[PD1/PD-L1 immunohistochemistry in thoracic oncology: Where are we?] / Immunohistochimie PD-1/PD-L1 en oncologie thoracique : où en sommes-nous ?

The assays for the assessment of the PD-L1 status by immunohistochemistry are available in clinical studies in thoracic oncology to predict response to immunotherapies targeting the PD-1/PD-L1 pathway. With the arrival of this new class of molecules in second line and very soon in first line of treatment for patients with advanced or metastatic non-small cell lung cancer, these tests will certainly be required in routine once these new drugs will be granted marketing authorization. The rapid introduction of these "companion" or "complementary" tests seems essential to select patients to benefit from these effective but also expensive and sometimes toxic therapies. Although challenged by some oncologists (as some patients not expressing PD-L1 may sometimes respond to PD-1/PD-L1 blockade), the anti-PD-L1 immunohistochemically approach seems inevitable in 2017. This new activity developed in the pathology laboratories raises several questions: which anti-PD-L1 clone should be used? On which device? What threshold of positivity should be considered? Should PD-L1 expression be assessed on tumor cells as well as on the immune cells? What controls should be used? Comparative studies are underway or have been already implemented in order to answer some of these questions. This review addresses the different evaluation criteria for immunohistochemistry using the main anti-PD-L1 antibodies used to date as well the recently published studies using these antibodies in thoracic oncology.

PD-L1 expression in basaloid squamous cell lung carcinoma: Relationship to PD-1+ and CD8+ tumor-infiltrating T cells and outcome.

PD-1/PD-L1 inhibitors demonstrated durable clinical responses in patients with lung squamous cell carcinoma. However, the expression pattern of PD-L1 and the presence of CD8+ and PD-1+ tumor-infiltrating T cells in the basaloid variant of squamous cell carcinoma remain unknown. immunohistochemistry analysis of PD-L1 expression, with three recently validated monoclonal antibodies used in clinical trials (clones SP142, SP263, and 28-8), and detection of CD8+ and PD-1+ tumor-infiltrating T cells was performed on whole-tissue sections from 56 patients following surgery for basaloid squamous cell carcinoma. Data were correlated to clinicopathological parameters and outcome. Fair to poor concordance was observed between the SP142 vs SP263 clones, and SP142 vs 28-8 (κ range, 0.018-0.412), while the 28-8 and SP263 demonstrated a strong correlation in both the tumor cell and immune cell compartments (κ=0.883, and κ=0.721). Expression of PD-L1 correlated with a high content of CD8+ and PD-1+ tumor-infiltrating T cells when using SP142 (P=0.012; P=0.022), but not with SP263 or 28-8 (P=0.314; P=0.611). In the multivariate analysis, we found significantly better disease-free and overall survival rates for high PD-L1 expression with SP142, CD8+ and PD-1+ tumor-infiltrating T cells (P=0.003; P=0.007). No significant prognosis value was observed for SP263 and 28-8 clones, except a correlation between improved overall survival and SP263 in the univariate analysis (P=0.039), not confirmed in the multivariate model. In conclusion, we report that the expression of PD-L1 and the content of CD8+ and PD-1+ tumor-infiltrating T cells is an independent indicator of better outcome in basaloid squamous cell carcinoma patients, although the observed effect is dependent on the PD-L1 immunohistochemistry assay.

Identification of PPAP2B as a novel recurrent translocation partner gene of HMGA2 in lipomas.

Most lipomas are characterized by translocations involving the HMGA2 gene in 12q14.3. These rearrangements lead to the fusion of HMGA2 with an ectopic sequence from the translocation chromosome partner. Only five fusion partners of HMGA2 have been identified in lipomas so far. The identification of novel fusion partners of HMGA2 is important not only for diagnosis in soft tissue tumors but also because these genes might have an oncogenic role in other tumors. We observed that t(1;12)(p32;q14) was the second most frequent translocation in our series of lipomas after t(3;12)(q28;q14.3). We detected overexpression of HMGA2 mRNA and protein in all t(1;12)(p32;q14) lipomas. We used a fluorescence in situ hybridization-based positional cloning strategy to characterize the 1p32 breakpoint. In 11 cases, we identified PPAP2B, a member of the lipid phosphate phosphatases family as the 1p32 target gene. Reverse transcription-polymerase chain reaction analysis followed by nucleotide sequencing of the fusion transcript indicated that HMGA2 3' untranslated region (3'UTR) fused with exon 6 of PPAP2B in one case. In other t(1;12) cases, the breakpoint was extragenic, located in the 3'region flanking PPAP2B 3'UTR. Moreover, in one case showing a t(1;6)(p32;p21) we observed a rearrangement of PPAP2B and HMGA1, which suggests that HMGA1 might also be a fusion partner for PPAP2B. Our results also revealed that adipocytic differentiation of human mesenchymal stem cells derived from adipose tissue was associated with a significant decrease in PPAP2B mRNA expression suggesting that PPAP2B might play a role in adipogenesis.

