Physician barriers and dilemmas in the execution of clinical trials impacting decision-making in the DAHANCA 35 proton therapy trial for head and neck cancer.

Background: Physicians manage multiple obligations, providing best-practice treatment and patient- centred care in the standard treatment pathway while contributing to clinical trials simultaneously. These multifaceted responsibilities may introduce barriers and dilemmas to clinical trial execution, potentially impacting the clinical trial decision- making process. This study explores physicians' barriers and dilemmas in executing clinical trials and the impact on clinical trial decision-making. Method: Qualitative semi-structured interviews were conducted with experienced oncologists. Moreover, participant observations were performed during clinical encounters involving discussions about clinical trials. The analysis followed a structured approach: (1) transcription of data, (2) inductive text coding, (3) exploration of patterns, and (4) interpretation, leading to the results. The results were discussed and validated by the study participants. Results: The results comprise (1) a description of the clinical practice, which presents the setting of clinical trial execution; (2) results regarding physicians' barriers and dilemmas in executing clinical trials, leading to (3) the impact on clinical trial decision- making. The results involve barriers to time constraints for clinical trial tasks, dilemmas emerging from trial requirements or deviations from standard guidelines, and challenges with providing sufficient trial communication and adequate decision-making support, balancing between a paternalistic approach and respecting patient autonomy. Conclusion: The demanding obligations of clinical practice constitute a complex setting for executing clinical trials, resulting in numerous barriers and dilemmas that impact the decision-making process in clinical trials. The study emphasises the need for tailored clinical trial decision-making interventions to facilitate supportive, informed, and non-directive clinical trial decision-making.

Coping and grief symptoms after parental loss in adolescence - a nationwide follow-up study.

Knowledge about effective coping strategies is important to support bereaved adolescents who have lost a parent. We used data on 104 bereaved adolescents (13-17 years) from the FALCON nationwide questionnaire study of parentally bereaved families. We examined associations between adolescents' control-oriented and escape-oriented coping strategies (KidCOPE scale) approximately two months after loss and grief symptoms (PG-13 scale) at six months follow-up. We also examined associations between the perceived efficacy of each coping strategy at baseline and grief symptoms at six months. The use of escape-oriented coping (e.g., distraction, self-criticism and social withdrawal) was associated with higher grief symptoms at six months follow-up (ß = 0.4, 95% CI 0.1-0.9, p = 0.02), but no associations were found for control-oriented coping or perceived coping efficacy. Finding alternatives to the use of escape-oriented coping strategies may be an important part of grief interventions for bereaved adolescents.

The Danish lung cancer registry: A nationwide validation study.

BACKGROUND: This study evaluates the validity of the information in the Danish Lung Cancer Registry (DLCR). Since 2000, the DLCR has been a tool for monitoring interventions and outcome of all Danish lung cancer patients with the intent to streamline and improve treatment and survival. The DLCR receives information from the Danish Patient Registries in addition to clinical information from the treating physicians. In the year 2022, more than 50 papers have been published using DLCR as a data source. However, the DLCR has not previously been validated. METHODS: A random sample of 1000 patients diagnosed with non-small cell lung cancer from 2014 to 2016 and recorded in the DLCR were included for validation. Medical records were reviewed and were considered as the "gold standard" to which data listed in the DLCR were compared. RESULTS: Information was retrieved from medical charts for all patients. Agreement on stage at diagnosis was 90.1 % (95 % CI 88.0-91.9) and on date of diagnoses was 93.8 (95 % CI 92.1-93.2). Agreement on smoking status in pack years (+/- 10 pack years) was 91.2 % (95 % CI 88.6-93.2). The positive predictive value of treatment intent was 87.4 (95 % CI 85.1-89.6). CONCLUSION: The data in the DLCR are complete, detailed and accurate. The comparison of data from the DLCR with the medical records revealed overall high validity of the data in the registry.

