Large variation in the utilization of liver resections in stage IV colorectal cancer patients with metastases confined to the liver

Colorectal Pulmonary Metastases: Pulmonary Metastasectomy or Stereotactic Radiotherapy?

BACKGROUND

Pulmonary metastasectomy and stereotactic ablative radiotherapy (SABR) are both guideline-recommended treatments for selected patients with oligometastatic colorectal pulmonary metastases. However, there is limited evidence comparing these local treatment modalities in similar patient groups.

METHODS

We retrospectively reviewed records of consecutive patients treated for colorectal pulmonary metastases with surgical metastasectomy or SABR from 2012 to 2019 at two Dutch referral hospitals that had different approaches toward the local treatment of colorectal pulmonary metastases, one preferring surgery, the other preferring SABR. Two comparable patient groups were identified based on tumor and treatment characteristics.

RESULTS

The metastasectomy group comprised 40 patients treated for 69 metastases, and the SABR group had 60 patients who were treated for 90 metastases. Median follow-up was 38 months (IQR: 26-67) in the surgery group and 46 months (IQR: 30-79) in the SABR group. Median OS was 58 months (CI: 20-94) in the metastasectomy group and 70 months (CI: 29-111) in the SABR group (p = 0.23). Five-year local recurrence-free survival (LRFS) was 44% after metastasectomy and 30% after SABR (p = 0.16). Median progression-free survival (PFS) was 15 months (CI: 3-26) in the metastasectomy group and 10 months (CI: 6-13) in the SABR group (p = 0.049). Local recurrence rate was 12.5/7.2% of patients/metastases respectively after metastasectomy and 38.3/31.1% after SABR (p < 0.001). Lower BED Gy10 was correlated with an increased likelihood of recurrence (p = 0.025). Clavien Dindo grade III-V complication rates were 2.5% after metastasectomy and 0% after SABR (p = 0.22).

CONCLUSION

In this retrospective cohort study, pulmonary metastasectomy and SABR had comparable overall survival, local recurrence-free survival, and complication rates, despite patients in the SABR group having a significantly lower progression-free survival and local control rate. These data would support a randomized controlled trial comparing surgery and SABR in operable patients with radically resectable colorectal pulmonary metastases.

The impact of a multi-hospital network on the inequality in odds of receiving resection or ablation for synchronous colorectal liver metastases

BACKGROUND

This study investigates whether inequalities in the utilization of resection and/or ablation for synchronous colorectal liver metastases (SCLM) between patients diagnosed in expert and non-expert hospitals changed since a multi-hospital network started.

MATERIALS AND METHODS

Patients diagnosed with SCLM between 2009 and 2020 were included. The likelihood of receiving ablation and/or resection was analyzed in the prenetwork (2009-2012), startup (2013-2016), and matured-network (2017-2020) periods.

RESULTS

Nationwide, 13.981patients were diagnosed between 2009 and 2020, of whom 1.624 were diagnosed in the network. Of patients diagnosed in the network's expert hospitals, 36.7% received ablation and/or resection versus 28.3% in nonexpert hospitals (p < 0.01). The odds ratio (OR) of receiving ablation and/or resection for patients diagnosed in expert versus nonexpert hospitals increased from 1.38 (p = 0.581, pre-network), to 1.66 (p = 0.108, startup), to 2.48 (p = 0.090, matured-network). Nationwide, the same trend occurred (respectively OR 1.41, p = 0.011; OR 2.23, p < 0.001; OR 3.20, p < 0.001).

CONCLUSIONS

Patients diagnosed in expert hospitals were more likely to receive ablation and/or resection for SCLM than patients diagnosed in non-expert hospitals. This difference increased over time despite the startup of a multi-hospital network. Establishing a multi-hospital network did not have an effect on reducing the existing unequal odds of receiving specialized treatment.

SYNOPSIS

Specialized oncology treatments are increasingly provided through multi-hospital networks. However, scant empirical evidence on the effectiveness of these networks exists. This study analyzes whether a regional multi-hospital network was able to improve equal access to specialized oncology treatments.

Hospital factors and metastatic surgery in colorectal cancer patients, a population-based cohort study

Background

Only a limited proportion of patients with metastatic colorectal cancer (mCRC) receives metastatic surgery (including local ablative therapy). The aim was to investigate whether hospital volume and hospital level were associated with the chance of metastatic surgery.