Significance of circulating tumor cell detection using the CellSearch system in patients with locally advanced head and neck squamous cell carcinoma.

The objective of this study was to evaluate the potential detection of circulating tumor cells (CTCs) using the CellSearch (CS) Assay™ in patients with locally advanced head and neck squamous cell carcinoma (HNSCC) and then to identify the clinical factors predictive of the presence of CTCs. The presence and number of CTCs were determined using the CS system before treatment, and in 10 healthy individuals (control group). The CS system was able to successfully identify the presence of CTCs in 8 of 49 patients (16 %) before therapy. No CTC was found in the control group. CTCs were detected before therapy in 1 of 19 patients (5 %) with N0 tumor and in 7 of 30 patients (23 %) with N1-2c tumor (p = 0.12; Fisher's exact test). CTCs were identified in a relatively low proportion of patients with locally advanced HNSCC.

[Accreditation of the activity of molecular pathology according to ISO 15189: key steps to follow and the main potential pitfalls]. / Accréditation de l'activité de pathologie moléculaire selon la norme ISO 15189. Principales étapes à respecter et principaux écueils possibles.

The quick emerging of the several targeted therapies and the concept of personnalized medicine underlie the necessity to develop and to well organize a molecular biology (or molecular pathology) unit of high quality, dedicated to clinical care, in order to look for tissular and cellular theragnosis biomarkers. This new and sudden area of activity for a clinical pathologist is strongly linked to the knowledge of a new medical speciality in health care institutions. Thus, the molecular pathology (or molecular biology made from cellular or tissular samples) can nicely be implemented in a clinical pathology laboratory. This new mission for a pathologist has to be done in respect with a great quality assurance which should allow obtaining in a short-term an ISO 15189 accreditation to keep going to perform this activity. The present work aims to describe the main steps to be set up in the order to get an ISO 15189 accreditation in molecular pathology. The different chapters of this norm will not be described in their exhaustivity, but in their large lines. Finally, we will describe the potential difficulties and pitfalls to be avoided before getting this accreditation.

[The accreditation of a surgical pathology and somatic genetic laboratory (LPCE, CHU of Nice) according to the ISO 15189 norm: Sharing of experience]. / L'accréditation selon la norme ISO 15189 d'un laboratoire de pathologie et de génétique somatique (LPCE, CHU de Nice) : retour d'expérience.

Accreditation is going to be vital and unavoidable in the medium term for medical biology laboratories in France. This accreditation will certainly condition the authorization to conduct biological testing in the health care system. All the biological specialities are now affected by this procedure, including the somatic genetics. The anatomo-pathology, which is a medical speciality in France, may be also concerned by the accreditation. However, the nature and the practices of this specialty increase the complexity of this approach to be implemented according to the standard requested by the authorities, i.e. the ISO 15189 normative standard (standard on "specific requirements for quality and competence for medical biology analysis laboratories"). The present article recounts the experience of a hospital laboratory (LPCE, Nice University Hospital) composed of a surgical pathology and a somatic genetics unit: (1) in the accreditation process according to the ISO 15189 standard, (2) at the time of the audit made by the team of "COFRAC" evaluators, and, (3) in evaluating the strategy implemented following the audit.

[Setting up a department of molecular pathology in oncology in a pathology laboratory (LPCE, CHU de Nice)]. / Mise en place d'un secteur de pathologie moléculaire en oncologie au sein d'un laboratoire d'anatomie pathologique (LPCE, CHU de Nice).

