Dose comparison of robustly optimized intensity modulated proton therapy (IMPT) vs IMRT and VMAT photon plans for testicular seminoma.

BACKGROUND: Patients with stage II seminoma have traditionally been treated with photons to the retroperitoneal and iliac space, which leads to a substantial dose bath to abdominal and pelvic organs at risk (OAR). As these patients are young and with excellent prognosis, reducing dose to OAR and thereby the risk of secondary cancer is of utmost importance. We compared IMPT to opposing IMRT fields and VMAT, assessing dose to OAR and both overall and organ-specific secondary cancer risk. MATERIAL AND METHODS: A comparative treatment planning study was conducted on planning CT-scans from ten patients with stage II seminoma, treated with photons to a 'dog-leg' field with doses ranging from 20 to 25 Gy and a 10 Gy sequential boost to the metastatic lymph node(s). Photon plans were either 3-4 field IMRT (Eclipse) or 1-2 arc VMAT (Pinnacle). Proton plans used robust (5 mm; 3.5%) IMPT (Eclipse), multi field optimization with 3 posterior fields supplemented by 2 anterior fields at the level of the iliac vessels. Thirty plans were generated. Mean doses to OARs were compared for IMRT vs IMPT and VMAT vs IMPT. The risk of secondary cancer was calculated according to the model described by Schneider, using excess absolute risk (EAR, per 10,000 persons per year) for body outline, stomach, duodenum, pancreas, bowel, bladder and spinal cord. RESULTS: Mean doses to all OARs were significantly lower with IMPT except similar kidney (IMRT) and spinal cord (VMAT) doses. The relative EAR for body outline was 0.59 for IMPT/IMRT (p < .05) and 0.33 for IMPT/VMAT (p < .05). Organ specific secondary cancer risk was also lower for IMPT except for pancreas and duodenum. CONCLUSION: Proton therapy reduced radiation dose to OAR compared to both IMRT and VMAT plans, and potentially reduce the risk of secondary cancer both overall and for most OAR.

Adverse health behaviours in long-term testicular cancer survivors: a Danish nationwide study.

BACKGROUND: Treatment for disseminated testicular cancer increases the risk of secondary malignancy and cardiovascular disease. The risk of developing these serious adverse effects may be positively affected by healthy living. The purpose of this study was to identify health behaviours with possible influence on late effects that could be targets for intervention. MATERIAL AND METHODS: In this cross-sectional study, testicular cancer survivors diagnosed in the period 1984-2007 from the Danish Testicular Cancer database completed a questionnaire on health behaviours (2014-2016). We estimated prevalence of smoking, alcohol consumption, sedentary lifestyle and overweight. Prevalence ratios described with 95% confidence intervals of adverse health behaviours were stratified by treatment modalities and compared to a reference population by means of logistic regression with adjustment for sociodemographic confounders. RESULTS: In total, 2395 testicular cancer survivors (surveillance, 1175; chemotherapy, 897; radiotherapy, 323), median time since diagnosis 19 years, and 65,289 noncancer males were included, questionnaire response rates were 60% and 54%, respectively. There were more current smokers (prevalence ratio; 1.14, 95% confidence interval (CI): 1.03-1.26) and patients with body mass index above 25 kg/m2 (prevalence ratio; 1.10, 95% CI: 1.01-1.20) among testicular cancer survivors than in the reference population. Testicular cancer survivors reported less sedentary lifestyle (prevalence ratio; 95% CI: 0.74, 0.64-0.85) and everyday drinkers were fewer (prevalence ratio; 0.79, 95% CI: 0.68-0.92) than in the reference population. CONCLUSION: We identified smoking cessation as primary target for intervention studies in testicular cancer survivors. The effect of smoking cessation interventions as part of treatment should be investigated. Whether drug-based intervention is effective in minimising the risk of exposure to conventional risk factors for cardiovascular disease is also of interest.

First clinical experiences with a high field 1.5 T MR linac.

