A new look at imines and their mixture with PC71BM for organic, flexible photovoltaics.

Due to its high electron affinity and electron mobility in a wide absorption range of the visible solar spectrum, [6,6]-phenyl-C71-butyric acid methyl ester (PC71BM) is often used as an efficient acceptor in organic photovoltaics. In turn, imines are additives to the active layer of organic solar cells, mainly due to the free electron pair of the imine nitrogen atom and the presence of various chemical groups affecting the polarity and conformations of molecules. However, the attainable efficiency is not as high as expected. Therefore, we have systematically investigated two imines and their mixtures with PC71BM by spectroscopic (the high pressure UV-Vis and frequency domain dielectric), thermoelectric, and mechanical methods for organic, flexible photovoltaics. Both the imines, (N,N'E,N,N'E)-N,N'-([2,2':5',2"-terthiophene]-5,5"-diylbis(methanylylidene))bis(benzo[d]thiazol-2-imine) (SC3) and (6E)-N-((5-(5-(5-((E)-(4-(4-(4-fluorophenyl)thiazol-2-yl)phenylimino)methyl)thiophen-2-yl)thiophen-2-yl)thiophen-2-yl)methylene)-4-(4-(4-fluorophenyl)thiazol-2-yl)benzenamine (SC13), have the same core composed of three thiophene rings but different terminal chains of the molecules. In the imine SC3, the imine bond is followed by benzothiazole rings on both sides of the core, while in SC13, a thiazole ring separates two benzene rings, the terminal one F-substituted. The difference in molecular structure affects the electric properties of the neat imine and its mixed layers. An addition of PC71BM to the imines improves their electric conductivity. The mechanical studies focused on the stress at break and elongation showed superior behaviour compared to fullerene derivative. High pressure systematically reduces the band gap energy, Eg, from 1.68 eV at 0.16 GPa to 1.51 eV at 2.69 GPa for PC71BM, from 1.77 eV at 0.1 MPa to 1.53 eV at 4.15 GPa for SC3, and from 1.99 eV at 0.11 GPa to 1.8 eV at 3.10 GPa for SC13, as determined by the UV-Vis absorbance measurements in a diamond-anvil cell. These Eg reductions reflect the compressed intermolecular interactions that can be used to monitor the structural stability of these compounds. Based on the dielectric studies it was found that the relaxation processes registered for both imines are probably the grain boundary relaxation. Two processes also appear in the systems with PC71BM, but none of them is the one characteristic of imines. The high-frequency process has a dipole character while the low-frequency one is probably the grain boundary relaxation of these systems. The mechanism of quasi-DC conduction in various temperature ranges in the studied systems was also determined.

Wound Healing Impairment in Type 2 Diabetes Model of Leptin-Deficient Mice-A Mechanistic Systematic Review.

Type II diabetes mellitus (T2DM) is one of the most prevalent diseases in the world, associated with diabetic foot ulcers and impaired wound healing. There is an ongoing need for interventions effective in treating these two problems. Pre-clinical studies in this field rely on adequate animal models. However, producing such a model is near-impossible given the complex and multifactorial pathogenesis of T2DM. A leptin-deficient murine model was developed in 1959 and relies on either dysfunctional leptin (ob/ob) or a leptin receptor (db/db). Though monogenic, this model has been used in hundreds of studies, including diabetic wound healing research. In this study, we systematically summarize data from over one hundred studies, which described the mechanisms underlying wound healing impairment in this model. We briefly review the wound healing dynamics, growth factors' dysregulation, angiogenesis, inflammation, the function of leptin and insulin, the role of advanced glycation end-products, extracellular matrix abnormalities, stem cells' dysregulation, and the role of non-coding RNAs. Some studies investigated novel chronic diabetes wound models, based on a leptin-deficient murine model, which was also described. We also discussed the interventions studied in vivo, which passed into human clinical trials. It is our hope that this review will help plan future research.

Adequacy of Mediastinal Lymph Node Sampling in Patients With Lung Cancer Undergoing Lung Resection.

