Identification of Inequalities in the Selection of Liver Surgery for Colorectal Liver Metastases in Sweden

Assessment by a multidisciplinary team conference affects treatment strategy and overall survival in patients with synchronous colorectal liver metastases

BACKGROUND

The aim of this retrospective observational study was to investigate the geographical or sex differences in patients with synchronous colorectal liver metastases (sCRLM) in terms of assessment by a multidisciplinary team conference (MDT), curative treatment, and overall survival.

METHOD

All sCRLM patients in the South-East Health Care Region of Sweden from 2009 to 2015 were included (n = 615). Data were derived from the Swedish Colorectal Cancer Registry, Swedish Registry of Liver and Bile Surgery and medical records.

RESULTS

Patients who had a hepatobiliary unit (HBU) at the nearest hospital were more likely to undergo liver surgery (HBU+, 37% (n = 106), compared to HBU-, 22% (n = 60); p = 0.001) and had a better median survival (p < 0.001). No sex differences were observed. In multivariate Cox regression analyses of overall survival, assessment by an MDT that included a liver surgeon was independently linked to better survival (HR 0.574, 0.433-0.760).

CONCLUSION

There were no sex differences in access to liver surgery or overall survival, however, there were geographical inequalities, where residency near a hospital with HBU was associated with increased overall survival and the possibility to receive liver surgery. Assessment at MDT with liver surgeon present was associated with greater survival, indicating its important role for treatment.

Importance of resection margin after resection of colorectal liver metastases in the era of modern chemotherapy: population-based cohort study

BACKGROUND

Resection margin has been associated with overall survival following liver resection for colorectal liver metastasis. The aim of this study was to examine how resection margins of 0.0 mm, 0.1-0.9 mm and ≥1 mm influence overall survival in patients resected for colorectal liver metastasis in a time of modern perioperative chemotherapy and surgery.

METHODS

Using data from the national registries Swedish Colorectal Cancer Registry and Swedish National Quality Registry for Liver, Bile Duct and Gallbladder Cancer, patients that had liver resections for colorectal liver metastasis between 2009 and 2013 were included. In patients with a narrow or unknown surgical margin the original pathological reports were re-reviewed. Factors influencing overall survival were analysed using a Cox proportional hazard model.

RESULTS

A total of 754 patients had a known margin status, of which 133 (17.6%) patients had a resection margin <1 mm. The overall survival in patients with a margin of 0 mm or 0.1-0.9 mm was 42 (95% c.i. 31 to 53) and 48 (95% c.i. 35 to 62) months respectively, compared with 75 (95% c.i. 65 to 85) for patients with ≥1 mm margin, P < 0.001. Margins of 0 mm or 0.1-0.9 mm were associated with poor overall survival in the multivariable analysis, HR 1.413 (95% c.i. 1.030 to 1.939), P = 0.032, and 1.399 (95% c.i. 1.025 to 1.910), P = 0.034, respectively.

CONCLUSIONS

Despite modern chemotherapy the resection margin is still an important factor for the survival of patients resected for colorectal liver metastasis, and a margin of ≥1 mm is needed to achieve the best possible outcome.

Risk Factors for Postoperative Complications Following Resection of Colorectal Liver Metastases and the Impact on Long-Term Survival: A Population-Based National Cohort Study

BACKGROUND

Postoperative complications (POCs) following resection of colorectal liver metastases (CRLM) are common. The objective of this study was to evaluate risk factors for developing complications and their impact on survival considering prognostic factors of the primary tumor, metastatic pattern and treatment in a well-defined national cohort.

METHODS

Patients treated with resection for CRLM that was also radically resected for their primary colorectal cancer (diagnosed in 2009-2013) were identified in Swedish national registers. Liver resections were categorized according to extent of surgery (Category I-IV). Risk factors for developing POCs as well as prognostic impact of POCs were evaluated in multivariable analyses. A subgroup analysis of minor resections was performed to evaluate POCs after laparoscopic surgery.

RESULTS

POCs were registered for 24% (276/1144) of all patients after CRLM resection. Major resection was a risk factor for POCs in multivariable analysis (IRR 1.76; P = 0.001). Comparing laparoscopic and open resections in the subgroup analysis of small resections, 6% (4/68) in the laparoscopic group developed POCs compared to 18% (51/289) after open resection (IRR 0.32; P = 0.024). POCs were associated with a 27% increased excess mortality rate (EMRR 1.27; P = 0.044). However, primary tumor characteristics, tumor burden in the liver, extrahepatic spread, extent of liver resection and radicality had higher impact on survival.

