Transplant Center Variability in Organ Offer Acceptance and Mortality Among US Patients on the Heart Transplant Waitlist

Importance

Under the current Centers for Medicare & Medicaid Services guidelines, there is incentivization to optimize posttransplant outcomes regardless of mortality among patients on the waitlist and transplant rates; few data exist with regard to transplant center acceptance practices and survival to heart transplant.

Objectives

To evaluate the extent of variability in organ acceptance practices in the US and whether this center-level behavior is associated with heart transplant candidate survival.

Design, Setting, and Participants

In this retrospective cohort study, the US National Transplant Registry was queried for all match runs of adult candidates listed for isolated heart transplant between May 1, 2007, and March 31, 2017. Data analysis was conducted from October 30, 2018, to May 1, 2019. The final cohort included 93 transplant centers, 19 703 donors, and 9628 candidates.

Main Outcomes and Measures

Center acceptance rates for heart allografts offered to the highest-priority candidates, association between center acceptance rate and mortality among patients on the waitlist, and posttransplant outcomes between candidates who accepted their first-rank offers vs those who accepted previously declined offers.

Results

Among 19 703 unique organ offers, 6302 hearts (32.0%) were accepted for first-rank candidates. After adjustment for donor, candidate, and geographic covariates, transplant centers varied in acceptance rates (12.3%-61.5%) of offers made to first-rank candidates. Higher acceptance rates were associated with lower cumulative incidence of 1-year mortality among patients on the waitlist. For every 10% increase in adjusted center acceptance rate, the risk of mortality decreased by 27% (subdistribution hazard ratio, 0.73; 95% CI, 0.67-0.80). No statistically significant difference was observed in 5-year adjusted posttransplant patient survival (adjusted hazard ratio, 1.02; 95% CI, 0.94-1.11) and graft failure (subdistribution hazard ratio; 0.95; 95% CI, 0.83-1.09) between hearts accepted at the first-rank compared with lower-rank positions.

Conclusions and Relevance

Variability in heart allograft acceptance rates appears to exist among transplant centers, with candidates listed at lower acceptance rate centers being more likely to experience mortality while on the waitlist. Comparable posttransplant survival suggests that allografts that were declined as a first offer perform as well as those that were accepted at their first offer. These findings suggest that organ acceptance rate or time to transplant from being added to the waitlist may be an additional measure of heart transplant program performance.

Predictors of nonuse of donation after circulatory death lung allografts

OBJECTIVE

Despite growing evidence of comparable outcomes in recipients of donation after circulatory death and donation after brain death donor lungs, donation after circulatory death allografts continue to be underused nationally. We examined predictors of nonuse.

METHODS

All donors who donated at least 1 organ for transplantation between 2005 and 2019 were identified in the United Network for Organ Sharing registry and stratified by donation type. The primary outcome of interest was use of pulmonary allografts. Organ disposition and refusal reasons were evaluated. Multivariable regression modeling was used to assess the relationship between donor factors and use.

RESULTS

A total of 15,458 donation after circulatory death donors met inclusion criteria. Of 30,916 lungs, 3.7% (1158) were used for transplantation and 72.8% were discarded primarily due to poor organ function. Consent was not requested in 8.4% of donation after circulatory death offers with donation after circulatory death being the leading reason (73.4%). Nonuse was associated with smoking history (P < .001), clinical infection with a blood source (12% vs 7.4%, P = .001), and lower PaO₂/FiO₂ ratio (median 230 vs 423, P < .001). In multivariable regression, those with PaO₂/FiO₂ ratio less than 250 were least likely to be transplanted (adjusted odds ratio, 0.03; P < .001), followed by cigarette use (0.28, P < .001), and donor age >50 (0.75, P = .031). Recent transplant era was associated with significantly increased use (adjusted odds ratio, 2.28; P < .001).

CONCLUSIONS

Nontransplantation of donation after circulatory death lungs was associated with potentially modifiable predonation factors, including organ procurement organizations' consenting behavior, and donor factors, including hypoxemia. Interventions to increase consent and standardize donation after circulatory death donor management, including selective use of ex vivo lung perfusion in the setting of hypoxemia, may increase use and the donor pool.

Resection of the irradiated esophagus: the impact of lymph node yield on survival

There is debate surrounding the appropriate threshold for lymph node harvest during esophagectomy in patients with esophageal cancer, specifically for those receiving preoperative radiation. The purpose of this study was to determine the impact of lymph node yield on survival in patients receiving preoperative chemoradiation for esophageal cancer. The National Cancer Database (NCDB) was utilized to identify patients with esophageal cancer that received preoperative radiation. The cohort was divided into patients undergoing minimal (<9) or extensive (≥9) lymph node yield. Demographic, operative, and postoperative outcomes were compared between the groups. Kaplan-Meier analysis with the log rank test was used to compare survival between the yield groups. Cox proportional hazards model was used to determine the association between lymph node yield and survival. In total, 886 cases were included: 349 (39%) belonging to the minimal node group and 537 (61%) to the extensive group. Unadjusted 5-year survival was similar between the minimal and extensive groups, respectively (37.3% vs. 38.8%; P > 0.05). After adjustment using Cox regression, extensive lymph node yield was associated with survival (hazard ratio 0.80, confidence interval 0.66-0.98, P = 0.03). This study suggests that extensive lymph node yield is advantageous for patients with esophageal cancer undergoing esophagectomy following induction therapy. This most likely reflects improved diagnosis and staging with extensive yield.

Variability in donor organ offer acceptance and lung transplantation survival

BACKGROUND

Lung transplantation offers a survival benefit for patients with end-stage lung disease. When suitable donors are identified, centers must accept or decline the offer for a matched candidate on their waitlist. The degree to which variability in per-center offer acceptance practices impacts candidate survival is not established. The purpose of this study was to determine the degree of variability in per-center rates of lung transplantation offer acceptance and to ascertain the associated contribution to observed differences in per-center waitlist mortality.

METHODS

We performed a retrospective cohort study of candidates waitlisted for lung transplantation in the US using registry data. Logistic regression was fit to assess the relationship of offer acceptance with donor, candidate, and geographic factors. Listing center was evaluated as a fixed effect to determine the adjusted per-center acceptance rate. Competing risks analysis employing the Fine-Gray model was undertaken to establish the relationship between adjusted per-center acceptance and waitlist mortality.

RESULTS

Of 15,847 unique organ offers, 4,735 (29.9%) were accepted for first-ranked candidates. After adjustment for important covariates, transplant centers varied markedly in acceptance rate (9%-67%). Higher cumulative incidence of 1-year waitlist mortality was associated with lower acceptance rate. For every 10% increase in adjusted center acceptance rate, the risk of waitlist mortality decreased by 36.3% (sub-distribution hazard ratio 0.637; 95% confidence interval 0.592-0.685).