BACKGROUND: Intraoperative mediastinal lymph node sampling (MLNS) is a crucial component of lung cancer surgery. Whilst several sampling strategies have been clearly defined in guidelines from international organizations, reports of adherence to these guidelines are lacking. We aimed to assess our center's adherence to guidelines and determine whether adequacy of sampling is associated with survival. MATERIALS AND METHODS: A single-center retrospective review of consecutive patients undergoing lung resection for primary lung cancer between January 2013 and December 2018 was undertaken. Sampling adequacy was assessed against standards outlined in the International Association for the Study of Lung Cancer 2009 guidelines. Multivariable logistic and Cox proportional hazards regression analyses were used to assess the impact of specific variables on adequacy and of specific variables on overall survival, respectively. RESULTS: A total of 2380 patients were included in the study. Overall adequacy was 72.1% (n= 1717). Adherence improved from 44.8% in 2013 to 85.0% in 2018 (P< 0.001). Undergoing a right-sided resection increased the odds of adequate MLNS on multivariable logistic regression (odds ratio 1.666, 95% confidence interval [CI]: 1.385-2.003, P< 0.001). Inadequate MLNS was not significantly associated with reduced overall survival on log rank analysis (P= 0.340) or after adjustment with multivariable Cox proportional hazards (hazard ratio 0.839, 95% CI 0.643-1.093). CONCLUSIONS: Adherence to standards improved significantly over time and was significantly higher for right-sided resections. We found no evidence of an association between adequate MLNS and overall survival in this cohort. A pressing need remains for the introduction of national guidelines defining acceptable performance.

Theoretical and Experimental Analysis of Inter-Layer Stresses in Filament-Wound Cylindrical Composite Structures.

This paper analyses the issues relative to the modelling of tubular (cylindrical) composite structures. This paper aims to describe the design of a multi-layer structure of filament-wound composite pipes where, after loading, the hoop-stress distribution would be as uniform as possible. That would allow the mass of the composite to decrease while maintaining the proper mechanical strength. This publication presents the development of a calculation model dedicated to mono- and multi-layered tubular composite structures. The equations describing the stress pattern were based on the Lamé Problem, whereas to describe the modelled structures, an anisotropy coefficient was introduced and interlayer pressures values were determined. To verify the calculations, experimental studies were performed. The test specimens were fabricated by winding fibre bundles around a steel core (as rings with an internal diameter of 113 mm and a height of 30 mm). For the test, the method of pressing a conical ring into a split ring, which acts on the internal surface of the tested cylindrical sample, was selected. The operation of the test rig (test stand) was simulated using the Finite Element Method (FEM). Measurements with strain gauges were conducted during the experiments.

Dielectric, Thermal and Mechanical Properties of l,d-Poly(Lactic Acid) Modified by 4'-Pentyl-4-Biphenylcarbonitrile and Single Walled Carbon Nanotube.

We report here the preparation and thermal, electrical and mechanical characterization of binary and ternary films based on l,d-poly(lactic acid) (l,d-PLA) and 4'-pentyl-4-biphenylcarbonitrile (5CB) and Single Walled Carbon Nanotubes (SWCN) with various weight ratio. The transitions for all investigated hybrid compositions detected by differential scanning calorimetry method were shifted to lower temperatures with increasing the concentration of 5CB in the mixture with polymer. Frequency domain dielectric spectroscopy method and thermal imaging together with polarized optical microscope were used to study electric and structural properties of created hybrid compositions. The best electrical conductivity was observed for hybrid composite l,d-PLA:5CB:SWCN with ratio 10:1:0.5 w/w/w - resistance of 41.0 Ω and thermal response up to 160 °C without causing any damages. Films in crystal form are much more inflexible than in amorphous and can be explain by the cold crystallization occurs at heating while the materials changed their physical state. The value of ε' increases with increasing the 5CB admixture. Moreover, the addition of 5CB to l,d-PLA resulted in increased flexibility of polymeric base films. The best material flexibility and short-term strength were obtained for l,d-PLA sample with 9% 5CB content.

