Trends and Variation in the Use of Radiotherapy in Non-metastatic Rectal Cancer: a 14-year Nationwide Overview from the Netherlands

AIMS

This study describes nationwide primary radiotherapy utilisation trends for non-metastasised rectal cancer in the Netherlands between 2008 and 2021. In 2014, both colorectal cancer screening and a new guideline specifying prognostic risk groups for neoadjuvant treatment were implemented.

MATERIALS AND METHODS

Patients with non-metastasised rectal cancer in 2008-2021 (n = 37 510) were selected from the Netherlands Cancer Registry and classified into prognostic risk groups. Treatment was studied over time and age. Multilevel logistic regression analyses were carried out to identify factors associated with (i) radiotherapy versus chemoradiotherapy use for intermediate rectal cancer and (ii) chemoradiotherapy without versus with surgery for locally advanced rectal cancer.

RESULTS

For early rectal cancer, the use of neoadjuvant radiotherapy decreased (15% to 5% between 2008 and 2021), whereas the use of endoscopic resections increased (8% in 2015, 17% in 2021). In intermediate-risk rectal cancer, neoadjuvant chemoradiotherapy (43% until 2011, 25% in 2015) shifted to radiotherapy (42% in 2008, 50% in 2015), the latter being most often applied in older patients. In locally advanced rectal cancer, the use of chemoradiotherapy without surgery increased (2-4% in 2008-2013, 17% in 2019-2021). Both neoadjuvant treatment in intermediate disease and omission of surgery following chemoradiotherapy in locally advanced disease varied with increasing age (odds ratio>75vs<50: 2.17, 95% confidence interval 1.54-3.06) and treatment region (Southwest and Northwest odds ratio 0.63, 95% confidence interval 0.42-0.93 and odds ratio 0.65, 95% confidence interval 0.44-0.95, respectively, compared with the North).

CONCLUSION

Treatment patterns in non-metastasised rectal cancer significantly changed over time. Effects of both the national screening programme and the new treatment guideline were apparent, as well as a paradigm shift towards organ preservation (watch-and-wait). Observed regional variations may indicate adoption differences regarding new treatment strategies.

Adjuvant chemotherapy in patients with clinically node-negative but pathologically node-positive rectal cancer in the Netherlands: A retrospective analysis

INTRODUCTION

Accurate clinical staging of rectal cancer is hampered by suboptimal sensitivity of MRI in the detection of regional lymph node metastases. Consequently, some patients may be understaged and have been withheld neoadjuvant (chemo)radiotherapy in retrospect. Although Dutch guidelines do not advocate adjuvant chemotherapy (ACT) in rectal cancer, some of these clinically understaged patients receive ACT according to local policy. We aim to assess the benefit of ACT in these patients.

METHODS

Population-based data from patients with clinically node-negative (cN0) but pathologically node-positive (pN+) rectal cancer that underwent total mesorectal excision (TME) without neoadjuvant treatment between 2008 and 2018 were obtained from the Netherlands Cancer Registry. Missing data were handled by multiple imputation. Stabilised inverse probability treatment weighting (sIPTW) was used to balance clinical characteristics. Overall survival (OS) was compared in ACT and non-ACT patients.

RESULTS

Of 34,724 patients, 13,861 had cN0 disease of whom 3016 were pN+ (21.8%). 1466 (48.6%) of these patients underwent upfront TME and were included. Median follow-up was 84 months (95% confidence interval [CI] 76-97) versus 79 months (95% CI 77-81) in patients that did (n = 290, 19.8%) and did not (n = 1176, 80.2%) receive ACT, respectively. After sIPTW adjustment, ACT was associated with improved OS (hazard ratio 0.70; 95% CI 0.49-0.99; p = 0.04). The estimated 5-year OS rate was 74.2% versus 65.3%, respectively.

CONCLUSION

In this population-based cohort of patients with cN0 but pN+ rectal cancer who underwent upfront TME, ACT was associated with a significant OS benefit. These data support to discuss ACT in this population.

Impact of colorectal cancer screening on survival after metachronous metastasis

BACKGROUND

An increasing proportion of colorectal cancer (CRC) cases in Europe are detected by screening with faecal immunochemical testing (FIT). Previous studies showed that population screening with FIT leads to a decrease in CRC incidence and to detection at an earlier stage. However, approximately twenty percent of patients with CRC without metastases at initial diagnosis still develop metachronous metastases. We investigated the association between detection mode of the primary tumor and overall survival (OS) after metachronous metastasis in patients with CRC.

METHODS

Nationwide registry-based data was obtained of 794 patients who developed metachronous metastases after being diagnosed with stage I-III CRC between January and June 2015. With multivariable Cox PH regression modelling, we analyzed the (causal) association between detection mode of the primary tumor (FIT screen-detected versus non-screen-detected) and OS after metachronous metastasis while adjusting for potential confounders.

RESULTS

Median OS and five-year OS after metachronous metastasis were significantly higher for patients with screen-detected (n = 152) vs. non-screen-detected primary tumors (n = 642): 38.3 vs. 19.2 months, and 35.4% vs. 18.8%, respectively, p < 0.0001). After adjustment for potential confounders, the association between detection mode and OS after metachronous metastasis remained significant (HR 0.70 [95% CI 0.56-0.89]).

CONCLUSIONS

Screen-detection of the primary tumor was independently associated with longer OS after metachronous metastasis. This may support the clinical utility of the population screening program and it shows the prognostic value of detection mode of the primary tumor once metachronous metastasis is diagnosed.

Differences in treatment of stage I colorectal cancers: a population-based study of colorectal cancers detected within and outside of a screening program

BACKGROUND

 Screen-detected colorectal cancers (CRCs) are often treated less invasively than stage-matched non-screen-detected CRCs, but the reasons for this are not fully understood. This study evaluated the treatment of stage I CRCs detected within and outside of the screening program in the Netherlands. METHODS : Data from the Netherlands Cancer Registry for all stage I CRCs diagnosed between January 1, 2008 and December 31, 2020 were analyzed, comparing patient, tumor, and treatment characteristics of screen-detected and non-screen-detected stage I CRCs. Multivariable logistic regression was used to assess the association between treatment (local excision only vs. surgical oncologic resection) and patient and tumor characteristics, stratified for T stage and tumor location.

RESULTS

 Screen-detected stage I CRCs were relatively more often T1 than T2 compared with non-screen-detected stage I CRCs (66.9 % vs. 53.3 %; P < 0.001). When only T1 tumors were considered, both screen-detected colon and rectal cancers were more often treated with local excision only than non-screen-detected T1 cancers (odds ratio [OR] 2.19, 95 %CI 1.93-2.49; and OR 1.29, 95 %CI 1.05-1.59, respectively), adjusted for sex, tumor location, lymphovascular invasion (LVI) status, and tumor differentiation. CONCLUSIONS : Less invasive treatment of screen-detected stage I CRC is partly explained by the higher rate of T1 cancers compared with non-screen-detected stage I CRCs. T1 stage I screen-detected CRCs were also more likely to undergo less invasive treatment than non-screen-detected CRCs, adjusted for risk factors such as LVI and tumor differentiation. Future research should investigate whether the choice of local excision was related to unidentified cancer-related factors or the expertise of the endoscopists.

Surgical treatment and overall survival in patients with right-sided obstructing colon cancer-a nationwide retrospective cohort study

PURPOSE

The aim of this study was to compare baseline characteristics, 90-day mortality and overall survival (OS) between patients with obstructing and non-obstructing right-sided colon cancer at a national level.

METHODS

All patients who underwent resection for right-sided colon cancer between January 2015 and December 2016 were selected from the Netherlands Cancer Registry and stratified for obstruction. Primary outcome was 5-year OS after excluding 90-day mortality as assessed by the Kaplan-Meier and multivariable Cox regression analysis.

RESULTS

A total of 525 patients (7%) with obstructing and 6891 patients (93%) with non-obstructing right-sided colon cancer were included. Patients with right-sided obstructing colon cancer (OCC) were older and had more often transverse tumour location, and the pathological T and N stage was more advanced than in those without obstruction (p < 0.001). The 90-day mortality in patients with right-sided OCC was higher compared to that in patients with non-obstructing colon cancer: 10% versus 3%, respectively (p < 0.001). The 5-year OS of those surviving 90 days postoperatively was 42% in patients with OCC versus 73% in patients with non-obstructing colon cancer, respectively (p < 0.001). Worse 5-year OS was found in patients with right-sided OCC for all stages. Obstruction was an independent risk factor for decreased OS in right-sided colon cancer (HR 1.79, 95% CI 1.57-2.03).

CONCLUSION

In addition to increased risk of postoperative mortality, a stage-independent worse 5-year OS after excluding 90-day mortality was found in patients with right-sided OCC compared to patients without obstruction.