CONCLUSIONS

Variability in center-level behavior represents a modifiable risk factor for waitlist mortality in lung transplantation. Further intervention is needed to standardize center-level offer acceptance practices and minimize waitlist mortality.

Pretransplant Desensitization with Costimulation Blockade and Proteasome Inhibitor Reduces DSA and Delays Antibody-Mediated Rejection in Highly Sensitized Nonhuman Primate Kidney Transplant Recipients

BACKGROUND

Patients with broad HLA sensitization have poor access to donor organs, high mortality while waiting for kidney transplant, and inferior graft survival. Although desensitization strategies permit transplantation via lowering of donor-specific antibodies, the B cell-response axis from germinal center activation to plasma cell differentiation remains intact.

METHODS

To investigate targeting the germinal center response and plasma cells as a desensitization strategy, we sensitized maximally MHC-mismatched rhesus pairs with two sequential skin transplants. We administered a proteasome inhibitor (carfilzomib) and costimulation blockade agent (belatacept) to six animals weekly for 1 month; four controls received no treatment. We analyzed blood, lymph node, bone marrow cells, and serum before desensitization, after desensitization, and after kidney transplantation.

RESULTS

The group receiving carfilzomib and belatacept exhibited significantly reduced levels of donor-specific antibodies (P=0.05) and bone marrow plasma cells (P=0.02) compared with controls, with a trend toward reduced lymph node T follicular helper cells (P=0.06). Compared with controls, carfilzomib- and belatacept-treated animals had significantly prolonged graft survival (P=0.02), and renal biopsy at 1 month showed significantly reduced antibody-mediated rejection scores (P=0.02). However, four of five animals with long-term graft survival showed gradual rebound of donor-specific antibodies and antibody-mediated rejection.

CONCLUSIONS

Desensitization using proteasome inhibition and costimulation blockade reduces bone marrow plasma cells, disorganizes germinal center responses, reduces donor-specific antibody levels, and prolongs allograft survival in highly sensitized nonhuman primates. Most animals experienced antibody-mediated rejection with humoral-response rebound, suggesting desensitization must be maintained after transplantation using ongoing suppression of the B cell response.

Failure to Rescue Contributes to Center-Level Differences in Mortality After Lung Transplantation

BACKGROUND

The clinical response to postoperative complications after lung transplantation (LTx) may contribute to mortality differences among transplantation centers. The ability to avoid mortality after a complication-failure to rescue (FTR)-may be an effective quality metric in LTx.

METHODS

The United Network for Organ Sharing database was queried for adult, first-time, lung-only transplantations from May 2005 to December 2015. Transplantation centers were stratified into equal-sized terciles on the basis of observed operative mortality rates. Several postoperative complications were identified, including stroke, acute rejection, acute kidney injury requiring hemodialysis, airway dehiscence, and extracorporeal membrane oxygenation 72 hours after surgery. Rates of FTR were calculated as the number of operative mortalities in patients who had complications divided by the number of patients who had any postoperative complications.

RESULTS

Our study population included 16,411 LTx operations performed at 69 transplantation centers. LTx centers were stratified into terciles with average perioperative mortality of 4.0% for low-mortality centers, 6.9% for intermediate-mortality centers, and 12.4% for high-mortality centers. Low-mortality centers had slightly lower complication rates (low, 15.0% vs intermediate, 17.1% vs high, 19.1%; P < .001). Differences in FTR rate were significantly more pronounced (low, 14.9% vs intermediate, 23.9% vs high, 34.2%; P < .001). Multivariable logistic regression and generalized linear models demonstrated an independent association between high FTR rates and high mortality in LTx (P < .001).

CONCLUSIONS

Differences in rates of FTR contribute significantly to per-center variability in mortality after LTx. FTR can serve as a quality metric to identify opportunities for improvement in management of perioperative adverse events.

Secondary lymphoid tissue and costimulation-blockade resistant rejection: A nonhuman primate renal transplant study

Naïve T cell activation requires antigen presentation combined with costimulation through CD28, both of which optimally occur in secondary lymphoid tissues such as lymph nodes and the spleen. Belatacept impairs CD28 costimulation by binding its ligands, CD80 and CD86, and in doing so, impairs de novo alloimmune responses. However, in most patients belatacept is ineffective in preventing allograft rejection when used as a monotherapy, and adjuvant therapy is required for control of costimulation-blockade resistant rejection (CoBRR). In rodent models, impaired access to secondary lymphoid tissues has been demonstrated to reduce alloimmune responses to vascularized allografts. Here we show that surgical maneuvers, lymphatic ligation, and splenectomy, designed to anatomically limit access to secondary lymphoid tissues, control CoBRR and facilitate belatacept monotherapy in a nonhuman primate model of kidney transplantation without adjuvant immunotherapy. We further demonstrate that animals sustained on belatacept monotherapy progressively develop an increasingly naïve T and B cell repertoire, an effect that is accelerated by splenectomy and lost at the time of belatacept withdrawal and rejection. These pilot data inform the role of secondary lymphoid tissues on the development of CoBRR and the use of costimulation molecule-focused therapies.

Single lung transplantation in patients with severe secondary pulmonary hypertension

BACKGROUND

The optimal transplant strategy for patients with end-stage lung disease complicated by secondary pulmonary hypertension (PH) is controversial. The aim of this study is to define the role of single lung transplantation in this population.

METHODS

We performed a retrospective study of lung transplant recipients using the Organ Procurement and Transplantation Network/United Network for Organ Sharing Standard Transplant Analysis and Research registry. Adult recipients that underwent isolated lung transplantation between May 2005 and June 2015 for end-stage lung disease because of obstructive or restrictive etiologies were identified. Patients were stratified by mean pulmonary artery pressure ([mPAP] ≥ or < 40 mm Hg) and by treatment-single (SOLT) or bilateral (BOLT) orthotopic lung transplantation. The primary outcome measure was overall survival (OS), which was estimated using the Kaplan-Meier method and compared by the log-rank test. To adjust for donor and recipient confounders, Cox proportional hazards models were developed to estimate the adjusted hazard ratio of mortality associated with elevated mPAP in SOLT and BOLT recipients.

