The metastatic potential of seminomatous germ cell tumours is associated with a specific microRNA pattern

BACKGROUND

Seminomatous germ cell tumours (SGCT) are the most frequent malignancy in young men. Reliable prognostic biomarkers for the prediction of metastasis at diagnosis and the risk of relapse in clinical stage I (CSI) are lacking. Adjuvant therapies carry a risk of overtreatment, whereas salvage therapies have a risk of high toxicities. Thus, the identification of reliable prognostic biomarkers is highly desirable to identify patients who will benefit from early adjuvant treatment. MicroRNAs (miRNAs) regulate tumour development and progression, and their potential as biomarkers has already been proven in a variety of malignancies.

OBJECTIVES

The aim of our study was to define a specific miRNA expression pattern that discriminates metastatic from non-metastatic primary SGCT.

MATERIALS AND METHODS

Total RNA was isolated from 24 formalin-fixed paraffin-embedded (FFPE) primary SGCT tumours (10 non-metastatic, five metachronously and nine synchronously metastatic) and from 10 normal testicular tissue samples. Microarray analysis was performed for global miRNA expression profiling. The results were validated by quantitative real-time polymerase chain reaction (qRT-PCR). Statistical analysis was performed using SPSS.

RESULTS

Microarray analyses revealed a specific miRNA pattern that distinguishes metastatic from non-metastatic SGCT. Sixty-three miRNAs were differentially expressed in metastatic compared to non-metastatic tumours (P < .01). Microarray results were confirmed by qRT-PCR for three out of five selected miRNAs (miR-29c-5p, miR-506-3p and miR-371a-5p; P < .05). All five miRNAs (miR-29c-5p, miR-506-3p, miR-1307-5p, miR-371a-5p and miR-371a-3p) showed differential expression between tumour and normal tissues (P < .05).

CONCLUSION

Metastatic primary SGCTs are characterized by a specific miRNA expression pattern. Therefore, specific miRNAs could represent a new tool to predict the metastatic potential in SGCT patients.

Changing Trends in Penetrating Keratoplasty Indications between 2011 and 2018 - Histopathology of 2123 Corneal Buttons in a Single Center in Germany

Purpose: To analyse the changing trends in penetrating keratoplasty indications between January 2011 and December 2018, at the Department of Ophthalmology, Saarland University Medical Center, Homburg/Saar, Germany. Patients and Methods: This is a retrospective review of 2123 corneal buttons of 1776 patients (1993 eyes, 56.0% males, age at the time of surgery 57.6 ± 18.7 years), who underwent penetrating keratoplasty (PKP) between January 2011 and December 2018. The classification was performed based on histological analysis and using the priority scheme of Brady et al., supplemented by a group of "failed endothelial keratoplasty grafts". Our groups were the following: pseudophakic or aphakic bullous keratopathy, regraft, failed endothelial keratoplasty graft, acute necrotizing and ulcerative keratitis, keratoconus, Fuchs' dystrophy, corneal dystrophy other than Fuchs', corneal scars and other diagnoses. Results: Between 2011 and 2018, keratoconus was the leading indication for PKP in 455 (21.5%) cases, followed by acute necrotizing and ulcerative keratitis in 384 (18.1%), regraft in 367 (17.3%), corneal scars in 350 (16.5%), pseudophakic or aphakic bullous keratopathy in 225 (10.6%), Fuchs' dystrophy in 194 (9.1%), other diagnoses in 64 (3.0%), corneal dystrophy other than Fuchs' in 52 (2.4%), and failed endothelial keratoplasty graft in 32 (1.5%) cases. Conclusions: With the introduction of posterior lamellar keratoplasty, keratoconus remains the leading PKP indication in our center with excimer laser-trephination on a routine basis. A trend towards increasing numbers can be observed regarding acute necrotizing and ulcerative keratitis patients and regrafts. However, the incidence of Fuchs' dystrophy decreased dramatically within PKP patients, with the introduction of posterior lamellar keratoplasty.