Towards patient-led follow-up after curative surgical resection of stage I, II and III colorectal cancer (DISTANCE-trial): a study protocol for a stepped-wedge cluster-randomised trial

BACKGROUND

Colorectal cancer (CRC) is among the most frequently diagnosed cancers. Approximately 20-30% of stage I-III CRC patients develop a recurrent tumour or metastases after curative surgical resection. Post-operative follow-up is indicated for the first five years after curative surgical resection. As intensified follow-up after curative surgical resection has shown no effect on survival, patient organisations and policy makers have advocated for a more patient-centred approach to follow-up. The objective of this study is to successfully implement patient-led, home-based follow-up (PHFU) in six hospitals in The Netherlands, with as ultimate aim to come to a recommendation for a patient-centred follow-up schedule for stage I-III CRC patients treated with surgical resection with curative intent.

METHODS

This study is designed as a stepped-wedge cluster-randomised trial (SW-CRT) in six participating centres. During the trial, three centres will implement PHFU after six months; the other three centres will implement PHFU after 12 months of inclusion in the control group. Eligible patients are those with pT2-4N0M0 or pT1-4N1-2M0 CRC, who are 18 years or older and have been free of disease for 12 months after curative surgical resection. The studied intervention is PHFU, starting 12 months after curative resection. The in-hospital, standard-of-care follow-up currently implemented in the participating centres functions as the comparator. The proportion of patients who had contact with the hospital regarding CRC follow-up between 12-24 months after curative surgical resection is the primary endpoint of this study. Quality of life, fear of cancer recurrence, patient satisfaction, cost-effectiveness and survival are the secondary endpoints.

DISCUSSION

The results of this study will provide evidence on whether nationwide implementation of PHFU for CRC in The Netherlands will be successful in reducing contact between patient and health care provider. Comparison of PROMs between in-hospital follow-up and PHFU will be provided. Moreover, the cost-effectiveness of PHFU will be assessed.

TRIAL REGISTRATION

Dutch Trail Register (NTR): NL9266 (Registered on January 1st, 2021).

Attendance characteristics of the breast and colorectal cancer screening programmes in a highly urbanised region of the Netherlands: a retrospective observational study

OBJECTIVES

Throughout Europe, many countries offer population-based cancer screening programmes (CSPs). In the Netherlands, two implemented CSPs are targeting people of 50 years and older, aiming at breast cancer (BC) and colorectal cancer (CRC). In order for a CSP to be (cost-)effective, high participation rates and outreach to the populations at risk are essential. People living in highly urbanised areas and big cities are known to participate less in CSPs. The aim of this study was to gain further insight into the participation patterns of a screening-eligible population of 50 years and over, living in a highly urbanised region, over a longer time period.

DESIGN

A retrospective observational study.

SETTING

Participation data of the regional screening organisation, linked to the cancer incidence data derived from the Netherlands Cancer Registry, concerning the city of The Hague, between 2005 and 2019. Attendance groups were defined as attenders (attending >50% of the invitations) and non-attenders (attending ≤50% of the invitations), and were mutually compared.

RESULTS

The databases contained 106 377 unique individuals on the BC screening programme (SP) and 73 669 on the CRC-SP. Non-attendance at both CSPs was associated with living in a lower socioeconomic status (SES) neighbourhood and as a counter effect, also associated with a more unfavourable, relatively late-stage, tumour diagnosis. When combining the results of the two CSPs, our results imply high screening adherence over time. Women who did not participate in both CSPs were older, and more often lived in neighbourhoods with a lower SES score.

CONCLUSIONS

Since low screening uptake is one of the factors that contribute to increasing inequalities in cancer survival, future outreach strategies should be focused on engaging specific non-attending subgroups.

Initial Impact of National CRC Screening on Incidence and Advanced Colorectal Cancer

BACKGROUND AND AIMS

Screening for colorectal cancer (CRC) aims to decrease CRC incidence and mortality. Biennial fecal immunochemical test screening started in the Netherlands in 2014 for individuals 55-75 years of age. This study investigated the effect of screening on stage-specific incidence, with focus on stage III and IV CRC.

METHODS

Inhabitants diagnosed with CRC in 2009-2018 were included. CRC incidence per stage, year, and detection method (ie, screen-detected vs clinically detected) was evaluated. Patient, tumor, and treatment characteristics, and survival of patients with stage III and IV CRC, were compared according to the detection method.

RESULTS

Included were 140,649 CRCs in 136,882 patients. An initial peak of stage I-III CRC diagnoses after initiation of screening was followed by a continuous decrease within screening-eligible ages. Total CRC incidence remained higher than before screening, although stage II and IV CRC incidence decreased below prescreening levels. Screen-detected CRCs were significantly more frequently located in the left-sided colon (stage III; 43.7% vs 30.9%; stage IV: 45.1% vs 36.1%), and the primary tumor resection rate was higher (stage III colon: 99.8% vs 99.0%, rectum: 97.3% vs 89.7%; stage IV colon: 65.4% vs 56.6%, rectum: 47.3% vs 33.5%). Patients with screen-detected stage IV CRC had significantly more often single-organ metastases (74.5% vs 57.0%; P < .001) and more frequently received treatment with curative intent (colon: 41.3% vs 27.4%; rectum: 33.8% vs 24.6%). Overall survival significantly improved for patients with screen-detected CRCs (stage III: P < .001; stage IV: P < .001).

CONCLUSIONS

Five years after the start of a nationwide CRC screening program, a decrease in stage II and IV CRC incidence was observed. Patients with screen-detected stage III and stage IV CRC had less extensive disease and improved survival compared with those with clinically detected CRC.

Predicting early extrahepatic recurrence after local treatment of colorectal liver metastases

BACKGROUND

Patients who develop early extrahepatic recurrence (EHR) may not benefit from local treatment of colorectal liver metastases (CRLMs). This study aimed to develop a prediction model for early EHR after local treatment of CRLMs using a national data set.

METHODS

A Cox regression prediction model for EHR was developed and validated internally using data on patients who had local treatment for CRLMs with curative intent. Performance assessment included calibration, discrimination, net benefit, and generalizability by internal-external cross-validation. The prognostic relevance of early EHR (within 6 months) was evaluated by landmark analysis.

RESULTS

During a median follow-up of 35 months, 557 of the 1077 patients had EHR and 249 died. Median overall survival was 19.5 (95 per cent c.i. 15.6 to 23.0) months in patients with early EHR after CRLM treatment, compared with not reached (45.3 months to not reached) in patients without an early EHR. The EHR prediction model included side and stage of the primary tumour, RAS/BRAFV600E mutational status, and number and size of CRLMs. The range of 6-month EHR predictions was 5.9-56.0 (i.q.r. 12.9-22.0) per cent. The model demonstrated good calibration and discrimination. The C-index through 6 and 12 months was 0.663 (95 per cent c.i. 0.624 to 0.702) and 0.661 (0.632 to 0.689) respectively. The observed 6-month EHR risk was 6.5 per cent for patients in the lowest quartile of predicted risk compared with 32.0 per cent in the highest quartile.

CONCLUSION

Early EHR after local treatment of CRLMs can be predicted.

Interregional practice variations in the use of local therapy for synchronous colorectal liver metastases in the Netherlands

BACKGROUND

The aim of this study was to evaluate the Dutch regional practice variation in treatment of synchronous colorectal liver metastases (CRLM) over time and assess their impact on patients survival.

METHODS

Two cohorts of patients with synchronous CRLM were selected from the Netherlands Cancer Registry (NCR). All patients diagnosed between 2014 and 2018 were selected to analyze interregional practice variations in local therapy (LT) with multivariable logistic regression. Overall survival (OS) was assessed for patients diagnosed from 2008 to 2013 using Kaplan Meier method and Cox regression analyses.

RESULTS

The proportion of patients who underwent LT increased from 15.5% to 21.9%. Interregional use of LT varied from 19.1% to 25.0%. Multivariable logistic regression showed significant differences between regions in the use of LT (p = 0.001) in 2014-2018. There was no association between OS and region of diagnosis for patients who underwent LT after correction for confounders.The use of LT for CRLM increased from 15.5% in 2008-2013 to 21.9% in 2014-2018. Three-year OS increased from 16% to 19% respectively.

CONCLUSION

Interregional practice variations have decreased. The remaining differences are not associated with OS. The use of local therapy and 3-year overall survival have increased over time. Local practice should be monitored to prevent undesirable variation in outcomes.

Proportion and stage distribution of screen-detected and non-screen-detected colorectal cancer in nine European countries: an international, population-based study

BACKGROUND

The effects of recently implemented colorectal cancer screening programmes in Europe on colorectal cancer mortality will take several years to be fully known. We aimed to analyse the characteristics and parameters of screening programmes, proportions of colorectal cancers detected through screening, and stage distribution in screen-detected and non-screen-detected colorectal cancers to provide a timely assessment of the potential effects of screening programmes in several European countries.