Identification of a Biomarker Panel for Early Detection of Lung Cancer Patients.

Lung cancer is the most common cause of cancer-related mortality worldwide, characterized by late clinical presentation (49-53% of patients are diagnosed at stage IV) and consequently poor outcomes. One challenge in identifying biomarkers of early disease is the collection of samples from patients prior to symptomatic presentation. We used blood collected during surgical resection of lung tumors in an iTRAQ isobaric tagging experiment to identify proteins effluxing from tumors into pulmonary veins. Forty proteins were identified as having an increased abundance in the vein draining from the tumor compared to "healthy" pulmonary veins. These protein markers were then assessed in a second cohort that utilized the mass spectrometry (MS) technique: Sequential window acquisition of all theoretical fragment ion spectra (SWATH) MS. SWATH-MS was used to measure proteins in serum samples taken from 25 patients <50 months prior to and at lung cancer diagnosis and 25 matched controls. The SWATH-MS analysis alone produced an 11 protein marker panel. A machine learning classification model was generated that could discriminate patient samples from patients within 12 months of lung cancer diagnosis and control samples. The model was evaluated as having a mean AUC of 0.89, with an accuracy of 0.89. This panel was combined with the SWATH-MS data from one of the markers from the first cohort to create a 12 protein panel. The proteome signature developed for lung cancer risk can now be developed on further cohorts.

Prevalence of nodal metastases in lymph node stations 8 & 9 in a large UK lung cancer surgical centre without routine pre-operative EUS nodal staging.

INTRODUCTION: Endoscopic ultrasound (EUS) allows access to the inferior mediastinal lymph node stations (8 and 9) which are beyond the reach of endobronchial ultrasound (EBUS). The addition of EUS to EBUS procedures requires cost and resource investment. This study sought to describe the prevalence of station 8/9 nodal metastases from intra-operative lymph node sampling in a UK region where routine pre-operative EUS is not available. METHODS: A retrospective review of all lung cancer resections at the University Hospital South Manchester from 2011 to 2014. Surgical variables, pre-operative PET variables and survival outcomes were collected and analysed. RESULTS: 1421 surgical resections were performed in the study period. Lymph node stations 8 and/or 9 were sampled in 52% (736/1421) of patients. Overall, there were 34 patients with lymph node metastases at station 8/9. This represents 2.4% of the study populations and 4.6% of patients in whom stations 8/9 were sampled intra-operatively. Of those patients with station 8/9 metastases, 65% (22/34) had multi-station N2 disease and the majority of the additional N2 disease was present in EBUS-accessible areas (lymph node stations 2, 4 and 7). Two percent (16/736) of patients in whom station 8/9 lymph nodes were sampled intra-operatively had N2 disease that was only accessible endoscopically with EUS. There was no significant difference in overall survival in patients with pathological N2 disease stratified according to whether stations 8/9 were involved or not. CONCLUSIONS: The prevalence of lymph node metastases in stations 8/9 in this UK surgical centre where routine pre-operative EUS is not performed is low at approximately 5%. Given the identification of N2 disease in two-thirds of these patients can potentially be achieved through EBUS alone, this questions whether the resource implications of EUS are justified by the impact on patient management.

Hybrid Materials Based on l,d-Poly(lactic acid) and Single-Walled Carbon Nanotubes as Flexible Substrate for Organic Devices.