Abstract P1-10-28: Role of Sec62 in prediction of response to neoadjuvant chemotherapy in patients with primary breast cancer

Background Chromosome 3q26 amplifications have been shown to represent a frequent alteration in various cancer entities including breast cancer. SEC62 - a 3q26 encoded gene - was identified as a potential oncogene and tumor-driver-gene for the pathogenesis of breast cancer. Although the precise physiological function of the respective protein Sec62 is not completely understood, it is hypothesized, that Sec62 induces an increased stress tolerance and enhances cell migration in SEC62 overexpressing cells resulting in a high rate of lymphatic metastasis and poorer overall prognosis in tumor tissue with a high Sec62 expression. We sought to further elucidate the function of Sec62 in breast cancer with special focus on its predictive role on the response to neoadjuvant chemotherapy. Materials and Methods All patients treated for primary breast cancer with neoadjuvant chemotherapy at the Department of Gynaecology and Obstetrics, Saarland University Hospital, Homburg, Germany between 01/2007 and 12/2018 were enrolled in this study. The study was approved by the Saarland institutional review board. Sec62 protein levels were analyzed in tumor tissue samples using immunohistochemistry (IHC). Sec62 immunoreactivity was evaluated by three independent examiners using the immunoreactive score (IRS) according to Remmele and Stegner (0-12). For the assessment of Sec62 protein expression in tumor cells, we rated Sec62 “negative” 0-3, “low” for a score of 4-8 and “high” for 9-12 as described in previous publications. IHC was performed on initial breast core biopsy (CB) tissue (pre-treatment) and on definite pathology specimen (PS) obtained during breast surgery after completion of neoadjuvant chemotherapy. Sec62 expression in both samples were compared and correlated with response to neoadjuvant chemotherapy evaluated pathologically using the semi-quantitative response to neoadjuvant chemotherapy scoring system by Sinn et al. ranging from 0 (no effect) to 4 (no tumor detectable). Additionally, Sec62 expression in tumor tissue was compared with the histologically tumor-free tissue of the same patient. Sec62 expression levels and correlation with response to neoadjuvant chemotherapy were compared using Wilcoxon signed-rank, Mann-Whitney and Pearson`s chi square test. Results 203 patients were assessed for eligibility. Nine cases were excluded, due to incomplete clinical information or insufficient slide quality, leaving 194 patients for final analysis. Median patient age was 54 (22-86) years and median response to neoadjuvant chemotherapy score of 2 (0-4). 20 patients (10 %) had luminal A, 46 (24 %) luminal B, 60 (31 %) Her2/neu positive and 68 (35 %) triple negative breast cancer. All analyzed slides showed an over-expression of Sec62 in breast cancer cells but no positive staining of physiologic breast tissue cells. Median Sec62 expression in core biopsies (CB) (8 (2-12)) was significantly higher compared to expression in final specimen (PS) (4 (0-12); p ≤ 0.01). Median difference between Sec62 expression of CB and PS was 2 (0-4). Regarding response to neoadjuvant chemotherapy patients with a low Sec62 expression in PS and a difference ≥ 6 between CB and PS showed a significant higher median response score compared to other patients (2 (0-4) vs. 1 (0-2); p ≤ 0.01; 4 (1-4) vs. 1 (0-4); p ≤ 0.01). When looking at breast cancer subtypes these effects were strongest in Her2/positive and triple negative patients and median Sec62 expression showed the highest decrease between CB and PS in these two subgroups (6 (-3-12); 2 (-6-12)). Conclusion We identified Sec62 as a potential biomarker for prediction of response to neoadjuvant chemotherapy in patients with primary breast cancer. This effect was observed to be strongest in patients with Her2/positive and triple negative breast cancer.

Citation Format: Julia Caroline Radosa, Mariz Kasoha, Merle Doerk, Barbara Linxweiler, Maximilian Linxweiler, Florian Bochen, Rainer M Bohle, Matthias Wagner, Marc P Radosa, Erich-Franz Solomayer, Zoltan Ferenc Takacs. Role of Sec62 in prediction of response to neoadjuvant chemotherapy in patients with primary breast cancer [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P1-10-28.

Crosstalk of estrogen receptors and Wnt/β-catenin signaling in endometrial cancer

PURPOSE

To investigate the interaction between Wnt/β-catenin and estrogen signaling pathways in endometrial cancer (EC).

METHODS

119 women were involved in this study, including 65 women with histologically confirmed EC and 54 healthy women as a control group. Serum protein levels of Dkk1 were measured using ELISA. Protein expression levels of Dkk1, β-catenin, ER-β isoforms (β1, β2, β5), and ER-α were tested in paraffin-embedded tissues using IHC. Gene expression levels of Dkk1, CTNNB, ESR1, and ESR2 were tested in fresh tumorous and normal endometrium tissues using RT-PCR.

