Molecular genetic differentiation between primary lung cancers and lung metastases of other tumors

Genomic landscape and actionable mutations of brain metastases derived from non-small cell lung cancer: A systematic review

Background

Brain metastases derived from non-small cell lung cancer (NSCLC) represent a significant clinical problem. We aim to characterize the genomic landscape of brain metastases derived from NSCLC and assess clinical actionability.

Methods

We searched Embase, MEDLINE, Web of Science, and BIOSIS from inception to 18/19 May 2022. We extracted information on patient demographics, smoking status, genomic data, matched primary NSCLC, and programmed cell death ligand 1 expression.

Results

We found 72 included papers and data on 2346 patients. The most frequently mutated genes from our data were EGFR (n = 559), TP53 (n = 331), KRAS (n = 328), CDKN2A (n = 97), and STK11 (n = 72). Common missense mutations included EGFR L858R (n = 80) and KRAS G12C (n = 17). Brain metastases of ever versus never smokers had differing missense mutations in TP53 and EGFR, except for L858R and T790M in EGFR, which were seen in both subgroups. Of the top 10 frequently mutated genes that had primary NSCLC data, we found 37% of the specific mutations assessed to be discordant between the primary NSCLC and brain metastases.

Conclusions

To our knowledge, this is the first systematic review to describe the genomic landscape of brain metastases derived from NSCLC. These results provide a comprehensive outline of frequently mutated genes and missense mutations that could be clinically actionable. These data also provide evidence of differing genomic landscapes between ever versus never smokers and primary NSCLC compared to the BM. This information could have important consequences for the selection and development of targeted drugs for these patients.

Small RNA sequencing to differentiate lung squamous cell carcinomas from metastatic lung tumors from head and neck cancers

Distinguishing lung squamous cell carcinoma (LSQCC) from a solitary metastatic lung tumor (MSQCC) from head and neck squamous cell carcinoma (HNSQCC) presents a difficult diagnostic challenge even after detailed pathological assessment. Treatment options and estimated survival outcomes after pulmonary resection differ between patients with LSQCC and MSQCC. This study aimed to investigate whether microRNA (miRNA) profiling by RNA sequencing of HNSQCC, MSQCC, and LSQCC was useful for differential diagnosis of MSQCC and LSQCC. RNA sequencing was performed to identify bioinformatically significant miRNAs from a formalin-fixed paraffin-embedded (FFPE) block from a derivation set. MiRNA levels were confirmed by validation sets using FFPE samples and serum extracellular vesicles from patients. Step-wise discriminant analysis and canonical discriminant analysis identified 13 miRNAs by which the different expression patterns of LSQCC, MSQCC, and HNSQCC groups were demonstrated. Six miRNAs (miR-10a/28/141/320b/3120) were assessed in validation sets, and 4 miRNAs (miR-10a/28/141/3120) were significantly upregulated in LSQCCs compared with MSQCCs and HNSQCCs. Serum extracellular vesicles from LSQCC patients demonstrated significantly elevated miR-10a (p = .042), miR-28 (p = .041), and miR-3120 (p = .047) levels compared with those from MSQCC patients. RNA sequencing is useful for differential diagnosis of LSQCC and MSQCC, and the expression level of miR-10a, miR-28, and miR-3120 in serum extracellular vesicles are promising noninvasive tools for this purpose.

TP53 is not a prognostic marker-clinical consequences of a generally disregarded fact

Technological progress within the last 15-20 years has significantly increased our knowledge about the molecular basis of cancer development, tumor progression, and treatment response. As a consequence, a vast number of biomarkers have been proposed, but only a small fraction of them have found their way into clinical use. The aim of this paper is to describe the specific demands a clinically relevant biomarker should meet and how biomarkers can be tested stepwise. We name this procedure the "triple-R principle": robustness, reproducibility, and relevance. The usefulness of this principle is illustrated with the marker TP53. Since it is mutated in a broad spectrum of cancer entities, TP53 can be considered a very promising marker. Thus, TP53 has been studied in detail but there is still no explicit consensus about its clinical value. By considering our own experience and reviewing the literature, we demonstrate that a major problem of current biomarker research is disregard of whether the biomarker is prognostic or predictive. As an example, it is demonstrated that TP53 is not a prognostic marker, but rather a purely predictive marker, and that disregard of this fact has made this otherwise strong biomarker appear as not being clinically useful so far.

