KRAS mutation is a weak, but valid predictor for poor prognosis and treatment outcomes in NSCLC: A meta-analysis of 41 studies

Concurrent ROS1 gene rearrangement and KRAS mutation in lung adenocarcinoma: A case report and literature review

Lung adenocarcinomas with gene rearrangement in the receptor tyrosine kinase ROS1 have emerged as a rare molecular subtype. Although these lung adenocarcinomas respond to ROS1tyrosine kinase inhibitors, many patients ultimately acquire resistance. ROS1gene rearrangement is generally mutually exclusive with other driver genomic alterations, such as those in EGFR, KRAS, or ALK, thus multiple genomic alterations are extremely rare. Herein, we report a case of a 42-year-old man diagnosed with lung adenocarcinoma positive for a SDC4-ROS1 fusion, who was treated with crizotinib followed by three cycles of chemotherapy. A biopsy acquired after disease progression revealed the original SDC4-ROS1 fusion along with a KRAS point mutation (p.G12D).We reviewed the related literature to determine the frequency of gene mutations in non-small cell lung cancer patients. A better understanding of the molecular biology of non-small cell lung cancer with multiple driver genomic aberrations will assist in determining optimal treatment.

Exploitation of Gene Expression and Cancer Biomarkers in Paving the Path to Era of Personalized Medicine

Cancer therapy agents have been used extensively as cytotoxic drugs against tissue or organ of a specific type of cancer. With the better understanding of molecular mechanisms underlying carcinogenesis and cellular events during cancer progression and metastasis, it is now possible to use targeted therapy for these molecular events. Targeted therapy is able to identify cancer patients with dissimilar genetic defects at cellular level for the same cancer type and consequently requires individualized approach for treatment. Cancer therapy begins to shift steadily from the traditional approach of “one regimen for all patients” to a more individualized approach, through which each patient will be treated specifically according to their specific genetic defects. Personalized medicine accordingly requires identification of indicators or markers that guide in the decision making of such therapy to the chosen patients for more effective therapy. Cancer biomarkers are frequently used in clinical practice for diagnosis and prognosis, as well as identification of responsive patients and prediction of treatment response of cancer patient. The rapid breakthrough and development of microarray and sequencing technologies is probably the main tool for paving the way toward “individualized biomarker-driven cancer therapy” or “personalized medicine”. In this review, we aim to provide an updated knowledge and overview of the current landscape of cancer biomarkers and their role in personalized medicine, emphasizing the impact of genomics on the implementation of new potential targeted therapies and development of novel cancer biomarkers in improving the outcome of cancer therapy.

Treating KRAS-mutant NSCLC: latest evidence and clinical consequences

KRAS mutations represent one of the most prevalent oncogenic driver mutations in non-small cell lung cancer (NSCLC). For many years we have unsuccessfully addressed KRAS mutation as a unique disease. The recent widespread use of comprehensive genomic profiling has identified different subgroups with prognostic implications. Moreover, recent data recognizing the distinct biology and therapeutic vulnerabilities of different KRAS subgroups have allowed us to explore different treatment approaches. Small molecules that selectively inhibit KRAS G12C or use of immune checkpoint inhibitors based on co-mutation status are some examples which anticipate that personalized treatment for this challenging disease is finally on the horizon.

Mutational Profile from Targeted NGS Predicts Survival in LDCT Screening-Detected Lung Cancers

Background:

The issue of overdiagnosis in low-dose computed tomography (LDCT) screening trials could be addressed by the development of complementary bio-markers able to improve detection of aggressive disease. The mutation profile of LDCT screening–detected lung tumors is currently unknown.

Methods:

Targeted next-generation sequencing was performed on 94 LDCT screening–detected lung tumors. Associations with clinicopathologic features, survival, and the risk profile of a plasma microRNA signature classifier were analyzed.

Results:

The mutational spectrum and frequency observed in screening series was similar to that reported in public data sets, although a larger number of tumors without mutations in driver genes was detected. The 5-year overall survival (OS) rates of patients with and without mutations in the tumors were 66% and 100%, respectively (p = 0.015). By combining the mutational status with the microRNA signature classifier risk profile, patients were stratified into three groups with 5-year OS rates ranging from 42% to 97% (p < 0.0001) and the prognostic value was significant after controlling for stage (p = 0.02).

Conclusion:

Tumor mutational status along with a microRNA-based liquid biopsy can provide additional information in planning clinical follow-up in lung cancer LDCT screening programs.

KRAS mutations in the circulating free DNA (cfDNA) of non-small cell lung cancer (NSCLC) patients

Circulating free DNA (cfDNA) is obtained from serum or plasma by non-invasive methods such as a simple blood draw, a technique known as "liquid biopsy". Genetic analyses of driver alterations in cfDNA have proved very effective to predict survival and treatment response of cancer patients according to tumoral cfDNA burden in blood. Non-small cell lung cancer (NSCLC) patients with higher concentration of tumoral cfDNA in blood have, on average, shorter progression-free survival (PFS) and overall survival (OS). Regarding specific genetic alterations, KRAS proto-oncogene, GTPase (KRAS) is one of the main genes involved in NSCLC and several studies have been performed to determine its value as a predictive and prognostic biomarker in liquid biopsy. Unfortunately, to date no strong conclusions can be drawn since they have yielded contradictory results. Therefore, further investigations are necessary to establish the value of KRAS testing in liquid biopsy as prognostic or predictive factor in NSCLC. Herein, we review the current knowledge on the importance of KRAS as prognostic and predictive biomarker using non-invasive approaches and the scientific data available regarding its application in clinical practice for treatment of NSCLC.