Nurse-Led Individualized Follow-Up Versus Regular Physician-Led Visits After Early Breast Cancer (MyHealth): A Phase III Randomized, Controlled Trial.

PURPOSE: Follow-up after breast cancer with regular visits has failed to detect recurrences, be cost-effective, and address patient needs. METHODS: MyHealth is a phase III randomized controlled trial (ClinicalTrials.gov identifier: NCT02949167). Patients, who recently completed primary treatment for stage I-II breast cancer, were randomly assigned in variable block sizes and stratified by age and human epidermal growth factor receptor 2 status to intervention or control follow-up. The nurse-led intervention comprised three to five individual self-management sessions, regular reporting of symptoms, and navigation to health care services. The control follow-up comprised regular outpatient visits with the physician. The primary outcome was breast cancer-specific quality of life (QoL) measured by the Trial Outcome Index-Physical/Functional/Breast summary score of the Functional Assessment of Cancer Therapy-Breast 2 years after random assignment. Secondary outcomes were fear of recurrence, anxiety, depression, and health care utilization. Analyses were intention-to-treat and P values were two-sided with 95% confidence level set at 0.005 because of multiple comparisons. RESULTS: Among 1,101 eligible patients, 875 were invited and 503 were randomly assigned to control (n = 252) or intervention (n = 251) follow-up. At 2 years, patients in the intervention group reported a significantly and clinically relevant higher QoL (mean, 75.69 [standard deviation [SD], 12.27]) than patients in the control group (71.26 [SD, 14.08]), with a mean difference of 5.05 (95% CI, 3.30 to 6.79; P < .001). The intervention group reported significantly less fear of recurrence, anxiety, and depression; they had fewer physician consultations but more nurse contacts and an unchanged diagnostic imaging pattern. The effect on all outcomes was stable through a 3-year follow-up. CONCLUSION: The MyHealth study suggested a new strategy for follow-up after early breast cancer as it provided significant improvements in QoL.

Cytoreductive Nephrectomy in Select Primary Metastatic Renal Cell Carcinoma Patients: A Comprehensive Nationwide Outcome Analysis.

(1) Background: The role of cytoreductive nephrectomy (CN) is controversial in patients with primary metastatic renal cell carcinoma (mRCC). (2) Methods: We evaluated the impact of CN, or no CN, followed by first-line targeted therapy (TT) in a nationwide unselected cohort of 437 consecutive patients with primary mRCC over a two-year period with a minimum of five years of follow-up. Data sources were national registries supplemented with manually extracted information from individual patient medical records. Cox proportional hazards estimated the hazard ratio (HR) of overall death and cancer-specific death after one and three years. (3) Results: 210 patients underwent CN and 227 did not. A total of 176 patients (40%) had CN followed by TT, 160 (37%) had TT alone, 34 (8%) underwent CN followed by observation, and 67 (15%) received no treatment. After adjustments in Model 2, patients treated with TT alone demonstrated a worsened overall survival (OS) compared to those treated with CN + TT, HR 0.63 (95% CI: 0.19-2.04). (4) Conclusions: In this nationwide study, CN was associated with enhanced outcomes in carefully selected patients with primary mRCC. Further randomized trials are warranted.

Exploring patient-reported barriers to participating in proton therapy clinical trials.