CONCLUSION

Minimal invasive resections were associated with a decreased risk of POCs following resection of CRLM which should be considered in surgical strategy. Postoperative complications were associated with a moderate risk for inferior survival.

Prognostic value of extrahepatic metastasis on colon cancer with liver metastasis: a retrospective cohort study

Introduction

The occurrence of metastasis is a threat to patients with colon cancer (CC), and the liver is the most common metastasis organ. However, the role of the extrahepatic organs in patients with liver metastasis (LM) has not been distinctly demonstrated. Therefore, this research aimed to explore the prognostic value of extrahepatic metastases (EHMs).

Methods

In this retrospective study, a total of 13,662 colon patients with LM between 2010 and 2015 were selected from the Surveillance, Epidemiology, and End Results database (SEER). Fine and Gray's analysis and K-M survival analysis were utilized to explore the impacts of the number of sites of EHMs and different sites of EHMs on prognosis. Finally, a prognostic nomogram model based on the number of sites of EHMs was constructed, and a string of validation methods was conducted, including concordance index (C-index), receiver operating characteristic curves (ROC), and decision curve analysis (DCA).

Results

Patients without EHMs had better prognoses in cancer-specific survival (CSS) and overall survival (OS) than patients with EHMs (p < 0.001). Varied EHM sites of patients had different characteristics of primary location site, grade, and histology. Cumulative incidence rates for CSS surpassed that for other causes in patients with 0, 1, 2, ≥ 3 EHMs, and the patients with more numbers of sites of EHMs revealed worse prognosis in CSS (p < 0.001). However, patients with different EHM sites had a minor difference in cumulative incidence rates for CSS (p = 0.106). Finally, a nomogram was constructed to predict the survival probability of patients with EHMs, which is based on the number of sites of EHMs and has been proven an excellent predictive ability.

Conclusion

The number of sites of EHMs was a significant prognostic factor of CC patients with LM. However, the sites of EHMs showed limited impact on survival. Furthermore, a nomogram based on the number of sites of EHMs was constructed to predict the OS of patients with EHMs accurately.

Prognosis of resectable colorectal liver metastases after surgery associated with pathological features of primary tumor

Background

Surgery is an important means for patients with colorectal liver metastases (CRLM) to improve their long-term survival, and accurate screening of high-risk factors is crucial to guiding postoperative monitoring and treatment. With this in mind, the aim of this study was to investigate the expression levels and prognostic roles of Mismatch Repair (MMR), Ki67, and Lymphovascular invasion(LVI) in the tumor tissues of colorectal of CRLM.

Methods

85 Patients with CRLM who received surgical treatment for liver metastases after colorectal cancer resection from June, 2017 and Jan, 2020 were included in this study. Independent risk factors affecting the survival of patients with CRLM were investigated using a Cox regression model and the Kaplan-Meier method, and a nomogram for predicting the OS of patients with CRLM was established according to a Cox multivariate regression model. Calibration plots and Kaplan-Meier curves were used to assess the performance of the nomogram.

Results

The median survival time was 39 months (95% CI: 32.05-45.950), and MMR, Ki67 and LVI were significantly correlated with prognosis. Univariate analysis indicated that larger metastasis size (p=0.028), more than one liver metastases (p=0.001),higher serum CA199 (p<0.001), N1-2 stage (p<0.001), the presence of LVI (p=0.001), higher Ki67 (p<0.001), and pMMR predicted worse OS. In addition, synchronous liver metastasis (p = 0.008), larger metastasis size (p=0.02), more than one liver metastases (p<0.001),higher serum CA199 (p<0.001), the presence of LVI (p=0.001), nerve invasion (p=0.042) higher Ki67 (p=0.014), and pMMR (p=0.038) were each associated with worse DFS. Multivariate analysis indicated that higher serum CA199 (HR = 2.275, 95%CI: 1.302-3.975 p=0.004), N1-2 stage(HR = 2.232, 95%CI: 1.239-4.020 p=0.008), the presence of LVI (HR = 1.793, 95%CI: 1.030-3.121 p=0.039), higher Ki67 (HR = 2.700, 95%CI: 1.388-5.253\ p=0.003), and pMMR (HR = 2.213, 95%CI: 1.181-4.993 p=0.046) all predicted worse OS. Finally, synchronous liver metastasis (HR = 2.059, 95%CI: 1.087-3.901 p=0.027), more than one liver metastases ((HR =2.025, 95%CI: 1.120-3.662 p=0.020),higher serum CA199 (HR =2.914, 95%CI: 1.497-5.674 p=0.002), present LVI (HR = 2.055, 95%CI: 1.183-4.299 p=0.001), higher Ki67 (HR = 3.190, 95%CI: 1.648-6.175 p=0.001) and pMMR(HR = 1.676, 95%CI: 1.772-3.637 p=0.047) predicted worse DFS, and the nomogram achieved an effective level of predictive ability.