RESULTS

A total of 12,392 recipients met inclusion criteria. Of recipients undergoing SOLT, those with mPAP ≥40 were shown to have lower survival, with 5-year OS of 43.9% (95% confidence interval 36.6-52.7; p = 0.007). Of recipients undergoing BOLT, OS was superior to SOLT, and no difference in 5-year OS between mPAP ≥ and <40 was observed (p = 0.15). In the adjusted analysis, mPAP ≥40 mm Hg was found to be an independent predictor for mortality in SOLT, but not BOLT recipients. This finding remained true on multivariable analysis. In patients undergoing SOLT, mPAP ≥40 was associated with an adjusted hazard ratio for mortality of 1.31 (1.08-1.59, p = 0.07). In BOLT, mPAP was not associated with increased hazard (adjusted hazard ratio 1.04, p = 0.48).

CONCLUSIONS

There is a reduced survival when a patient with severe secondary PH undergoes SOLT. This increased mortality hazard is not seen in BOLT. It appears that a BOLT may negate the adverse effect that severe PH has on OS, and may be superior to SOLT in patients with mPAP over 40 mm Hg.

Impact of Donor Brain Death Duration on Outcomes After Lung Transplantation

BACKGROUND

Donor brain death duration (BDD) may impact posttransplant graft function and survival in lung transplant.

METHODS

We queried the 2007 to 2018 United Network for Organ Sharing Registry for adult recipients undergoing first-time isolated lung transplant. Cox proportional hazard modeling with splines enabled identification of 3 donor brain death intervals for subsequent analysis: short (<24 hours), reference (24-60 hours), and long (>60 hours). The primary outcome was posttransplant survival.

RESULTS

In total, 19,721 donors and recipients met inclusion criteria. Median time from donor brain death until cross-clamp was 36.6 hours (interquartile range, 19.5). Unadjusted overall survival between cohorts was equivalent (log-rank P = .42); however, longer BDD was associated with improved bronchiolitis obliterans syndrome (BOS)-free survival (log-rank P < .001). On multivariable Cox proportional hazards regression, BDD was not associated with recipient survival (P > .05). Similarly, logistic regression did not identify an independent association between BDD and primary graft dysfunction (P > .05). Increased BDD was, however, associated with a decreased risk of acute rejection (long vs reference; adjusted odds ratio, 0.78; 95% confidence interval, 0.64-0.94) and improved BOS-free survival (long vs reference; adjusted hazard ratio, 0.88; 95% confidence interval, 0.81-0.96).

CONCLUSIONS

Donor BDD is not associated with posttransplant survival or primary graft dysfunction. Long donor BDD, however, is associated with a decreased risk for acute rejection and improved BOS-free survival. Therefore, lung allografts from donors with a prolonged length of time from brain death until explant should not be viewed less favorably by donor selection centers.

The role of human CD46 in early xenoislet engraftment in a dual transplant model

BACKGROUND

Membrane cofactor protein CD46 attenuates the complement cascade by facilitating cleavage of C3b and C4b. In solid organ xenotransplantation, organs expressing CD46 have been shown to resist hyperacute rejection. However, the incremental value of human CD46 expression for islet xenotransplantation remains poorly defined.

METHODS

This study attempted to delineate the role of CD46 in early neonatal porcine islet engraftment by comparing Gal-knocked out (GKO) and hCD46-transgenic (GKO/CD46) islets in a dual transplant model. Seven rhesus macaques underwent dual transplant and were sacrificed at 1 hour (n = 4) or 24 hours (n = 3). Both hemilivers were recovered and fixed for immunohistochemistry (CD46, insulin, neutrophil elastase, platelet, IgM, IgG, C3d, C4d, CD68, Caspase 3). Quantitative immunohistochemical analysis was performed using the Aperio Imagescope.

RESULTS

Within 1 hour of intraportal infusion of xenografts, no differences were observed between the two types of islets in terms of platelet, antibody, or complement deposition. Cellular infiltration and islet apoptotic activity were also similar at 1 hour. At 24 hours, GKO/CD46 islets demonstrated significantly less platelet deposition (P = 0.01) and neutrophil infiltration (P = 0.01) compared to GKO islets. In contrast, C3d (P = 0.38) and C4d (P = 0.45) deposition was equal between the two genotypes.

CONCLUSIONS

Our findings suggest that expression of hCD46 on NPIs potentially provides a measurable incremental survival advantage in vivo by reducing early thrombo-inflammatory events associated with instant blood-mediated inflammatory reaction (IBMIR) following intraportal islet infusion.

Endoscopic cyclophotocoagulation (ECP) for childhood glaucoma: a large single-center cohort experience

PURPOSE

To assess the factors associated with successful outcomes in the management of childhood glaucoma treated with endoscopic cyclophotocoagulation (ECP) as both primary and adjunctive surgery.

METHODS

The medical records of consecutive children with glaucoma treated by a single surgeon at a single center over a 17-year period using ECP procedures were reviewed retrospectively. Treatment failure was defined as (1) intraocular pressure (IOP) >24 mm Hg at two consecutive examinations despite maximal medical treatment, (2) any additional glaucoma surgery, (3) sight-threatening complications, or (4) progression to no light perception visual acuity. Success was defined as the absence of treatment failure.

RESULTS

A total of 107 ECP procedures on 80 eyes of 70 children were included. Glaucoma diagnoses included: following-cataract-surgery (60%), anterior segment dysgenesis (13%), primary congenital (9%), and other (19%). Most eyes (67 [84%]) had prior glaucoma surgery, and 73 (91%) were aphakic or pseudophakic at first ECP. Median follow-up was 2.2 years (IQR, 1.1-3.5) after initial ECP; mean number of ECP treatments per eye was 1.3 (range, 1-3). Success for a single ECP treatment at 1, 3, and 5 years (Kaplan-Meier analysis) was 64% (95% CI, 54-76), 36% (26-50), and 16% (7-37), respectively. Cumulative success (≥1 ECP) at 5 years was 34% (23-50). In multivariable analysis, of many risk factors considered, only a preoperative IOP of <32 mm Hg was significantly associated with treatment success.

CONCLUSIONS

ECP represents a modestly effective long-term therapy for childhood glaucoma and may be most successful in patients with preoperative IOP of <32 mm Hg.

Early experience with the use of hepatitis C antibody-positive, nucleic acid testing-negative donors in lung transplantation

Historically, potential lung donors who have detectable antibodies to hepatitis C virus have been declined by most centers due to concern for possible disease transmission. We sought to evaluate hepatitis C viral transmission rates from donors who were known to be HCV Ab positive but HCV NAT negative. We performed a single-center retrospective review of a prospectively collected database for lung transplant recipients at our center including HCV Ab+NAT- donors (approved January 2017). Donor and recipient demographic data were compiled, and records were queried to ascertain rate of seroconversion. During the study period (1/1/17 to 8/9/17), a total of 64 recipients underwent lung transplantation. Thirteen (20%) donors were HCV Ab+NAT-. All recipients of HCV Ab+NAT- grafts were HCV Ab- at the time of transplant. Recipients of grafts from HCV Ab+NAT- donors underwent protocol NAT at 2 and 12 months and all are NAT- to date. One recipient developed reactive HCV Ab at 6 months post-transplant. Follow-up NAT showed HCV RNA to be undetectable. To date, use of HCV Ab+NAT- donors in lung transplantation has yielded favorable outcomes, with evidence of one transient seroconversion suggesting this practice may increase access to life-saving transplantation to those in need.