Introduction: Clinical trials lead the progress in healthcare. To ensure reliable research conclusions, it is essential to enroll diverse patient groups. Identifying and understanding patient-reported barriers to clinical trials may help enhance recruitment among diverse patient groups.The clinical potential of proton therapy (PT) to reduce late effects is being investigated in clinical trials worldwide. Thus, for some patients, PT is only accessible by participating in clinical trials.Individuals with smoking-related head and neck cancer (HNC) are sometimes socioeconomically deprived, leading to barriers to trial participation. This study aims to identify barriers to their participation in a randomised controlled trial (RCT) involving PT. Method: Interviews were conducted with 14 HNC patients declining participation in an RCT involving PT. The interviews were transcribed and systematically analysed using an inductive approach identifying categories and themes. Results: The identified barriers to RCT-participation are: (1) existential distress, which influenced participants' mental and cognitive capacities, (2) insufficient RCT-related knowledge arising from information overload during clinical consultations, (3) the wish for safety and familiarity during the treatment trajectory, particularly for participants needing accommodation during  radiotherapy, and (4) the motivation for study participation was impacted by uncertainty due to randomisation and clinical equipoise. Existential distress is identified as an overarching theme because it influences and amplifies the other three themes. Conclusion: Existential distress is a central theme that influences and amplifies other participation barriers in PT RCTs. It affects participants' comprehension of trial information, their preference for familiar environments, and their motivation to participate in clinical trials.

Barriers and facilitators to national guideline implementation for palliative cancer care in a Danish cross-sectoral healthcare setting: A qualitative study of healthcare professionals' experiences.

OBJECTIVE: Patients with incurable cancer should receive general palliative care according to their needs, as provided through collaboration between hospital departments, municipalities, and general practices and as outlined in national guidelines. However, the implementation of general palliative care in Denmark has been inadequate. This study aimed to investigate the healthcare professionals' (HCPs') perceptions on barriers to and facilitators of the implementation of the Danish National Guideline (NG) for general palliative care. METHODS: This descriptive, qualitative study was guided by the Consolidated Framework for Implementation Research (CFIR). Qualitative focus group and individual interviews were conducted with 23 HCPs. The interview guide, coding, analysis, and reporting of findings were developed within the CFIR framework. RESULTS: The main barriers to implementing NG were as follows: lack of knowledge about the NG, lack of an implementation plan, and insufficient communication and collaboration across sectors. Important facilitators were as follows: HCP motivation to meet palliative care needs, HCPs with special functions taking responsibility for incorporating NG into local guidelines, and the role of district nurses specialised in palliative care as opinion leaders providing security and continuity for the HCPs working in palliative care. CONCLUSIONS: To address the needs of patients with incurable cancer, greater efforts are required on implementing general palliative care. Although HCPs in our setting were motivated to improve NG implementation, financial resources and strategies are necessary to ensure sufficient knowledge uptake and accommodate identified barriers in order to translate the NG into practice.

Machine learning applied in patient-reported outcome research-exploring symptoms in adjuvant treatment of breast cancer.

BACKGROUND: Patient-reported outcome (PRO) data may help us better understand the life of breast cancer patients. We have previously collected PRO data in a national Danish breast cancer study in patients undergoing adjuvant chemotherapy. The aim of the present post-hoc explorative study is to apply Machine Learning (ML) algorithms using permutation importance to explore how specific PRO symptoms influence nonadherence to six cycles of planned adjuvant chemotherapy in breast cancer patients. METHODS: We here investigate ePRO-data from the 347 patients. The ePRO presented 42 PROCTCAE questions on 25 symptoms. Patients completed the ePRO before each cycle of chemotherapy. Number of patients with completion of the scheduled six cycles of chemotherapy were registered. Two ML models were applied. One aimed at discovering the individual relative importance of the different questions in the dataset while the second aimed at discovering the relationships between the questions. Permutation importance was used. RESULTS: Out of 347 patients 238 patients remained in the final dataset, 15 patients dropped out. Two symptoms: aching joints and numbness/tingling, were the most important for dropout in the final dataset, each with an importance value of about 0.04. Model's average ROC-AUC-score being 0.706. In the second model a low performance score made the results very unreliable. CONCLUSION: In conclusion, this explorative data analysis using ML methodologies in an ePRO dataset from a population of women with breast cancer treated with adjuvant chemotherapy unravels that the symptoms aching joints and numbness/tingling could be important for drop out of planned adjuvant chemotherapy.