Methods

This national cohort retrieved from the CRCBaSe linkage included all Swedish adult patients diagnosed with synchronous mCRC in 2009–2016. The association between annual hospital volume of incident mCRC patients and the chance of metastatic surgery, and survival, were assessed using logistic regression and Cox regression models, respectively. Hospital level (university/non-university) was evaluated as a secondary exposure in a similar manner. Both uni- and multivariable (adjusted for sex, age, Charlson comorbidity index, year of diagnosis, cancer characteristics and socioeconomic factors) models were fitted.

Results

A total of 1,674 (17%) out of 9,968 mCRC patients had metastatic surgery. High hospital volume was not associated with increased odds of metastatic surgery after including hospital level in the model, whereas hospital level was (odds ratio (OR) (95% confidence interval (CI)): 1.94 (1.68–2.24)). All-cause mortality was lower in university versus non-university hospitals (hazard ratio (95% CI): 0.83 (0.78–0.88)).

Conclusions

Patients with mCRC initially cared for by a university hospital experienced a greater chance to receive metastatic surgery and had superior overall survival. High hospital volume in itself was not associated with a greater chance to receive metastatic surgery nor a greater survival probability. Additional efforts should be imposed to provide more equal care for mCRC patients across Swedish hospitals.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-10005-8.

Surgical Resection of Colorectal Liver Metastases: Attitudes and Practice Patterns in the Deep South

BACKGROUND

Metastatic disease is the leading cause of mortality in colorectal cancer. Resection of colorectal liver metastases, when possible, is associated with improved long-term survival and the possibility of cure. However, nationwide studies suggest that liver resection is under-utilized in the treatment of colorectal liver metastases. This study was undertaken to understand attitudes and practice patterns among medical oncologists in the Deep South.

METHODS

A survey of medical oncologists in the states of Alabama, Mississippi, and the Florida panhandle was performed. Respondents were queried regarding perceptions of resectability and attitudes towards surgical referral.

RESULTS

We received 63 responses (32% response rate). Fifty percent of respondents reported no liver surgeons in their practice area. Commonly perceived contraindications to liver resection included extrahepatic metastatic disease (72%), presence of > 4 metastases (72%), bilobar metastases (61%), and metastases > 5 cm (46%). Bilobar metastatic disease was perceived as a contraindication more frequently by non-academic medical oncologists (70% vs. 33%, p = 0.03).

CONCLUSIONS

Wide variations exist in perceptions of resectability and referral patterns for colorectal liver metastases among surveyed medical oncologists. There is a need for wider dissemination of resectability criteria and more liver surgeon involvement in the management of patients with colorectal liver metastases.

Nationwide oncological networks for resection of colorectal liver metastases in the Netherlands: Differences and postoperative outcomes

INTRODUCTION

Widespread differences in patient demographics and disease burden between hospitals for resection of colorectal liver metastases (CRLM) have been described. In the Netherlands, networks consisting of at least one tertiary referral centre and several regional hospitals have been established to optimize treatment and outcomes. The aim of this study was to assess variation in case-mix, and outcomes between these networks.

METHODS

This was a population-based study including all patients who underwent CRLM resection in the Netherlands between 2014 and 2019. Variation in case-mix and outcomes between seven networks covering the whole country was evaluated. Differences in case-mix, expected 30-day major morbidity (Clavien-Dindo ≥3a) and 30-day mortality between networks were assessed.

RESULTS

In total 5383 patients were included. Thirty-day major morbidity was 5.7% and 30-day mortality was 1.5%. Significant differences between networks were observed for Charlson Comorbidity Index, ASA 3+, previous liver resection, liver disease, preoperative MRI, preoperative chemotherapy, ≥3 CRLM, diameter of largest CRLM ≥55 mm, major resection, combined resection and ablation, rectal primary tumour, bilobar and extrahepatic disease. Uncorrected 30-day major morbidity ranged between 3.3% and 13.1% for hospitals, 30-day mortality ranged between 0.0% and 4.5%. Uncorrected 30-day major morbidity ranged between 4.4% and 6.0% for networks, 30-day mortality ranged between 0.0% and 2.5%. No negative outliers were observed after case-mix correction.

CONCLUSION

Variation in case-mix and outcomes are considerably smaller on a network level as compared to a hospital level. Therefore, auditing is more meaningful at a network level and collaboration of hospitals within networks should be pursued.