The advent of targeted therapies and personalized medicine in oncology has led in France to the settlement and organisation of a network of hospital molecular genetic platforms under the impetus of the National Cancer Institute (INCa). These platforms are, according to the concerned sites, integrated or not in pathology laboratories. The development of molecular biology methods, the choice of the procedures, the establishment of sample workflow, the quality control and the selection of the genomic alterations to be detected on each platform, have been left to the discretion of the different laboratories. Based on calls for project made by the INCa, hospital molecular genetic platforms were able to adapt their activity according to the assigned budgets. While the presence of some genomic alterations (i.e. KRAS gene mutations in metastatic colon adenocarcinoma or EGFR gene mutations in lung adenocarcinomas), may lead to administration of targeted therapies under the Marketing Authorization Application (MAA), others are associated with therapeutic clinical trials. However, increasing number of MAA for new molecules targeting genomic alterations is likely in the near future. In this context, it is necessary to quickly adapt the organisation of work of the hospital pathology laboratories performing molecular biology tests in order to meet the growing demand of oncologists in the field of targeted therapies. The purpose of this article is to describe the different steps of the settlement of a molecular genetic platform in an academic pathology laboratory (LPCE, CHU de Nice) and to show the experience of this laboratory specifically oriented on the support of the morphological and molecular diagnosis of lung cancer, thyroid cancer and malignant melanoma.

[Setting up indicators in biobanking: why and how?]. / Mise en place d'indicateurs de suivi au sein d'une tumorothèque et/ou d'un centre de ressources biologiques : pourquoi et comment ?

The biobanking area is highly complex, and its complexity is increasing along with its growth and demand. Due to the advancements in genetic research, stem cell research and regenerative medicine, biobanking has become ever more important and plays a key role in biomedical research. The robustness and the reproducibility of research results depend greatly on the quality and on the number of the samples used, and thus on the expertise of biobanks having supplied these samples. Undoubtedly, the recognition of a research biobank depends on the impact of the research projects conducted with samples obtained from tumour bank(s), but also on many other criteria. It thus seems important to determine a number of indicators within a biobank to estimate objective criteria for the performance of these structures. These indicators can allow to make some strategic decisions knowing that biobanks are expensive structures to maintain in the present hospital context. The use of these indicators could also contribute to the elaboration of an "biobank impact factor of" or so called "bioresource research impact factor" (BRIF). We describe here four major categories of indicators (quality, activity, scientific production, visibility), which seem to be useful for the evaluation of a biobank by making a proposition of allocation of coefficients for the various considered items.

Detection of circulating tumor cells as a prognostic factor in patients undergoing radical surgery for non-small-cell lung carcinoma: comparison of the efficacy of the CellSearch Assay™ and the isolation by size of epithelial tumor cell method.

Comparison of the efficacy of different enrichment methods for detection of circulating tumor cells (CTCs) before radical surgery is lacking in non-small-cell lung carcinoma (NSCLC) patients. Detection and enumeration of CTCs in 210 consecutive patients undergoing radical surgery for NSCLC were evaluated with the CellSearch Assay™ (CS), using the CellSearch Epithelial Cell Kit, and by the isolation by size of epithelial tumor (ISET) method, using double immunolabeling with anti-cytokeratin and anti-vimentin antibodies. CTCs were detected in 144 of 210 (69%) patients using CS and/or ISET and in 104 of 210 (50%) and 82 of 210 (39%) patients using ISET and CS, respectively. Using ISET, 23 of 210 (11%) patients had vimentin-positive cells with cytological criteria of malignancy. Disease-free survival (DFS) was worse for patients with CTCs compared to patients without CTCs detected by CS alone (p < 0.0001; log rank = 30.59) or by ISET alone (p < 0.0001; log rank = 33.07). The presence of CTCs detected by both CS and ISET correlated even better with shorter DFS at a univariate (p < 0.0001; log rank = 42.15) and multivariate level (HR, 1.235; 95% CI, 1.056-1.482; p < 0.001). CS and ISET are complementary methods for detection of CTCs in preoperative radical surgery for NSCLC. CTC detection in resectable NSCLC patients using CS and/or ISET could be a prognostic biomarker of great interest and may open up new avenues into improved therapeutic strategies for lung carcinoma patients.

Targeted Assessment of the EGFR Status as Reflex Testing in Treatment-Naive Non-Squamous Cell Lung Carcinoma Patients: A Single Laboratory Experience (LPCE, Nice, France).