We report on the application of l,d-poly(lactic acid) (l,d-PLA) with dispersed Single-Walled Carbon Nanotubes (SWCN) as a flexible translucent electrode for organic devices. We used commercially available nanotubes in various weight ratios from 0 to 8% dispersed in chloroform polymeric solution by ultrasonication and were drop cast. The created hybrid materials were investigated by differential scanning calorimetry to determine the influence of SWCN content on the thermal behavior, while polarizing optical microscope was used to find the effect of mechanical deformations on the textures. Drop-cast films were studied by optical transmittance, conductivity, dielectric properties and by thermal imaging under applied potential. Thermal imaging provided evidence of visible voltage-activated conduction. Simple mechanical deformation such as bending with stretching at edge to ca. 90 and elongation test were performed. Moreover, interactions between l,d-poly(lactic acid) and SWCN were investigated by FT-IR and NMR spectroscopy. Finally, we can conclude that the thermographic examination of created films permits fast, simple and inexpensive localization of defects on the surface of l,d-PLA:SWCN film, together with the electrical properties of the films.

Adequacy of Intraoperative Nodal Staging during Surgical Resection of NSCLC: Influencing Factors and Its Relationship to Survival.

INTRODUCTION: Adequate intraoperative lymph node sampling is a fundamental part of lung cancer surgery, but adherence to standards is not well known. This study sought to measure the adequacy of intraoperative lymph node sampling at a regional Thoracic Surgery Centre and a tertiary lung cancer center in the United Kingdom. METHODS: This retrospective study analyzed the pathological reports from NSCLC resections over the 4-year period 2011-2014. Adequacy of sampling was assessed against International Association for the Study of Lung Cancer recommendations of at least three mediastinal lymph node stations: station 7 in all patients, station 5 or 6 in left upper lobe tumors, and station 9 in lower lobe tumors. The influence of clinical variables (age, tumor T stage, type of surgery, and laterality) on adequacy of sampling and the effect of adequacy on overall survival were also assessed. RESULTS: A total of 1301 NSCLC resections were performed from January 11, 2011, to December 31, 2014. Adequate intraoperative lymph node sampling increased significantly from 14% (22 of 160) in 2011 to 53% (206 of 390) in 2014 (p = 0.001). Secondary analysis of clinical variables also revealed that patients with T1a or T4 tumors, those undergoing sublobar resections, those undergoing video-assisted thoracic surgery resections, and those undergoing left-sided resections have significantly higher rates of inadequate lymph node sampling. Overall, there was no statistically significant difference in survival between patients with adequate versus inadequate intraoperative lymph node sampling or when survival was stratified according to overall stage. There was worse survival in inadequate sampling for patients with pN2 disease than for patients with pN2 disease and adequate sampling. CONCLUSION: This study provides a much-needed benchmark of current thoracic surgical practice in lung cancer in the United Kingdom and important granularity to facilitate changes to improve adequacy of staging.

Persistent air leak after pulmonary transplantation.

A 59-year-old man with bilateral apical emphysema underwent a double lung transplant for end-stagechronic obstructive pulmonary disease leaving remnant right apical native tissue due to pleural adhesions. Initial postoperative course was uneventful until the chest drains were removed. This revealed a small pneumomediastinum, which progressively increased in size causing gross surgical emphysema. Re-insertion of the chest drain stabilised the patient so that the cause could be identified and corrected. Two bronchoscopies excluded anastomotic dehiscence as a cause. Therefore the subcostal wound was refashioned under video-assisted thoracoscopic surgery in case there was a defect. Unfortunately this also failed to halt the air leak; therefore another cause was sought. A multidisciplinary team meeting review of the radiology revealed that the patient's native bullous tissue was still inflated. Subsequent bronchoscopy revealed a native bronchial communication, due to variant anatomy, proximal to the surgical anastomosis. This was subsequently occluded using a bronchial valve allowing the patient to make a swift recovery.

Prognostic Significance of CD44 and Orthopedia Homeobox Protein (OTP) Expression in Pulmonary Carcinoid Tumours.