RESULTS

EC patients had significantly higher serum levels of Dkk1 protein compared with healthy women. Dkk1 and β-catenin showed different expression pattern in tumor cells compared to it in normal cells at the protein level but not at the gene level. Protein expression levels of ERβ2 and ERα were significantly lower in tumor cells compared with tumor-adjacent normal cells. Increased protein expression levels of ERα were associated with favorable clinicopathological features and better overall survival rate (OS). Protein expression levels of ERα were correlated with protein expression levels of Dkk1 and cytoplasmic β-catenin. The association between ERα expression levels and OS was no more significant when tested in regard to Dkk1- and cytoplasmic β-catenin expression levels.

CONCLUSIONS

Our data demonstrated that Wnt/β-catenin and estrogen signaling systems are dysregulated in EC showing; for the first time, a potential crosstalk between certain components of these two pathways, which in turn has affected the specificity of these molecules in disease characteristics. Understanding the signaling networks in EC is crucial in designing clinical trials to evaluate the efficacy of molecular-targeted agents and providing more successful therapies in the future.

Identification of 3q oncogene SEC62 as a marker for distant metastasis and poor clinical outcome in invasive ductal breast cancer

PURPOSE

In previous studies, we have shown that SEC62 has an essential function in cell migration, epithelial-to-mesenchymal transition, and endoplasmic reticulum stress tolerance of cancer cells. SEC62 expression correlated with distant and lymph node metastasis and poor outcome in different cancer entities. In this initial study, we investigated SEC62 expression and its possible role as a prognostic and predictive biomarker in breast cancer (BC).

METHODS

Formalin-fixed, paraffin-embedded tissue samples of 53 BC patients were analyzed by immunohistochemistry. The immunoreactive score (IRS) according to Remmele and Stegner was evaluated and correlated with clinico-pathological findings and overall survival (OS).

RESULTS

We found increased SEC62 protein levels in tumor tissue compared to tumor-free tissue samples from the same patients. Tumors with high SEC62 expression (IRS > 8), or containing isolated cells with high SEC62 staining intensity, independent of the IRS, had more frequently distant metastases (48.4% vs. 18.2%; p = 0.024 and 47.4 vs. 6.7%; p = 0.005, respectively). Overall survival was significantly worse in BC patients with high SEC62 expression (SEC62 IRS > 8) (54.8% vs. 81.8%; p = 0.011) and in cases with isolated high-intensity SEC62 staining cells independently of SEC62 IRS (55.3% vs 93.3%; p = 0.024).

CONCLUSIONS

We are the first to describe the SEC62 expression and its correlation to clinicopathological parameters in mammary carcinoma. Our results suggest that SEC62 expression may serve as a prognostic marker for patients with invasive ductal breast cancer.

Sec62/Ki67 and p16/Ki67 dual-staining immunocytochemistry in vulvar cytology for the identification of vulvar intraepithelial neoplasia and vulvar cancer: a pilot study

PURPOSE

The aim of this study was to analyze the diagnostic performance of a newly established immunocytochemical dual-staining protocol for the simultaneous expression of SEC62 and Ki67 in vulvar liquid-based cytology specimens for the identification of vulvar intraepithelial neoplasia (VIN) and vulvar cancer. In addition, we investigated the p16/Ki67 dual stain, which has already been established in cervical cytology.

MATERIALS AND METHODS

For this pilot study, residual material from liquid-based cytology was collected retrospectively from 45 women. The presence of one or more double-immunoreactive cells was considered as a positive test result for Sec62/Ki67 and p16/Ki67 dual staining. The test results were correlated with the course of histology.

RESULTS

All cases of VIN and vulvar cancer were Sec62/Ki67 and p16/Ki67 dual-stain positive, and normal and low-grade squamous intraepithelial lesions were all negative. The sensitivity of cytology for VIN + cases was 100% (22/22), whereas punch biopsy classified one case of vulvar carcinoma as inflammation. All cases with high-intensity (grades 3 and 4) Sec62 staining in Sec62/Ki67-positive cases were carcinomas.

CONCLUSIONS

The results of this study demonstrate that Sec62/Ki67 and p16 Ki67 dual-staining cytology could be a promising adjunctive diagnostic tool for VIN and squamous cell carcinoma, in addition to standard histology.

Patient-derived, three-dimensional spheroid cultures provide a versatile translational model for the study of organ-confined prostate cancer

PURPOSE

To generate and characterize 3D spheroid suspension cultures from radical prostatectomy (RP) specimens as a versatile model system for organ-confined prostate cancer (PCa).