METHODS

We conducted this population-based study in nine European countries for which data on mode of detection were available (Belgium, Denmark, England, France, Italy, Ireland, the Netherlands, Slovenia, and Spain). Data from 16 population-based cancer registries were included. Patients were included if they were diagnosed with colorectal cancer from the year that organised colorectal cancer screening programmes were implemented in each country until the latest year with available data at the time of analysis, and if their age at diagnosis fell within the age groups targeted by the programmes. Data collected included sex, age at diagnosis, date of diagnosis, topography, morphology, clinical and pathological TNM information based on the edition in place at time of diagnosis, and mode of detection (ie, screen detected or non-screen detected). If stage information was not available, patients were not included in stage-specific analyses. The primary outcome was proportion and stage distribution of screen-detected versus non-screen detected colorectal cancers.

FINDINGS

228 667 colorectal cancer cases were included in the analyses. Proportions of screen-detected cancers varied widely across countries and regions. The highest proportions (40-60%) were found in Slovenia and the Basque Country in Spain, where FIT-based programmes were fully rolled out, and participation rates were higher than 50%. A similar proportion of screen-detected cancers was also found for the Netherlands in 2015, where participation was over 70%, even though the programme had not yet been fully rolled out to all age groups. In most other countries and regions, proportions of screen-detected cancers were below 30%. Compared with non-screen-detected cancers, screen-detected cancers were much more often found in the distal colon (range 34·5-51·1% screen detected vs 26·4-35·7% non-screen detected) and less often in the proximal colon (19·5-29·9% screen detected vs 24·9-32·8% non-screen detected) p≤0·02 for each country, more often at stage I (35·7-52·7% screen detected vs 13·2-24·9% non-screen detected), and less often at stage IV (5·8-12·5% screen detected vs 22·5-31·9% non-screen detected) p<0·0001 for each country.

INTERPRETATION

The proportion of colorectal cancer cases detected by screening varied widely between countries. However, in all countries, screen-detected cancers had a more favourable stage distribution than cancers detected otherwise. There is still much need and scope for improving early detection of cancer across all segments of the colorectum, and particularly in the proximal colon and rectum.

FUNDING

Deutsche Krebshilfe.

External Validation of Two Established Clinical Risk Scores Predicting Outcome after Local Treatment of Colorectal Liver Metastases in a Nationwide Cohort

Optimized surgical techniques and systemic therapy have increased the number of patients with colorectal liver metastases (CRLM) eligible for local treatment. To increase postoperative survival, we need to stratify patients to customize therapy. Most clinical risk scores (CRSs) which predict prognosis after CRLM resection were based on the outcome of studies in specialized centers, and this may hamper the generalizability of these CRSs in unselected populations and underrepresented subgroups. We aimed to externally validate two CRSs in a population-based cohort of patients with CRLM. A total of 1105 patients with local treatment of CRLM, diagnosed in 2015/2016, were included from a nationwide population-based database. Survival outcomes were analyzed. The Fong and more recently developed GAME CRS were externally validated, including in pre-specified subgroups (≤70/>70 years and with/without perioperative systemic therapy). The three-year DFS was 22.8%, and the median OS in the GAME risk groups (high/moderate/low) was 32.4, 46.7, and 68.1 months, respectively (p < 0.005). The median OS for patients with versus without perioperative therapy was 47.6 (95%CI [39.8, 56.2]) and 54.9 months (95%CI [48.8, 63.7]), respectively (p = 0.152), and for below/above 70 years, it was 54.9 (95%CI [49.3−64.1]) and 44.2 months (95%CI [37.1−54.3]), respectively (p < 0.005). The discriminative ability for OS of Fong CRS was 0.577 (95%CI [0.554, 0.601]), and for GAME, it was 0.596 (95%CI [0.572, 0.621]), and was comparable in the subgroups. In conclusion, both CRSs showed predictive ability in a population-based cohort and in predefined subgroups. However, the limited discriminative ability of these CRSs results in insufficient preoperative risk stratification for clinical decision-making.

Limited impact of the COVID-19 pandemic on colorectal cancer care in the Netherlands in 2020

PURPOSE

The COVID-19 pandemic had a major impact on the health services worldwide. We aimed to investigate the impact of the pandemic on colorectal cancer (CRC) care in the Netherlands in 2020.

METHODS

CRC patients, diagnosed in 2018-2020 in the Netherlands, were selected from the Netherlands Cancer Registry (NCR). The year 2020 was divided in four periods reflecting COVID-19 developments in the Netherlands (pre-COVID, 1st peak, recovery period, 2nd peak) and compared with the same periods in 2018/2019. Patient characteristics and treatment were compared using the Chi-squared test. Median time between diagnosis and treatment, and between (neo)adjuvant therapy and surgery were analyzed by the Mann-Whitney U test.

RESULTS

In total, 38,021 CRC patients were diagnosed in 2018/2019 (n = 26,816) and 2020 (n = 11,205). Median time between diagnosis and initial treatment decreased on average 4 days and median time between neoadjuvant radiotherapy and surgery in clinical stage II or III rectal cancer patients increased on average 34 days during the three COVID-19 periods compared to the same periods of 2018/2019. The proportion of colon cancer patients that underwent elective surgery significantly decreased with 3.0% during the 1st peak. No differences were found in the proportion of patients who received (neo)adjuvant therapy, systemic therapy, or no anti-cancer treatment.

CONCLUSION

Only minor changes in the care for CRC patients occurred during the COVID-19 pandemic, mostly during the 1^st peak. In conclusion, the impact on CRC care in the Netherlands was found to be limited. However, long-term effects cannot be precluded.

Impact of COVID-19 and suspension of colorectal cancer screening on incidence and stage distribution of colorectal cancers in the Netherlands

Many countries had to suspend their colorectal cancer (CRC) screening programme as a result of the COVID-19 pandemic. This eventually may lead to postponed diagnoses of premalignant lesions and CRC, resulting in increased incidence or more advanced CRCs rates. This study aimed to assess the impact of the COVID-19 pandemic on incidence and stage distribution of CRCs in the Netherlands, by monitoring CRC diagnoses and stage distribution in the months before, during and after the first COVID-19 wave. Data on incidence and stage distribution of CRCs of individuals aged 55-75 years in 25 hospitals in the Netherlands were extracted from the Netherlands Cancer Registry. The observed incidence after the suspension (March 2020-December 2020) was compared to the expected incidence in the same period. In the period April to June 2020, we observed the largest decrease in the total incidence of CRC. We found that 48% of the decrease was due to stage I, 23% due to stage II, 23% due to stage III and 5% due to stage IV. After gradually resuming screening mid May 2020, we observed an increase in CRC diagnoses from July 2020 onwards. As of October 2020, the observed number of diagnoses was higher than the expected number. As the decrease was mainly limited to stage I CRCs, it seems that the temporary suspension of the CRC screening programme due to the COVID-19 pandemic will have a minimal long-term impact on stage distribution and CRC mortality.

Treatment of metachronous colorectal cancer metastases in the Netherlands: A population-based study

BACKGROUND

This study aimed to describe the treatment of metachronous colorectal cancer metastases in a recent population-based cohort.

METHOD

Patients with stage I-III colorectal cancer (CRC), diagnosed between January 1st and June 30th^, 2015 who were surgically treated with curative intent were selected from the Netherlands Cancer Registry. Follow-up was at least 3 years after diagnosis of the primary tumour. Treatment of metachronous metastases was categorized into local treatment, systemic treatment, and best supportive care. Overall survival was estimated using Kaplan-Meier method.

RESULTS

Out of 5412 patients, 782 (14%) developed metachronous metastases, of whom 393 (50%) underwent local treatment (LT) with or without systemic therapy, 30% of patients underwent only systemic therapy (ST) and 19% only best supportive care (BSC). The most common metastatic site was the liver (51%) followed by lungs (33%) and peritoneum (22%). LT rates were 69%, 66%, and 44% for liver-only, lung-only and, peritoneal-only metastases respectively. Patients receiving LT and ST were significantly younger than patients receiving LT alone, while patients receiving BSC were significantly older than the other groups (p < 0.001). Patients with liver-only or lung-only metastases had a 3-year OS of 50.2% (43.3-56.7 95% CI) and 61.5% (50.7-70.6 95% CI) respectively. Patients with peritoneal-only disease had a lower 3-year OS, 18.1% (10.1-28.0 95% CI).

CONCLUSION

Patients with metastases confined to the liver and lung have the highest rates of local treatment for metachronous metastatic colorectal cancer. The number of patients who underwent local treatment is higher than reported in previous Dutch and international studies.

Changes in rectal cancer treatment after the introduction of a national screening program; Increasing use of less invasive strategies within a national cohort

AIM

Organ preserving treatment strategies and the introduction of a colorectal cancer-screening program have likely influenced the resection rates of rectal cancer. The aim of this study is to assess the influence of these developments on rectal cancer treatment and resection rates in the Netherlands.

METHODS

Patients diagnosed with non-metastatic rectal cancer between 2013 and 2018, were selected from the Netherlands Cancer Registry. The distribution of surgical and neo-adjuvant treatment and resection rates were analyzed and compared over time.

