Differences in the management and survival of metastatic colorectal cancer in Europe. A population-based study

Net survival in colon and rectal cancer by stage according to neoadjuvant treatment. A French population-based study

AIM

Real-life estimations of survival by stage in colorectal cancer are scanty. We estimated population-based net survival by pathological stage and location, and for rectal cancer by patterns of evolution according to clinical and pathological stage with regard to neoadjuvant therapy.

METHOD

Age-standardized net survival was estimated on 19,630 colorectal cancers diagnosed between 2009 and 2015.

RESULTS

Five-year net survival was 64 % for colon and 62 % for rectal cancer. The highest absolute difference between colon and rectum was 12 % for stage II women aged 75 (91% vs. 79 %). Among patients with clinical stage III rectal cancer, 67 % no longer had pathological node involvement after neoadjuvant treatment. Survival was similar in clinical stage I, II or III and pathological stage III after neoadjuvant treatment and in pathological stage III without neoadjuvant treatment (between 67 % and 72 %). It ranged between 80 and 82 % in pathological stage II, without neoadjuvant treatment or with clinical stage I, II or III before neoadjuvant treatment. Survival ranged between 93 % and 95 % in pathological stage I, treated with surgery only or with clinical stage II or III before neoadjuvant treatment.

CONCLUSION

Prognosis is associated with stage determined on surgical specimens rather than stage at the initial workup.

Microwave coagulation for liver metastases

BACKGROUND

Liver metastases (i.e. secondary hepatic malignancies) are significantly more common than primary liver cancer. Long-term survival after radical surgical treatment is approximately 50%. For people in whom resection for cure is not feasible, other treatments must be considered. One treatment option is microwave coagulation utilising electromagnetic waves. It involves placing an electrode into a lesion under ultrasound or computed tomography guidance.

OBJECTIVES

To evaluate the beneficial and harmful effects of microwave coagulation versus no intervention, other ablation methods, or systemic treatments in people with liver metastases regardless of the location of the primary tumour.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest date of search was 14 April 2023.

SELECTION CRITERIA

Randomised clinical trials assessing beneficial or harmful effects of microwave coagulation and its comparators in people with liver metastases, irrespective of the location of the primary tumour. We included trials no matter the outcomes reported.

DATA COLLECTION AND ANALYSIS

We followed standard Cochrane methodological procedures. Our primary outcomes were: all-cause mortality at the last follow-up and time to mortality; health-related quality of life (HRQoL); and any adverse events or complications. Our secondary outcomes were: cancer mortality; disease-free survival; failure to clear liver metastases; recurrence of liver metastases; time to progression of liver metastases; and tumour response measures. We used risk ratios (RR) and hazard ratios (HR) with 95% confidence intervals (CI) to present the results. Two review authors independently extracted data and assessed the risk of bias using the Cochrane RoB 1 tool. We used GRADE methodology to assess the certainty of the evidence.

MAIN RESULTS

Three randomised clinical trials fulfilled the inclusion criteria. The control interventions differed in the three trials; therefore, meta-analyses were not possible. The trials were at high risk of bias. The certainty of evidence of the assessed outcomes in the three comparisons was very low. Data on our prespecified outcomes were either missing or not reported. Microwave coagulation plus conventional transarterial chemoembolisation (TACE) versus conventional TACE alone One trial, conducted in China, randomised 50 participants (mean age 60 years, 76% males) with liver metastases from various primary sites. Authors reported that the follow-up period was at least one month. The trial reported adverse events or complications in the experimental group only and for tumour response measures. There were no dropouts in the trial. The trial did not report on any other outcomes. Microwave ablation versus conventional surgery One trial, conducted in Japan, randomised 40 participants (mean age 61 years, 53% males) with multiple liver metastases of colorectal cancer. Ten participants were excluded after randomisation (six from the experimental and four from the control group); thus, the trial analyses included 30 participants. Follow-up was three years. The reported number of deaths from all causes was 9/14 included participants in the microwave group versus 12/16 included participants in the conventional surgery group. The mean overall survival was 27 months in the microwave ablation and 25 months in the conventional surgery group. The three-year overall survival was 14% with microwave ablation and 23% with conventional surgery, resulting in an HR of 0.91 (95% CI 0.39 to 2.15). The reported frequency of adverse events or complications was comparable between the two groups, except for the required blood transfusion, which was more common in the conventional surgery group. There was no intervention-related mortality. Disease-free survival was 11.3 months in the microwave ablationgroup and 13.3 months in the conventional surgery group. The trial did not report on HRQoL. Microwave ablation versus radiofrequency ablation One trial, conducted in Germany, randomised 50 participants (mean age 62.8 years, 46% males) who were followed for 24 months. Two-year mortality showed an RR of 0.62 (95% CI 0.26 to 1.47). The trial reported that, by two years, 76.9% of participants in the microwave ablationgroup and 62.5% of participants in the radiofrequency ablation group survived (HR 0.63, 95% CI 0.23 to 1.73). The trial reported no deaths or major complications during the procedures in either group. There were two minor complications only in the radiofrequency ablation group (RR 0.19, 95% CI 0.01 to 3.67). The trial reported technical efficacy in 100% of procedures in both groups. Distant recurrence was reported for 10 participants in the microwave ablation group and nine participants in the radiofrequency ablation group (RR 1.03, 95% CI 0.50 to 2.08). No participant in the microwave ablation group demonstrated local progression at 12 months, while that occurred in two participants in the radiofrequency ablation group (RR 0.19, 95% CI 0.01 to 3.67). The trial did not report on HRQoL. One trial reported partial support by Medicor (MMS Medicor Medical Supplies GmbH, Kerpen, Germany) for statistical analysis. The remaining two trials did not provide information on funding. We identified four ongoing trials.