METHODS

Cancerous tissue samples from RP specimens were excised by a uropathologist. Preparation of 3D spheroids was done by mechanical disintegration and limited enzymatic digestion followed by serial filtration through 100 μm- and 40 μm-cell strainers. Thereafter, spheroids were cultured in a modified stem cell medium and characterized by a live/dead assay, whole-spheroid immunohistochemistry (IHC; CK5, CK8, AMACR, PSA, Ki67, AR, αSMA, Vimentin, E-Cadherin) and PSA-measurements in culture medium. Furthermore, their response to pharmaceutical treatment with docetaxel, bicalutamide, enzalutamide and abiraterone was tested.

RESULTS

173 RP cases were included. The median preoperative PSA-level was 16.12 ng/ml [range 0.99;345], the median Gleason score was 7b [6;10]. 64 cases were excluded due to low tumor content in frozen sections (43) or to insufficient spheroid formation (21). In the remaining 109 cases, spheroids formed successfully and stayed viable for up to several months. IHC analysis revealed AR-, CK8-, and AMACR-positivity in nearly all cases, while CK5-positive cells were detectable only occasionally as were α-SMA and Vimentin. E-Cadherin was positive in most cases. Furthermore, spheroids proved to be amenable to cryopreservation. While abiraterone had no effect and docetaxel only a moderate effect, spheroid viability was markedly reduced upon bicalutamide and enzalutamide treatment.

CONCLUSIONS

Multicellular 3D spheroids can be generated from patient-derived RP tissue samples and serve as an innovative in vitro model of organ-confined PCa.

Flavonifractor (Eubacterium) plautii bloodstream infection following acute cholecystitis

Flavonifractor plautii (formerly Eubacterium plautii) is an anaerobic gram positive rod shaped bacterium belonging to the family of Clostridiales, and a common member of the human gut microbiome. However, it is very rarely isolated from clinical human specimens, so data about its clinical significance are scarce. Here we report of a bloodstream infection due to F. plautii following gangrenous cholecystitis in a 69 year old man. After cholecystectomy and empirical antimicrobial treatment with ceftriaxone and metronidazole the patient recovered. F. plautii was the only bacterium detected in blood culture, suggesting that it might have been causative for cholecystitis. Antimicrobial resistance testing identified decreased susceptibilities against linezolid and penicillin indicating that a targeted therapy might be necessary. F. plautii can be considered a potential pathogen for cholecystitis.

Uterine Leiomyosarcoma

Uterine leiomyosarcoma (uLMS) is a rare entity among malignant gynecologic tumors with a very unfavorable prognosis and the highest prevalence in the pre- and peri-menopause. Only early-stage tumors have an acceptable prognosis, provided the patient has been treated without injuring the uterus. uLMS is often diagnosed accidentally and the correct diagnosis ishampered by equivocal features similar to the far more frequent benign uterine fibroids. Surgery is the basis of therapy, and it should be done in order to remove the uterus intact. As vaginal, abdominal, and endoscopic surgery - possibly including morcellation - are the methods of choice for the treatment of uterine fibroids, pre-operatively undiagnosed leiomyosarcoma detected by pathologic examination will have a worsened prognosis. Systemic treatment and radiotherapy are of no proven value in the adjuvant setting. Thus, there is strong need for a reliable pre-operative risk score for leiomyosarcoma in order to justify diagnostic means beyond clinical routine and to choose the correct surgical pathway. The clinical problems in the diagnosis of leiomyosarcoma and treatment are exemplified by a case report of a 30-year-old childless patient. Diagnostic tools as well as treatment options in adjuvant and palliative situations are reviewed.

Robust method for isolation of tumor infiltrating lymphocytes with a high vital cell yield from small samples of renal cell carcinomas by a new collagenase-free mechanical procedure

BACKGROUND

Tumor-infiltrating lymphocytes (TIL) play an important role in the pathogenesis of renal cell carcinoma. Characterization of TIL requires efficient isolation procedures, especially in early stage disease when the tumor is of small in size. Conventional methods for isolating TIL are based on enzymatic tissue digestion, most frequently with collagenase. Collagenase isolation is limited by poor cell recovery, altered expression of cell-surface molecules, and impaired TIL-functionality. To overcome these limitations, we developed and optimized conditions for a robust collagenase-free mechanical procedure for improved isolation of TIL from renal cell carcinoma samples.

