Synchronous metastatic colon cancer and the importance of primary tumor laterality - A National Cancer Database analysis of right- versus left-sided colon cancer

Prognostic value of primary tumor location in colorectal cancer: an updated meta-analysis

The clinical, histological, and molecular differences between right-sided colon cancer (RCC) and left-sided colon cancer (RCC) have received considerable attention. Over the past decade, many articles have been published concerning the association between primary tumor location (PTL) of colorectal cancer and survival outcomes. Therefore, there is a growing need for an updated meta-analysis integrating the outcomes of recent studies to determine the prognostic role of right vs left-sidedness of PTL in patients with colorectal cancer. We conducted a comprehensive database review using PubMed, SCOPUS, and Cochrane library databases from February 2016 to March 2023 for prospective or retrospective studies reporting data on overall survival (OS) and cancer-specific survival (CSS) of RCC compared with LCC. A total of 60 cohort studies comprising 1,494,445 patients were included in the meta-analysis. We demonstrated that RCC is associated with a significantly increased risk of death compared with LCC by 25% (hazard ratio (HR), 1.25; 95% confidence interval (CI), 1.19-1.31; I2 = 78.4%; Z = 43.68). Results showed that patients with RCC have a worse OS compared with LCC only in advanced stages (Stage III: HR, 1.275; 95% CI 1.16-1.4; P = 0.0002; I2 = 85.8%; Stage IV: HR, 1.34; 95% CI 1.25-1.44; P < 0.0001; I2 = 69.2%) but not in primary stages (Stage I/II: HR, 1.275; 95% CI 1.16-1.4; P = 0.0002; I2 = 85.8%). Moreover, a meta-analysis of 13 studies including 812,644 patients revealed that there is no significant difference in CSS between RCC and LCC (HR, 1.121; 95% CI 0.97-1.3; P = 0.112). Findings from the present meta-analysis highlight the importance of PTL in clinical decision-making for patients with CRC, especially in advanced stages. We provide further evidence supporting the hypothesis that RCC and LCC are distinct disease entities that should be managed differently.

Influence of Sex and Age on Site of Onset, Morphology, and Site of Metastasis in Colorectal Cancer: A Population-Based Study on Data from Four Italian Cancer Registries

The prognosis of colorectal cancer is affected by factors such as site of origin, tumor morphology, and metastasis at diagnosis, but also age and sex seem to play a role. This study aimed to investigate within the Italian population how sex and age interact in influencing certain aspects of the disease and how they affect patient survival, particularly in the metastatic cohort. Data from four cancer registries were collected, and patients were classified by sex and age (<50, 50-69, and >69 years). Two separate analyses were conducted: one for patients having right or left colon cancer with adenocarcinoma or mucinous morphology, and one for patients having metastases at diagnosis. Women showed significant differences in right colon cases from the youngest to oldest age group (36% vs. 45% vs. 60%). Men <50 years had a significantly higher mucinous carcinoma percentage than their female counterparts (22% vs. 11%), while in the oldest age group women had the highest percentage (15% vs. 11%). The metastatic pattern differed between men and women and by age. The three-year relative survival in the <50 age group was better for women than men, but this survival advantage was reversed in the oldest group. In conclusion, sex and age are factors that influence the biological and clinical characteristics of colorectal cancer, affecting the metastatic pattern as well as patient survival.

Comparison of Resected Malignant Tumors of the Right- and Left-Sided Colon—Is There a Difference?

Embryological, anatomical, and immunological differences between the right-sided and left-sided colons are well known, but the difference in oncological behavior of colon tumors has only recently become the main subject of studies. Published articles propose that there is a difference not only in symptoms, but also in survival. Our aim was to analyze the clinicopathological and oncological differences among our patients who had been operated for colon cancer in our department. We examined the historical data of our patients who underwent colon resection for malignancy between 1st of January 2016 and 31st of December 2018. Tumor markers, histological results, postoperative complications, and oncological therapies were investigated. The primary outcome was overall survival. We analyzed our patients’ survival data with Kaplan–Meier log-rank test and Cox regression analysis. In our study, 267 patients were enrolled. One hundred thirty-three (49.8%) patients had right-sided colon cancer; 134 (50.2%) patients had left-sided colon cancer. Patients with right-sided colon cancer were significantly more likely to have mucinous adenocarcinoma (p = 0.037). No significant differences were revealed in overall survival between right-sided colon cancer and left-sided colon cancer patients (p = 0.381). Additional subgroup analysis showed that there were no significant differences in overall survival for laterality neither in the metastatic group (p = 0.824) nor in the non-metastatic group (p = 0.345). Based on the conflicting previous study results, our findings repeatedly highlight that the relationship between tumor location in the colon and overall survival is not straightforward.