Conclusion

This study showed that MMR, Ki67, and Lymphovascular invasion were independent risk factors for the postoperative survival of CRLM patients, and a nomogram model was constructed to predict the OS of these patients after liver metastasis surgery. These results can help surgeons and patients to develop more accurate and individualized follow-up strategies and treatment plans after this surgery.

Case Report: Long-term survival of a patient with advanced rectal cancer and multiple pelvic recurrences after seven surgeries

Background

Rectal cancer has a high risk of recurrence and metastasis, with median survival ranging from 24 months to 36 months. K-RAS mutation is a predictor of poor prognosis in rectal cancer. Advanced rectal cancer can be stopped in its tracks by pelvic exenteration.

Case summary

A 51-year-old woman was diagnosed with advanced rectal cancer (pT4bN2aM1b, stage IV) with the KRAS G12D mutation due to a change in bowel habits. The patient had experienced repeated recurrences of rectal cancer after initial radical resection, and the tumor had invaded the ovaries, sacrum, bladder, vagina and anus. Since the onset of the disease, the patient had undergone a total of seven surgeries and long-term FOLFIRI- or XELOX-based chemotherapy regimens, with the targeted agents bevacizumab and regorafenib. Fortunately, the patient was able to achieve intraoperative R0 resection in almost all surgical procedures and achieve tumor-free survival after pelvic exenteration. The patient has been alive for 86 months since her diagnosis.

Conclusions

Patients with advanced rectal cancer can achieve long-term survival through active multidisciplinary management and R0 surgery.

Determinants of Pre-Surgical Treatment in Primary Rectal Cancer: A Population-Based Study

When preoperative radiotherapy (RT) is best used in rectal cancer is subject to discussions and guidelines differ. To understand the selection mechanisms, we analysed treatment decisions in all patients diagnosed between 2010-2020 in two Swedish regions (Uppsala with a RT department and Dalarna without). Information on staging and treatment (direct surgery, short-course RT, or combinations of RT/chemotherapy) in the Swedish Colorectal Cancer Registry were used. Staging magnetic resonance imaging (MRI) permitted a division into risk groups, according to national guidelines. Logistic regression explored associations between baseline characteristics and treatment, while Cohen's kappa tested congruence between clinical and pathologic stages. A total of 1150 patients without synchronous metastases were analysed. Patients from Dalarna were older, had less advanced tumours and were pre-treated less often (52% vs. 63%, p < 0.001). All MRI characteristics (T-/N-stage, MRF, EMVI) and tumour levels were important for treatment choice. Age affected if chemotherapy was added. The correlation between clinical and pathological T-stage was fair/moderate and poor for N-stage. The MRI-based risk grouping influenced treatment choice the most. Since the risk grouping was modified to diminish the pre-treated proportion, fewer patients were irradiated with time. MRI staging is far from optimal. A stronger wish to decrease irradiation may explain why fewer patients from Dalarna were irradiated, but inequality in health care cannot be ruled out.

Clinical strategy of conversion therapy and surgical treatment for liver metastases from colorectal cancer