METHODS

TIL from tumor samples and T cells from peripheral blood were collected from 12 patients undergoing partial or radical nephrectomy. Samples were subjected to an enzymatic reference protocol and to a newly established mechanical isolation protocol. After viability staining, TIL-subpopulations were quantified and phenotyped by immunohistochemistry and flow-cytometric analysis, and were compared to characteristics of peripheral blood T cells. As a marker for TIL-functionality, T-cell cytokine induction was quantified after polyclonal stimulation.

RESULTS

We show that this new technique is rapid and allows identification of CD4 and CD8 T-cell subpopulations including CD4, CD8, and regulatory T cells expressing anergy markers such as programmed death-1 (PD-1) or B- and T-lymphocyte attenuator. When compared to the reference protocol involving collagenase digestion, the yield of TIL after mechanical isolation was higher and the expression of cell-surface markers was better preserved. Moreover, although antitumor activity was not assessed, mechanically isolated TIL are at least equally functional as T cells from peripheral blood, as polyclonal stimulation induced cytokines such as interferon-γ and tumor necrosis factor-α in both TIL and T cells from peripheral blood.

CONCLUSION

The mechanical procedure may be applied as a robust and rapid alternative to collagenase digestion for isolation of high amounts of phenotypically and functionally intact TIL from fresh tumor samples.

A novel mouse model of human prostate cancer to study intraprostatic tumor growth and the development of lymph node metastases

BACKGROUND

In this study, we aimed to establish a versatile in vivo model of prostate cancer, which adequately mimics intraprostatic tumor growth, and the natural routes of metastatic spread. In addition, we analyzed the capability of high-resolution ultrasonography (hrUS), in vivo micro-CT (μCT), and 9.4T MRI to monitor tumor growth and the development of lymph node metastases.

METHODS

A total of 5 × 10⁵ VCaP cells or 5 × 10⁵ cells of LuCaP136- or LuCaP147 spheroids were injected into the prostate of male CB17-SCID mice (n = 8 for each cell type). During 12 weeks of follow-up, orthotopic tumor growth, and metastatic spread were monitored by repetitive serum-PSA measurements and imaging studies including hrUS, μCT, and 9.4T MRI. At autopsy, primary tumors and metastases were harvested and examined by histology and immunohistochemistry (CK5, CK8, AMACR, AR, Ki67, ERG, and PSA). From imaging results and PSA-measurements, tumor volume doubling time, tumor-specific growth rate, and PSA-density were calculated.

RESULTS

All 24 mice developed orthotopic tumors. The tumor growth could be reliably monitored by a combination of hrUS, μCT, MRI, and serum-PSA measurements. In most animals, lymph node metastases could be detected after 12 weeks, which could also be well visualized by hrUS, and MRI. Immunohistochemistry showed positive signals for CK8, AMACR, and AR in all xenograft types. CK5 was negative in VCaP- and focally positive in LuCaP136- and LuCaP147-xenografts. ERG was positive in VCaP- and negative in LuCaP136- and LuCaP147-xenografts. Tumor volume doubling times and tumor-specific growth rates were 21.2 days and 3.9 %/day for VCaP-, 27.6 days and 3.1 %/day for LuCaP136- and 16.2 days and 4.5 %/day for LuCaP147-xenografts, respectively. PSA-densities were 433.9 ng/mL per milliliter tumor for VCaP-, 6.5 ng/mL per milliliter tumor for LuCaP136-, and 11.2 ng/mL per milliliter tumor for LuCaP147-xenografts.

CONCLUSIONS

By using different monolayer and 3D spheroid cell cultures in an orthotopic xenograft model, we established an innovative, versatile in vivo model of prostate cancer, which enables the study of both intraprostatic tumor growth as well as metastatic spread to regional lymph nodes. HrUS and MRI are feasible tools to monitor tumor growth and the development of lymph node metastases while these cannot be visualized by μCT.