CD44 and orthopedia homeobox protein (OTP) expressions have shown to be predictive of overall survival in pulmonary carcinoid (PC) tumours. The scope of the present study was to validate their role in PC patients and investigate potential application in clinical practice. Data was collected from patients presenting to a tertiary cancer centre diagnosed with PC between 2003 and 2015. Diagnosis was confirmed by central pathology review. Formalin-fixed paraffin-embedded (FFPE) tissue samples collected at diagnosis were scored using immunohistochemistry (H score) for standard CD44 and nuclear and cytoplasmic OTP protein expression. The study included 108 patients. High CD44/nuclear OTP (nOTP) expression was strongly associated with typical carcinoid (TC) histology (p < 0.001). Eighty-six patients, who underwent radical surgical resection, were selected to assess the impact of patient and tumour parameters on relapse-free survival (RFS). Sixty-nine (80 %) had TC and 17 (20 %) had atypical carcinoid tumours. On multivariate analysis, high CD44 and nOTP expression, TC histology and non-infiltrative tumour growth were associated with superior RFS. Early stage TC (stage pT1aN0) patients (N = 32; 46 %) had excellent prognosis irrespective of CD44/nOTP status. Importantly, TC patients with locally advanced disease (defined as >pT1aN0) and high CD44/nOTP expression (N = 26; 38 %) had excellent RFS (p = 0.005) compared to those with the same stage but low CD44 and/or nOTP (N = 11; 16 %). Additionally, the combination of CD44/nOTP expression and tumour growth pattern led to a more accurate prognostic system compared to the established WHO classification of PC tumours (concordance index = 0.902 vs 0.811, respectively, p < 0.001). Assessment of CD44/nOTP expression combined with tumour growth pattern identifies clear groups with largely different prognosis. These findings provide important information on how patients with these resected cancers should be followed up.

Circulating Tumor Cells Detected in the Tumor-Draining Pulmonary Vein Are Associated with Disease Recurrence after Surgical Resection of NSCLC.

Tumor recurrence after surgical resection of NSCLC obstructs long-term disease-free survival in approximately 50% of cases. Our data suggest that combining circulating tumor cell enumeration (as single cells or clusters) in tumor-draining pulmonary vein and peripheral blood (assessed by CellSearch) at the time of NSCLC surgery better identifies those patients at higher risk for lung cancer recurrence than does peripheral circulating tumor cell number alone.

Oxygenation via a Biventricular Assist Device for Emergency Airway Management.

A 56-year-old man receiving mechanical circulatory support via a biventricular assist device suffered an airway emergency secondary to bleeding into the airway. An improvised solution to gain control of the airway in the short term was devised, and an oxygenator was inserted into the circuit, providing an alternative means of gas exchange while definitive control of the airway was achieved. This case changed practice in our institution, where we now make contingency plans for emergency oxygenator insertion into the circuits of all patients with a biventricular assist device who show any sign of airway hemorrhage.

Is there a role for the high-risk multidisciplinary team meeting in thoracic surgery?

OBJECTIVES: There is little information on the impact of a high-risk multidisciplinary team (HRMDT) for thoracic surgery. In our unit, patients considered high risk for thoracic surgery have been discussed at this meeting since its inception in June 2013. The aim of this study was to audit our selection of patients discussed at the HRMDT and its effect on patient outcomes. METHODS: Data were prospectively collected on all patients (n = 820) who underwent lung resection for lung cancer between July 2013 and September 2014. Patients were analysed as two groups HRMDT versus non-HRMDT. Referral to the HRMDT was at the operating surgeons' discretion. Referred patients usually had a higher-than-expected mortality or morbidity risk for the indicated procedure. The median time from HRMDT to surgery was 27 days (IQR 27.75). The median follow-up for all patients was 415 days (IQR 240). RESULTS: There were 102 patients in the HRMDT group and 718 in the non-HRMDT group (males 54 vs 46%; P = 0.12). The median duration from HRMDT to surgery was 27 days (IQR 27.75). Mean age (P = 0.0001), cardiac risk score (P = 0.001) and Thoracoscore (P = 0.0001) were significantly higher in the HRMDT group. There was also a significantly higher proportion of pneumonectomies in the HRMDT group (12 vs 4%; P = 0.001). There were no significant differences between the groups in cardiac, cerebrovascular, GI, pulmonary, renal or composite complications. There was no significant difference in 30-day (3 vs 1%; P = 0.24) or 90-day (5 vs 3%; P = 0.48) mortality between the groups. Operated HRMDT patients had better survival at 200 days (P = 0.002), but there was no difference in long-term survival compared with patients turned down for surgery. CONCLUSIONS: Despite a higher predicted mortality rate by Thoracoscore, HRMDT patients had the same outcome as lower risk non-HRMDT patients. Within the HRMDT cohort, survival in the operated patients was significantly better than that in non-operated patients in the short term. The HRMDT has managed to offer patients a radical treatment option who might have been refused surgery prior to this due to their higher risk profile. We would recommend this forum as a means to further assess and discuss high-risk patients.