RESULTS

Between 2013 and 2018 22640 patients were diagnosed with non-metastatic rectal cancer. The incidence of early stage (cT1) disease increased from 141 (4%) in 2013 to 448 (12%) in 2018. The use of neoadjuvant radiotherapy and chemo-radiotherapy dropped from 39% to 21% and 34%-25%, respectively. A decrease in surgical resection rates (including TEM) was observed from 85% to 73%. The proportion of patients who underwent endoscopic resections increased from 3% to 10%. The decrease in surgical resection rates was larger in patients treated with neo-adjuvant chemo-radiotherapy.

CONCLUSION

An increase in stage I disease is noted after the introduction of the screening program. Surgical resection rates for rectal cancer have fallen over time. Endoscopic resections due to more early-stage disease probably accounts for a large part of this decline. Furthermore, a watch and wait approach after neo-adjuvant chemo-radiotherapy may play an important role as well.

Colorectal cancer incidence, mortality, tumour characteristics, and treatment before and after introduction of the faecal immunochemical testing-based screening programme in the Netherlands: a population-based study

BACKGROUND

In 2014, a population-based colorectal cancer (CRC) screening programme was stepwise implemented in the Netherlands comprising faecal immunochemical testing once every 2 years, with a cutoff value for positivity of 47 μg haemoglobin per g faeces. We aimed to assess CRC incidence, mortality, tumour characteristics, and treatment before and after introduction of this screening programme.

METHODS

We did a retrospective, observational, population-based study in the Netherlands and gathered CRC incidence data from the Netherlands Cancer Registry from Jan 1, 2010, to Dec 31, 2019, in people aged 55 years or older. Patients with a CRC diagnosis between Jan 1, 2014, and Dec 31, 2018, in the Netherlands Cancer Registry were linked with the nationwide registry of histopathology and cytopathology (PALGA) to identify mode of detection (ie, screening-detected vs clinically detected). We calculated age-standardised CRC incidence rates and used data from Statistics Netherlands to calculate CRC-related mortality in 2010-19. We compared localisation, stage distribution, and treatment of screening-detected CRCs with clinically detected CRCs diagnosed in 2014-18 in patients aged 55-75 years.

FINDINGS

Between Jan 1, 2010, and Dec 31, 2019, 125 215 CRCs were diagnosed in individuals aged 55 years or older and were included in the analyses for CRC incidence. Before the introduction of the screening programme, the age-standardised CRC incidence rate was 214·3 per 100 000 population in 2013 in people aged 55 years or older. After the introduction of the screening programme, this rate initially increased to 259·2 per 100 000 population in 2015, and subsequently decreased to 181·5 per 100 000 population in 2019. Age-standardised incidence rates for advanced CRCs (stage III and IV) were 117·0 per 100 000 population in 2013 and increased to 122·8 per 100 000 population in 2015; this rate then decreased to 94·7 per 100 000 population in 2018. Age-standardised CRC mortality decreased from 87·5 deaths per 100 000 population in 2010 to 64·8 per 100 000 population in 2019. Compared with clinically detected CRCs, screening-detected CRCs were more likely to be located in the left side of the colon (48·6% vs 35·2%) and to be detected at an early stage (I or II; 66·7% vs 46·2%). Screening-detected CRCs were more likely to be treated by local excision compared with clinically detected CRCs, and this finding persisted when stage I CRCs were analysed separately.

INTERPRETATION

After introduction of this national screening programme, a decrease in overall and advanced-stage CRC incidence was observed. In view of this observation, together with the observed shift to detection at earlier stages and more screening-detected CRCs being treated by local excision, we might cautiously conclude that, in the long-term, faecal immunochemical testing-based screening could ultimately lead to a decrease in CRC-related morbidity and mortality.

FUNDING

None.

Treatment of clinical T1 rectal cancer in the Netherlands; a population-based overview of clinical practice

INTRODUCTION

Local excision is increasingly used as an alternative treatment for radical surgery in patients with early stage clinical T1 (cT1) rectal cancer. This study provides an overview of incidence, staging accuracy and treatment strategies in patients with cT1 rectal cancer in the Netherlands.

MATERIALS AND METHODS

Patients with cT1 rectal cancer diagnosed between 2005 and 2018 were included from the Netherlands Cancer Registry. An overview per time period (2005-2009, 2010-2014 and 2015-2018) of the incidence and various treatment strategies used, e.g. local excision (LE) or major resection, with/without neoadjuvant treatment (NAT), were given and trends over time were analysed using the Chi Square for Trend test. In addition, accuracy of tumour staging was described, compared and analysed over time.

RESULTS

In total, 3033 patients with cT1 rectal cancer were diagnosed. The incidence of cT1 increased from 540 patients in 2005-2009 to 1643 patients in 2015-2018. There was a significant increased use of LE. In cT1N0/X patients, 9.2% received NAT, 25.5% were treated by total mesorectal excision (TME) and 11.4% received a completion TME (cTME) following prior LE. Overall accuracy in tumour staging (cT1 = pT1) was 77.3%, yet significantly worse in cN1/2 patients, as compared to cN0 patients (44.8% vs 77.9%, respectively, p < 0.001).

CONCLUSION

Over time, there was an increase in the incidence of cT1 tumours. Both the use of neoadjuvant therapy and TME surgery in clinically node negative patients decreased significantly. Clinical accuracy in T1 tumour staging improved over time, but remained significantly worse in clinical node positive patients.

Nationwide evaluation of mutation-tailored anti-EGFR therapy selection in patients with colorectal cancer in daily clinical practice

For a nationwide real-word data study on the application of predictive mutation testing of patients with colorectal cancer (CRC) for anti-epidermal growth factor receptor (EGFR) therapy stratification, pathology data were collected from the Dutch Pathology Registry from October 2017 until June 2019 (N=4060) and linked with the Netherlands Cancer Registry. Mutation testing rates increased from 24% at diagnosis of stage IV disease to 60% after 20-23 months of follow-up (p<0.001). Application of anti-EGFR therapy in KRAS/NRAS wild-type patients was mainly observed from the third treatment line onwards (65% vs 17% in first/second treatment line (p<0.001)). The national average KRAS/NRAS/BRAF mutation rate was 63.9%, being similar for next-generation sequencing (NGS)-based approaches and single gene tests (64.4% vs 61.2%, p=ns). NGS-based approaches detected more additional potential biomarkers, for example, ERBB2 amplifications (p<0.05). Therefore, single gene tests are suitable to stratify patients with mCRC for anti-EGFR therapy, but NGS is superior enabling upfront identification of therapy resistance or facilitate enrolment into clinical trials.

Colorectal cancer incidence, mortality, and stage distribution in European countries in the colorectal cancer screening era: an international population-based study

BACKGROUND

Colorectal cancer screening programmes and uptake vary substantially across Europe. We aimed to compare changes over time in colorectal cancer incidence, mortality, and stage distribution in relation to colorectal cancer screening implementation in European countries.

METHODS

Data from nearly 3·1 million patients with colorectal cancer diagnosed from 2000 onwards (up to 2016 for most countries) were obtained from 21 European countries, and were used to analyse changes over time in age-standardised colorectal cancer incidence and stage distribution. The WHO mortality database was used to analyse changes over time in age-standardised colorectal cancer mortality over the same period for the 16 countries with nationwide data. Incidence rates were calculated for all sites of the colon and rectum combined, as well as the subsites proximal colon, distal colon, and rectum. Average annual percentage changes (AAPCs) in incidence and mortality were estimated and relevant patterns were descriptively analysed.

FINDINGS

In countries with long-standing programmes of screening colonoscopy and faecal tests (ie, Austria, the Czech Republic, and Germany), colorectal cancer incidence decreased substantially over time, with AAPCs ranging from -2·5% (95% CI -2·8 to -2·2) to -1·6% (-2·0 to -1·2) in men and from -2·4% (-2·7 to -2·1) to -1·3% (-1·7 to -0·9) in women. In countries where screening programmes were implemented during the study period, age-standardised colorectal cancer incidence either remained stable or increased up to the year screening was implemented. AAPCs for these countries ranged from -0·2% (95% CI -1·4 to 1·0) to 1·5% (1·1 to 1·8) in men and from -0·5% (-1·7 to 0·6) to 1·2% (0·8 to 1·5) in women. Where high screening coverage and uptake were rapidly achieved (ie, Denmark, the Netherlands, and Slovenia), age-standardised incidence rates initially increased but then subsequently decreased. Conversely, colorectal cancer incidence increased in most countries where no large-scale screening programmes were available (eg, Bulgaria, Estonia, Norway, and Ukraine), with AAPCs ranging from 0·3% (95% CI 0·1 to 0·5) to 1·9% (1·2 to 2·6) in men and from 0·6% (0·4 to 0·8) to 1·1% (0·8 to 1·4) in women. The largest decreases in colorectal cancer mortality were seen in countries with long-standing screening programmes.

INTERPRETATION

We observed divergent trends in colorectal cancer incidence, mortality, and stage distribution across European countries, which appear to be largely explained by different levels of colorectal cancer screening implementation.

FUNDING

German Cancer Aid (Deutsche Krebshilfe) and the German Federal Ministry of Education and Research.