FGFR1 gene amplification in squamous cell carcinomas of the lung: a potential favorable prognostic marker for women and for patients with advanced cancer

In squamous cell carcinoma (SCC) of the lung, mutations within the genes of fibroblast growth factor receptors (FGFR) such as K660N/K660E in FGFR2 and R248C/S249C in FGFR3 and FGFR1 gene amplification have been described, but their prognostic relevance still remains unclear. In order to detect the mutation frequencies and to define their prognostic value for associated clinicopathologic features and survival of patients, resected ΔNp63/p40-positive SCC of the lung (n = 101) were screened for FGFR1 gene amplification by fluorescence in situ hybridization performed on formalin-fixed paraffin embedded tissues and for the presumed driver mutations in genes of FGFR2 and FGFR3 by PCR and Sanger sequencing. Twenty-two of 101 SCCs (22%) were positive for amplification based on a FGFR1/centromere (chromosome 8) ratio > 2.0 or higher. In advanced tumor stages (III-IV), the overall survival of patients carrying FGFR1 gene amplification was significantly higher (p = 0.006). Among women, FGFR1 gene amplification was significantly associated with longer overall survival (p = 0.023). The presence of FGFR1 gene amplification was associated with patient age (65 versus 69 years, p = 0.046), but not with gender, tumor stage, histologic subtype, tumor grade, or ΔNp63/p40 immunoreactivity. The S249C mutation in the FGFR3 gene was identified in one out of 101 SCCs (1%); the K600N, K660E, or R248C mutations were not identified. These results suggest that FGFR1 gene amplification is a frequent alteration in SCC of the lung and appears not to be a negative but rather a favorable prognostic marker for women and particularly for patients with advanced SCC of the lung (stage III-IV).

The long non-coding RNA H19 suppresses carcinogenesis and chemoresistance in hepatocellular carcinoma

The long non-coding RNA (lncRNA) H19 represents a maternally expressed and epigenetically regulated imprinted gene product and is discussed to have either tumor-promoting or tumor-suppressive actions. Recently, H19 was shown to be regulated under inflammatory conditions. Therefore, aim of this study was to determine the function of H19 in hepatocellular carcinoma (HCC), an inflammation-associated type of tumor. In four different human HCC patient cohorts H19 was distinctly downregulated in tumor tissue compared to normal or non-tumorous adjacent tissue. We therefore determined the action of H19 in three different human hepatoma cell lines (HepG2, Plc/Prf5, and Huh7). Clonogenicity and proliferation assays showed that H19 overexpression could suppress tumor cell survival and proliferation after treatment with either sorafenib or doxorubicin, suggesting chemosensitizing actions of H19. Since HCC displays a highly chemoresistant tumor entity, cell lines resistant to doxorubicin or sorafenib were established. In all six chemoresistant cell lines H19 expression was significantly downregulated. The promoter methylation of the H19 gene was significantly different in chemoresistant cell lines compared to their sensitive counterparts. Chemoresistant cells were sensitized after H19 overexpression by either increasing the cytotoxic action of doxorubicin or decreasing cell proliferation upon sorafenib treatment. An H19 knockout mouse model (H19Δ3) showed increased tumor development and tumor cell proliferation after treatment with the carcinogen diethylnitrosamine (DEN) independent of the reciprocally imprinted insulin-like growth factor 2 (IGF2). In conclusion, H19 suppresses hepatocarcinogenesis, hepatoma cell growth, and HCC chemoresistance. Thus, mimicking H19 action might be a potential target to overcome chemoresistance in future HCC therapy.

[Grading of lung cancer]

In comparison with other tumor entities there is no common generally accepted grading system for lung cancer with clearly defined criteria and clinical relevance. In the recent fourth edition of the World Health Organization (WHO) classification from 2015 of tumors of the lungs, pleura, thymus and heart, there is no generally applicable grading for pulmonary adenocarcinomas, squamous cell carcinomas or rarer forms of carcinoma. Since the new IASLC/ATS/ERS classification of adenocarcinomas published in 2011, 5 different subtypes with significantly different prognosis are proposed. This results in an architectural (histologic) grading, which is usually applied to resection specimens. For squamous cell carcinoma the number of different histological subtypes in the new WHO classification was reduced compared to earlier versions but without a common grading system. In recent publications nesting and budding were proposed as the main (histologic) criteria for a grading of squamous cell carcinomas. The grading of neuroendocrine tumors (NET) of the lungs in comparison with NET in other organs is presented in a separate article in this issue. Certain rare tumor types are high grade per definition: small cell, large cell and pleomorphic carcinomas, carcinosarcomas and pulmonary blastomas. In the future it is to be expected that these developments will be further refined, e. g. by adding further subtypes for adenocarcinomas and cytologic and/or nuclear criteria for adenocarcinoma and/or squamous cell carcinomas.