Purpose: A 1.5 T MR Linac (MRL) has recently become available. MRL treatment workflows (WF) include online plan adaptation based on daily MR images (MRI). This study reports initial clinical experiences after five months of use in terms of patient compliance, cases, WF timings, and dosimetric accuracy. Method and materials: Two different WF were used dependent on the clinical situation of the day; Adapt To Position WF (ATP) where the reference plan position is adjusted rigidly to match the position of the targets and the OARs, and Adapt To Shape WF (ATS), where a new plan is created to match the anatomy of the day, using deformable image registration. Both WFs included three 3D MRI scans for plan adaptation, verification before beam on, and validation during IMRT delivery. Patient compliance and WF timings were recorded. Accuracy in dose delivery was assessed using a cylindrical diode phantom. Results: Nineteen patients have completed their treatment receiving a total of 176 fractions. Cases vary from prostate treatments (60Gy/20F) to SBRT treatments of lymph nodes (45 Gy/3F) and castration by ovarian irradiation (15 Gy/3F). The median session time (patient in to patient out) for 127 ATPs was 26 (21-78) min, four fractions lasted more than 45 min due to additional plan adaptation. For the 49 ATSs a median time of 12 (1-24) min was used for contouring resulting in a total median session time of 42 (29-91) min. Three SBRT fractions lasted more than an hour. The time on the MRL couch was well tolerated by the patients. The median gamma pass rate (2 mm,2% global max) for the adapted plans was 99.2 (93.4-100)%, showing good agreement between planned and delivered dose. Conclusion: MRL treatments, including daily MRIs, plan adaptation, and accurate dose delivery, are possible within a clinically acceptable timeframe and well tolerated by the patients.

Trends in prostate cancer in elderly in Denmark, 1980-2012.

BACKGOUND: The purpose of the study is to elucidate the epidemiology of elderly patients with prostate cancer in Denmark and identify the differences between younger (<70 years) and elderly (≥70 years) patients. MATERIAL AND METHODS: Prostate cancer was defined as ICD-10 code C61. Data were derived from the NORDCAN database with comparable data on cancer incidence, mortality, prevalence and relative survival in the Nordic countries, where the Danish data are delivered from the Danish Cancer Registry and the Danish Cause of Death Registry. RESULTS: The average annual number of newly diagnosed prostate cancers in Denmark has risen from 1297 patients in 1980 to 4315 patients in 2012. The prevalence increased consistently in all age groups more than seven-fold in the period, from 3987 patients in 1980 to 28 951 patients in 2012. The cancer-specific mortality in Denmark has slightly increased over the observed period, in coherence with the growth of the population, resulting in unchanged mortality rates, with the exception of the patients above 80 years, where the mortality rates are increased. The one- and five-year relative survival for prostate cancer improved significantly for all age groups over the time period from 1980 to 2012. CONCLUSION: The incidence, prevalence, and survival of elderly prostate cancer patients has increased over the observed period but with unchanged mortality rates, except in patients above 80 years, where the mortality rates were increasing.

Postchemotherapy Retroperitoneal Lumpectomy in Patients with Nonseminoma Testicular Cancer: A Nationwide Study.

BACKGROUND AND OBJECTIVE: Optimal treatment outcomes in patients with metastatic nonseminoma testicular cancer are achieved with chemotherapy and subsequent surgery in cases with residual tumor. In Denmark, postchemotherapy retroperitoneal lumpectomy (RPLP) is performed in patients with residual tumors >1 cm. There is a need to clarify whether this surgical method provides acceptable treatment results. Our objective was to describe morbidity and oncological outcomes of postchemotherapy RPLP. METHODS: This was a retrospective population-based multicenter study including patients with nonseminoma testicular cancer and postchemotherapy RPLP performed in Denmark between 1990 and 2015. A total of 219 patients were eligible, with median follow-up of 19 yr. Postoperative complications were evaluated according to the Clavien-Dindo classification. The cumulative incidence of recurrence inside or outside the borders of a bilateral surgical template, progression-free survival (PFS), and overall survival estimates were calculated using the Kaplan-Meier method. KEY FINDINGS AND LIMITATIONS: After median follow-up of 19 yr, 31/219 patients (14%) experienced a surgical complication, of which 5% were Clavien-Dindo grade ≥III. In total, 37 patients experienced a recurrence. The 5-yr, 10-yr, and 20-yr cumulative risk of recurrence inside a bilateral template was 4.3%, 5.9%, and 5.9%, respectively. The 10-yr PFS rate was 83% and the 10-yr overall survival rate was 96%. The main limitation of the study is the retrospective design. CONCLUSIONS AND CLINICAL IMPLICATIONS: With few patients experiencing a major postoperative complication and a 10-yr cumulative rate of 5.9% for recurrence inside a bilateral surgical template, postchemotherapy RPLP appears to be a safe alternative to template surgery for disseminated nonseminoma. PATIENT SUMMARY: We looked at minimal surgery to remove tumor tissue remaining after chemotherapy in patients with testicular cancer. We found a low frequency of complications, tumor recurrence, and death.