Prognostic Factors in Stage IV Colorectal Cancer Patients With Resection of Liver and/or Pulmonary Metastases: A Population-Based Cohort Study

Importance

Currently, surgical resection of distant metastatic lesions has become the preferred treatment for select colorectal cancer (CRC) patients with liver metastasis (LM) and/or pulmonary metastasis (PM). Metastasectomy is the most common curative method. However, evidence of the factors affecting the prognosis of CRC patients after resection of LM and/or PM is still insufficient.

Objective

To explore the prognostic factors of CRC patients with LM and/or PM who have undergone resection of metastatic tumors and to provide reliable selection factors for surgical treatment in patients affected by LM and/or PM from CRC.

Methods

The SEER database was used to identify eligible CRC LM and/or PM patients who underwent resection of the primary tumor and distant metastases from January 1, 2010, to December 31, 2018. The Kaplan-Meier method was used to calculate survival, and comparisons were performed using the log-rank test for univariate analysis. A Cox proportional hazards regression model was used to identify prognostic factors for the multivariate analysis. The outcomes included overall survival (OS) and cancer-specific survival (CSS).

Results

A total of 3,003 eligible colorectal cancer patients with LM and/or PM were included in this study. The 3-year and 5-year OS rates were 53% and 33.6%, respectively, and the 3-year and 5-year CSS rates were 54.2% and 35.3%, respectively. In the adjusted multivariate analysis, age < 65 years (OS: p=0.002, CSS: p=0.002) was associated with better long-term outcomes, and primary tumors located on the left side of the colon (OS: p=0.004, CSS: p=0.006) or rectum (OS: p=0.004, CSS: p=0.006), T3 stage (OS: p<0.001, CSS: p<0.001), number of regional lymph nodes examined ≥ 12 (OS: p<0.001, CSS: p=0.001), and CRC LM (OS: p<0.001, CSS: p<0.001) were positive prognostic factors for survival after resection of metastatic tumors.

Conclusion

Age < 65 years is associated with better long-term outcomes in colorectal cancer patients with LM and/or PM, analogously to the left sided primary tumor, T3 stage, number of regional lymph nodes examined ≥ 12 and liver metastases.

Genomic and Metabolomic Landscape of Right-Sided and Left-Sided Colorectal Cancer: Potential Preventive Biomarkers

Colorectal cancer (CRC) is the third most common cancer worldwide. The incidence and mortality rates of CRC are significantly higher in Taiwan than in other developed countries. Genes involved in CRC tumorigenesis differ depending on whether the tumor occurs on the left or right side of the colon, and genomic analysis is a keystone in the study and treatment of CRC subtypes. However, few studies have focused on the genetic landscape of Taiwanese patients with CRC. This study comprehensively analyzed the genomes of 141 Taiwanese patients with CRC through whole-exome sequencing. Significant genomic differences related to the site of CRC development were observed. Blood metabolomic profiling and polygenic risk score analysis were performed to identify potential biomarkers for the early identification and prevention of CRC in the Taiwanese population. Our findings provide vital clues for establishing population-specific treatments and health policies for CRC prevention in Taiwan.

Interaction Between Primary Tumor Resection, Primary Tumor Location, and Survival in Synchronous Metastatic Colorectal Cancer: A Population-Based Study

OBJECTIVES

Location of the primary tumor has prognostic value and predicts the effect of certain therapeutics in synchronous metastatic colorectal cancer. We investigated whether the association between primary tumor resection (PTR) and overall survival (OS) also depends on tumor location.