Analysis of the clinicopathologic characteristics and prognostic of stage I invasive mucinous adenocarcinoma

PURPOSE

The correlations between histological, clinical features and prognosis of stage I invasive mucinous adenocarcinoma (IMA) have not been thoroughly studied for its rare incidence. This study aimed to compare the prognosis among IMA with different percentage of mucinous component and the effect of adjuvant chemotherapy on IMA patients.

METHODS

A total of 145 stage I IMA and 3536 invasive nonmucinous adenocarcinoma patients with R0 resection were included. Based on the percentage of mucinous pattern presented in tumor, IMA were classified into two subgroups: pure mucinous (>90 % invasive mucinous pattern) and mixed mucinous/nonmucinous (≥10 % of each histologic component). Invasive nonmucinous adenocarcinomas were classified into three subgroups: lepidic (LEP), acinar/papillary (ACN/PAP) and solid/micropapillary (SOL/MIP). Disease-free survival (DFS) and overall survival (OS) were assessed and compared among IMA and invasive nonmucinous patients.

RESULTS

For IMA patients, DFS (p = 0.003) was worse for mixed mucinous/nonmucinous compared with pure mucinous subgroup, OS (p = 0.514) was not prognostically different between two groups. There were no significant difference for DFS (p = 0.428) and OS (p = 0.232) between IMA and invasive nonmucinous adenocarcinoma. However, statistical significance were seen for DFS (p < 0.001) and OS (p < 0.001) between 5 major histological subgroups: LEP and pure IMA showed excellent prognosis, mixed mucinous/nonmucinous IMA and SOL/MIP subtypes presented the worst prognosis. No significant survival benefit from adjuvant chemotherapy for IMA patients.

CONCLUSIONS

Mixed mucinous/nonmucinous IMA had a worse DFS compared with pure mucinous. Early stage IMA could not benefit from adjuvant chemotherapy.

Specific KRAS amino acid substitutions and EGFR mutations predict site-specific recurrence and metastasis following non-small-cell lung cancer surgery

Background:

We aimed to evaluate whether EGFR mutations (mEGFR) and KRAS amino acid substitutions can predict first site of recurrence or metastasis after non-small-cell lung cancer (NSCLC) surgery.

Methods:

Data were reviewed from 481 patients who underwent thoracic surgery for NSCLC between 2007 and 2012.

Results:

Patients with KRAS G12C developed significantly more bone metastases compared with the remainder of the cohort (59% vs 16%, P<0.0001). This was confirmed in multivariate analysis (MA) (odds ratio (OR): 0.113 (95% confidence interval (CI): 0.055–0.231), P<0.0001). Significantly, more patients with mEGFR developed liver and brain metastases compared with the remainder of the cohort (30% vs 10%, P=0.006; 59% vs 1%, P<0.0001, respectively). These were confirmed in MA (OR: 0.333 (95% CI: 0.095–0.998), P=0.05; OR: 0.032 (95% CI: 0.008–0.135), P<0.0001, respectively). Patients with KRAS G12V developed significantly more pleuro-pericardial metastases compared with the remainder of the cohort (94% vs 12%, P<0.0001). This was confirmed in MA (OR: 0.007 (95% CI: 0.001–0.031), P<0.0001). Wild-type patients developed significantly more lung metastases (35% vs 10%, P<0.0001). This was confirmed in MA (OR: 0.383 (95% CI: 0.193–0.762), P=0.006).

Conclusion:

Epidermal growth factor receptor mutation and KRAS amino acid substitutions seem to predict site-specific recurrence and metastasis after NSCLC surgery.

Circulating cell-free nucleic acids and platelets as a liquid biopsy in the provision of personalized therapy for lung cancer patients

Lung cancer is the predominant cause of cancer-related mortality in the world. The majority of patients present with locally advanced or metastatic non-small-cell lung cancer (NSCLC). Treatment for NSCLC is evolving from the use of cytotoxic chemotherapy to personalized treatment based on molecular alterations. Unfortunately, the quality of the available tumor biopsy and/or cytology material is not always adequate to perform the necessary molecular testing, which has prompted the search for alternatives. This review examines the use of circulating cell-free nucleic acids (cfNA), consisting of both circulating cell-free (tumoral) DNA (cfDNA-ctDNA) and RNA (cfRNA), as a liquid biopsy in lung cancer. The development of sensitive and accurate techniques such as Next-Generation Sequencing (NGS); Beads, Emulsion, Amplification, and Magnetics (BEAMing); and Digital PCR (dPCR), have made it possible to detect the specific genetic alterations (e.g. EGFR mutations, MET amplifications, and ALK and ROS1 translocations) for which targeted therapies are already available. Moreover, the ability to detect and quantify these tumor mutations has enabled the follow-up of tumor dynamics in real time. Liquid biopsy offers opportunities to detect resistance mechanisms, such as the EGFR T790M mutation in the case of EGFR TKI use, at an early stage. Several studies have already established the predictive and prognostic value of measuring ctNA concentration in the blood. To conclude, using ctNA analysis as a liquid biopsy has many advantages and allows for a variety of clinical and investigational applications.