Cumulative incidence of second primary cancers in a large nationwide cohort of Danish cancer survivors: a population-based retrospective cohort study.

BACKGROUND: A new primary cancer is a serious late effect of a pre-existing cancer diagnosis, and can be attributed to hereditary cancer syndromes, immune or hormonal factors, cancer treatment, or modifiable lifestyle or environmental factors. We investigated the absolute and relative incidence of second primary cancers in a large cohort of Danish cancer survivors. Furthermore, we examined the association between alcohol-related, smoking-related, virus-related, and hormone-related first and second primary cancers. METHODS: In this retrospective cohort study, we identified a cohort of Danish adults (aged ≥40 years) diagnosed with cancer from Jan 1, 1997, to Dec 31, 2014 and alive 1 year after diagnosis. Follow-up was from date of first cancer diagnosis and lasted up to 24 years, ending on Dec 31, 2020. Cohort identification and information on second primary cancers was obtained from the Danish Cancer Registry, and comorbidity and sociodemographic information was obtained from Danish population-based registries. Overall, and for 27 cancer types, cumulative incidence functions and Cox proportional hazard regression models were used to estimate the incidence of second primary cancer and death, and hazard ratios (HRs) and 95% CIs of second primary cancer adjusted for sex, age and year of diagnosis, cohabitation status, income, and comorbidity. FINDINGS: 457 334 Danish adults were included in our study (230 150 [50·3%] male individuals and 227 184 [49·7%] female individuals; median age at diagnosis 68·3 years, IQR 59·7-76·6; median follow-up 3·6 years, IQR 0·6-9·3). The cumulative incidence of second primary cancer increased over time from 6·3% (95% CI 6·2-6·4) 5 years after diagnosis to 10·5% (10·4-10·6) 10 years after diagnosis and to 13·5% (13·4-13·7) 15 years after diagnosis. The highest cumulative incidence of second primary cancer 10 years after diagnosis was observed in survivors of cancers in the larynx (21·8%, 20·5-23·1), oropharynx and oral cavity (19·5%, 18·7-20·3), and bladder and urinary tract (18·5%, 18·0-19·0). Survivors of cancers related to alcohol (HR 1·09, 95% CI 1·06-1·13), smoking (1·73, 1·68-1·78), diet high in red or processed meat (1·32, 1·24-1·39), or virus (1·23, 1·13-1·35) were at increased risk of developing a second cancer with the same aetiology, whereas having had a hormone-related first cancer was associated with lower risk of a second hormone-related cancer (0·77, 0·73-0·81). INTERPRETATION: Our results could help optimise prevention efforts targeting modifiable risk factors to reduce risk of developing a second primary cancer. FUNDING: Nordic Cancer Union and The Health Foundation (Helsefonden).

Cohort profile of FALCON: a prospective nationwide cohort of families with minor children who have lost a parent in Denmark in 2019-2021.

Difficulties in recruiting newly bereaved families and following them over time present a major barrier in grief research following the death of a spouse/parent. We established FALCON-the first prospective nationwide cohort of families with children below age 18 years whose parent died in Denmark between April 2019 and July 2021. Data from parents and children were collected within 2 months of death with ongoing follow-up assessments up to 18 months post-death. A total of 992 families were invited. The final cohort consisted of 250 families (250 widowed parents, 134 adolescents, 120 children aged 6-12 years and 63 children aged 0-5 years). In this paper, we describe the rationale for the cohort's creation, the challenges of researching grief in families, the methods used and future plans to utilize this unique family-level dataset.

Preoperative multimodal prehabilitation before elective colorectal cancer surgery in patients with WHO performance status I or II: randomized clinical trial.