AUTHORS' CONCLUSIONS

The evidence is very uncertain about the effect of microwave ablation in addition to conventional TACE compared with conventional TACE alone on adverse events or complications. We do not know if microwave ablation compared with conventional surgery may have little to no effect on all-cause mortality. We do not know the effect of microwave ablation compared with radiofrequency ablation on all-cause mortality and adverse events or complications either. Data on all-cause mortality and time to mortality, HRQoL, adverse events or complications, cancer mortality, disease-free survival, failure to clear liver metastases, recurrence of liver metastases, time to progression of liver metastases, and tumour response measures were either insufficient or were lacking. In light of the current inconclusive evidence and the substantial gaps in data, the pursuit of additional good-quality, large randomised clinical trials is not only justified but also essential to elucidate the efficacy and comparative benefits of microwave ablation in relation to various interventions for liver metastases. The current version of the review, in comparison to the previous one, incorporates two new trials in two additional microwave ablation comparisons: 1. in addition to conventional TACE versus conventional TACE alone and 2. versus radiofrequency ablation.

Predictors of Survival in Elderly Patients with Metastatic Colon Cancer: A Population-Based Cohort Study

Oncological strategies in the elderly population are debated. The objective of this study was to determine the predictive factors of survival in patients aged 80 years and older with metastatic colon cancer. Data from four digestive tumour registry databases were used in this analysis. This population-based retrospective study included 1115 patients aged 80 years and older with stage IV colon adenocarcinoma diagnosed between 2007 and 2016. Cox regression was used to assess the impact of different prognostic factors. Age was significantly correlated with the surgical treatment (p < 0.001) but not with overall survival. Patients with a low comorbidity burden had better survival than patients with higher comorbidities scores (9.4 (0−123) versus 7.9 (0−115) months) (p = 0.03). Surgery was more common for proximal colon cancer (p < 0.001), but the location of the primary lesion was not correlated with improved survival (p = 0.07). Patients with lung metastases had a better prognosis than those with liver metastases (HR 0.56 95% CI 0.40, 0.77 p < 0.001); multiple organ involvement had the worst survival (HR 1.32 95% CI 1.15, 1.51 p < 0.001). Chemotherapy was associated with improved survival for both operated (HR 0.45 95% CI 0.35, 0.58 p < 0.001) and non-operated patients (HR 0.41 95% CI 0.34, 0.50 p < 0.001). The majority of patients receiving adjuvant treatment had a low comorbidity burden. In our study, the location of metastases but not the primary tumor location had an impact on overall survival. Low comorbidity burden, curative surgery, and chemotherapy had a significant advantage for elderly patients with metastatic colon cancer.

Incidence and Survival in Synchronous and Metachronous Liver Metastases From Colorectal Cancer

IMPORTANCE

Although treatment and prognosis of synchronous liver metastases from colorectal cancer are relatively well known, a comparative description of the incidence, epidemiological features, and outcomes of synchronous and metachronous liver metastases is lacking. The difference in prognosis between patients with synchronous and metachronous liver metastases is controversial.

OBJECTIVE

To investigate temporal patterns in the incidence and outcomes of synchronous vs metachronous liver metastases from colorectal cancer.

DESIGN, SETTING, AND PARTICIPANTS

This population-based cohort study used information from a French regional digestive cancer registry accounting for 1 082 000 inhabitants. A total of 26 813 patients with a diagnosis of incident colorectal adenocarcinoma diagnosed between January 1, 1976, and December 31, 2018, were included. Data were analyzed from February 7 to May 20, 2022.

MAIN OUTCOMES AND MEASURES

Age-standardized incidence was calculated. Univariate and multivariate net survival analyses were performed.

RESULTS

Of 26 813 patients with colorectal cancer (15 032 men [56.1%]; median [IQR] age, 73 [64-81] years), 4546 (17.0%) presented with synchronous liver metastases. The incidence rate of synchronous liver metastases was 6.9 per 100 000 inhabitants in men and 3.4 per 100 000 inhabitants in women, with no significant variation since 2000. The 5-year cumulative incidence of metachronous liver metastases decreased from 18.6% (95% CI, 14.9%-22.2%) during the 1976 to 1980 period to 10.0% (95% CI, 8.8%-11.2%) during the 2006 to 2011 period. Cancer stage at diagnosis was the strongest risk factor for liver metastases; compared with patients diagnosed with stage II cancer, patients with stage III cancer had a 2-fold increase in risk (subdistribution hazard ratio, 2.42; 95% CI, 2.08-2.82) for up to 5 years. Net survival at 1 year was 41.8% for synchronous liver metastases and 49.9% for metachronous metastases, and net survival at 5 years was 6.2% for synchronous liver metastases and 13.2% for metachronous metastases. Between the first (1976-1980) and last (2011-2016) periods, the adjusted ratio of death after synchronous and metachronous metastases was divided by 2.5 for patients with synchronous status and 3.7 for patients with metachronous status.

CONCLUSIONS AND RELEVANCE

In this study, the incidence of colorectal cancer with synchronous liver metastases changed little over time, whereas there was a 2-fold decrease in the probability of developing metachronous liver metastases. Survival improved substantially for patients with metachronous liver metastases, whereas improvement was more modest for those with synchronous metastases. The differences observed in the epidemiological features of synchronous and metachronous liver metastases from colorectal cancer may be useful for the design of future clinical trials.