Use of Risk Factors To Select Adjuvant Therapy Versus Surveillance for Testicular Nonseminoma and Seminoma Germ Cell Tumors.

New risk factors associated with relapse of stage I testicular cancer have been identified. These new factors reflect the risk of recurrence much better than previous parameters and can be used to assess the possible effect of adjuvant chemotherapy.

Prognostic Factors for Relapse in Patients With Clinical Stage I Testicular Seminoma: A Nationwide, Population-Based Cohort Study.

PURPOSE: Approximately 20% of patients with clinical stage I seminoma relapse. Tumor size and rete testis invasion have been identified as risk factors for relapse. However, the level of evidence supporting the use of these risk factors in clinical decision making is low. Previous studies have been hampered by selection bias and variable pathology reporting that limit interpretation and generalization of results. We assessed prognostic factors for relapse in an unselected nationwide population-based setting with centralized pathology review. METHODS: Patients with clinical stage I seminoma diagnosed from January 2013 to December 2018 were identified in the prospective Danish Testicular Cancer database. By linkage to the Danish National Pathology Registry, histologic slides from the orchiectomy specimens were retrieved and reviewed blinded to the clinical outcome. Clinical data were obtained from medical records with follow-up until July 2022. The association between prespecified potential clinical and histopathologic prognostic factors and relapse was assessed by the use of Cox regression analysis. RESULTS: Of 924 patients included, 148 (16%) patients relapsed during a median follow-up of 6.3 years. Invasion of the testicular hilum (rete testis and hilar soft tissue), lymphovascular invasion, and elevated preorchiectomy levels of ß-human chorionic gonadotropin and lactate dehydrogenase were independent predictors of relapse. The estimated 5-year risk of relapse ranged from 6% in patients with no risk factors to 62% in patients with all four risk factors with tumor extension into the hilar soft tissue of the testicular hilum. After internal model validation, the prognostic model had an overall concordance statistic of 0.70. CONCLUSION: The provided prognostic factors could replace current risk factors in guidelines and be used in future studies investigating risk-adapted follow-up and treatment strategies.

Prognostic factors for relapse in patients with clinical stage I testicular non-seminoma: A nationwide, population-based cohort study.

BACKGROUND: Approximately 30% of patients with clinical stage I non-seminoma (CSI-NS) relapse. Current risk stratification is based on lymphovascular invasion (LVI) alone. The extent to which additional tumor characteristics can improve risk prediction remains unclear. OBJECTIVE: To determine the most important prognostic factors for relapse in CSI-NS patients. DESIGN, SETTING, AND PARTICIPANTS: Population-based cohort study including all patients with CSI-NS diagnosed in Denmark between 2013 and 2018 with follow-up until 2022. Patients were identified in the prospective Danish Testicular Cancer database. By linkage to the Danish National Pathology Registry, histological slides from the orchiectomy specimens were retrieved. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Histological slides were reviewed blinded to the clinical outcome. Clinical data were obtained from medical records. The association between prespecified potential prognostic factors and relapse was assessed using Cox regression analysis. Model performance was evaluated by discrimination (Harrell's C-index) and calibration. RESULTS: Of 453 patients included, 139 patients (30.6%) relapsed during a median follow-up of 6.3 years. Tumor invasion into the hilar soft tissue of the testicular hilum, tumor size, LVI and embryonal carcinoma were independent predictors of relapse. The estimated 5-year risk of relapse ranged from < 5% to > 85%, depending on the number of risk factors. After internal model validation, the model had an overall concordance statistic of 0.75. Model calibration was excellent. CONCLUSION AND RELEVANCE: The identified prognostic factors provide a much more accurate risk stratification than current clinical practice, potentially aiding clinical decision-making.

Development of Prostate Bed Delineation Consensus Guidelines for Magnetic Resonance Image-Guided Radiotherapy and Assessment of Its Effect on Interobserver Variability.