BACKGROUND: Assessment of actionable EGFR mutations is mandatory for treatment-naïve advanced or metastatic non-squamous lung carcinoma (NSLC), but the results need to be obtained in less than 10 working days. For rapid EGFR testing, an EGFR-specific polymerase chain reaction (PCR) assay is an alternative and simple approach compared to next generation sequencing (NGS). Here, we describe how a rapid EGFR-specific PCR assay can be implemented in a single laboratory center (LPCE, Nice, France) as reflex testing in treatment-naïve NSLC. METHODS: A total of 901 biopsies from NSLC with more than 10% of tumor cells were prospectively and consecutively evaluated for EGFR mutation status between November 2017 and December 2019 using the Idylla system (Biocartis NV, Mechelen, Belgium). NGS was performed for nonsmokers with NSLC wild type for EGFR, ALK, ROS1, and BRAF and with less than 50% PD-L1 positive cells using the Hotspot panel (Thermo Fisher Scientific, Waltham, MA, USA). RESULTS: Results were obtained from 889/901 (97%) biopsies with detection of EGFR mutations in 114/889 (13%) cases using the Idylla system. Among the 562 EGFR wild type tumors identified with Idylla, NGS detected one actionable and one nonactionable EGFR mutation. CONCLUSIONS: Rapid and targeted assessment of EGFR mutations in treatment-naïve NSLC can be implemented in routine clinical practice. However, it is mandatory to integrate this approach into a molecular algorithm that allows evaluation of potentially actionable genomic alterations other than EGFR mutations.

Real-world assessment of the BRAF status in non-squamous cell lung carcinoma using VE1 immunohistochemistry: A single laboratory experience (LPCE, Nice, France).

INTRODUCTION: International guidelines recommend BRAF mutational status assessment in treatment-naive advanced non-squamous non-small cell lung carcinoma (NSCLC) patients since the presence of a BRAFV600 mutation enables specific BRAF inhibitor treatment. For this purpose, the mutational status needs to be obtained in 10 working days. Herein, we prospectively evaluated the feasibility of systematic assessment of the BRAF status using immunohistochemistry (IHC) in a single institution (LPCE, Nice) at baseline for NSCLC diagnosed. METHODS: 1317 NSCLC were evaluated using BRAF IHC from 2011 to 2019. Initially the BRAF status was prospectively assessed using NGS and/or pyrosequencing in 618 consecutively diagnosed NSCLC patients from 2012 to 2016; BRAFV600E and BRAF nonV600E mutated tumors detected in this cohort were retrospectively evaluated using BRAF IHC. Secondarily, 699 biopsies of NSCLC were prospectively analyzed between 2017 and 2019 using BRAF IHC. BRAF IHC positive tumors were tested using a rapid BRAF specific PCR based assay. RESULTS: Initially, 21/618 (3%) of tumors (15 early and 6 late stage tumors) were BRAFV600E mutated according to the results of NGS and/or pyrosequencing. BRAF IHC was positive in 21/21 of these cases and negative in 51/51 (100 %) BRAF non V600E mutated cases. In the prospective BRAF IHC tested cohort of patients, 24/699 (3%) tumors (13 early and 11 late stage tumors) were positive with VE1 IHC. The BRAF PCR assay was positive in 20/24 (83 %) of these cases. CONCLUSION: BRAFV600E IHC screening of treatment-naïve NSCLC patients is a rapid, specific and very sensitive method which can lead in advanced stage positive NSCLC tumors to a BRAF inhibitor treatment. This test can be routinely integrated into mandatory predictive biomarker 'testing of NSCLC. According to the organization of patient care and the physician's request, this practice can be proposed as an alternative to NGS-based tissue biopsy made at baseline.

Establishment of a Collection of Blood-Derived Products from COVID-19 Patients for Translational Research: Experience of the LPCE Biobank (Nice, France).

In only a few months after its inception, the COVID-19 pandemic lead to the death of hundreds of thousands of patients and to the infection of millions of people on most continents, mostly in the United States and in Europe. During this crisis, it was demonstrated that a better understanding of the pathogenicity, virulence, and contagiousness of SARS-CoV-2, all of which were initially underestimated, was urgently needed. The development of diagnostic tests to identify SARS-CoV-2 or to detect anti-SARS-CoV2 antibodies in blood, of vaccines, and of preventive and curative treatments has been relying on intense activity of scientists in academia and industry. It is noteworthy that these scientists depend on the use of high-quality biological samples taken from positive COVID-19 patients in a manner that preserves their integrity. Given this unique and emergent situation, it was necessary to urgently establish biological collections clinically annotated for immediate development of clinical and translational research projects focusing on COVID-19 biological aspects. It is in this very specific context that biobanks must rapidly adapt their infrastructure and/or operational capacity to fulfill new critical needs. We report the establishment of a biobank dedicated to the collection of blood-derived products (plasma, serum, and leukocytes) from COVID-19 patients hospitalized in the Nice Pasteur Hospital (Nice, France).