Improved contemporary outcomes of liver transplantation for pediatric hepatoblastoma and hepatocellular carcinoma

PURPOSE

Improvement in outcomes of LT for pediatric HB and HCC has been reported in small series. We analyzed national outcomes and changes in donor, recipient, and perioperative factors over time that may contribute to survival differences.

METHODS

The UNOS database was queried for patients age <21 years that underwent LT for a primary diagnosis of HB or HCC (1987-2017). Subjects were divided into historic (transplant before 2010) and contemporary (transplant after 2010) cohorts. Baseline characteristics were compiled and examined. Survival was estimated using the Kaplan-Meier method and compared using the log-rank test.

RESULTS

In total, 599 children with HB received LT (320 historic vs 279 contemporary). Concurrently, 141 children with HCC received LT (92 historic vs 49 contemporary). For both tumors, waitlist time decreased (HB 56.2 days historic vs 33.2 days contemporary, P = 0.017; HCC 189.3 days historic vs 71.7 days contemporary, P = 0.012). In the historic cohorts, patients with HB had a 1-year and 5-year OS of 84.6% and 75.1%, respectively. Survival for HCC was 84.4% and 59.9%, respectively. Outcomes improved in the contemporary era to 89.1% and 82.6% for HB, and 94.7% and 80.8% for HCC, respectively (both log-rank test P < 0.0001).

CONCLUSION

Outcomes of LT have improved significantly, with contemporary survival now equivalent between these tumors and exceeding 80% 5-year OS. Future studies are needed to explore whether offering LT in patients that are resectable is justifiable.

Higher Use of Surgery Confers Superior Survival in Stage I Non-Small Cell Lung Cancer

BACKGROUND

Lobar resection is the gold standard therapy for medically fit patients with stage I non-small cell lung cancer (NSCLC). However, considerable variability exists in the use of surgical therapy. This study tested the hypothesis that center-based variation in the use of surgical therapy affects survival in NSCLC.

METHODS

We queried the National Cancer Database for patients with stage I NSCLC. Mixed-effects multivariable models were developed to establish the per-center adjusted rate of surgical therapy. Patients were stratified into quartiles based on the treating center's adjusted rate of surgical therapy. Survival was estimated and then tested by using Kaplan-Meier and the log-rank test. Multivariable Cox proportional hazard models were developed to estimate the effect of rate of surgical therapy on overall survival.

RESULTS

A total of 139,802 patients met the criteria. There was wide variation in the per-center rate of surgical resection in the highest (80.8%) versus lowest (41.4%, p < 0.001) quartile. Across cohorts, patients were similar in age (mean 68.8 years in the highest quartile versus 69.7 in the lowest quartile) and Charlson-Deyo Score of 2 or greater (15.1% in the highest quartile versus 14.4% in the lowest quartile). Five-year survival was higher for patients treated at high-use centers (52.7% versus 36.7%, p < 0.001). After adjustment, an adjusted rate of surgical therapy in the lowest 25th percentile was associated with lower survival (adjusted hazard ratio 1.40, 95% confidence interval: 1.37 to 1.40, p < 0.001).

CONCLUSIONS

Treatment at a center with a higher rate of surgical therapy confers a considerable survival advantage, even after adjustment for hospital volume, surgical approach, and other confounders. Targeted efforts to improve adherence to guidelines about provision of surgical therapy in early-stage NSCLC may represent a meaningful opportunity to improve outcomes.

Surgical resection after neoadjuvant chemoradiation for oesophageal adenocarcinoma: what is the optimal timing?

OBJECTIVES

The purpose of this study was to determine the optimal timing of surgical resection of oesophageal adenocarcinoma following neoadjuvant chemoradiotherapy (nCRT).

METHODS

nCRT before resection of oesophageal adenocarcinoma yields improved overall and progression-free survival. Despite the wide acceptance of tri-modal therapy, the optimal timing of surgical resection after nCRT is not well defined and existing studies are limited. Adults with Stage II/III oesophageal adenocarcinoma undergoing nCRT before surgery were identified from the National Cancer Database. Multivariable analysis using restricted cubic splines was used to identify an inflection point in clinical outcomes as a function of time between nCRT and surgery, dividing the cohort into short- and long-interval treatment groups, which were then compared. Adjusted rates of survival and margin status were compared between groups using multivariable analysis.

RESULTS

Among 2444 patients, restricted cubic splines identified an inflection point at 56 days, dividing our cohort into 1533 short-interval and 911 long-interval patients. Long-interval patients had a higher adjusted incidence of pathologic downstaging (odds ratio 1.38, confidence interval 1.02-1.85, P = 0.04) but no difference in margin positivity compared with short-interval patients (odds ratio 0.91, confidence interval 0.56-1.47, P = 0.69). Worse overall survival was noted in the long-interval subgroup (hazard ratio 1.44, confidence interval 1.22-1.71, P < 0.001), but 30-day postoperative mortality was not statistically different (odds ratio 1.56, confidence interval 0.9-2.72, P = 0.12).

CONCLUSIONS

Restricted cubic splines provides an objective mechanism to more accurately delineate optimum timing between nCRT and surgical resection. A time interval of 56 days represents an interval where increased pathologic downstaging is balanced by decreased overall survival.

Fatal SV40-associated pneumonia and nephropathy following renal allotransplantation in rhesus macaque

Recrudescence of latent and dormant viruses may lead to overwhelming viremia in immunosuppressed hosts. In immunocompromised hosts, Simian virus 40 (SV40) reactivation is known to cause nephritis and demyelinating central nervous system disease. Here, we report SV40 viremia leading to fatal interstitial pneumonia in an immunosuppressed host following renal allotransplantation.

Lung transplantation in the most critically-III: forging ahead

Lung transplantation is the gold standard therapy for patients with end-stage lung disease. The use of the lung allocation score (LAS) has permitted improved allocation of scarce pulmonary allografts. Recently, Crawford et al. examined the experience in the United States in lung transplantation in candidates with the highest LAS, demonstrating that outcomes for candidates with the highest LAS scores have improved significantly. This editorial places these data in the broader context of thoracic transplantation, and highlights the critical need for ongoing examination of this critically-ill patient population.