Results of surgery for chronic pulmonary Aspergillosis, optimal antifungal therapy and proposed high risk factors for recurrence--a National Centre's experience.

BACKGROUND: Surgery for pulmonary aspergillosis is infrequent and often challenging. Risk assessment is imprecise and new antifungals may ameliorate some surgical risks. We evaluated the medical and surgical management of these patients, including perioperative and postoperative antifungal therapy. METHODS: Retrospective study of patients who underwent surgery for pulmonary aspergillosis between September 1996 and September 2011. RESULTS: 30 patients underwent surgery with 23 having a preoperative tissue diagnosis while 7 were confirmed post-resection. The median age was 57 years (17-78). The commonest presenting symptoms were cough (40%, n = 12) and haemoptysis (43%, n = 13). Twelve (40%) patients had simple aspergilloma (including 2 with Aspergillus nodules) while the remaining 18 (60%) had chronic cavitary pulmonary aspergillosis (CCPA) (complex aspergilloma). Most of the patients had underlying lung disease: tuberculosis (20%, n = 6), asthma (26%, n = 8) and COPD (20%, n = 6). The procedures included lobectomy 50% (n = 15), pneumonectomy 10% (n = 3), sublobar resection 27% (n = 8), decortication 7% (n = 2), segmentectomy 3% (n = 1), thoracoplasty 3% (n = 1), bullectomy and pleurectomy 3% (n = 1), 6% (n = 2) lung transplantation for associated disease. Median hospital stay was 9.5 days (3-37). There was no operative and 30 day mortality. Main complications were prolonged air leak (n = 7, 23%), empyema (n = 6, 20%), respiratory failure requiring tracheostomy /reintubation (n = 4, 13%). Recurrence of CCPA was noted in 8 patients (26%), most having prior CCPA (75%). Taurolidine 2% was active against all 9 A. fumigatus isolates and used for pleural decontamination during surgery. CONCLUSIONS: Surgery in patients with chronic pulmonary aspergillosis offered good outcomes with an acceptable morbidity in a difficult clinical situation; recurrence is problematic.

Is type and screen only policy safe for patients undergoing elective lobectomy?

OBJECTIVE: The purpose of this study was to establish the safety and feasibility of a recently adopted policy to type and screen (TS) (group and save) only for selected patients who had low likelihood of transfusion requirement. METHODS: The TS only policy was applied to patients undergoing first-time elective lobectomy with Hb of >11 g/dl, aged <70 years, with no clotting abnormality and no history of neoadjuvant therapy. A retrospective analysis of prospectively collected data was made of 208 consecutive patients undergoing elective lobectomy from November 2009 to October 2010. The patients who were only type and screened (Group TS, n = 87) were compared with those who had preoperative cross matching (XM) (Group XM, n = 121). The perioperative characteristics, transfusion requirements and outcomes were compared between the two groups. RESULTS: Preoperative characteristics of the two groups were similar, except that the XM group were significantly older, with lower mean preoperative haemoglobin levels. Postoperative complications (9 vs 13%, P = 0.24) and hospital mortality (0 vs 0.8%, P = 0.5) were similar between TS and XM, respectively. On the day of operation, 16 patients (13%) required transfusion in the XM group. Six patients in the TS group were cross matched, of whom only 3 (3.4%) actually required transfusion. The mean postoperative Hb levels in XM were also significantly lower (12.96 vs 10.88 gm/dl). In the XM group, 260 units of blood were unnecessarily cross matched and had to be returned to the blood bank compared with zero units in the TS group. There was no delay caused by unavailability of blood at the time of clinical need. CONCLUSION: Our data suggest that it is safe and feasible to adopt a policy of type and screen only in selected patients undergoing elective lobectomy, who have low likelihood of transfusion requirement.