Primary clear cell meningioma of the orbit mimicking a metastatic carcinoma: usefulness of immunohistochemistry and cytogenetic analysis.

Clear cell meningiomas (CCM) are rare tumors of the nervous system that usually occur in young patients and display high recurrence rates and potentially aggressive behavior. In this report, we describe a primary CCM of the orbit in an 84-year-old man with a previous history of a clear cell carcinoma of the kidney. Histologically, the tumor demonstrated a sheet-like proliferation of clear polygonal cells. Differential diagnosis includes metastasis of clear cell carcinomas. Immunohistochemistry, by showing that tumor cells expressed vimentin, epithelial membrane antigen, and progesterone antigens, and cytogenetic analysis, by identifying a monosomy 22, confirmed the diagnosis of CCM.

Pericardial effusion as primary manifestation of metastatic cutaneous adenoid cystic carcinoma: diagnostic cytopathology from an exfoliative sample.

Adenoid cystic carcinoma (ACC) occurs not only as a tumor of salivary glands, but also in very unusual locations, such as in the skin. Only very few cases of primary cutaneous of ACC have metastasized to the lymph nodes and lungs. We present a 53-year-old man with metastasis of the pericardium from a primary cutaneous ACC (PCACC) of the scalp, which had been surgically treated 14 years ago. Exfoliative cytologic findings from pericardial effusion included small clusters of basaloid cells with occasional cystlike spaces containing mucoid material. To our knowledge, this is the first case of pericardial metastasis from a PCACC.

Intestinal occlusion caused by Rosai-Dorfman disease mimicking colonic diverticulitis.

Rosai-Dorfman disease (RDD) involves the gastrointestinal tract only in exceptional cases, and this very unusual site of presentation can confuse the pathologist. We present a case of RDD manifesting as an intestinal occlusion caused by colonic diverticulitis. The patient was a 79-year-old man with myelodysplasia, who presented with fever, abdominal pain, and constipation. Colonoscopy revealed sigmoiditis and diverticulosis. Microscopic study of the sigmoid colon surgical specimen showed the histological and immunological features of RDD. No human DNA of herpesvirus types 6 and 8 (HHV6/HHV8), Epstein-Barr virus (EBV), and cytomegalovirus (CMV) was detected in tissue by polymerase chain reaction. Electron microscopic study revealed no microbes or viral particles. Widespread nodal and extranodal RDD occurred, and the patient died 2y after initial surgery. The etiology of RDD is still under debate. We discuss the association of RDD with hematological disorders.

[Issues and current limits for immunohistochemical assessment of PD-L1 status in bronchial biopsies]. / Enjeux et limites actuelles de l'évaluation du statut de PD-L1 par immunohistochimie sur des biopsies bronchiques.

Immunotherapy targeting the PD-L1/PD-1 axis has shown recently some promising results in metastatic lung cancer patients. This treatment seems to be more effective when a high expression of PD-L1 is detected by immunohistochemistry in bronchial biopsies. In this regard, this targeted therapy will be proposed soon in metastatic lung cancer patients. This immunotherapy could be dependent to the immunohistochemical (IHC) assessment of PD-L1 expression, thus considered as a companion diagnostic test. This near perspective poses challenges with regard to the positivity threshold value for PD-L1 expression before therapy administration, the positive cellular compartment (tumour cells and/or immune cells), the percentage of positive cells and the clone which is used. A couple of patients have a good response to treatment targeting the PD-1/PD-L1 axis despite the absence or a weak PD-L1 expression. However the assessment of PD-L1 expression by immunohistochemistry will be the only mandatory approach before therapeutic strategies targeting the PD1/PD-L1 axis for lung cancer patients. In this review, the main challenges of using PD-L1 immunohistochemistry as a potential companion diagnostic tool for metastatic lung cancer patient immunotherapy will be discussed.

High expression of TRF2, SOX10, and CD10 in circulating tumor microemboli detected in metastatic melanoma patients. A potential impact for the assessment of disease aggressiveness.