BACKGROUND: Multimodal prehabilitation is a promising adjunct to the current surgical treatment pathway for colorectal cancer patients to further improve postoperative outcomes, especially for high-risk patients with low functional capacity. The aim of the present study was to test the effect of prehabilitation on immediate postoperative recovery. METHOD: The study was designed as a RCT with two arms (intervention and control). The intervention consisted of 4 weeks of multimodal prehabilitation, with supervised physical training, nutritional support and medical optimization. The control group received standard of care. A total of 40 patients with colorectal cancer (WHO performance status I or II) undergoing elective surgery with curative intent were included. The primary outcome was postoperative recovery within the first 3 postoperative days, measured by Quality of Recovery-15, a validated questionnaire with a scoring range between 0 and 150 and a minimal clinically relevant difference of 8. RESULTS: In total, 36 patients were analysed with 16 in the intervention group and 20 in the control group. The mean age of the included patients was 79 years. The overall treatment effect associated with the intervention was a 21.9 (95% c.i. 4.5-39.3) higher quality of recovery-15 score during the first 3 postoperative days compared to control, well above the minimal clinically relevant difference. CONCLUSION: Four weeks of multimodal prehabilitation prior to elective curative intended colorectal cancer surgery in patients with WHO performance status I or II was associated with a clinically relevant improvement in postoperative recovery.Registration number: NCT04167436 (http://www.clinicaltrials.gov).

Nurse navigation, symptom monitoring and exercise in vulnerable patients with lung cancer: feasibility of the NAVIGATE intervention.

We developed the Navigate intervention to improve survival among vulnerable lung cancer patients. In this intervention-only study, we examined feasibility in terms of recruitment, retention, attendance, adherence, and acceptability to specify adjustments to study procedures and intervention components prior to a randomized trial. The Navigate intervention includes nurse navigation, patient-reported outcomes, and physical exercise. Patients ≥ 18 years old, diagnosed with non-small cell lung cancer at any stage, with performance status ≤ 2, eligible for cancer treatment and vulnerable according to a screening instrument were included. The recruitment goal of eligible patients was 40% while the retention goal was 85%. The predefined cut-offs for sufficient attendance and adherence were ≥ 75%. Acceptability was evaluated by semi-structured interviews with participants, nurse navigators, and physiotherapists. Seventeen (56%) out of 30 screened patients were considered vulnerable and eligible for the study, 14 (82%) accepted participation, and 3 (21%) were subsequently excluded due to ineligibility, leaving 11 patients. Four patients dropped out (36%) and four patients died (36%) during follow-up and 3 (27%) were retained. All 11 patients participated in nurse sessions (mean 16, range 1-36) with 88% attendance and dialogue tools being applied in 68% of sessions. Ninety-one percent of patients responded to PROs (mean of 9 PROs, range 1-24) with 76% of the PRO questionnaires used (attendance) and 100% adherence (completion of all questions in PRO questionnaires), and 55% participated in exercise sessions with 58% attendance and 85% adherence. We identified important barriers primarily related to transportation, but overall acceptability was high. The Navigate intervention was feasible with high participation, acceptability and satisfactory adherence. Retention and exercise attendance were low, which resulted in adjustments.Trial registration: The feasibility study was initiated prior to the multicenter randomized controlled trial registered by ClinicalTrials.gov (number: NCT05053997; date 23/09/2021).

Socioeconomic differences in health-related quality of life among cancer survivors and comparison with a cancer-free population: a PROFILES study.