Surgery for rectal cancer: Differences in resection rates among hospitals in the Netherlands

AIM

Numerous quality improvement initiatives for rectal cancer surgery have focused on textbook outcome parameters. In these studies, resection rate and patients who did not undergo surgery are not included, but these parameters might help to evaluate the surgical care for rectal cancer. The aim of this study is to assess the variation of non-metastatic rectal cancer resection rates among hospitals and its effect on patient outcomes.

METHODS

All patients diagnosed with non-metastatic rectal cancer between 2013 and 2018 were selected from the Netherlands Cancer Registry. Hospitals were categorized in quartiles according to resection rates. A multivariable logistic analysis was performed to determine variation in resection rate between these quartiles using a logistic regression analysis to correct for confounders. The association between resection rates and survival was analyzed using Kaplan-Meier method and Cox-regression analysis.

RESULTS

A total of 22,530 patients were included in the analysis. Resection rates varied from 68 to 89% between hospitals. After multivariable analysis, resection rate remained significantly different among the quartiles when correcting for several factors (odds ratio (95%Confidence-interval) 1.71 (1.56-1.88), 2.42 (2.19-2.67), and 4.04 (3.61-4.53) for increasing resection rate quartiles, in reference to the lowest quartile). A higher resection rate was associated with better overall survival, in multivariable analysis this survival benefit could no longer be identified.

CONCLUSION

There is a substantial variation in resection rates for rectal cancer among hospitals in the Netherlands with an impact on overall survival. This may be a relevant issue when analyzing the overall quality of rectal cancer care.

The impact of the temporary suspension of national cancer screening programmes due to the COVID-19 epidemic on the diagnosis of breast and colorectal cancer in the Netherlands

Oncological care was largely derailed due to the reprioritisation of health care services to handle the initial surge of COVID-19 patients adequately. Cancer screening programmes were no exception in this reprioritisation. They were temporarily halted in the Netherlands (1) to alleviate the pressure on health care services overwhelmed by the upsurge of COVID-19 patients, (2) to reallocate staff and personal protective equipment to support critical COVID-19 care, and (3) to mitigate the spread of COVID-19. Utilising data from the Netherlands Cancer Registry on provisional cancer diagnoses between 6 January 2020 and 4 October 2020, we assessed the impact of the temporary halt of national population screening programmes on the diagnosis of breast and colorectal cancer in the Netherlands. A dynamic harmonic regression model with ARIMA error components was applied to assess the observed versus expected number of cancer diagnoses per calendar week. Fewer diagnoses of breast and colorectal cancer were objectified amid the early stages of the initial COVID-19 outbreak in the Netherlands. This effect was most pronounced among the age groups eligible for cancer screening programmes, especially in breast cancer (age group 50–74 years). Encouragingly enough, the observed number of diagnoses ultimately reached and virtually remained at the level of the expected values. This finding, which emerged earlier in age groups not invited for cancer screening programmes, comes on account of the decreased demand for critical COVID-19 care since early April 2020, which, in turn, paved the way forward to resume screening programmes and a broad range of non-critical health care services, albeit with limited operating and workforce capacity. Collectively, transient changes in health-seeking behaviour, referral practices, and cancer screening programmes amid the early stages of the initial COVID-19 epidemic in the Netherlands conjointly acted as an accelerant for fewer breast and colorectal cancer diagnoses in age groups eligible for cancer screening programmes. Forthcoming research is warranted to assess whether the decreased diagnostic scrutiny of cancer during the COVID-19 pandemic resulted in stage migration and altered clinical management, as well as poorer outcomes.

Informing metastatic colorectal cancer patients by quantifying multiple scenarios for survival time based on real-life data

Reported median overall survival (mOS) in metastatic colorectal cancer (mCRC) patients participating in systemic therapy trials has increased to over 30 months. It is uncertain whether trial results translate to real-life populations. Moreover, patients prefer presentation of multiple survival scenarios. Population-based data of all stage IV CRC patients diagnosed between 2008 and 2016 were obtained from the Netherlands Cancer Registry, which has a case ascertainment completeness surpassing 95%. We calculated the following percentiles (scenarios) of OS per year of diagnosis for the total population, and for treatment subgroups: 10th (best-case), 25th (upper-typical), 50th (median), 75th (lower-typical) and 90th (worst-case). Twenty-five percent of patients did not receive any antitumor treatment. From 2008 to 2016, mOS of the total population (n = 27275) remained unchanged at approximately 12 months. OS improved only for the upper-typical and best-case patients; by 4.2 to 29.1 months (P < .001), and by 6 to 62 months (P < .001), respectively. No clinically relevant change was observed among patients who received systemic therapy, with mOS close to 15 months and best-case scenario approximately 40 months. A clinically relevant improvement in survival over time was observed in patients who initially received metastasectomy and/or HIPEC only. In contrast to the wide belief based on trial data that mOS of mCRC patients receiving systemic therapy has improved substantially, improvement could not be demonstrated in our real-life population. Clinicians should consider quoting multiple survival scenarios based on real-life data instead of point estimates from clinical trials, when informing patients about their life expectancy.

Increased risk for second primary rectal cancer after pelvic radiation therapy

BACKGROUND

The aim of this study was to analyse the association between pelvic radiation therapy (RT) and the development of rectal cancer as a second primary cancer.

METHODS

Data on patients treated for a primary pelvic cancer between 1989 and 2007 were retrieved from the population-based Netherlands Cancer Registry. Patients treated for more than one pelvic cancer were excluded. To estimate the cumulative incidence of rectal cancer, Fine and Gray's competing risk model was used with death as a competing event. Survival was calculated using multivariable Cox regression.

RESULTS

A total of 192,658 patients were included, of which 62,630 patients were treated with RT for their pelvic cancer. Primary tumours were located in the prostate (50.1%), bladder (19.2%), endometrium (13.9%), ovaries (10.0%), cervix (6.4%) and vagina (0.4%). At a median interval of 6 years (range 0-24), 1369 patients developed a rectal cancer. Overall, the risk for rectal cancer was increased in patients who underwent RT for the previous pelvic cancer (subhazard ratio [SHR]: 1.72, 95% confidence interval [CI]: 1.55-1.91). Analysis for each tumour location specifically showed an increased risk in patients who received RT for prostate (SHR: 1.89, 95% CI: 1.66-2.16) or endometrial cancer (SHR: 1.50, 95% CI: 1.13-2.00). A protective effect of RT was observed for patients with bladder cancer (SHR 0.67, 95% CI: 0.47-0.94). There was no survival difference between patients with rectal cancer with or without previous RT (hazard ratio: 0.94, 95% CI: 0.79-1.11).

CONCLUSIONS

Patients who received RT for a previous pelvic cancer were at increased risk for rectal cancer. The risk was modest and pronounced in patients receiving RT for prostate and endometrial cancer.

Tumor response after long interval comparing 5x5Gy radiation therapy with chemoradiation therapy in rectal cancer patients

BACKGROUND

In the era of organ preserving strategies in rectal cancer, insight into the efficacy of preoperative therapies is crucial. The goal of the current study was to evaluate and compare tumor response in rectal cancer patients according to their type of preoperative therapy.

METHODS

All rectal cancer patients diagnosed between 2005 and 2014, receiving radiation therapy (RT, 5 × 5Gy; N = 764) or chemoradiation therapy (CRT; N = 5070) followed by total mesorectal excision after an interval of 5-15 weeks were retrieved from the nationwide Netherlands Cancer registry. Logistic regression was used for multivariable analysis.

RESULTS

Median age of patients treated with RT was 76 years (range 28-92) compared to 64 years (range 21-92) for patients treated with CRT (P < 0.001). Patients treated with RT had a significantly lower clinical stage (P < 0.001). A complete pathologic response (ypT0N0) was found in 9.3% of patients treated with RT, significantly less than in patients treated with CRT (17.5%; odds ratio [OR] 0.37, 95% confidence interval [CI] 0.24-0.57). A good response (ypT0-1N0) was observed in 17.5% of patients treated with RT and in 22.6% of patients treated with CRT (OR 0.70, 95% CI 0.51-0.95). Histological subtype, clinical stage and distance to anus were identified as independent predictors for tumor response.

CONCLUSIONS

Despite a more advanced clinical stage, complete pathologic response was more common in patients treated with CRT than in patients treated with RT. Prospective trials are needed to establish the differences in other outcome parameters, including the impact on organ preserving strategies.

Incidence of second tumors after treatment with or without radiation for rectal cancer

Background

The aim of this study was to analyze the association between radiation therapy (RT) for rectal cancer and the development of second tumors.

Patients and methods

Data on all surgically treated non-metastatic primary rectal cancer patients diagnosed between 1989 and 2007 were retrieved from the Netherlands population-based cancer registry. Fine and Gray's competing risk model was used for estimation of the cumulative incidence of second tumors. Multivariable analysis was conducted using Cox regression.