The Role of KRAS Mutational Analysis to Determine the Site of Origin of Metastatic Carcinoma to the Lung: A Case Report

Metastatic carcinomas involving the lung are a common specimen encountered in surgical pathology. These metastases may have different morphologic, and architectural patterns and may mimic primary pulmonary adenocarcinoma, especially the intra-alveolar (lepidic) pattern of spread which may simulate a primary pulmonary bronchioloalveolar carcinoma (adenocarcinoma in situ). We present the case of a metastatic pancreatic adenocarcinoma that morphologically mimicked bronchioloalveolar carcinoma of the lung in that the tumor had an exclusive intra-alveolar pattern of spread and had an immunophenotype that was noninformative as to the site of origin (cytokeratin 7+, cytokeratin 20−, TTF-1−). In this case, we used KRAS gene mutation analysis to support that the lung carcinoma represented a metastatic pancreatic carcinoma as they both possessed identical codon 12 KRAS mutations. We show that this method may be a useful way to prove site of origin of metastatic carcinoma—particularly if standard morphologic or immunohistochemical analysis is not definitive.

Genetic detection of lymph node micrometastases: a selection criterion for liver transplantation in patients with liver metastases after colorectal cancer

BACKGROUND

Liver transplantation for nonresectable liver metastases from colorectal cancer was abandoned in 1994 on account of high recurrence rates. The aim of this study was to investigate whether the genetic detection of micrometastases in histologically negative lymph nodes of the primary colon cancer could be applied to select patients for liver transplantation.

METHODS

We analyzed 21 patients with colorectal cancer who had undergone liver transplantation between 1983 and 1994 for liver metastases. Eleven patients were histologically lymph node negative at the time of surgery; ten patients with lymph node metastases served as control group. DNA sequencing was used to screen tumor material for p53 and K-ras mutations. Mutant allele-specific amplification (MASA) was then used to search for micrometastases in DNA from regional lymph nodes of the primary colorectal cancer.

RESULTS

p53 and K-ras mutations were detected in 12 (57%) and 3 (14%) of 21 patients in the colorectal cancer, respectively. The mutations were confirmed in the corresponding liver metastases. Of 11 patients with histologically negative lymph nodes, nine were eligible for MASA due to presence of p53 or K-ras mutation. MASA revealed six of nine patients to be genetically positive for micrometastases. Three patients were both genetically and histologically negative. These three patients showed a significantly longer overall survival (P = 0.011) of 4, 5, and 20 years, respectively.

CONCLUSIONS

We conclude that the genetic detection of micrometastases by MASA could be a powerful prognostic indicator for selecting patients with colorectal liver metastases who could benefit from liver transplantation.

Benign metastasizing leiomyoma and lymphangioleiomyomatosis: sex-specific diseases?

The striking similarity between benign metastasizing leiomyoma and lymphangioleiomyomatosis is that they both affect young women. This observation underscores the importance of gender-dependent variables in disease and our lack of understanding of gender differences. Many researchers are currently investigating the link between disease and hormone levels in the body. The beneficial role of estrogens remains in question in pulmonary medicine, and further ongoing research should help to define the role of hormones in the lung.

A case of pulmonary metastasis from breast cancer following an 18-year disease-free interval that responded to tamoxifen treatment

A 61-year-old woman was admitted to our hospital with an abnormal shadow on chest roentgenogram. She had undergone a radical mastectomy for right breast cancer 18 years previously. Since pleural dissemination was noted at the time of thoracotomy, only tumor biopsy was performed. Although a decisive diagnosis could not be obtained histologically, the tumor resembled breast cancer and the estrogen receptor status was positive. She underwent post-operative chemotherapy and tamoxifen treatment. After tamoxifen treatment, complete response was observed. The patient is now doing well without recurrence about 10 years after thoracotomy. Based on the clinical course, we obtained both a definitive diagnosis and complete remission.

p53 mutation analysis for definite diagnosis of multiple primary lung carcinoma

BACKGROUND

The detection of a second tumor in patients with lung carcinoma raises the question whether this lesion is a metastasis or a second primary lung carcinoma. Patients cannot always be categorized satisfactorily according the criteria of multiple lung carcinoma proposed by Martini and Melamed. This may result in an inadequate treatment schedule in individual patients. Because p53 mutations can be used as clonal marker, the authors investigated whether p53 mutation analysis can differentiate between primary lung carcinomas and metastatic disease.

METHODS

Sixty-four tumors in 31 patients with synchronous and metachronous lung tumors were investigated by p53 mutation analysis.