PURPOSE: This study investigates the association between socioeconomic position (SEP) and health-related quality of life (HRQoL) in a cross-sectional cohort among cancer survivors and compares with cancer-free people. METHODS: Survivors of colorectal, hematological, gynecological, prostate, thyroid cancer, and melanoma diagnosed 2000-2014 were identified in the PROFILES registry, and an age- and sex-matched cancer-free population were identified in the CentER panel. HRQoL, education, and comorbidity were self-reported. Street-level income and clinical factors were obtained from Statistics Netherlands and the Netherlands Cancer Registry. Multivariable logistic regression was used to examine associations of SEP (measured by education and income) and impaired HRQoL among cancer survivors and the cancer-free population, adjusting for age, sex, and time since diagnosis. RESULTS: We included 6693 cancer survivors and 565 cancer-free people. Cancer survivors with low versus medium SEP more frequently reported impaired HRQoL (odds ratio (OR) range for all HRQoL outcomes, 1.06-1.78 for short education and 0.94-1.56 for low income). Survivors with high compared to medium SEP reported impaired HRQoL less frequently (OR range for all HRQoL outcomes, 0.46-0.81 for short education and 0.60-0.84 for low income). The association between SEP and HRQoL was similar in the matched cancer-free population. CONCLUSION: Low SEP was associated with impaired HRQoL in both cancer survivors and cancer-free people. IMPLICATIONS FOR CANCER SURVIVORS: Targeted care is warranted for cancer survivors with impaired HRQoL, especially among those with low SEP.

Impact of multimorbidity and polypharmacy on mortality after cancer: a nationwide registry-based cohort study in Denmark 2005-2017.

BACKGROUND: Concurrent chronic diseases and treatment hereof in patients with cancer may increase mortality. In this population-based study we examined the individual and combined impact of multimorbidity and polypharmacy on mortality, across 20 cancers and with 13-years follow-up in Denmark. MATERIALS AND METHODS: This nationwide study included all Danish residents with a first primary cancer diagnosed between 1 January 2005 and 31 December 2015, and followed until the end of 2017. We defined multimorbidity as having one or more of 20 chronic conditions in addition to cancer, registered in the five years preceding diagnosis, and polypharmacy as five or more redeemed medications 2-12 months prior to cancer diagnosis. Cox regression analyses were used to estimate the effects of multimorbidity and polypharmacy, as well as the combined effect on mortality. RESULTS: A total of 261,745 cancer patients were included. We found that patients diagnosed with breast, prostate, colon, rectal, oropharynx, bladder, uterine and cervical cancer, malignant melanoma, Non-Hodgkin lymphoma, and leukemia had higher mortality when the cancer diagnosis was accompanied by multimorbidity and polypharmacy, while in patients with cancer of the lung, esophagus, stomach, liver, pancreas, kidney, ovarian and brain & central nervous system, these factors had less impact on mortality. CONCLUSION: We found that multimorbidity and polypharmacy was associated with higher mortality in patients diagnosed with cancer types that typically have a favorable prognosis compared with patients without multimorbidity and polypharmacy. Multimorbidity and polypharmacy had less impact on mortality in cancers that typically have a poor prognosis.

The use and timing of rehabilitation and palliative care to cancer patients, and the influence of social vulnerability - a population-based study.

OBJECTIVES: To identify and investigate different cohorts of cancer patients' use of physical rehabilitation and specialised palliative care (SPC) services, focusing on patients with incurable cancer and the impact of social vulnerability. METHODS: The sample originated from patients diagnosed during 2013-2018 and alive 1 January 2015. Use of physical rehabilitation and/or SPC units were identified from contacts registered in population-based administrative databases. Competing-risks regression models were applied to investigate disparities with regard to social vulnerability, disease duration, gender and age. RESULTS: A total of 101 268 patients with cancer were included and 60 125 survived longer than 3 years after their diagnosis. Among the 41 143 patients, who died from cancer, 66%, survived less than 1 year, 23% survived from 1 to 2 years and 11% survived from 2 to 3 years. Contacts regarding physical rehabilitation services appeared in the entire cancer trajectory, whereas contacts regarding SPC showed a steep increase as time drew closer to death. The largest disparity was related to disease duration. Socially vulnerable patients had less contact with SPC, while a larger proportion of the socially vulnerable cancer survivors used rehabilitation, compared with the non-vulnerable patients. CONCLUSIONS: This study provides a previously unseen detailed overview of the use of physical rehabilitation and/or SPC among patients with incurable cancer. The services appeared to overlap at a group level in the cancer trajectory, emphasising the importance of awareness with regard to coordination and combination of the services. Disparities between socially vulnerable or non-vulnerable patients were identified.