Active treatment rates for lung cancer in south Manchester: are we doing enough?

In an effort to improve the current lung cancer treatment outcomes in Britain, National guidelines were published followed by the introduction of National Lung Cancer Audit (LUCADA) project. LUCADA has defined active treatment as any therapeutic intervention with the aim of improving the quality or length of patients' survival irrespective of whether it is curative or palliative. From August 2003 to December 2006, all patients diagnosed to be new primary lung cancer referrals were enrolled into a prospective study. Out of the total of 433 patients the majority of patients were male (62%) and the mean age was 69 years. The histologies were small cell lung cancer (SCLC), non-small cell lung cancer (NSCLC) and other cancers in 67 (15.5%), 306 (70.7%) and 11 (2.5%) patients, respectively, while 49 (11.3%) patients had no histological confirmation. Overall, the active treatment rate was 72% with 74 (18%), 158 (36%), 66 (15%) and 11 (3%) undergoing surgery, chemotherapy, radiotherapy and other methods, respectively. The active treatment rates for histologically proven SCLC, NSCLC and all lung cancers excluding SCLC were 83%, 77% and 71%, respectively, compared to the LUCADA national average of 73.5%, 66% and 56.5%, respectively. Among the NSCLC patients overall five-year survival was 27.4%. The stage specific survivals were 64.0%, 58.3%, 24.1% and 11.5%, respectively, for stages I, II, III and IV. These reassuring results show that south Manchester has good active treatment rates for lung cancer with survival outcomes comparable to other major series.

Implications of a negative bronchoscopy on waiting times to treatment for lung cancer patients: results of a prospective tracking study.

OBJECTIVE: To ascertain the causes of delays in treatment to all patients presenting to our centre with a working diagnosis of lung cancer. All were entered prospectively into a 'tracking study'. METHODS: Of 342 consecutive confirmed cases of newly diagnosed lung cancer presenting between September 2003 and December 2005, 193 were general practitioner referrals and 149 presented through casualty and internal referrals. The former group formed the basis of the study. Of GP referral patients, 92 had a positive diagnostic bronchoscopy (group Bronch+). Their waiting times were compared with 94 others with negative result (group Bronch-). For uniformity of comparison the non-GP referral patients were excluded from this study. RESULTS: There were no significant differences in the age, clinical presentation or clinical staging of the two groups. Bronch+ had higher proportion of male patients (p=0.05). Bronch+ group had higher proportion of small cell and squamous cell carcinoma whereas Bronch- group had higher prevalence of adenocarcinoma (p=0.02). More patients in Bronch- underwent curative (36 vs 18, p=0.01) intent treatment. Though the median intervals (days) between the referral to first chest outpatient appointments were similar between the two groups (1 vs 1, p=0.89), the intervals from out-patient to decision-to-treat (33 vs 57, p=0.001) and decision-to-treat to treatment (8 vs 12, p=0.05) were significantly longer for Bronch- group. Overall the median referral to treatment interval for Bronch- was significantly longer compared to Bronch+ (45 vs 75, p=0.001). Most of these delays occurred in the intervals from outpatient appointments to decision-to-treat. CONCLUSIONS: A negative initial bronchoscopy in a suspected lung cancer patient implies a greater potential for excessive delays in diagnosis and treatment in spite of a greater chance of curative treatment. Most of the delay occurs in the interval from the outpatient appointment to decision-to-treat. Patients with negative bronchoscopy require a more concerted effort to achieve a timely diagnosis and treatment.