Colorectal cancer is one of the common malignant tumors of the digestive system in clinical practice. Due to the anatomical characteristics of the colorectum itself, colorectal cancer is prone to liver metastasis. Approximately 15%-25% of colorectal cancer cases are complicated with liver metastasis at diagnosis, 15%-25% are complicated with liver metastasis after radical resection of colorectal cancer, and 80%-90% with liver metastasis cannot undergo radical resection initially. The 5-year survival rate is less than 5%, and liver metastasis is the main cause of death in patients with colorectal cancer. In recent years, with the clinical application of effective chemotherapy and molecular targeted drugs, as well as the rapid development of surgical techniques, an individualized safe, efficient, fast, treatment plan can be formulated according to patients' age, primary colorectal tumor location, degree of differentiation, Ras and B-Raf gene status, tumor size, number and distribution of metastases in the liver. By shrinking the tumor volume in the liver and increasing the residual liver volume, liver metastatic tumors can undergo surgical resection or disease-free status can be achieved in patients with liver metastasis. As a result, patients with colorectal liver metastases can achieve a 5-year survival rate of 30%-57%, which greatly improves the prognosis after operation. According to the postoperative adverse factors, individualized preventive measures are worked out to reduce the impact of adverse factors and improve the prognosis of patients with colorectal liver metastases. In this paper, we systematically discuss the clinical strategy of conversion therapy and surgical treatment for unresectable colorectal cancer liver metastases by reviewing the relevant domestic and foreign literature, so as to provide a theoretical reference for the selection of clinical treatment and program for patients with unresectable colorectal cancer liver metastases.

Temporal development in survival, and gender and regional differences in the Swedish population of patients with synchronous and metachronous metastatic colorectal cancer

BACKGROUND

Survival in patients with metastatic colorectal cancer (mCRC) has markedly improved in patients included in clinical trials. In population-based materials, improvements were seen until about a decade ago, but it is unclear if survival has continued to improve. It is also unclear if regional or gender differences exist.

MATERIAL AND METHODS

All patients with mCRC (N = 19,566) in Sweden between 2007 and 2016 were identified from the national quality register, SCRCR, with almost complete coverage. Overall survival (OS) from diagnosis of metastatic disease was calculated in two calendar periods, 2007-2011 and 2012-2016. Differences between groups were compared using Cox regression.

RESULTS

Median age was 72 years, 55% were males, synchronous presentation was seen in 13,630 patients and metachronous in 5936. In synchronous disease, the primary tumour was removed more often during the first than the second period (51% vs 41%, p < 0.001). Median OS (mOS) was 14.0 months. It was longer in those with metachronous than synchronous disease (17.6 vs 13.1 months, p < 0.001) and in males (15.0 vs 12.8 months, p < 0.001), and markedly influenced by age and primary location. It was longer in patients diagnosed during the second period than during the first (14.9 vs 13.1 months, HR 0.89 (95% CI 0.86-0.92), p < 0.001). This difference was seen in all subgroups according to sex, age, presentation, and sidedness. mOS was about one month shorter in 1/6 healthcare regions, most pronounced during the first period. Differences in median of up to 5 months were seen between the region with the shortest and longest mOS.

CONCLUSIONS

Overall survival in Swedish patients with mCRC has improved during the past decade but is still substantially worse than reported from clinical trials/hospital-based series, reflecting the selection of patients to trials. Regional differences were seen, but they decreased with time. Women did not have a poorer prognosis in multivariable analyses.

Type IV Collagen in Human Colorectal Liver Metastases—Cellular Origin and a Circulating Biomarker

Simple Summary

Patients with colorectal liver metastases (CLM) can be cured through surgery if metastases are detected early in disease progression. Today, CLM diagnosis relies heavily on diagnostic imaging, and cheap, non-invasive, and efficiently measurable biomarkers are needed. Circulating type IV collagen (COL IV) is a potential biomarker for detecting CLM. Patients with CLM show elevated circulating levels of COL IV and increased tissue expression of COL IV in CLM tissue, which could result from enhanced production and degradation of COL IV. This study aimed to establish the cellular source behind enhanced COL IV levels, which is helpful in the evaluation of the biomarker potential of COL IV. We show that fibroblasts express COL IV both in vitro and in the stromal tissue of CLM. We also found that CLM tissue expresses COL IV-degrading proteases. Lastly, CLM patients have higher circulating COL IV levels than healthy controls.

Abstract

Circulating type IV collagen (cCOL IV) is a potential biomarker for patients with colorectal liver metastases (CLM) who present with elevated levels of COL IV in both CLM tissue and circulation. This study aimed to establish the cellular origin of elevated levels of COL IV and analyze circulating COL IV in CLM patients. The cellular source was established through in situ hybridization, immunohistochemical staining, and morphological evaluation. Cellular expression in vitro was assessed by immunofluorescence. Tissue expression of COL IV-degrading matrix metalloproteinases (MMPs)-2, -7, -9, and -13 was studied with immunohistochemical staining. Plasma levels of COL IV in CLM patients and healthy controls were analyzed with ELISA. This study shows that cancer-associated fibroblasts (CAFs) express COL IV in the stroma of CLM and that COL IV is expressed in vitro by fibroblasts but not by tumor cells. MMP-2, -7, -9, and -13 are expressed in CLM tissue, mainly by hepatocytes and immune cells, and circulating COL IV is significantly elevated in CLM patients compared with healthy controls. Our study shows that stromal cells, not tumor cells, produce COL IV in CLM, and that circulating COL IV is elevated in patients with CLM.