Systematic failure to operate on colorectal cancer liver metastases in California

Background

Despite evidence that liver resection improves survival in patients with colorectal cancer liver metastases (CRCLM) and may be potentially curative, there are no population‐level data examining utilization and predictors of liver resection in the United States.

Methods

This is a population‐based cross‐sectional study. We abstracted data on patients with synchronous CRCLM using California Cancer Registry from 2000 to 2012 and linked the records to the Office of Statewide Health Planning Inpatient Database. Quantum Geographic Information System (QGIS) was used to map liver resection rates to California counties. Patient‐ and hospital‐level predictors were determined using mixed‐effects logistic regression.

Results

Of the 24 828 patients diagnosed with stage‐IV colorectal cancer, 16 382 (70%) had synchronous CRCLM. Overall liver resection rate for synchronous CRCLM was 10% (county resection rates ranging from 0% to 33%) with no improvement over time. There was no correlation between county incidence of synchronous CRCLM and rate of resection (R² = .0005). On multivariable analysis, sociodemographic and treatment‐initiating‐facility characteristics were independently associated with receipt of liver resection after controlling for patient disease‐ and comorbidity‐related factors. For instance, odds of liver resection decreased in patients with black race (OR 0.75 vs white) and Medicaid insurance (OR 0.62 vs private/PPO); but increased with initial treatment at NCI hospital (OR 1.69 vs Non‐NCI hospital), or a high volume (10 + cases/year) (OR 1.40 vs low volume) liver surgery hospital.

Conclusion

In this population‐based study, only 10% of patients with liver metastases underwent liver resection. Furthermore, the study identifies wide variations and significant population‐level disparities in the utilization of liver resection for CRCLM in California.

Variation in the Use of Resection for Colorectal Cancer Liver Metastases

The aim of this study was to investigate variation in the frequency of resections for colorectal cancer liver metastases across the English NHS.

Liver Resection Improves Survival in Colorectal Cancer Patients: Causal-effects From Population-level Instrumental Variable Analysis

OBJECTIVE

The aim of this study was to estimate population-level causal effects of liver resection on survival of patients with colorectal cancer liver metastases (CRC-LM).

BACKGROUND

A randomized trial to prove that liver resection improves survival in patients with CRC-LM is neither feasible nor ethical. Here, we test this assertion using instrumental variable (IV) analysis that allows for causal-inference by controlling for observed and unobserved confounding effects.

METHODS

We abstracted data on patients with synchronous CRC-LM using the California Cancer Registry from 2000 to 2012 and linked the records to the Office of Statewide Health Planning and Development Inpatient Database. We used 2 instruments: resection rates in a patient's neighborhood (within 50-mile radius)-NALR rate; and Medical Service Study Area resection rates-MALR rate. IV analysis was performed using the 2SLS method.

RESULTS

A total of 24,828 patients were diagnosed with stage-IV colorectal cancer of which 16,382 (70%) had synchronous CRC-LM. Liver resection was performed in 1635 (9.8%) patients. NALR rates ranged from 8% (lowest-quintile) to 11% (highest-quintile), whereas MALR rates ranged from 3% (lowest quintile) to 19% (highest quintile). There was a strong association between instruments and probability of liver resection (F-statistic at median cut-off: NALR 24.8; MALR 266.8; P < 0.001). IV analysis using both instruments revealed a 23.6 month gain in survival (robust SE 4.4, P < 0.001) with liver resection for patients whose treatment choices were influenced by the rates of resection in their geographic area (marginal patients), after accounting for measured and unmeasured confounders.

CONCLUSION

Less than 10% of patients with CRC-LM had liver resection. Significant geographic variation in resection rates is attributable to community biases. Liver resection leads to extensive survival benefit, accounting for measured and unmeasured confounders.

Whole-Exome Sequencing Characterized the Landscape of Somatic Mutations and Pathways in Colorectal Cancer Liver Metastasis

Purpose

Liver metastasis remains the leading cause of cancer-related mortality in colorectal cancer. The mechanism of occurrence and development of liver metastasis from colorectal cancer is unclear.

Methods

The primary tumor tissues and blood samples of 8 patients with liver metastasis of colorectal cancer were collected, followed by nucleic acid extraction and library construction. Whole-exome sequencing was performed to detect the genomic variations. Bioinformatics was used to comprehensively analyze the sequencing data of these samples, including the differences of tumor mutation burden, the characteristics of gene mutations, and signaling pathways.