PURPOSE: The use of magnetic resonance imaging (MRI) in radiotherapy planning is becoming more widespread, particularly with the emergence of MRI-guided radiotherapy systems. Existing guidelines for defining the prostate bed clinical target volume (CTV) show considerable heterogeneity. This study aimed to establish baseline interobserver variability (IOV) for prostate bed CTV contouring on MRI, develop international consensus guidelines, and evaluate its effect on IOV. METHODS AND MATERIALS: Participants delineated the CTV on 3 MRI scans, obtained from the Elekta Unity MR-Linac, as per their normal practice. Radiation oncologist contours were visually examined for discrepancies, and interobserver comparisons were evaluated against simultaneous truth and performance level estimation (STAPLE) contours using overlap metrics (Dice similarity coefficient and Cohen's kappa), distance metrics (mean distance to agreement and Hausdorff distance), and volume measurements. A literature review of postradical prostatectomy local recurrence patterns was performed and presented alongside IOV results to the participants. Consensus guidelines were collectively constructed, and IOV assessment was repeated using these guidelines. RESULTS: Sixteen radiation oncologists' contours were included in the final analysis. Visual evaluation demonstrated significant differences in the superior, inferior, and anterior borders. Baseline IOV assessment indicated moderate agreement for the overlap metrics while volume and distance metrics demonstrated greater variability. Consensus for optimal prostate bed CTV boundaries was established during a virtual meeting. After guideline development, a decrease in IOV was observed. The maximum volume ratio decreased from 4.7 to 3.1 and volume coefficient of variation reduced from 40% to 34%. The mean Dice similarity coefficient rose from 0.72 to 0.75 and the mean distance to agreement decreased from 3.63 to 2.95 mm. CONCLUSIONS: Interobserver variability in prostate bed contouring exists among international genitourinary experts, although this is lower than previously reported. Consensus guidelines for MRI-based prostate bed contouring have been developed, and this has resulted in an improvement in contouring concordance. However, IOV persists and strategies such as an education program, development of a contouring atlas, and further refinement of the guidelines may lead to additional improvements.

An open-source nnU-net algorithm for automatic segmentation of MRI scans in the male pelvis for adaptive radiotherapy.

Background: Adaptive MRI-guided radiotherapy (MRIgRT) requires accurate and efficient segmentation of organs and targets on MRI scans. Manual segmentation is time-consuming and variable, while deformable image registration (DIR)-based contour propagation may not account for large anatomical changes. Therefore, we developed and evaluated an automatic segmentation method using the nnU-net framework. Methods: The network was trained on 38 patients (76 scans) with localized prostate cancer and tested on 30 patients (60 scans) with localized prostate, metastatic prostate, or bladder cancer treated at a 1.5 T MRI-linac at our institution. The performance of the network was compared with the current clinical workflow based on DIR. The segmentation accuracy was evaluated using the Dice similarity coefficient (DSC), mean surface distance (MSD), and Hausdorff distance (HD) metrics. Results: The trained network successfully segmented all 600 structures in the test set. High similarity was obtained for most structures, with 90% of the contours having a DSC above 0.9 and 86% having an MSD below 1 mm. The largest discrepancies were found in the sigmoid and colon structures. Stratified analysis on cancer type showed that the best performance was seen in the same type of patients that the model was trained on (localized prostate). Especially in patients with bladder cancer, the performance was lower for the bladder and the surrounding organs. A complete automatic delineation workflow took approximately 1 minute. Compared with contour transfer based on the clinically used DIR algorithm, the nnU-net performed statistically better across all organs, with the most significant gain in using the nnU-net seen for organs subject to more considerable volumetric changes due to variation in the filling of the rectum, bladder, bowel, and sigmoid. Conclusion: We successfully trained and tested a network for automatically segmenting organs and targets for MRIgRT in the male pelvis region. Good test results were seen for the trained nnU-net, with test results outperforming the current clinical practice using DIR-based contour propagation at the 1.5 T MRI-linac. The trained network is sufficiently fast and accurate for clinical use in an online setting for MRIgRT. The model is provided as open-source.

A Validated Algorithm for Register-Based Identification of Patients with Relapse of Clinical Stage I Testicular Cancer.

Purpose: The Danish Testicular Cancer (DaTeCa) database aims to monitor and improve quality of care for testicular cancer patients. Relapse data registered in the DaTeCa database rely on manual registration. Currently, some safeguarding against missing registrations is attempted by a non-validated register-based algorithm. However, this algorithm is inaccurate and entails time-consuming medical record reviews. We aimed (1) to validate relapse data as registered in the DaTeCa database, and (2) to develop and validate an improved register-based algorithm identifying patients diagnosed with relapse of clinical stage I testicular cancer. Patients and Methods: Patients registered in the DaTeCa database with clinical stage I testicular cancer from 2013 to 2018 were included. Medical record information on relapse data served as a gold standard. A pre-specified algorithm to identify relapse was tested and optimized on a random sample of 250 patients. Indicators of relapse were obtained from pathology codes in the Danish National Pathology Register and from diagnosis and procedure codes in the Danish National Patient Register. We applied the final algorithm to the remaining study population to validate its performance. Results: Of the 1377 included patients, 284 patients relapsed according to the gold standard during a median follow-up time of 5.9 years. The completeness of relapse data registered in the DaTeCa database was 97.2% (95% confidence interval (CI): 95.2-99.1). The algorithm achieved a sensitivity of 99.6% (95% CI: 98.7-100), a specificity of 98.9% (95% CI: 98.2-99.6), and a positive predictive value of 95.9% (95% CI: 93.4-98.4) in the validation cohort (n = 1127, 233 relapses). Conclusion: The registration of relapse data in the DaTeCa database is accurate, confirming the database as a reliable source for ongoing clinical quality assessments. Applying the provided algorithm to the DaTeCa database will optimize the accuracy of relapse data further, decrease time-consuming medical record review and contribute to important future clinical research.