METHODS

Data on synchronous metastatic colorectal cancer patients from the Netherlands Cancer Registry (n=16,106) and Surveillance, Epidemiology, and End Results (SEER) registry (n=19,584) were extracted. Cox models using time-varying covariates were implemented. Median OS for right-sided colon cancer (RCC), left-sided colon cancer, and rectal cancer was calculated using inverse probability weighting and a landmark point of 6 months after diagnosis as reference.

RESULTS

The association between PTR and OS was dependent on tumor location (P<0.05), with a higher median OS of upfront PTR versus upfront systemic therapy in Netherlands Cancer Registry (NCR) of 1.9 (95% confidence interval: 0.9-2.8), 4.3 (3.3-5.6), and 3.4 (0.6-7.6) months in RCC, left-sided colon cancer and rectal cancer, respectively. In SEER data, the difference was 6.0 (4.0-8.0), 8.0 (5.0-10.0), and 10.0 (7.0-13.0) months, respectively. Hazard plots indicate a higher hazard of death 2 to 3 months after PTR in RCC.

CONCLUSION

Upfront PTR is associated with improved survival regardless of primary tumor location. Patients with RCC appear to have less benefit because of higher mortality during 2 to 3 months after PTR.

Primary tumor location impacts survival in colorectal cancer patients after resection of liver metastases

BACKGROUND AND OBJECTIVES

Right-sided colon cancers (R-CC) are associated with worse outcomes compared to left-sided colon cancers (L-CC). We hypothesize that R-CC with synchronous liver metastases who undergo resection of primary and metastatic sites have worse survival and that survival will vary significantly among R-CC, L-CC, and rectal cancer (ReC).

METHODS

The Surveillance, Epidemiology, and End Results (SEER) database from 2010 to 2016 was used to identify colorectal cancer patients with liver metastases who underwent surgical resection of both primary and metastatic disease. Survival was analyzed by multivariate Cox regression.

RESULTS

A total of 2275 patients were included; 38% R-CC, 46% L-CC, and 16% ReC. R-CC primary tumors tended to be larger than 5 cm, higher grade, and mucinous (all P < .001). Compared to patients with R-CC, both L-CC and ReC had improved overall (HR 0.72; P < .001; HR 0.75, P = .006) and disease-specific (HR 0.71, P < .001; HR 0.73, P = .008) survival. There was no difference in survival between L-CC and ReC.

CONCLUSIONS

Patients with R-CC have significantly worse survival than L-CC or ReC. This provides additional evidence that R-CC tumors are fundamentally different from L-CC and ReC tumors. Future studies should determine factors responsible for this disparity, and identify targeted treatment based on primary tumor location.

Effect of primary colorectal cancer tumor location on survival after pulmonary metastasectomy

OBJECTIVES

Although colorectal cancer bowel segment location has been shown to independently predict the outcomes in early stage disease, it has not been previously studied in the setting of pulmonary metastases. We sought to determine whether colorectal cancer location affects survival after pulmonary metastasectomy.

METHODS

Patients who had undergone pulmonary metastasectomy for colorectal cancer at a single institution from 2011 to 2018 were reviewed. Univariable and multivariable Cox regression analyses were performed to identify predictors of overall survival and disease-free survival. The Kaplan-Meier survival method was used to determine differences between groups.

RESULTS

A total of 194 patients were evaluated. The median follow-up, survival time, and 5-year survival rate were 36.8 months, 75.8 months, and 57%, respectively, and 122 patients (63%) had experienced disease recurrence at any location. On univariable analysis, age, primary tumor location, pulmonary nodule size, ≥3 pulmonary nodules, and intrathoracic nodal disease were associated with overall survival. On multivariable analysis, patients with left-sided tumors experienced a survival benefit (hazard ratio, 0.31; P = .036). Kaplan-Meier analysis revealed a median survival time of 90 months (95% confidence interval, 82 months to not reached) compared with 55 months (95% confidence interval, 49 months to not reached) for patients with left-sided and rectal tumors, respectively, after metastasectomy (P = .078). Location was not associated with disease-free survival on Cox multivariable regression.

CONCLUSIONS

We found that left-sided colorectal cancer is associated with prolonged survival after pulmonary metastasectomy. Future investigations are required to determine the validity of such findings, including the effect of location in the prognostication for patients who are candidates for pulmonary metastasectomy.