Transplant size mismatch in restrictive lung disease

To maximize the benefit of lung transplantation, the effect of size mismatch on survival in lung transplant recipients with restrictive lung disease (RLD) was examined. All single and bilateral RLD lung transplants from 1987 to 2011 in the United Network for Organ Sharing (UNOS) Database were identified. Donor predicted total lung capacity (pTLC):Recipient pTLC ratio (pTLCr) quantified mismatch. pTLCr was segregated into five strata. A Cox proportional hazards model evaluated the association of pTLCr with mortality hazard. To identify a critical pTLCr, a Cox model using a restricted cubic spline for pTLCr was used. A total of 6656 transplants for RLD were identified. Median pTLCr for single orthotopic lung transplant (SOLT) and bilateral orthotopic lung transplant (BOLT) was 1.0 (0.69-1.47) and 0.98 (0.66-1.45). Examination of pTLCr as a categorical variable revealed that undersizing (pTLCr <0.8) for SOLT and moderate oversizing (pTLCr = 1.1-1.2) for SOLT and BOLT had a harmful survival effect [for SOLT pTLC <0.8: HR 1.711 (95% CI 1.146-2.557), P = 0.01 and for BOLT pTLC 1.1-1.2: HR 1.717 (95% CI 1.112-2.651), P = 0.02]. Spline analysis revealed significant changes in SOLT mortality by variation of pTLCr between 0.8-0.9 and 1.1-1.2. RLD patients undergoing SOLT are susceptible to detriments of an undersized lung. RLD patients undergoing BOLT have higher risk of mortality when pTLCr falls between 1.1 and 1.2.

Survival after lung transplantation in recipients with alpha-1-antitrypsin deficiency compared to other forms of chronic obstructive pulmonary disease: a national cohort study

Alpha-1-antitrypsin deficiency (AATD) is grouped with chronic obstructive pulmonary disease (COPD); however, this may not be appropriate. This study assessed whether AATD confers a different prognosis than COPD following lung transplantation. We employed the United Network for Organ Sharing (UNOS) database, grouping patients by diagnoses of AATD or COPD. Kaplan-Meier methods and Cox modeling were performed to determine the association of diagnosis and overall survival. Of 9569 patients, 1394 (14.6%) had a diagnosis of AATD. Patients with AATD who received a single-lung transplant had reduced 1-year survival [adjusted hazard ratio (AHR): 1.68, 95% CI: 1.26, 2.23]. Among patients who received a bilateral lung transplant, there was no significant difference in survival by diagnosis (AHR for AATD as compared to COPD: 0.96, 95% CI: 0.82, 1.12). After the implementation of the lung allocation score (LAS), there was no significant difference in survival among patients who received a single (AHR: 1.15, 95% CI: 0.69, 1.95) or bilateral (AHR: 0.99, 95% CI: 0.73, 1.34) lung transplant by diagnosis. Lung transplantation is increasingly employed in the care of the patient with COPD. Although recipients undergoing LTX for AATD are at increased risk of both acute rejection and airway dehiscence post-transplant, in the post-LAS era, survival rates are similar for recipients with AATD in comparison with COPD.

Induction chemotherapy for T3N0M0 non-small-cell lung cancer increases the rate of complete resection but does not confer improved survival

OBJECTIVES

The objective of this study was to evaluate outcomes of induction therapy prior to an operation in patients with cT3 non-small-cell lung cancer (NSCLC).

METHODS

Patients diagnosed with cT3N0M0 NSCLC from 2006 to 2011 in the National Cancer Database who were treated with lobectomy or pneumonectomy were stratified by treatment strategy: an operation first versus induction chemotherapy. Propensity scores were developed and matched cohorts were generated. Short-term outcomes included margin status, 30- and 90-day mortality rates, readmission and length of stay. Survival analyses using Kaplan-Meier methods were performed on both the unadjusted and propensity matched cohorts.

RESULTS

A total of 3791 cT3N0M0 patients were identified for inclusion, of which 580 (15%) were treated with induction chemotherapy. Prior to adjustment, patients treated with induction chemotherapy were younger, had a higher comorbidity burden and were more likely to have private insurance (all P  < 0.001). Following matching, patients receiving induction chemotherapy were more likely to subsequently undergo an open procedure (87.3 vs 77.8%, P  = 0.005). These patients were more likely to obtain R0 resection (93.1% vs 90.0%, P  = 0.04) and were thereby less likely to have positive margins at the time of resection (6.9% vs 10.0%, P  = 0.03). Patients who received induction therapy had higher rates of 90-day mortality (6.6% vs 3.4%) but there was no difference in long-term survival between the groups.

CONCLUSIONS

Despite yielding increased rates of R0 resection, induction chemotherapy for cT3N0M0 NSCLC is not associated with improved survival and should not be considered routinely. Further studies are warranted to elucidate cohorts that may benefit from induction therapy.

Adjuvant Chemotherapy Does Not Confer Superior Survival in Patients With Atypical Carcinoid Tumors

BACKGROUND

Although the use of adjuvant chemotherapy in patients with pathologically node-positive (pN+) atypical carcinoid tumor of the lung is an accepted practice, controversy exists about its use in pathologically node-negative (pN0) patients. Our aim was to determine whether a survival advantage exists in patients receiving chemotherapy postoperatively for pN0 or pN+ atypical carcinoid tumors of the lung.

METHODS

Adult patients treated with lobectomy or pneumonectomy for pulmonary atypical carcinoid tumor were identified using the National Cancer Data Base, 2006 to 2011. Propensity scoring (4:1 nearest neighbor algorithm) and survival analysis were used to examine the association between adjuvant chemotherapy and pN+ versus pN0 atypical carcinoid tumors.

RESULTS

Of the total 581 patients identified with a diagnosis of atypical carcinoid of the lung, 363 (62.5%) were found to be node negative at the time of operation and 218 (37.5%) had node-positive disease. Adjuvant chemotherapy was used in 15 patients (4.1%) with pN0 disease and 89 patients (40.8%) with pN+ disease. Unadjusted survival, at 12 and 60 months, was similar between pN+ patients who were treated with adjuvant chemotherapy versus patients who received operation alone (adjuvant chemotherapy: 98.9% at 12 months and 47.9% at 60 months versus operation alone: 98.4% and 12 months and 67.1% at 60 months, p = 0.46) and for propensity-matched pN0 (adjuvant chemotherapy: 86.7% at 12 months and 73.3% at 60 months versus operation alone: 87.9% at 12 months and 72.3% at 60 months, p = 0.54).

CONCLUSIONS

In a national-level analysis, the use of adjuvant chemotherapy postoperatively in patients with pN+ and pN0 disease conferred no survival advantage; further study is needed to determine proper chemotherapy use for these patients.