Online adaptive radiotherapy potentially reduces toxicity for high-risk prostate cancer treatment.

BACKGROUND AND PURPOSE: With daily, MR-guided online adapted radiotherapy (MRgART) it may be possible to reduce the PTV in pelvic RT. This study investigated the potential reduction in normal tissue complication probability (NTCP) of MRgART compared to standard radiotherapy for high-risk prostate cancer. MATERIALS AND METHODS: Twenty patients treated with 78 Gy to the prostate and 56 Gy to elective pelvic lymph nodes were included. VMAT plans were generated with standard clinical PTV margins. Additionally to the planning MR, patients had three MRI scans during treatment to simulate an MRgART. A reference plan with PTV margins determined for MRgART was created per patient and adapted to each of the following MRs. Adapted plans were warped to the planning MR for dose accumulation. The standard plan was rigidly registered to each adaptation MR before it was warped to the planning MR for dose accumulation. Dosimetric impact was compared by DVH analysis and potential clinical effects were assessed by NTCP modeling. RESULTS: MRgART yielded statistically significant lower doses for the bladder wall, rectum and peritoneal cavity, compared to the standard RT, which translated into reduced median risks of urine incontinence (ΔNTCP 2.8%), urine voiding pain (ΔNTCP 2.8%) and acute gastrointestinal toxicity (ΔNTCP 17.4%). Mean population accumulated doses were as good or better for all investigated OAR when planned for MRgART as standard RT. CONCLUSION: Online adapted radiotherapy may reduce the dose to organs at risk in high-risk prostate cancer patients, due to reduced PTV margins. This potentially translates to significant reductions in the risks of acute and late adverse effects.

Long-term neurotoxicity and quality of life in testicular cancer survivors-a nationwide cohort study.

PURPOSE: To evaluate neurotoxicity in testicular cancer survivors (TCSs) years after treatment and secondly the influence of neurotoxicity on quality-of-life (QoL). METHODS: We identified 2234 TCSs who completed the Functional Assessment of Cancer Therapy/Gynecologic Oncology Group-Neurotoxicity questionnaire. QoL was evaluated with the European Organization for Research and Treatment of Cancer QLQ-C30. Patients were grouped according to treatment strategy: surveillance (N = 1113), infradiaphragmatic radiotherapy (N = 301), cisplatin-etoposide-bleomycin (BEP) (N = 759), and more than one line of treatment (MTOL) (N = 61). Association of treatment modality with long-term neurotoxicity was analyzed with ordinal logistic regression. Secondly, associations between neurotoxicity and QoL were analyzed in BEP-treated patients. Analyses were age-adjusted and repeated with additional adjustment for comorbidity, smoking, and alcohol consumption. RESULTS: After a median follow-up of 18.4 years, treatment with BEP and MTOL was associated with overall increased risk of neurotoxicity (odds ratio 2.4-4.7 depending on treatment intensity, P < 0.001) as well as subscales (peripheral neuropathy, ototoxicity, and dysfunction associated with neuropathy, all P < 0.001). Radiotherapy and surveillance were not associated with neurotoxicity. In patients treated with BEP, neurotoxicity was highly associated with all indicators of worse QoL outcomes (P-trend: 1.5 × 10-17 to 1.1 × 10-28) after almost 20 years of follow-up. CONCLUSIONS: Treatment with BEP was associated with long-term neurotoxicity, which was highly associated with decreased QoL. Strategies to ameliorate or prevent neurotoxicity should be investigated. IMPLICATIONS FOR CANCER SURVIVORS: Treatment with chemotherapy for testicular cancer induces long-term neuro- and ototoxicity which may have severe influence on quality-of-life years after treatment cessation.

