[Application of FISH in the diagnosis of lung cancer]

Advancements in the diagnosis and treatment of sub‑centimeter lung cancer in the era of precision medicine (Review)

Lung cancer is the malignancy with the highest global mortality rate and imposes a substantial burden on society. The increasing popularity of lung cancer screening has led to increasing number of patients being diagnosed with pulmonary nodules due to their potential for malignancy, causing considerable distress in the affected population. However, the diagnosis and treatment of sub-centimeter grade pulmonary nodules remain controversial. The evolution of genetic detection technology and the development of targeted drugs have positioned the diagnosis and treatment of lung cancer in the precision medicine era, leading to a marked improvement in the survival rate of patients with lung cancer. It has been established that lung cancer driver genes serve a key role in the development and progression of sub-centimeter lung cancer. The present review aimed to consolidate the findings on genes associated with sub-centimeter lung cancer, with the intent of serving as a reference for future studies and the personalized management of sub-centimeter lung cancer through genetic testing.

Current treatment and novel insights regarding ROS1-targeted therapy in malignant tumors

BACKGROUND

The proto-oncogene ROS1 encodes an intrinsic type I membrane protein of the tyrosine kinase/insulin receptor family. ROS1 facilitates the progression of various malignancies via self-mutations or rearrangements. Studies on ROS1-directed tyrosine kinase inhibitors have been conducted, and some have been approved by the FDA for clinical use. However, the adverse effects and mechanisms of resistance associated with ROS1 inhibitors remain unknown. In addition, next-generation ROS1 inhibitors, which have the advantage of treating central nervous system metastases and alleviating endogenous drug resistance, are still in the clinical trial stage.

METHOD

In this study, we searched relevant articles reporting the mechanism and clinical application of ROS1 in recent years; systematically reviewed the biological mechanisms, diagnostic methods, and research progress on ROS1 inhibitors; and provided perspectives for the future of ROS1-targeted therapy.

RESULTS

ROS1 is most expressed in malignant tumours. Only a few ROS1 kinase inhibitors are currently approved for use in NSCLC, the efficacy of other TKIs for NSCLC and other malignancies has not been ascertained. There is no effective standard treatment for adverse events or resistance to ROS1-targeted therapy. Next-generation TKIs appear capable of overcoming resistance and delaying central nervous system metastasis, but with a greater incidence of adverse effects.

CONCLUSIONS

Further research on next-generation TKIs regarding the localization of ROS1 and its fusion partners, binding sites for targeted drugs, and coadministration with other drugs is required. The correlation between TKIs and chemotherapy or immunotherapy in clinical practice requires further study.

Current treatments for non-small cell lung cancer

Despite improved methods of diagnosis and the development of different treatments, mortality from lung cancer remains surprisingly high. Non-small cell lung cancer (NSCLC) accounts for the large majority of lung cancer cases. Therefore, it is important to review current methods of diagnosis and treatments of NSCLC in the clinic and preclinic. In this review, we describe, as a guide for clinicians, current diagnostic methods and therapies (such as chemotherapy, chemoradiotherapy, targeted therapy, antiangiogenic therapy, immunotherapy, and combination therapy) for NSCLC.

Detection of MET amplification by droplet digital PCR in peripheral blood samples of non-small cell lung cancer

PURPOSE

Mesenchymal-epithelial transition (MET) amplification is one of the mechanisms accounting for the resistance of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) in lung cancer patients, as well as the poor prognosis. Fluorescence in situ hybridization (FISH) is the most widely used method for MET amplification detection. However, it is inapplicable when tissue samples were unavailable. Herein, we assessed the value of droplet digital PCR (ddPCR) in MET copy number gain (CNG) detection in non-small cell lung cancer (NSCLC) patients treated with EGFR-TKIs.

MATERIALS AND METHODS

A total of 103 cancer tissues and the paired peripheral blood samples from NSCLC patients were collected for MET CNG detection using ddPCR. In parallel, MET amplification in tissue samples was verified by FISH. Also, the relationships between MET CNG and EGFR T790M, as well as the EGFR-TKI resistance were also evaluated using Chi-square or Fisher's exact tests.

RESULT

The concordance rate of ddPCR and FISH in detecting MET CNG in tissue samples was 100% (102/102), and it was 94.17% (97/103) for ddPCR method in detecting the MET CNG among peripheral blood and tissue samples. No statistical difference was observed between MET amplification and EGFR T790M (p = 0.65), while MET amplification rate was significantly increased in patients with resistance to third generations of EGFR-TKIs as compared with patients with resistance to first/second EGFR-TKIs (p < 0.05).

CONCLUSIONS

ddPCR is an alternative method to detect MET CNG in both tissues and peripheral blood samples, which is of worthy in clinical promotion.

State of affairs regarding targeted pharmacological therapy of cancers metastasized to the brain

In 1999 a visionary short article by The Wall Street Journal writers Robert Langreth and Michael Waldholz popularized the new term "personalized medicine," that is to say, the targeting of drugs to each unique genetic profile. From today's perspective, targeted approaches have clearly found the widest use in the antineoplastic domain. The current review was initiated to review the progress that has been made regarding the treatment of patients with advanced cancer and brain metastases. PubMed was searched for the terms brain metastasis, brain metastases, or metastatic brain in the Title/Abstract. Selection was limited to randomized controlled trial (RCT) and publication date January 2010 to February 2022. Following visual review, 51 papers on metastatic lung cancer, 12 on metastatic breast cancer, and 9 on malignant melanoma were retained and underwent full analysis. Information was extracted from the papers giving specific numbers for intracranial response rate and/or overall survival. Since most pharmacological trials on advanced cancers excluded patients with brain metastases and since hardly any information on adjuvant radiotherapy and radiosurgery is available from the pharmacological trials, precise assessment of the effect of targeted medication for the subgroups with brain metastases is difficult. Some quantitative information regarding the success of targeted pharmacological therapy is only available for patients with breast and lung cancer and melanoma. Overall, targeted approaches approximately doubled the lifespan in the subgroups of brain metastases from tumors with targetable surface receptors such as anaplastic lymphoma kinase (ALK) fusion receptor in non-small cell lung cancer or human epidermal growth factor receptor 2 (HER2)-positive breast cancer. For these types, overall survival in the situation of brain metastases is now more than a year. For receptor-negative lung cancer and melanoma, introduction of immune checkpoint blockers brought a substantial advance, although overall survival for melanoma metastasized to the brain appears to remain in the range of 6 to 9 months. The outlook for small cell lung cancer metastasized to the brain apparently remains poor. The introduction of targeted therapy roughly doubled survival times of advanced cancers including those metastasized to the brain, but so far, targeted therapy does not differ essentially from chemotherapy, therefore also facing tumors developing escape mechanisms. With the improved perspective of patients suffering from brain metastases, it becomes important to further optimize treatment of this specific patient group within the framework of randomized trials.