Elevated HbA1c in donor organs from patients without a diagnosis of diabetes portends worse liver allograft survival

Recipients of liver allografts from diabetic donors have decreased graft survival. However, limited data exist on the effects of donor HbA1c. We hypothesized that allografts from nondiabetic donors with elevated HbA1c would be associated with decreased survival. Liver transplant recipients from the UNOS database from nondiabetic donors were stratified into two groups: euglycemic (HbA1c<6.5) and hyperglycemic (HbA1c≥6.5). Propensity score matching (10:1) was used to adjust for donor and recipient characteristics. Kaplan-Meier analysis was used to assess survival. Donors of hyperglycemic allografts were older (49 vs 36, P<.001), were more likely to be non-white, had a higher BMI (29.8 vs 26.2, P<.001), were more likely to engage in heavy cigarette use (1.5% vs 1.3%, P=.004), had higher serum creatinine levels (1.3 vs 1.0, P=.002), and were more likely to be an expanded-criteria donor (35.8% vs 14.4%, P<.001). After propensity matching to account for these differences, allograft survival was significantly decreased in the recipients of hyperglycemic allografts (P=.049), and patient survival showed a trend toward reduction (P=.082). These findings suggest that HbA1c may be a simple and inexpensive test with potential utility for better organ risk stratification.

Extracorporeal membrane oxygenation following lung transplantation: indications and survival

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) is employed to rescue patients with early graft dysfunction after lung transplantation (LTx). Rates of post-LTx ECMO and subsequent outcomes have been limited to single-center reports.

METHODS

UNOS registry was queried for LTx recipients from March 2015 to March 2016; 2,001 recipients were identified and stratified by need for post-LTx ECMO. Logistic regression was used to determine variables associated with post-LTx ECMO. Cox proportional hazards modeling identified factors associated with survival. Kaplan-Meier analysis with log-rank testing was employed for survival analysis.

RESULTS

Of 2,001 recipients identified, 107 required post-LTx ECMO (5.1%). Recipients requiring ECMO were younger (56 vs 60 years, p = 0.007) and had higher body mass index (27.2 vs 25.8, p = 0.012). Recipients requiring post-LTx ECMO were more likely to have required mechanical ventilation before transplant (9.3% vs 4.9%, p = 0.049) and were more likely to have required pre-transplant ECMO (15% vs 3.7%, p < 0.001). On multivariable analysis, pre-transplant ECMO and increasing ischemic time were associated with post-LTx ECMO. Six-month survival for recipients requiring ECMO was 62.2%. On multivariable analysis, need for post-transplant dialysis was associated with mortality. Six-month survival for recipients requiring ECMO with and without dialysis was 25.8% and 86.7% (p < 0.001).

CONCLUSIONS

In a nationally representative database, ischemic time and pre-transplant ECMO and/or ventilator requirement were associated with need for post-LTx ECMO. Need for post-transplant dialysis was associated with mortality in patients requiring post-LTx ECMO. These data may permit improved prediction of graft dysfunction. Strategies to minimize renal toxicity in the perioperative phase may lead to improved early survival post-LTx.

The association of donor age and survival is independent of ischemic time following deceased donor lung transplantation

PURPOSE

Early research suggests prolonged ischemic time in older donor lungs is associated with decreased survival following lung transplantation. The purpose of this study was to determine whether this association holds in the post-lung allocation score era.

METHODS

We analyzed the United Network for Organ Sharing database 2005-2013 for adult recipients of cadaveric lung transplants. Cox proportional hazards modeling was utilized to determine the association of donor age, ischemic time, and the interaction of donor age and ischemic time with transplant-free survival.

RESULTS

Eleven thousand eight hundred thirty-five patients met criteria. Median donor age was 32 years, and median ischemic time was 4.9 hours. Cox modeling demonstrated that donor age 50-60 (adjusted hazard ratio (HR): 1.11) and ≥60 (adjusted HR: 1.42) were associated with reduced overall survival. Neither ischemic time nor interaction of ischemic time and donor age were significantly associated with overall survival. Subanalysis demonstrated that this finding held true for patients undergoing either single or bilateral lung transplantation.

CONCLUSIONS

Prolonged ischemic time is not associated with decreased overall survival in patients undergoing lung transplantation regardless of the donor's age. However, donor age >50 is independently associated with decreased survival. The lack of an association between ischemic time and survival should encourage broader geographic allocation of pulmonary allografts.

Elevated donor hemoglobin A1c does not impair early survival in cardiac transplant recipients

BACKGROUND

Orthotopic heart transplantation (OHT) is the gold-standard therapy for end-stage heart failure. An increasing deficit between suitable allograft availability and clinical demand for OHT exists. The role of donor diabetes mellitus (DM) on post-transplant recipient outcomes in OHT is controversial. The purpose of this study was to examine donor hemoglobin A1c (HbA1c) levels to identify the impact of donor glycemic control on recipient survival.

METHODS

Adult OHT recipients with donor HbA1c data were identified in the UNOS database from 2010 to 2015. Recipients were stratified on the basis of donor glycemic status: Hyperglycemic-donor and euglycemic-donor cohorts were defined as HbA1c levels ≥6.5% and <6.5%, respectively. Outcomes were compared between unadjusted and propensity-matched hyperglycemic versus euglycemic donors. Primary end point was three-year survival.

RESULTS

Of 5342 OHT recipients, 208 (3.89%) received an allograft from a hyperglycemic donor and 5134 (96.1%) received an allograft from a euglycemic donor. There was no significant difference in survival in the hyperglycemic group before (P=.87) or after (P=.78) propensity matching.

CONCLUSIONS

No difference in four-year survival was noted in recipients who received allografts from hyperglycemic donors. These results suggest that recent cumulative donor glycemic status alone may not be an important predictor of recipient outcomes.

Elevated donor hemoglobin A1c does not impair early survival in cardiac transplant recipients

BACKGROUND

Orthotopic heart transplantation (OHT) is the gold-standard therapy for end-stage heart failure. An increasing deficit between suitable allograft availability and clinical demand for OHT exists. The role of donor diabetes mellitus (DM) on post-transplant recipient outcomes in OHT is controversial. The purpose of this study was to examine donor hemoglobin A1c (HbA1c) levels to identify the impact of donor glycemic control on recipient survival.

METHODS

Adult OHT recipients with donor HbA1c data were identified in the UNOS database from 2010 to 2015. Recipients were stratified on the basis of donor glycemic status: Hyperglycemic-donor and euglycemic-donor cohorts were defined as HbA1c levels ≥6.5% and <6.5%, respectively. Outcomes were compared between unadjusted and propensity-matched hyperglycemic versus euglycemic donors. Primary end point was three-year survival.