Accuracy of automatic deformable structure propagation for high-field MRI guided prostate radiotherapy.

BACKGROUND: In this study we have evaluated the accuracy of automatic, deformable structure propagation from planning CT and MR scans for daily online plan adaptation for MR linac (MRL) treatment, which is an important element to minimize re-planning time and reduce the risk of misrepresenting the target due to this time pressure. METHODS: For 12 high-risk prostate cancer patients treated to the prostate and pelvic lymph nodes, target structures and organs at risk were delineated on both planning MR and CT scans and propagated using deformable registration to three T2 weighted MR scans acquired during the treatment course. Generated structures were evaluated against manual delineations on the repeated scans using intra-observer variation obtained on the planning MR as ground truth. RESULTS: MR-to-MR propagated structures had significant less median surface distance and larger Dice similarity index compared to CT-MR propagation. The MR-MR propagation uncertainty was similar in magnitude to the intra-observer variation. Visual inspection of the deformed structures revealed that small anatomical differences between organs in source and destination image sets were generally well accounted for while large differences were not. CONCLUSION: Both CT and MR based propagations require manual editing, but the current results show that MR-to-MR propagated structures require fewer corrections for high risk prostate cancer patients treated at a high-field MRL.

The impact of comprehensive geriatric assessment for optimal treatment of older patients with cancer: A randomized parallel-group clinical trial.

OBJECTIVES: The aim was to investigate if oncologic treatment decision based on G8 screening followed by comprehensive geriatric assessment (CGA) and a multidisciplinary team conference in patients with G8 ≤ 14 was better than treatment decision based on standard assessment. ClinicalTrials.gov Identifier: NCT02671994. MATERIALS AND METHODS: From January 2016 to June 2018, 96 patients with cancer, aged ≥70 years, were included. Patients were randomized to treatment decision based on the oncologist's clinical judgement (control) or based on screening with G8. If G8 > 14 treatment decision was made as in the control group and if G8 ≤ 14, patients were referred to CGA including intervention as needed and treatment decision after a multidisciplinary team conference (MDT). RESULTS: The study was closed early. 47 patients were randomized to the control group and 49 to the intervention group; 28 had a G8 ≤ 14, 24 of whom attended CGA. In the intervention group 48% completed treatment as planned compared to 54% in the control group (p = .208). Thirty-eight percent experienced grade 3-4 toxicity in the control group compared with only 20% in the intervention group (p = .055). Median overall survival (OS) was 14.2 months in the control group and 19.1 months in the intervention group (p = .911). Median progression-free survival (PFS) was 9.0 months in the control group and 7.8 months for the intervention group (p = .838). CONCLUSION: Treatment decision based on G8 screening followed by CGA had no impact on completion rate of planned oncologic treatment, OS or PFS, but resulted in a borderline significant lower incidence of grade 3-4 toxicity.

Molecular biology from bench-to-bedside - which colorectal cancer patients should be referred for genetic counselling and risk assessment.

Lynch syndrome is associated with deficiency of the mismatch repair genes MLH1, MSH2, MSH6 or PMS2. However, most MLH1 deficient tumours are sporadic in origin, and they can be identified if harbouring a BRAF V600E mutation or hypermethylation of the MLH1 gene promoter. The aim of this study was to validate our previously suggested clinically applicable strategy based on molecular characteristics for identifying which patients to refer for genetic counselling. The strategy was validated in an unselected cohort of 287 colorectal cancer patients. All tumours were tested for MLH1, PMS2, MSH2 and MSH6 protein expression with immunohistochemistry. DNA from MLH1 negative tumours was sequenced for BRAF mutations. If BRAF was wild-type, MLH1 promoter was subsequently analyzed for promoter hypermethylation. Most tumours, 251 (88%), stained positive for all four proteins. Six (2%) had negative MSH2 and one (<1%) isolated loss of MSH6. MLH1 and PMS2 were negative in 29 cases (10%). DNA quality allowed BRAF analysis in 27 of these with 14 mutations and 13 wild-type. DNA quality allowed methylation analysis in 11 of the 13 BRAF wild-type, and all but one were methylated. Subsequently, Lynch syndrome could not be ruled out in 12 patients. A follow-up at 8-10 years revealed four definite cases of Lynch syndrome and three highly suspicious. An easy and clinically applicable step-wise approach with immunohistochemistry (100%), BRAF sequencing (10%) and methylation analysis (5%) identified several patients with hereditary cancer. It is feasible to perform a molecular screening to select patients for genetic counselling.