Efficacy of Near-Infrared Fluorescence-Guided Hepatectomy for the Detection of Colorectal Liver Metastases: A Randomized Controlled Trial

BACKGROUND

The application of indocyanine green fluorescence-guided hepatectomy for liver metastases from colorectal cancer is in the preliminary stage of clinical practice; thus, its efficacy needs to be determined. This study compared the number of intrahepatic colorectal liver metastases detected intraoperatively and postoperative recovery data between patients who underwent traditional hepatectomy (nonindocyanine green group) and traditional hepatectomy plus intraoperative indocyanine green fluorescence imaging (indocyanine green group).

STUDY DESIGN

Between January 2018 and March 2020, patients with potentially resectable colorectal liver metastases were randomly assigned to the nonindocyanine green or indocyanine green group. The number of intrahepatic colorectal liver metastases identified intraoperatively and based on postoperative recovery data were compared between both groups.

RESULTS

Overall, we recruited 80 patients, among whom 72 eligible patients were randomly assigned. After allocation, 64 patients, comprising 32 in each group, underwent the allocated intervention and follow-up. Compared with the nonindocyanine green group, the mean number of intrahepatic colorectal liver metastases identified intraoperatively in the indocyanine green group was significantly greater (mean [standard deviation], 3.03 [1.58] vs 2.28 [1.35]; p = 0.045), the postoperative hospital stay was shorter (p = 0.012) and the 1-year recurrence rate was also lower (p = 0.017). Postoperative complications and 90-day mortality were comparable, with no statistical differences.

CONCLUSIONS

Indocyanine green fluorescence imaging significantly increases the number of intrahepatic colorectal liver metastases identified and reduces postoperative hospital stay and 1-year recurrence rate without increasing hepatectomy-related complications and mortality rates.

An analysis of gender differences in treatment and outcome of periampullary tumours in Sweden - A national cohort study

BACKGROUND

Little is known of possible gender differences in treatment of periampullary tumours and outcome after pancreatoduodenectomy (PD), and the aim of this study was therefore to investigate any variances from national multicentre perspective.

METHODS

Data from the Swedish National Registry for Pancreatic and Periampullary Cancer for all patients diagnosed with a periampullary tumour from 2012 throughout 2017 was collected. The material was analysed in two groups, men and women, for palliative treatment and curative intended resection.

RESULTS

A total of 5677 patients were included, 2906 (51%) men and 2771 (49%) women. Women were older than men, 72 (65-78) years vs. 70 (64-76), p < 0.001. A lesser proportion of women were planned for resection (1131 (41%) vs. 1288 (44%), p = 0.008), but after adjusting for age and tumour location no difference was seen. Postoperative morbidity was equal, but women had significantly better long-term survival than men. The survival was equal for palliative men and women.

CONCLUSION

No gender bias could be established when analysing treatment for periampullary tumours in Sweden, even though less women were offered surgery. Data suggest that even though women were older they tolerate surgery well and hence offering PD at a higher age for women could be suggested.

Impact of patient, primary tumor and metastatic pattern including tumor location on survival in patients undergoing ablation or resection for colorectal liver metastases: A population-based national cohort study

INTRODUCTION

Selecting the optimal treatment strategy for patients with colorectal liver metastases (CRLM) aim to improve survival for the total cohort. Following the introduction of laparoscopic resections and ablation, localization may direct choice of method. The aim with this study was to re-evaluate prognostic factors that should be considered at the preoperative multidisciplinary tumor board, based on a national population cohort.

MATERIALS AND METHODS

A national cohort with radically operated colorectal cancer in 2009-2013, also treated for CRLM was identified in Swedish national registries. Prognostic factors were identified and evaluated in multivariable analyses.