Socioeconomic position and the pre-diagnostic interval among patients diagnosed with head and neck squamous cell carcinoma - a population-based study from DAHANCA.

BACKGROUND: The socioeconomic differences in survival are pronounced for patients diagnosed with head and neck cancer; disease stage at diagnosis is suggested to be a main driver of this association. This nationwide, population-based study investigates socioeconomic differences in the pre-diagnostic interval and disease stage at diagnosis. MATERIAL AND METHODS: Information on patient-reported symptoms, symptom onset and disease-specific factors was obtained from the nationwide population-based Danish Head and Neck Cancer Group (DAHANCA) database for patients diagnosed with head and neck squamous cell carcinoma between 2008 and 2019 in Denmark. Socioeconomic position (SEP) was measured by individual-level education, income and cohabitation status obtained from administrative registers. Socioeconomic differences in the interval from symptom onset to diagnosis were investigated in general linear models with 95% confidence intervals (CIs); overall and by subsite, symptom and comorbidity score. Consultation patterns prior to diagnosis were examined using methods for change-point detection. Associations with advanced-stage disease were estimated in logistic regression models. RESULTS: Patients with low, medium and high SEP had a similar interval from patient-reported symptom onset to diagnosis of 10 weeks. Although this interval varied according to primary symptom and anatomical subsite, no apparent socioeconomic differences were observed within these subgroups. Aligned with the patient-reported symptom onset, a distinct increase in consultation rates was observed at 9 weeks (95% CI [7.3; 10.7]) for patients with low SEP and 7 weeks (95% CI [4.8; 9.2]) for patients with high SEP, with overlapping CIs. Patients with low compared to high SEP had increased odds for advanced-stage glottic and oral cavity squamous cell carcinoma. For the remaining subsites the association varied according to SEP-indicator and TNM-edition. CONCLUSION: The interval from symptom onset to diagnosis and consultation patterns were similar across SEP groups. Still, socioeconomic differences in stage at diagnosis were observed for some - but not all - subsites.

Who are the vulnerable lung cancer patients at risk for not receiving first-line curative or palliative treatment?

BACKGROUND: To identify non-small-cell lung cancer (NSCLC) patients in need of comprehensive support, we examined the association between patient and disease-related factors of vulnerability related to not receiving guideline-recommended treatment. MATERIAL AND METHODS: We identified 14,597 non-small-cell lung cancer (NSCLC) patients with performance status <3 during 2013-2018 in the Danish Lung Cancer Registry. Multivariate logistic regression models were used to estimate Odds Ratios (ORs) and 95% confidence intervals (CIs) for receiving guideline-recommended treatment according to stage, comorbidities, age, performance status, long distance to hospital, cohabitation status, education and alcohol abuse. RESULTS: 21% of stage I-IIIA NSCLC patients did not receive curative treatment while 10% with stage IIIB-IV did not receive any oncological therapy. Factors associated with reduced likelihood of receiving curative treatment included: advanced stage (OR = 0.45; 95% CI = 0.42-0.49), somatic comorbidity (OR = 0.72; 95% CI = 0.63-0.83), age ≥ 80 years (OR = 0.59; 95% CI = 0.55-0.64), performance status = 2 (OR = 0.33; 95% CI = 0.28-0.39) and living alone (OR = 0.79; 95% CI = 0.69-0.90). Results were similar for stage IIIB-IV NSCLC patients, although a statistically significant association was also seen for long distances to the hospital (OR = 0.71; 95% CI = 0.58-0.86). CONCLUSIONS: Several factors are associated with not receiving guideline-recommended NSCLC treatment with age, performance status, comorbidity and stage being most predictive of no treatment receipt. Efforts should be made to develop support for vulnerable lung cancer patients to improve adherence to optimal first-line therapy.