Results

The cohort consisted of 29 027 patients of which 15 467 patients had undergone RT. Median follow-up was 7.7 years (range 0-27). Among all 4398 patients who were diagnosed with a second primary tumor, 1030 had one or more pelvic tumors. The standardized incidence risk for any second tumor was 1.16 (95% confidence interval [CI] 1.12-1.19), resulting in 27.7/10 000 excess cancer cases per year in patients treated for rectal cancer compared with the general population. RT reduced the cumulative incidence of second pelvic tumors compared with patients who did not receive RT (subhazard ratio [SHR] 0.77, CI 0.68-0.88). Second prostate tumors were less common in patients who received RT (SHR 0.54, CI 0.46-0.64), gynecological tumors were more frequently observed in patients who received RT (SHR 1.49, CI 1.11-2.00).

Conclusions

Patients with previous rectal cancer had a marginally increased risk of a second tumor compared with the general population. Gynecological tumors occurred more often in females who received RT, but this did not result in an overall increased risk for a second cancer. RT even seemed to have a protective effect on the development of other second pelvic tumors, pre-dominantly for prostate cancer. These findings are highly important and can contribute to improved patient counseling.

Tumor-stroma ratio as prognostic factor for survival in rectal adenocarcinoma: A retrospective cohort study

AIM

To evaluate the prognostic value of the tumor-stroma ratio (TSR) in rectal cancer.

METHODS

TSR was determined on hematoxylin and eosin stained histological sections of 154 patients treated for rectal adenocarcinoma without prior neoadjuvant treatment in the period 1996-2006 by two observers to assess reproducibility. Patients were categorized into three categories: TSR-high [carcinoma percentage (CP) ≥ 70%], TSR-intermediate (CP 40%, 50% and 60%) and TSR-low (CP ≤ 30%). The relation between categorized TSR and survival was analyzed using Cox proportional hazards model.

RESULTS

Thirty-six (23.4%) patients were scored as TSR-low, 70 (45.4%) as TSR-intermediate and 48 (31.2%) as TSR-high. TSR had a good interobserver agreement (κ = 0.724, concordance 82.5%). Overall survival (OS) and disease free survival (DFS) were significantly better for patients with a high TSR (P = 0.01 and P = 0.02, respectively). A similar association existed for disease specific survival (P = 0.06). In multivariate analysis, patients without lymph node metastasis and an intermediate TSR had a higher risk of dying from rectal cancer (HR = 5.27, 95%CI: 1.54-18.10), compared to lymph node metastasis negative patients with a high TSR. This group also had a worse DFS (HR = 6.41, 95%CI: 1.84-22.28). An identical association was seen for OS. These relations were not seen in lymph node metastasis positive patients.

CONCLUSION

The TSR has potential as a prognostic factor for survival in surgically treated rectal cancer patients, especially in lymph node negative cases.

Ethnic differences in colon cancer care in the Netherlands: a nationwide registry-based study

Background

Ethnic differences in colon cancer (CC) care were shown in the United States, but results are not directly applicable to European countries due to fundamental healthcare system differences. This is the first study addressing ethnic differences in treatment and survival for CC in the Netherlands.

Methods

Data of 101,882 patients diagnosed with CC in 1996–2011 were selected from the Netherlands Cancer Registry and linked to databases from Statistics Netherlands. Ethnic differences in lymph node (LN) evaluation, anastomotic leakage and adjuvant chemotherapy were analysed using stepwise logistic regression models. Stepwise Cox regression was used to examine the influence of ethnic differences in adjuvant chemotherapy on 5-year all-cause and colorectal cancer-specific survival.

Results

Adequate LN evaluation was significantly more likely for patients from ‘other Western’ countries than for the Dutch (OR 1.09; 95% CI 1.01–1.16). ‘Other Western’ patients had a significantly higher risk of anastomotic leakage after resection (OR 1.24; 95% CI 1.05–1.47). Patients of Moroccan origin were significantly less likely to receive adjuvant chemotherapy (OR 0.27; 95% CI 0.13–0.59). Ethnic differences were not fully explained by differences in socioeconomic and hospital-related characteristics. The higher 5-year all-cause mortality of Moroccan patients (HR 1.64; 95% CI 1.03–2.61) was statistically explained by differences in adjuvant chemotherapy receipt.

Conclusion

These results suggest the presence of ethnic inequalities in CC care in the Netherlands. We recommend further analysis of the role of comorbidity, communication in patient-provider interaction and patients’ health literacy when looking at ethnic differences in treatment for CC.

Treatment Interval between Neoadjuvant Chemoradiotherapy and Surgery in Rectal Cancer Patients: A Population-Based Study

Background

Neoadjuvant chemoradiation therapy (CRT) has been widely implemented in the treatment of rectal cancer patients, but optimal timing of surgery after neoadjuvant therapy is unclear. The purpose of this study was to evaluate the effects of prolonged intervals between long-course CRT and surgery in rectal cancer patients.

Methods

Data on all rectal cancer patients diagnosed between 2006 and 2011 were retrieved from the population-based Netherlands Cancer Registry; the main outcome parameters were pathologic complete response (pCR) and overall survival (OS). Outcomes were reported separately for patients with early tumors (ETs; N = 217) and locally advanced rectal cancer (LARC; N = 1073). Patients were divided into 2-week interval groups according to treatment interval, ranging from 5–6 to 13–14 weeks. Kaplan–Meier curves, and logistic regression and Cox regression models were used for data analysis.

Results

No significant difference in pCR rate was observed for ET patients according to treatment interval. Compared with a treatment interval of 7–8 weeks, pCR rates in LARC patients were higher after 9–10 weeks (18.4 %; odds ratio [OR] 1.56, 95 % CI 1.03–2.37) and 11–12 weeks of treatment interval (20.8 %; OR 1.94, 95 % CI 1.15–3.26). Treatment interval did not influence OS in ET or LARC patients.

Conclusions

Treatment intervals of 9–12 weeks between surgery and CRT seem to improve the chances of pCR in LARC patients, without an effect on OS. The length of treatment interval did not affect outcomes in patients with ET. The ongoing search for minimally invasive surgery drives the need for exploration of factors that improve pathologic response.

Electronic supplementary material

The online version of this article (doi:10.1245/s10434-016-5294-0) contains supplementary material, which is available to authorized users.

The incidence of secondary pelvic tumors after previous (chemo)radiation for rectal cancer

491

Background: The aim of this study was to analyze the association between radiotherapy (RT) for rectal cancer and the development of second primary tumors. Methods: Data on all surgically treated, non-metastasized primary rectal cancer patients diagnosed between 1989 and 2007 were retrieved from a population-based cancer registry and retrospectively reviewed. To estimate the cumulative incidence of a second tumor, Fine and Gray’s competing risk model was used with death as a competing event. Standardized incidence ratios (SIR’s) were calculated for comparison with the incidence of primary tumors in the general population, taking in account sex, age and calendar year. Results: The cohort consisted of 29,214 patients of which 15,454 patients had undergone (chemo)RT. Median follow-up was 6.2 years (range 0-24). 3655 patients were diagnosed with at least one second primary tumor of which 808 patients had pelvic tumors. The SIR for any second tumor was 1.14 (95% confidence interval [CI] 1.10-1.17), resulting in 23.3/10,000 excess cases per year. RT reduced the cumulative incidence of second pelvic tumors compared to patients who received no RT (SHR 0.70, 95% CI 0.61-0.81). Second pelvic tumors were more common in patients who underwent post-operative RT than in patients who underwent pre-operative RT (SHR 1.37, 95% CI 1.10-1.70). Organ-specific analyses showed that second prostate tumors were less common in patients who received RT compared to patients who received no RT (SHR = 0.51, 95% CI 0.43-0.62). RT also reduced the risk for a second primary tumor in the rectum(sigmoid) compared to patients who did not receive RT (SHR 0.59 95% CI 0.37-0.94). Patients who received post-operative RT had higher chances of developing a second rectum(sigmoid) tumor then patients who received pre-operative RT (SHR 2.25, 95% CI 1.07-4.73). Patients without RT had worse overall survival than patients who received RT (hazard ratio 1.22, 95% CI 1.19-1.26). Conclusions: In this nationwide study, patients with previous rectal cancer had a slightly increased chance of developing another primary tumor compared with the general population. We found a protective effect of RT on the development of secondary pelvic tumors, predominantly for prostate cancer.

Long-term effects of a regional care pathway for patients with rectal cancer

PURPOSE

Introducing care pathways is seen as a method to realise patient-focussed care conform evidence-based guidelines. The goal of this study is to determine the long-term effects of a regional care pathway for patients with rectal cancer.

PATIENTS AND METHODS

Data on almost 400 patients with rectal carcinoma from three hospitals were obtained from the Netherlands Cancer Registry and the Dutch Surgical Colorectal Audit. Results on seven structure and process indicators were analysed and compared before and at two time points after implementing a regional care pathway over a total period from 2007 to 2012. To determine motivation and interpret the results, relevant professionals of the participating hospitals were interviewed.