RESULTS

1200 patients treated with resection and 125 with ablation only were included in the study cohort. Relative five-year survival was 54.7% (50.9%-58.4%) and 32.0% (22.4%-41.9%), respectively). High age, acute surgery and complications at time of primary tumor resection remained important risk factors at liver surgery, as well as the primary tumor characteristics; vascular invasion and high lymph node ratio. As for metastatic pattern; tumor size, location in segment 4, 6, 7 or 8, multiple metastatic sites and progress after preoperative chemotherapy were significant risk factors. In multivariate analyses, ablation therapy doubled the risk of death within 5 years. This strong negative impact was confirmed in a weighted propensity score analysis (HR = 2.1 (95 % CI 1.5 -3.0)).

CONCLUSION

Segmental localization and tumor size were prognostic factors but also patient and primary tumor factors significantly impacted survival after intervention for CRLM. Long-term survival was significantly lower after ablation therapy compared to surgical resection.

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.

Shanghai international consensus on diagnosis and comprehensive treatment of colorectal liver metastases (version 2019)

The liver is the most common anatomical site for hematogenous metastases from colorectal cancer. Therefore effective treatment of liver metastases is one of the most challenging elements in the management of colorectal cancer. However, there is rare available clinical consensus or guideline only focusing on colorectal liver metastases. After six rounds of discussion by 195 clinical experts of the Shanghai International Consensus Expert Group on Colorectal Liver Metastases (SINCE) from 29 countries or regions, the Shanghai Consensus has been finally completed, based on current research and expert experience. The consensus emphasized the principle of multidisciplinary team, provided detailed diagnosis approaches, and guided precise local and systemic treatments. This Shanghai Consensus might be of great significance to standardized diagnosis and treatment of colorectal liver metastases all over the world.

Influence of primary tumour and patient factors on survival in patients undergoing curative resection and treatment for liver metastases from colorectal cancer

Background

Resection of the primary tumour is a prerequisite for cure in patients with colorectal cancer, but hepatic metastasectomy has been used increasingly with curative intent. This national registry study examined prognostic factors for radically treated primary tumours, including the subgroup of patients undergoing liver metastasectomy.

Methods

Patients who had radical resection of primary colorectal cancer in 2009–2013 were identified in a population‐based Swedish colorectal registry and cross‐checked in a registry of liver tumours. Data on primary tumour and patient characteristics were extracted and prognostic impact was analysed.

Results

Radical resection was registered in 20 853 patients; in 38·7 per cent of those registered with liver metastases, surgery or ablation was performed. The age‐standardized relative 5‐year survival rate after radical resection of colorectal cancer was 80·9 (95 per cent c.i. 80·2 to 81·6) per cent, and the rate after surgery for colorectal liver metastases was 49·6 (46·0 to 53·2) per cent. Multivariable analysis identified lymph node status, multiple sites of metastasis, high ASA grade and postoperative complications after resection of the primary tumour as strong risk factors after primary resection and following subsequent liver resection or ablation. Age, sex and primary tumour location had no prognostic impact on mortality after liver resection.

Conclusion

Lymph node status and complications have a negative impact on outcome after both primary resection and liver surgery. Older age and female sex were underrepresented in the liver surgical cohort, but these factors did not influence prognosis significantly.

Detailed Analysis of the Characteristics of Sample Volume in Blood Culture Bottles

Blood volume is the most important variable for the detection of microorganisms in blood cultures (BCs). Most standards recommend 40 to 60 ml blood, collected in several BC bottles filled up to 10 ml. We measured blood volume in individual BC bottles and analyzed the associations of hospital, bottle type, day of the week, daily sampling time, and age and sex of the patient with sampling volume and BC result. The variation in blood volume per BC bottle was analyzed in a mixed linear model using hospital, bottle type, weekday, sampling time, age, and sex as fixed factors and patient identification (ID) and episode as random factors to control for repetitive sampling of individual patients. Only 18% of all bottles were filled with the recommended 8 to 10 ml, and 47% were filled with less than 8 ml. The mean (± standard error) volume was larger in positive bottles (9.09 ± 0.15) than in negative bottles (8.47 ± 0.07) (P < 0.001). Blood volume was larger in BacT/Alert-FA Plus bottles than in -FN Plus BC bottles (P < 0.001). There were significantly lower volumes collected during the night (P < 0.001). The volume of blood collected decreased significantly with increasing patient age (P < 0.001). Larger volumes were collected from male patients than from female patients: 8.78 (± 0.06) versus 8.36 (± 0.06) ml (mean ± standard error [SE]), respectively (P < 0.001). The odds of detecting a positive patient increases by 13% for each additional milliliter of blood drawn. Our results show that we need to work actively with the development of blood sampling routines to overcome age and sex effects and to optimize blood sampling volumes.