Results

The results showed that the top three genes with the highest mutation frequency were TP53, APC, and KRAS. Tumor mutation burden of this study, with a median of 8.34 mutations per MB, was significantly different with The Cancer Genome Atlas databases. Analysis of molecular function and signaling pathways showed that the mutated genes could be classified into five major categories and 39 signaling pathways, involving in Wnt, angiogenesis, P53, Alzheimer disease-presenilin pathway, notch, and cadherin signaling pathway.

Conclusions

In conclusion, we identified the extensive landscape of altered genes and pathways in colorectal cancer liver metastasis, which will be useful to design clinical therapy for personalized medicine.

Cancer Survival Data Representation for Improved Parametric and Dynamic Lifetime Analysis

Survival functions are often characterized by a median survival time or a 5-year survival. Whether or not such representation is sufficient depends on tumour development. Different tumour stages have different mean survival times after therapy. The validity of an exponential decay and the origins of deviations are substantiated. The paper shows, that representation of survival data as logarithmic functions visualizes differences better, which allows for differentiating short- and long-term dynamic lifetime. It is more instructive to represent the changing lifetime expectancy for an individual who has survived a certain time, which can be significantly different from the initial expectation just after treatment. Survival data from 15 publications on cancer are compared and re-analysed based on the well-established: (i) exponential decay (ii) piecewise constant hazard (iii) Weibull model and our proposed parametric survival models, (iv) the two-τ and (v) the sliding-τ model. The new models describe either accelerated aging or filtering out of defects with numerical parameters with a physical meaning and add information to the usually provided log-rank P-value or median survival. The statistical inhomogeneity in a group by mixing up different tumour stages, metastases and treatments is the main origin for deviations from the exponential decay.

A systematic review and meta-analysis comparing the short- and long-term outcomes for laparoscopic and open liver resections for liver metastases from colorectal cancer

BACKGROUND

The laparoscopic approach to liver resection has experienced exponential growth in recent years. However, evidence-based guidelines are needed for its safe future progression. The main aim of our study was to perform a systematic review and meta-analysis comparing the short- and long-term outcomes of laparoscopic and open liver resections for colorectal liver metastases (CRLM).

METHODS

To identify all the comparative manuscripts between laparoscopic and open liver resections for CRLM, all published English language studies with more than ten cases were screened. In addition to the primary meta-analysis, 3 specific subgroup analyses were performed on patients undergoing minor-only, major-only and synchronous resections. The quality of the studies was assessed using the Scottish Intercollegiate Guidelines Network (SIGN) methodology and Newcastle-Ottawa Score.

RESULTS

From the initial 194 manuscripts identified, 21 were meta-analysed, including results from the first randomized trial comparing open and laparoscopic resections of CRLM. Five of these were specific to patients undergoing a synchronous resection (399 cases), while six focused on minor (3 series including 226 cases) and major (3 series including 135 cases) resections, respectively. Thirteen manuscripts compared 2543 cases but could not be assigned to any of the above sub-analyses, so were analysed independently. The majority of short-term outcomes were favourable to the laparoscopic approach with equivalent rates of negative resection margins. No differences were observed between the approaches in overall or disease-free survival at 1, 3 or 5 years.

CONCLUSION

Laparoscopic liver resection for CRLM offers improved short-term outcomes with comparable long-term outcomes when compared to open approach.

Liver Resection for Metastatic Disease; A Population-Based Analysis of Trends

OBJECTIVE

The study aims to evaluate all patients who underwent liver resection for metastatic disease for demographics, characteristics of the primary tumor and metastasis, volume of liver resection specimens per pathology laboratory and to describe trends in surgical treatment.

METHODS

Data were prospectively collected using the Dutch nationwide pathology network. All pathology reports containing details on liver resections for metastatic disease between January 2001 and December 2010 were evaluated.

RESULTS

A total of 3,916 liver resections were performed in 3,699 patients with a median age of 63 years (range 1-91). The primary tumor was mainly colorectal (n = 3,256; 88.0%). The number of 'high volume liver centers' increased from 2 to 12 in the study period, whereas the number of 'low volume centers' decreased. The number of liver resections increased from 224 to 596 per year (p ≤ 0.0001). A significant increase was demonstrated in elderly patients, patients with multiple metastases, liver resections for smaller metastases and minor liver resections.

CONCLUSION

Although the majority of patients were young and had solitary metastasis, indications for liver resection are expanding as indicated by increasing numbers of elderly and patients with multiple liver metastases. Patients with non-colorectal liver metastases were seldom candidates for resection.