RESULTS

After implementing the care pathway, the performance of computed tomography (CT) scans in the diagnostic phase significantly improved (p = 0.007/0.07). The number of patients discussed in the preoperative multidisciplinary team (MDT) meeting improved significantly (p = <0.001), and after implementing the care pathway, 94% of the patients were discussed. Further, a significant reduction in time between the first tumour biopsy and the MDT meeting was realised (p = 0.01). Professionals stated that the regional care pathway has led to more clarity about the patient route and more awareness about complying with evidence-based guidelines.

CONCLUSIONS

The regional care pathway provided a solid basis for uniforming care, working according evidence-based guidelines and further cooperation on regional level. For mainly the waiting and throughput times, the guidelines and norms had probably a stronger effect on the results than the care pathway.

Nationwide trends in incidence, treatment and survival of colorectal cancer patients with synchronous metastases

The aim of this study was to determine trends in incidence, treatment and survival of colorectal cancer (CRC) patients with synchronous metastases (Stage IV) in the Netherlands. This nationwide population-based study included 160,278 patients diagnosed with CRC between 1996 and 2011. We evaluated changes in stage distribution, location of synchronous metastases and treatment in four consecutive periods, using Chi square tests for trend. Median survival in months was determined, using Kaplan-Meier analysis. The proportion of Stage IV CRC patients (n = 33,421) increased from 19 % (1996-1999) to 23 % (2008-2011, p < 0.001). This was predominantly due to a major increase in the incidence of lung metastases (1.7-5.0 % of all CRC patients). During the study period, the primary tumor was resected less often in Stage IV patients (65-46 %) and the use of systemic treatment has increased (29-60 %). Also an increase in metastasectomy was found in patients with one metastatic site, especially in patients with liver-only disease (5-18 %, p < 0.001). Median survival of all Stage IV CRC patients increased from 7 to 12 months. Especially in patients with metastases confined to the liver or lungs this improvement in survival was apparent (9-16 and 12-24 months respectively, both p < 0.001). In the last two decades, more lung metastases were detected and an increasing proportion of Stage IV CRC patients was treated with systemic therapy and/or metastasectomy. Survival of patients has significantly improved. However, the prognosis of Stage IV patients becomes increasingly diverse.

Metachronous metastases from colorectal cancer: a population-based study in North-East Netherlands

PURPOSE

The main cause of death of colorectal cancer patients is metastatic disease. Approximately 20-25% of the patients present with metastases at time of diagnosis. The clinical course of patients who develop metachronous metastases, however, is less clear. The aims of this study were to describe the incidence, treatment and survival of patients with metachronous metastases from colorectal cancer and to determine risk factors for developing metachronous metastases.

METHODS

From the Netherlands Cancer Registry, patients diagnosed with colorectal carcinoma in the period 2002-2003 in North-East Netherlands were selected. Patients were followed for 5 years after diagnosis of the primary tumour. Kaplan-Meier method and Cox regression analyses were used to determine predictors for developing metastases and to analyse overall survival.

RESULTS

In total, 333 of 1743 (19%) patients developed metachronous metastases. The majority (83%) of these metastases were diagnosed within 3 years, and the most frequent site was the liver. Patients with advanced stage and patients with tumours in the descending colon or in the rectum were more likely to develop metastases. Approximately 10% of all patients underwent intentionally curative treatment for their metastases, with a 5-year survival rate of 60%. Treatment of metastases and pathologic N (pN) status were independent prognostic factors for overall survival.

CONCLUSIONS

Site and stage of the primary tumour were predictors for developing metachronous metastases. A limited number of patients with metastatic disease were treated with a curative intent. These patients had a good prognosis. Therefore, focus should be on identifying more patients who could benefit from curative treatment.

Colorectal signet-ring cell carcinoma: Responsive to adjuvant chemotherapy but still a poor prognosis

529

Background: Colorectal signet-ring cell carcinoma (SRCC) has been associated with a poor survival compared to mucinous adenocarcinoma (MC) and the common adenocarcinoma (AC). Prognostic impact of tumor localization is unknown and efficacy of adjuvant chemotherapy in SRCC has never been assessed. This study analyses prognostic impact of SRCC and determines whether SRCC patients benefit from adjuvant chemotherapy for colon cancer equally compared with AC. Methods: Data on 196,757 patients with CRC in the Netherlands in the period 1989 and 2010 was included in this nationwide population-based study. Five-year relative survival estimates were calculated and multivariate relative survival analyses using a multiple regression model of relative excess risk (RER) were performed. Results: SRCC was found in 1.0% of CRC patients. SRCC patients presented more frequently with stage III or IV disease than AC (75.2% versus 43.6%, P<0.0001) and SRCC was more frequently found in the proximal colon (57.7% versus 32.0%, P<0.0001). SRCC patients had a poor 5-year relative survival of 31% in colon and 20% in the rectum compared to 57% and 59% in AC (P<0.0001). This poorer survival for SRCC was found in stage II, III and IV. In comparison with AC, there was no significant interaction between SRCC and adjuvant chemotherapy (RER 1.10, 95% CI 0.81-1.51), suggesting a comparable benefit from adjuvant chemotherapy in AC and SRCC. Conclusions: Prognostic impact of SRCC is dismal in both colon and rectal cancer patients, but colonic SRCC patients seem to benefit from adjuvant chemotherapy equally compared with AC. Reduced efficacy of adjuvant chemotherapy therefore does not seem to explain the poor outcome in SRCC patients. We recommend to adhere to adjuvant treatment guidelines for all histological subtypes, but encourage clinical trials to take histological subtype into account for stratification.

[Colorectal carcinoma in the Netherlands: the situation before and after population surveillance]

Colorectal cancer is one of the most common cancers in the Netherlands; in both men and women it is the third most common type of cancer. Yearly more than 13,000 patients are diagnosed with colorectal cancer and over 5000 patients die of this disease. The incidence has increased gradually over time, whereas mortality has decreased. At time of diagnosis, almost half of patients have lymph node metastases or distant metastases. Relative 5-year survival is about 60%, but greatly depends on the stage of the disease at diagnosis. A nationwide colorectal cancer screening programme started in January 2014. All men and women aged 55-75 years will receive biennially an invitation to participate. Introduction of the screening programme will have an effect on the incidence, stage distribution, treatment and mortality of colorectal cancer.

Time trends in chemotherapy (administration and costs) and relative survival in stage III colon cancer patients - a large population-based study from 1990 to 2008

BACKGROUND

Use of adjuvant chemotherapy for stage III colon cancer has increased since several trials have shown the beneficial effect on survival. In this population-based study we show time trends in the administration and costs of chemotherapy and relative survival of patients with stage III colon cancer.

METHODS

All patients surgically treated for adenocarcinoma of the colon stage III between 1990 and 2008 in The Netherlands were included. Relative survival (using period analyses) and Relative Excess Risks of death (RER) were calculated. The costs of chemotherapy were estimated.

RESULTS

A total of 24 111 colon cancer patients with stage III were included in the cohort. The administration (from 9.5% in 1990 to 61.8% in 2008; p < 0.001) and costs of chemotherapy (from €38 467 in 1990 to €3 876 150 in 2008) increased during the study period. Multivariable relative survival improved for patients receiving adjuvant chemotherapy (RER 0.93; 95% CI 0.92-0.94; p < 0.001). In contrast, relative survival remained stable for patients, younger than 80 years, who did not receive chemotherapy (RER 1.00; 95% CI 1.00-1.01; p = 0.3). Patients aged 80 years and older without chemotherapy, relative survival increased during the study period (RER 0.98; 95% CI 0.97-0.99; p < 0.001).

CONCLUSIONS

The administration, the costs of chemotherapy and the survival of patients with stage III colon cancer increased over time. Whereas the costs and administration of chemotherapy increased extensively, relative survival increased to a lesser extent. For patients treated with adjuvant chemotherapy relative survival increased equally in all age groups.

Prognostic factors for locoregional recurrences in colon cancer

BACKGROUND

There is increased interest in locoregional recurrences of rectal cancer. Despite comparable locoregional recurrence rates in colon cancer, only a few studies on locoregional recurrences among colon cancer patients have been published. This study was designed to identify prognostic factors for locoregional recurrences among patients with colon cancer in the Netherlands.

METHODS

The study population was composed of patients who underwent radical surgical resections for invasive colon carcinoma, diagnosed in three regions of the Netherlands from 2000 to 2003. The Kaplan-Meier method was used to calculate 5-year locoregional recurrence rates (LRR). Conditional hazard rates were estimated by the life-table method. Multivariate Cox regression analyses were performed to identify prognostic factors and to calculate a Locoregional Recurrence Risk Score (LRRS).

RESULTS

In total 127 of 2,282 patients developed locoregional recurrences within 5 years (LRR 6.4%). The risk of developing a locoregional recurrence was highest at 0.5-1 year after surgery. Patients with left-sided tumors, T3-T4 tumors, and positive lymph nodes and those who did not receive adjuvant chemotherapy were more likely to develop locoregional recurrences. Four risk groups based on the LRRS were defined. Five-year LRR was 2.5% for the very low-risk group and 25.1% for the high-risk group.