RESULTS

Of 5342 OHT recipients, 208 (3.89%) received an allograft from a hyperglycemic donor and 5134 (96.1%) received an allograft from a euglycemic donor. There was no significant difference in survival in the hyperglycemic group before (P=.87) or after (P=.78) propensity matching.

CONCLUSIONS

No difference in four-year survival was noted in recipients who received allografts from hyperglycemic donors. These results suggest that recent cumulative donor glycemic status alone may not be an important predictor of recipient outcomes.

Selective Targeting of High-Affinity LFA-1 Does Not Augment Costimulation Blockade in a Nonhuman Primate Renal Transplantation Model

Costimulation blockade (CoB) via belatacept is a lower-morbidity alternative to calcineurin inhibitor (CNI)-based immunosuppression. However, it has higher rates of early acute rejection. These early rejections are mediated in part by memory T cells, which have reduced dependence on the pathway targeted by belatacept and increased adhesion molecule expression. One such molecule is leukocyte function antigen (LFA)-1. LFA-1 exists in two forms: a commonly expressed, low-affinity form and a transient, high-affinity form, expressed only during activation. We have shown that antibodies reactive with LFA-1 regardless of its configuration are effective in eliminating memory T cells but at the cost of impaired protective immunity. Here we test two novel agents, leukotoxin A and AL-579, each of which targets the high-affinity form of LFA-1, to determine whether this more precise targeting prevents belatacept-resistant rejection. Despite evidence of ex vivo and in vivo ligand-specific activity, neither agent when combined with belatacept proved superior to belatacept monotherapy. Leukotoxin A approached a ceiling of toxicity before efficacy, while AL-579 failed to significantly alter the peripheral immune response. These data, and prior studies, suggest that LFA-1 blockade may not be a suitable adjuvant agent for CoB-resistant rejection.

Long-term survival following kidney transplantation in previous lung transplant recipients-An analysis of the unos registry

BACKGROUND

Kidney transplantation has been advocated as a therapeutic option in lung recipients who develop end-stage renal disease (ESRD). This analysis outlines patterns of allograft survival following kidney transplantation in previous lung recipients (KAL).

METHODS

Data from the UNOS lung and kidney transplantation registries (1987-2013) were cross-linked to identify lung recipients who were subsequently listed for and/or underwent kidney transplantation. Time-dependent Cox models compared the survival rates in KAL patients with those waitlisted for renal transplantation who never received kidneys. Survival analyses compared outcomes between KAL patients and risk-matched recipients of primary, kidney-only transplantation with no history of lung transplantation (KTx).

RESULTS

A total of 270 lung recipients subsequently underwent kidney transplantation (KAL). Regression models demonstrated a lower risk of post-listing mortality for KAL patients compared with 346 lung recipients on the kidney waitlist who never received kidneys (P<.05). Comparisons between matched KAL and KTx patients demonstrated significantly increased risk of death and graft loss (P<.05), but not death-censored graft loss, for KAL patients (P = .86).

CONCLUSIONS

KAL patients enjoy a significant survival benefit compared with waitlisted lung recipients who do not receive kidneys. However, KAL patients do poorly compared with KTx patients. Decisions about KAL transplantation must be made on a case-by-case basis considering patient and donor factors.

The utility of 6-minute walk distance in predicting waitlist mortality for lung transplant candidates

BACKGROUND

The lung allocation score (LAS) has led to improved organ allocation for transplant candidates. At present, the 6-minute walk distance (6MWD) is treated as a binary categorical variable of whether or not a candidate can walk more than 150 feet in 6 minutes. In this study, we tested the hypothesis that 6MWD is presently under-utilized with respect to discriminatory power, and that, as a continuous variable, could better prognosticate risk of waitlist mortality.

METHODS

A retrospective cohort analysis was performed using the Organ Procurement and Transplantation Network/United Network for Organ Sharing (OPTN/UNOS) transplant database. Candidates listed for isolated lung transplant between May 2005 and December 2011 were included. The population was stratified by 6MWD quartiles and unadjusted survival rates were estimated. Multivariable Cox proportional hazards modeling was used to assess the effect of 6MWD on risk of death. The Scientific Registry of Transplant Recipients (SRTR) Waitlist Risk Model was used to adjust for confounders. The optimal 6MWD for discriminative accuracy in predicting waitlist mortality was assessed by receiver-operating characteristic (ROC) curves.

RESULTS

Analysis was performed on 12,298 recipients. Recipients were segregated into quartiles by distance walked. Waitlist mortality decreased as 6MWD increased. In the multivariable model, significant variables included 6MWD, male gender, non-white ethnicity and restrictive lung diseases. ROC curves discriminated 6-month mortality was best at 655 feet.

CONCLUSIONS

The 6MWD is a significant predictor of waitlist mortality. A cut-off of 150 feet sub-optimally identifies candidates with increased risk of mortality. A cut-off between 550 and 655 feet is more optimal if 6MWD is to be treated as a dichotomous variable. Utilization of the LAS as a continuous variable could further enhance predictive capabilities.

Clinical predictors and outcome implications of early readmission in lung transplant recipients

BACKGROUND

The purpose of this study was to identify risk factors and outcome implications for 30-day hospital readmission in lung transplant recipients.

METHODS

We conducted a retrospective cohort study of lung transplant cases from a single, high-volume lung transplant program between January 2000 and March 2012. Demographic and health data were reviewed for all patients. Risk factors for 30-day readmission (defined as readmission within 30 days of discharge from index lung transplant hospitalization) were modeled using logistic regression, with selection of parameters by backward elimination.

RESULTS

The sample comprised 795 patients after excluding scheduled readmissions and in-hospital deaths. Overall 30-day readmission rate was 45.4% (n = 361). Readmission rates were similar across different diagnosis categories and procedure types. By univariate analysis, post-operative complications that predisposed to 30-day readmission included pneumonia, any infection, and atrial fibrillation (all p < 0.05). In the final multivariate model, occurrence of any post-transplant complication was the most significant risk factor for 30-day readmission (odds ratio = 1.764; 95% confidence interval, 1.259-2.470). Even for patients with no documented perioperative complication, readmission rates were still >35%. Kaplan-Meier analysis and multi-variate regression modeling to assess readmission as a predictor of long-term outcomes showed that 30-day readmission was not a significant predictor of worse survival in lung recipients.

CONCLUSIONS

Occurrence of at least 1 post-transplant complication increases risk for 30-day readmission in lung transplant recipients. In this patient population, 30-day readmission does not predispose to adverse long-term survival. Quality indicators other than 30-day readmission may be needed to assess hospitals that perform lung transplantation.