Circulating tumors cells (CTCs) can be detected in the blood of metastatic melanoma patients (MMPs) both as isolated circulating tumor cells (iCTCs) and circulating tumor microemboli (CTMs), but their clinical significance remains unknown. The aim of this work was to evaluate the prognostic impact in metastatic cutaneous melanoma of CTMs and iCTCs identified by a cytomorphological approach using the isolation by size of tumor cell (ISET) method. We characterized the phenotype of CTCs using anti-PS100, anti-SOX10, anti-CD10, and anti-TRF2 antibodies. 128 MMPs and 37 control healthy individuals with benign nevi were included in this study. Results were compared to the follow-up of patients. 109/128 (85%) MMPs showed CTCs, 44/128 (34%) with 2 to 6 CTMs and 65/128 (51%) with 4 to 9 iCTCs. PS100 expression was homogeneous in iCTCs and heterogeneous in CTMs. SOX10, CD10, and TRF2 were mainly expressed in CTMs. None of the control subjects demonstrated circulating malignant tumor cells. Overall survival was significantly decreased in patients with CTMs, independently of the therapeutic strategies. In conclusion, the presence of CTMs is an independent predictor of shorter survival from the time of diagnosis of MMPs.

MicroRNA-375/SEC23A as biomarkers of the in vitro efficacy of vandetanib.

In this study, we performed microRNA (miRNA) expression profiling on a large series of sporadic and hereditary forms of medullary thyroid carcinomas (MTC). More than 60 miRNAs were significantly deregulated in tumor vs adjacent non-tumor tissues, partially overlapping with results of previous studies. We focused our attention on the strongest up-regulated miRNA in MTC samples, miR-375, the deregulation of which has been previously observed in a variety of human malignancies including MTC. We identified miR-375 targets by combining gene expression signatures from human MTC (TT) and normal follicular (Nthy-ori 3-1) cell lines transfected with an antagomiR-375 inhibitor or a miR-375 mimic, respectively, and from an in silico analysis of thyroid cell lines of Cancer Cell Line Encyclopedia datasets. This approach identified SEC23A as a bona fide miR-375 target, which we validated by immunoblotting and immunohistochemistry of non-tumor and pathological thyroid tissue. Furthermore, we observed that miR-375 overexpression was associated with decreased cell proliferation and synergistically increased sensitivity to vandetanib, the clinically relevant treatment of metastatic MTC. We found that miR-375 increased PARP cleavage and decreased AKT phosphorylation, affecting both cell proliferation and viability. We confirmed these results through SEC23A direct silencing in combination with vandetanib, highlighting the importance of SEC23A in the miR-375-associated increased sensitivity to vandetanib.Since the combination of increased expression of miR-375 and decreased expression of SEC23A point to sensitivity to vandetanib, we question if the expression levels of miR-375 and SEC23A should be evaluated as an indicator of eligibility for treatment of MTC patients with vandetanib.

Stratification of resectable lung adenocarcinoma by molecular and pathological risk estimators.

BACKGROUND: Mortality in early stage, resectable lung cancer is sufficiently high to warrant consideration of post-surgical treatment. Novel markers to stratify resectable lung cancer patients may help with the selection of treatment to improve outcome. METHODS: Primary tumour tissue from 485 patients, surgically treated for stage I-II lung adenocarcinoma, was analysed for the RNA expression of 31 cell cycle progression (CCP) genes by quantitative polymerase chain reaction (PCR). The expression average, the CCP score, was combined with pathological stage into a prognostic score (PS). Cox proportional hazards regression assessed prediction of 5-year lung cancer mortality above clinical variables. The PS threshold was tested for risk discrimination by the Mantel-Cox log-rank test. RESULTS: The CCP score added significant information above clinical markers (all patients, P=0.0029; stage I patients, P=0.013). The prognostic score was a superior predictor of outcome compared to pathological stage alone (PS, P=0.00084; stage, P=0.24). Five-year lung cancer mortality was significantly different between the low-risk (90%, 95% confidence interval (CI) 81-95%), and high-risk groups (65%, 95% CI 57-72%), P=4.2×10(-6)). CONCLUSIONS: The CCP score is an independent prognostic marker in early stage lung adenocarcinoma. The prognostic score provides superior risk estimates than stage alone. The threefold higher risk in the high-risk group defines a subset of patients that should consider therapeutic choices to improve outcome.