right-sided tumor impacted on long-term survival outcome of colorectal liver metastases following local treatment.

METHOD

Eligible trials were identified from the Embase, PubMed, Web of Science and the Cochrane database that were published before October in 2018. English language trials that compared long-term survival outcome of primary left-sided tumor with right-sided tumor colorectal liver metastases following local treatment were included. Hepatic resection for colorectal liver metastases was investigated. The main study outcomes included overall survival and disease free survival of primary right-sided colorectal liver metastases following local treatment. The risk factors of largest tumor size, primary node metastases, multiple tumor and RAS mutation were also analyzed. A systematic review and meta-analysis was done using a fixed-effects model. Hazard ratio with a 95% confidence interval was used to measure the pooled effect.

RESULTS

A total of twelve studies with 6387 patients were included. For primary right-sided colorectal liver metastases patients following hepatic resection, the overall pooled HR for 5-year overall survival rate was 1.354 (95% CI: 1.238-1.482; p = 0.000; I² = 33.7%, p = 0.138). The pooled HR for 5-year disease free survival rate of primary right-sided CRLM in the included studies calculated using the fix-effects model was 1.104 (95% CI: 0.987-1.235; p = 0.084; I² = 0%, p = 0.477).

CONCLUSION

It demonstrated that primary right-sided for colorectal liver metastases location was a significantly worse prognostic factor in terms of overall survival.

Association between Primary Tumor Location and Prognostic Survival in Synchronous Colorectal Liver Metastases after Surgical Treatment: A Retrospective Analysis of SEER Data

The prognostic and predictive role of primary tumor location (PTL) in localized and metastatic colorectal cancer (CRC) is a hotspot issue in recent years. However, its prognostic role is still unclear in synchronous colorectal liver metastases (sCRLM), especially in those receiving surgical treatment of primary tumor and liver metastases. Here, a retrospective survival analysis was performed using the Surveillance, Epidemiology, and End Results Program (SEER) database between 2010 and 2014, on patients who were pathologically confirmed sCRLM, and received surgical treatment of both primary tumor and liver metastases. After stringent exclusive procedure, a total of 1508 patients with sCRLM (872 men [57.8%] and 636 women [42.2%]; mean age, 60.9 years) were eligible for the final study. Compared with sCRLM with left-sided PTL, cases with right-sided PTL were more likely to be T4 (31.3% vs. 20.1%, p<0.001), N2 (42.5% vs. 31.8%, p<0.001) and poorly differentiated (30.5% vs. 15.1%, p<0.001). Furthermore, right-sided sCRLM showed significantly shorter cancer specific survival (CSS) than those from left-side (p<0.001). After Cox hazard regression analysis, right-sided PTL still remained to be a strong independent predictor for poor prognosis in this cohort of sCRLM patients (OS, HR=1.75, 95% CI 1.34-2.29; CSS, HR=1.76, 95% CI 1.33-2.35). In conclusion, according to this population-based cohort from the SEER database, PTL was a critical prognostic factor that affect long-term OS and CSS in patients with sCRLM after surgical treatment of primary tumor and liver metastases.

Metastatic Profile of Colorectal Cancer: Interplay Between Primary Tumor Location and KRAS Status

BACKGROUND

Mutant KRAS tumors are purported to metastasize differently than wild-type KRAS tumors. The biological heterogeneity of tumors from different parts of the colon are also reported to affect metastasis. This study aims to characterize the metastatic profile by evaluating these factors in unison.

METHODS

Retrospective analysis of 899 patients with metastatic colorectal cancers treated from January 2010 to December 2014 was conducted. KRAS mutation status and primary tumors location were correlated with single-site metastasis (liver, lung, and peritoneum) and dual-site metastases (liver-peritoneum, liver-lung, and lung-peritoneum). Patients without KRAS analyses were excluded.

RESULTS

Right-sided tumors had highest frequency of peritoneal metastasis as compared to left-sided or rectal tumors (34.7% versus 15.8% versus 8.8%, P = 0.00) regardless of KRAS status (32.6% versus 38.5%, P = 0.62). Left-sided tumors with wild-type KRAS had greater proportion of liver metastasis (78.6% versus 53.5%, P = 0.00), whereas those with mutant KRAS had greater proportion of lung metastasis (23.3% versus 8.7%, P = 0.02). Rectal tumors with wild-type KRAS tend to spread to the liver (81.4% versus 48.0%, P = 0.00) and not to the peritoneum (2.3% versus 20.0%, P = 0.01). In dual-site metastases, left-sided tumors with wild-type KRAS had more liver-peritoneal metastases (75.0% versus 29.4%, P = 0.00), whereas mutant KRAS had greater lung-liver metastases (64.7% versus 20.8%, P = 0.01). Rectal tumors had the predilection for lung-liver metastases as compared to right-sided and left-sided tumors (92.3% versus 40.0% versus 39.0%, P = 0.00) regardless of KRAS status (100% versus 75%, P = 0.12).

CONCLUSIONS

Our results may streamline surveillance programs based on primary tumor location and KRAS mutational status.