Lung transplantation at Duke

Lung transplantation represents the gold-standard therapy for patients with end-stage lung disease. Utilization of this therapy continues to rise. The Lung Transplant Program at Duke University Medical Center was established in 1992, and since that time has grown to one of the highest volume centers in the world. The program to date has performed over 1,600 lung transplants. This report represents an up-to-date review of the practice and management strategies employed for safe and effective lung transplantation at our center. Specific attention is paid to the evaluation of candidacy for lung transplantation, donor selection, surgical approach, and postoperative management. These evidence-based strategies form the foundation of the clinical transplantation program at Duke.

Long-term outcomes after lobectomy for non-small cell lung cancer when unsuspected pN2 disease is found: A National Cancer Data Base analysis

OBJECTIVE

There are few studies evaluating whether to proceed with planned resection when a patient with non-small cell lung cancer (NSCLC) unexpectedly is found to have N2 disease at the time of thoracoscopy or thoracotomy. To help guide management of this clinical scenario, we evaluated outcomes for patients who were upstaged to pN2 after lobectomy without induction therapy using the National Cancer Data Base (NCDB).

METHODS

Survival of NSCLC patients treated with lobectomy for clinically unsuspected mediastinal nodal disease (cT1-cT3 cN0-cN1, pN2 disease) from 1998-2006 in the NCDB was compared with "suspected" N2 disease patients (cT1-cT3 cN2) who were treated with chemotherapy with or without radiation followed by lobectomy, using matched analysis based on propensity scores.

RESULTS

Unsuspected pN2 disease was found in 4.4% of patients (2047 out of 46,691) who underwent lobectomy as primary therapy for cT1-cT3 cN0-cN1 NSCLC. The 5-year survival was 42%, 36%, 21%, and 28% for patients who underwent adjuvant chemotherapy (n = 385), chemoradiation (n = 504), radiation (n = 300), and no adjuvant therapy (n = 858), respectively. Five-year survival of the entire unsuspected pN2 cohort was worse than survival of 2302 patients who were treated with lobectomy after induction therapy for clinical N2 disease (30% vs 40%; P < .001), although no significant difference in 5-year survival was found in a matched-analysis of 655 patients from each group (37% vs 37%; P = .95).

CONCLUSIONS

This population-based analysis suggests that, in the setting of unsuspected pN2 NSCLC, proceeding with lobectomy does not appear to compromise outcomes if adjuvant chemotherapy with or without radiation therapy can be administered following surgery.

The role of stem cells in airway repair: implications for the origins of lung cancer

Lung cancer is the leading cause of cancer-related deaths worldwide. Recently, advancements in our ability to identify and study stem cell populations in the lung have helped researchers to elucidate the central role that cells with stem cell-like properties may have in lung tumorigenesis. Much of this research has focused on the use of the airway repair model to study response to injury. In this review, we discuss the primary evidence of the role that cancer stem cells play in lung cancer development. The implications of a stem cell origin of lung cancer are reviewed, and the importance of ongoing research to identify novel therapeutic and prognostic targets is reiterated.

Gremlin is overexpressed in lung adenocarcinoma and increases cell growth and proliferation in normal lung cells

BACKGROUND

Gremlin, a member of the Dan family of BMP antagonists, is a glycosylated extracellular protein. Previously Gremlin has been shown to play a role in dorsal-ventral patterning, in tissue remodeling, and recently in angiogenesis. Evidence has previously been presented showing both over- and under-expression of Gremlin in different tumor tissues. Here, we sought to quantify expression of Gremlin in cancers of the lung and performed in vitro experiments to check whether Gremlin promotes cell growth and proliferation.

METHODOLOGY/PRINCIPAL FINDINGS

Expression of Gremlin in 161 matched tumor and normal lung cancer specimens is quantified by quantitative real-time PCR and protein level is measured by immunohistochemistry. GREM1 was transfected into lung fibroblast and epithelial cell lines to assess the impact of overexpression of Gremlin in vitro.

RESULTS

Lung adenocarcinoma but not squamous cell carcinoma shows a significant increase in Gremlin expression by mRNA and protein level. Lung fibroblast and epithelial cell lines transfected with GREM1 show significantly increased cell proliferation.

CONCLUSIONS/SIGNIFICANCE

Our data suggest that Gremlin acts in an oncogenic manner in lung adenocarcinoma and could hold promise as a new diagnostic marker or potential therapeutic target in lung AD or general thoracic malignancies.

A practical molecular assay to predict survival in resected non-squamous, non-small-cell lung cancer: development and international validation studies

BACKGROUND

The frequent recurrence of early-stage non-small-cell lung cancer (NSCLC) is generally attributable to metastatic disease undetected at complete resection. Management of such patients depends on prognostic staging to identify the individuals most likely to have occult disease. We aimed to develop and validate a practical, reliable assay that improves risk stratification compared with conventional staging.

METHODS

A 14-gene expression assay that uses quantitative PCR, runs on formalin-fixed paraffin-embedded tissue samples, and differentiates patients with heterogeneous statistical prognoses was developed in a cohort of 361 patients with non-squamous NSCLC resected at the University of California, San Francisco. The assay was then independently validated by the Kaiser Permanente Division of Research in a masked cohort of 433 patients with stage I non-squamous NSCLC resected at Kaiser Permanente Northern California hospitals, and on a cohort of 1006 patients with stage I-III non-squamous NSCLC resected in several leading Chinese cancer centres that are part of the China Clinical Trials Consortium (CCTC).

FINDINGS

Kaplan-Meier analysis of the Kaiser validation cohort showed 5 year overall survival of 71·4% (95% CI 60·5-80·0) in low-risk, 58·3% (48·9-66·6) in intermediate-risk, and 49·2% (42·2-55·8) in high-risk patients (p(trend)=0·0003). Similar analysis of the CCTC cohort indicated 5 year overall survivals of 74·1% (66·0-80·6) in low-risk, 57·4% (48·3-65·5) in intermediate-risk, and 44·6% (40·2-48·9) in high-risk patients (p(trend)<0·0001). Multivariate analysis in both cohorts indicated that no standard clinical risk factors could account for, or provide, the prognostic information derived from tumour gene expression. The assay improved prognostic accuracy beyond National Comprehensive Cancer Network criteria for stage I high-risk tumours (p<0·0001), and differentiated low-risk, intermediate-risk, and high-risk patients within all disease stages.

INTERPRETATION

Our practical, quantitative-PCR-based assay reliably identified patients with early-stage non-squamous NSCLC at high risk for mortality after surgical resection.

FUNDING

UCSF Thoracic Oncology Laboratory and Pinpoint Genomics.