CONCLUSIONS

Although the locoregional recurrence rate in this study was relatively low, it remains a considerable problem. Identifying individual patients who might benefit from adjuvant chemotherapy may reduce the locoregional recurrence rate.

Variation in treatment and outcome of patients with rectal cancer by region, hospital type and volume in the Netherlands

BACKGROUND

Aim of this study was to describe treatment patterns and outcome according to region and hospital type and volume among patients with rectal cancer in the Netherlands.

METHODS

All patients with rectal carcinoma diagnosed in the period 2001-2006 were selected from the Netherlands Cancer Registry. Logistic regression analyses were performed to examine the influence of relevant factors on the odds of receiving preoperative radiotherapy and on the odds of postoperative mortality. Relative survival analysis was used to estimate relative excess risk of dying according to hospital type and volume.

RESULTS

In total, 16 039 patients were selected. Patients diagnosed in a teaching or university hospital had a lower odds (OR 0.85; 95% CI 0.73-0.99 and OR 0.70; 95% CI 0.52-0.92) and patients diagnosed in a hospital performing >50 resections per year had a higher odds (OR 1.95; 95% CI 1.09-1.76) of receiving preoperative radiotherapy. A large variation between individual hospitals in rates of preoperative radiotherapy and between Comprehensive Cancer Centre-regions in the administration of preoperative chemoradiation was revealed. Postoperative mortality was not correlated to hospital type or volume. Patients with T1-M0 tumours diagnosed in a hospital with >50 resections per year had a better survival compared to patients diagnosed in a hospital with <25 resections per year (RER 0.11; 95% CI 0.02-0.78).

CONCLUSION

This study demonstrated variation in treatment and outcome of patients with rectal cancer in the Netherlands, with differences related to hospital volume and hospitals teaching or academic status. However, variation in treatment patterns between individual hospitals proved to be much larger than could be explained by the investigated characteristics. Future studies should focus on the reasons behind these differences, which could lead to a higher proportion of patients receiving optimal treatment for their stage of the disease.

Variation in treatment and outcome in patients with non-small cell lung cancer by region, hospital type and volume in the Netherlands

BACKGROUND

Care processes for patients with NSCLC can vary by provider, which may lead to unwanted variation in outcomes. Therefore, in modern health care an increased focus on guideline development and implementation is seen. It is expected that more guideline adherence leads to a higher number of patients receiving optimal treatment for their cancer which could improve overall survival.

OBJECTIVE

The aim of this study was to evaluate variations in treatment patterns and outcomes of patients with NSCLC treated in different (types of) hospitals and regions in the Netherlands. Especially, variation in the percentage of patients receiving the optimal treatment for the stage of their disease, according to the Dutch national guideline of 2004, was analyzed.

METHODS

All patients with a histological confirmed primary NSCLC diagnosed in the period 2001-2006 in all Dutch hospitals (N = 97) were selected from the population-based Netherlands Cancer Registry. Hospitals were divided in groups based on their region (N = 9), annual volume of NSCLC patients, teaching status and presence of radiotherapy facilities. Stage-specific differences in optimal treatment rates between (groups of) hospitals and regions were evaluated.

RESULTS

In the study period 43 544 patients were diagnosed with NSCLC. The resection rates for stage I/II NSCLC patients increased during the study period, but resection rates varied by region and were higher in teaching hospitals for thoracic surgeons (OR 1.5; 95%CI 1.2-1.9, p = 0.001) and in hospitals with a diagnostic volume of more than 50/year (OR 1.3; 95%CI 1.1-1.5, p = 0.001). Also the use of chemoradiation in stage III patients increased, though marked differences between hospitals in the use of chemoradiation for stage III patients were revealed. Differences in optimal treatment rates between hospitals led to differences in survival.

CONCLUSION

Treatment patterns and outcome of NSCLC patients in the Netherlands varied by region and the hospital their cancer was diagnosed in. Though resection rates were higher in hospitals training thoracic surgeons, variation between individual hospitals was much more distinct. Hospital characteristics like a high diagnostic volume, teaching status or availability of radiotherapy facilities proved no guarantee for optimal treatment rates.

Large variation between hospitals and pathology laboratories in lymph node evaluation in colon cancer and its impact on survival, a nationwide population-based study in the Netherlands

BACKGROUND

adequate lymph node (LN) evaluation is important for planning treatment in patients with colon cancer. Aims of this study were to identify factors associated with adequate nodal examination and to determine its relationship with stage distribution and survival.

PATIENTS AND METHODS

data from patients with colon carcinoma stages I-III who underwent surgical treatment and diagnosed in the period 2000-2006 were retrieved from the Netherlands Cancer Registry. Multilevel logistic analysis was carried out to examine the influence of relevant factors on the number of evaluated LNs. The relationship with survival was analysed using Cox regression analysis.

RESULTS

the number of examined LN was determined for 30 682 of 33 206 tumours. Median number of evaluated LN was 8, ranging from 4 to 15 between pathology laboratories. Females, younger patients, right-sided pN+ tumours with higher pT stage and patients diagnosed in an academic centre were less likely to have nine or less LN evaluated. Unexplained variation between hospitals and pathology laboratories remained, leading to differences in stage distribution. With increasing number of evaluated LN, the risk of death decreased.

CONCLUSION

there was large diversity in nodal examination among patients with colon cancer, leading to differences in stage distribution and being associated with survival.

Improved survival of colon cancer due to improved treatment and detection: a nationwide population-based study in The Netherlands 1989-2006

BACKGROUND

We described changes in treatment of colon cancer over time and the impact on survival in The Netherlands in the period 1989-2006.

PATIENTS AND METHODS

All 103,744 patients with invasive colon cancer during 1989-2006 in The Netherlands were included. Data were extracted from The Netherlands Cancer Registry. Trends in treatment over time were analysed and multivariable relative survival analysis was carried out.

RESULTS

The administration of adjuvant chemotherapy in stage III patients <75 years increased from 19% in 1989-1993 to 79% in 2004-2006 and from 1% to 19% in stage III patients ≥75 years. Among stage IV patients, resection rates of the primary tumour decreased from 72% to 63%, while chemotherapy administration increased from 23% to 64% in those <75 years. Survival increased from 52% to 58% in males and from 55% to 58% among females. Stage III patients with adjuvant chemotherapy exhibited a relative excess risk of 0.4 (95% confidence interval 0.4-0.4) compared with those without. Among stage IV patients, resection of primary tumour, palliative chemotherapy, and metastasectomy were important prognostic factors.

CONCLUSIONS

There were substantial improvements in management and survival of colon cancer from 1989 to 2006. Stage III disease patients with colon cancer experienced the largest improvement in survival, most likely related to the increased administration of adjuvant chemotherapy.

Regional radiotherapy versus an axillary lymph node dissection after lumpectomy: a safe alternative for an axillary lymph node dissection in a clinically uninvolved axilla in breast cancer. A case control study with 10 years follow up

BACKGROUND

The standard treatment of the axilla in breast cancer used to be an axillary lymph node dissection. An axillary lymph node dissection is known to give substantial risks of morbidity. In recent years the sentinel node biopsy has become common practice. Future randomized study results will determine whether the expected decrease in morbidity can be proven.

METHODS

Before the introduction of the sentinel node biopsy, we conducted a study in which 180 women of 50 years and older with T1/T2 cN0 breast cancer were treated with breast conserving therapy. Instead of an axillary lymph node dissection regional radiotherapy was given in combination with tamoxifen (RT-group). The study group was compared with 341 patients, with the same patient and tumour characteristics, treated with an axillary lymph node dissection (S-group).

RESULTS

The treatment groups were comparable, except for age. The RT-group was significantly older than the S-group. The median follow up was 7.2 years. The regional relapse rates were low and equal in both treatment groups, 1.1% in RT-group versus 1.5% in S-group at 5 years. The overall survival was similar; the disease free survival was significant better in the RT-group.

CONCLUSION

Regional recurrence rates after regional radiotherapy are very low and equal to an axillary lymphnode dissection.

Epidemiology and treatment of extramammary Paget disease in the Netherlands

AIM

To determine the incidence of EMPD and to describe its epidemiology, treatment, survival and the risk of developing other malignancies.

METHOD

All cases of EMPD, diagnosed between 1989 and 2001, were selected from the Netherlands Cancer Registry.

RESULTS

In total, 178 cases of invasive and 48 cases of in situ EMPD had been registered. The overall relative 5-year survival for invasive tumours was 72%. Most patients with invasive as well as in situ cancer underwent surgery. Other malignancies were found in 32% of patients with invasive EMPD and 35% of patients with in situ EMPD. Patients had an increased risk of developing a second primary cancer (standardized incidence ratio: 1.7; 95% confidence interval 1.2-2.4). The most frequent localizations of the other cancers were the colorectum, the prostate, the breast and the extragenital skin.

CONCLUSIONS

For EMPD, which is a rare disease in the Netherlands, there are no clear diagnostic and treatment guidelines. The prognosis is fairly good. A thorough search for other tumours is recommended for these patients.