RESULTS

In 21 patients, the tumors showed different p53 mutations, and therefore a definite diagnosis of multiple primary lung carcinoma was made. One of these patients did not meet the criteria of Martini and Melamed. In two other patients not matching these criteria, identical mutations were demonstrated in both tumors, indicating the presence of metastatic disease. In eight patients, analysis was not conclusive or possible.

CONCLUSIONS

p53 mutation analysis can be a useful tool to confirm or rule out multiple primary lung carcinoma, and the results confirm the criteria of Martini and Melamed. However, in patients not meeting these criteria, the diagnosis of multiple lung carcinoma still has to be considered, and metastatic disease has to be ruled out. P53 mutation analysis can be helpful for this purpose.

Staging of non-small cell lung cancer: consensus, controversies and challenges

Stage is with performance status, the most potent prognostic factor in non-small cell lung cancer. In the past decades, much effort has been directed towards the definition, description, development and implementation of staging guidelines. This has undoubtedly resulted in improvements in therapy and insight in the biology of the disease. The new millennium sees us confronted with an increasing epidemic of lung cancer. Hence, the need for further improvements in staging accuracy and cost effectiveness, in order to use the available therapeutic armament at its best and provide the patient with a treatment that is best adjusted to his or her condition. Current controversies and future challenges in staging will be addressed.

Contralateral breast cancer: molecular differentiation between metastasis and second primary cancer

Previous cancer in one breast is a strong known risk factor for cancer in the contralateral breast. Differences in tumor histology and nuclear grading are applied to distinguish between a metastatic spread and a second primary cancer, although cancers of the breast often share the same histological features. Comparison of genetic alterations in paired tumors may provide the most reliable approach for discerning clonal relationships, hence uncovering the presence or absence of multiple primary cancers. We compared tumors from 33 patients with cancer in both breasts for mutations in the p53 gene. With this molecular approach, we were able to define the relationship within paired tumors in 13 patients. The paired tumors of two patients shared the same mutation, revealing the second lesion in one case as a contralateral metachronous lymph node metastasis appearing 29 months after first surgery, and in the other as a spread to the opposite breast. In 11 patients, mutations were either discordant or solely present in one of the lesions, confirming the diagnosis of bilateral breast cancer. Histopathological evaluation had failed to provide firm diagnosis in nine out of 11 instances on account of concordances in pathological parameters such as histological type and grading. In our study, we could show that bilateral breast malignancies most frequently represent two primary breast cancers. We could also demonstrate that contralateral breast cancer spread does occur. Standard pathological assessment allowed a firm diagnosis only in the presence of different histological types.

p53 tumor suppressor gene as a clonal marker in head and neck squamous cell carcinoma: p53 mutations in primary tumor and matched lymph node metastases

In order to define the diagnostic value of p53 tumor suppressor gene as a clonal marker in head and neck squamous cell carcinoma (HNSCC), we investigated p53 mutations in primary tumors (PT) and matched lymph node metastases (LNM); the underlying question being whether differentiation between metastatic disease of a known PT or (a metastasis of) a synchronous or metachronous second tumor is possible by means of p53 sequencing-based mutation analysis. In 15 PT, the p53 status was analyzed, following RNA isolation, cDNA synthesis and polymerase chain reaction amplification, by direct sequencing full-length mRNA. Mutations thus found were confirmed by DNA sequencing analysis of the corresponding exon in the PT. When RNA isolation was defective, DNA sequencing analysis of exons 1 through 11 was performed. In the matched LNM, DNA analysis of the corresponding exon was performed to prove the presence of the same p53 mutation. In the event of small clones not detectable by direct sequencing, an oligo ligation assay was developed to detect a specific mutation. The presence of germline mutations was excluded by DNA sequencing analysis of the corresponding exon of peripheral blood leucocytes. In 14 PT (94%), a mutation was identified. In one PT, no p53 mutation could be identified either after full-length mRNA sequencing or after sequencing exons 1 through 11. In all cases of PT and matched LNM, the mutations proved to be identical. We conclude that p53 mutations develop in carcinogenesis before metastases occur and are maintained during metastasis. Consequently, p53 may serve as a clonal marker not susceptible to change during tumor metastasis. This merits further exploration of the application of p53 mutation analysis in differentiating between metastatic disease from a known PT versus a metastasis of another second PT.

Cytological and immunocytochemical evaluation of thyroid and breast masses in patients with a previous neoplasm: case reports

The diagnosis of secondary tumours represents one of the most important fields in the application of fine needle aspiration cytology (FNAC). We studied two patients, one with a history of breast cancer and one with a previous tumour of the thyroid, who showed a second mass, in the thyroid and in the breast, respectively, during follow up. The aim of our study was to evaluate if cytology, performed on FNAC smears, may distinguish a metastatic lesion from a second primary tumour, or if further immunocytochemistry should be performed. Our data demonstrate that, while cytology may be indicative of a second primary tumour, the histotype should be confirmed by immunocytochemical staining.

Discrimination of double primary lung cancer from intrapulmonary metastasis by p53 gene mutation

When multiple synchronous lung tumours are identified, discrimination of multicentric lung cancers from intrapulmonary metastases by clinical findings is often difficult. We used genetic alterations in p53 gene as a discrimination marker of double primary lung cancers from single lung cancer with intrapulmonary metastasis. Twenty of 861 patients with primary lung cancer who underwent lung resection were selected as subjects because they showed synchronous double solid tumours of the same histological type in the unilateral lung without distant metastases. In addition, they had been diagnosed as lung carcinoma with intrapulmonary metastasis by clinical and histological findings. DNAs were extracted from paraffin-embedded tissue of paired tumours from these 20 patients. Exons 5-9 of the p53 gene were examined for genetic alterations in the tumours by polymerase chain reaction, single-strand conformation polymorphism analysis and subsequent DNA sequencing analysis. Three different patterns in the distribution of p53 mutations in double lung tumours were observed: [A] mutation in only one of the tumours (four cases), [B] different mutations in the tumours (two cases), and [C] same mutation in both tumours (one case). The cases of [A] or [B] patterns could be classified as double primary lung cancers, while the case of the [C] pattern was suggested to be lung cancer with intrapulmonary metastasis. These results suggested that the multicentric cancers were more frequent than the intrapulmonary metastatic cancers in double cancer cases.

Pulmonary metastases of breast carcinomas: ligandohistochemical, nuclear, and structural analysis of primary and metastatic tumors with emphasis on period of occurrence of metastases and survival

BACKGROUND AND OBJECTIVES

Pulmonary metastases of breast carcinomas have a high frequency and are often subject to surgical intervention. To contribute to advances in the knowledge about morphometric and biochemical parameters of primary tumors and their metastatic lesions, analysis of syntactic structure and thermodynamic aspects as well as of expression of distinct glycohistochemical features with respect to period of metastasis occurrence and patient survival is desirable.

METHODS

Clinical history, surgical findings, histopathological reports, survival of the patients with a maximum follow-up of 15 years, and paraffin blocks of 32 breast carcinoma specimens and their pulmonary metastases were examined. Only potentially curative resections of both the breast carcinoma and their metastases have been included for analysis. The following markers were applied: neoglycoconjugates with histoblood group A- and H-trisaccharides, lactose, alpha-N-acetyl-D-galactosamine and the Forssman disaccharide, a polyclonal immunoglobulin G fraction from human serum with specificity for 9-0-acetylated sialic acid, which is a tumor marker for melanomas, the serum lectins serum amyloid P component and mannan-binding lectin, the mannose-specific plant lectin concanavalin A, and monoclonal antibodies specific for estrogen and progesterone receptors, respectively. In addition, measurements of the integrated optical density (IOD) and tissue structure were performed.

RESULTS

The frequency of expression of hormone receptors and expression of binding capacities to most of the applied probes was similar between the primary and metastatic tumors; however, it varied markedly between different patients. For the IOD parameters, a close association between the primary tumors and their metastases was seen, especially a rather low S-phase-related tumor cell fraction and a high percentage of tumor cells with an IOD >5C. The mean time for the development of intrapulmonary metastases measured 43 months. It was considerably longer in progesterone receptor-negative tumors (49.7 months) and those with a lack of expression of sites with specificity for the Forssman disaccharide (48.7 months). The survival was positively correlated with the presence of binding capacity of histoblood group A-trisaccharide and certain structural parameters, especially the structural entropy and its current. The presence of estrogen and progesterone receptors was not associated with the total survival at a statistically significant level.

CONCLUSIONS

Histochemical features between the primary breast carcinoma and their intrapulmonary metastases can evidently vary. Analysis of the hormone receptor status in metastatic lesions seems to be useful for diagnostic purposes only in rare cases, i.e., distinguishing metastases from primary lung carcinoma. Nonetheless, the survival of patients with metastasizing breast carcinoma is associated with features of the primary tumors, especially the detection of binding capacities for the Forssman disaccharide and the histoblood group A-trisaccharide. Extent of lymph node involvement of the breast carcinoma is not prognostic for later pulmonary involvement.