Impact of EGFR mutations and KRAS amino acid substitution on the response to radiotherapy for brain metastasis of non-small-cell lung cancer

Stereotactic radiosurgery for post operative brain metastasic surgical cavities: a single institution experience

BACKGROUND

The standard therapy for brain metastasis was surgery combined with whole brain radiotherapy (WBRT). The latter is however, associated with important neurocognitive toxicity. To reduce this toxicity, postoperative stereotactic radiosurgery (SRS) is a promising technique. We assessed the efficacy and the tolerance to postoperative Gamma Knife radiosurgery (GK) on the tumor bed after resection of brain metastases.

METHODS

Between February 2011 and December 2016, following macroscopic complete surgical resection, 64 patients and 65 surgical cavities were treated by GK in our institution. The indication for adjuvant radiosurgery was a multidisciplinary decision. The main assessment criteria considered in this study were local control, intracranial metastasis-free survival (ICMFS), overall survival and toxicity.

RESULTS

Median follow-up: 11.1 months. Median time between surgery and radiosurgery: 35 days. Median dose was 20 Gy prescribed to the 50% isodose line, for a median treated volume of 5.6 cc. Four patients (7%) suffered from local recurrence. Local recurrence-free, intracranial recurrence-free and overall survival at 1 year were 97.5%, 57.6% and 62.4% respectively. In total, 23 patients (41%) suffered from intracranial recurrence outside the tumor bed. In univariate analysis: concomitant GK treatment of multiple lesions and the tumor bed was associated with a decrease in ICMFS (HR = 1.16 [1.005-1.34] p = 0.04). In multivariate analysis: a non-lung primary tumor was significantly associated with a decrease in ICMFS (HR = 8.04 [1.82-35.4] p = 0.006). An increase in performance status (PS) and in the initial number of cerebral metastases significantly reduced overall survival (HR = 5.4 [1.11-26.3] p = 0.037, HR = 2.7 [1.004-7.36] p = 0.049, respectively) and One radiation necrosis histologically proven.

CONCLUSION

Our study confirmed that postoperative GK after resection of cerebral metastases is an efficient and well-tolerated technique, to treat volumes of all sizes (0.8 to 40 cc). Iterative SRS or salvage WBRT can be performed in cases of intracranial relapse, postponing WBRT with its potential side effects.

Impact and clinical usefulness of genetic data in the surgical management of colorectal cancer liver metastasis: a narrative review

Importance

In patients who undergo surgery for colorectal cancer liver metastases (CRLM), a number of somatic mutations have been associated with worse overall (OS) and recurrence-free survival (RFS). Although useful, an association with prognosis does not necessarily equate to an impact on surgical management.

Objective

The aim of this review was to investigate whether the best-studied somatic mutations impact surgical management of CRLM by informing: (I) post-hepatectomy surveillance; (II) selection of surgical technique; (III) selection of optimal margin width; and (IV) selection of patients for surgery. Lastly, we discuss the refinement of genetic data from overall mutation status to specific variants, as well as lesser studied somatic mutations.

Evidence Review

We conducted a computerized search using PubMed and Google Scholar for reports published so far, using mesh headings and keywords related to genetic data and CRLM.

Findings

Genetic data may impact surgical management of CRLM in three ways. Firstly, KRAS mutations can predict lung recurrences. Secondly, KRAS mutations may help tailor margin width. Thirdly, KRAS mutations may help tailor surgical technique.

Conclusions

Although genetic data may impact post-hepatectomy surveillance, selection of surgical technique and optimal margin width, their use to guide surgical selection remains elusive, as the data cannot support denying surgery to patients according to their somatic mutation profile.

Role of immunotherapy and co-mutations on KRAS-mutant non-small cell lung cancer survival

Background

KRAS mutations reported in non-small cell lung cancer (NSCLC) represent a significant percentage of patients diagnosed with NSCLC. However, there still remains no therapeutic option designed to target KRAS. In an era with immunotherapy as a dominant treatment option in metastatic NSCLC, the role of immunotherapy in

KRAS

mutated patients is not clear.

Methods

Eligible patients diagnosed with NSCLC and found to have a KRAS mutation were identified in an institutional lung cancer database. Demographic, clinical, and molecular data was collected and analyzed.

Results

A total of 60 patients were identified for this retrospective analysis. Majority of patients were Caucasian (73%), diagnosed with stage IV (70%) adenocarcinoma (87%), and had a KRAS codon 12 mutation (78%). Twenty percent of patients were treated with immunotherapy. Median overall survival was 28 months in the cohort and patients who received immunotherapy were found to have better survival versus those who did not (33 vs. 22 months, P=0.31). Furthermore, there was an association between high survival and patients who received immunotherapy (P=0.007).

Conclusions

Patients with KRAS mutations have a unique co-mutation phenotype that requires further investigation. Immunotherapy seems to be an effective choice of treatment for KRAS positive patients in any treatment-line setting and yields better outcomes than conventional chemotherapy. The relationship between immunotherapy and KRAS mutations requires further studies to confirm survival advantage.

Response rate of patients with baseline brain metastases from recently diagnosed non-small cell lung cancer receiving radiotherapy according to EGFR, ALK and KRAS mutation status

Background

Previous studies have identified that patients with EGFR mutations tend to have better responses to targeted therapy, as well as chemotherapy; however, the effect of genetic alterations in terms of radiotherapy (RT)‐related outcomes has not been fully assessed. We studied the impact of common non‐small cell lung cancer (NSCLC) genetic alterations (EGFR, ALK and KRAS) in relation to objective response rate (ORR) to RT in patients with brain metastases.

Methods

From 2009–2015, 153 patients with an available genotyping status were treated with whole‐brain irradiation (WBI) before receiving systemic therapy. Primary outcome was ORR; secondary outcomes included intracranial progression‐free survival (IPFS) and overall survival (OS).

Results

Overall, ORR was 47.1%. ORR to RT varied significantly according to molecular status: EGFR (64.5%) ALK (54.5%) KRAS (20%) and WT (35.4%) (P = 0.001). EGFR mutation was the only independently associated factor for response to WBI (RR 3.52 [95% CI 1.6–7.7]; P = 0.002). Median IPFS was 10.8 months [95% CI 8.2–13.5] overall; however, IPFS also varied significantly according to molecular status: EGFR (18.2 months), ALK (18.4 months), KRAS (6.0 months) and WT (8.7 months) (P < 0.0001). OS for EGFR, ALK, KRAS and WT patients was 36.6, 32.2, 15.5 and 22.4 months, respectively (P = 0.014). Intracranial‐ORR (HR 0.4 [95% CI 0.2–0.6], P < 0.001) and mutation status (HR 0.7 [95% CI 0.6–0.9], P < 0.042) were independently associated with a higher OS.

Conclusions

RT response varies as per tumor molecular status. The presence of EGFR mutations favors the organ‐specific response to RT, and is associated with longer OS in patients with NSCLC and BM.

Key points

This study addressed for the first time the difference in radiotherapy‐related outcomes in patients with different genotypes of non‐small cell lung cancer (NSCLC) before they received systemic therapy.

Results show that response to radiotherapy varies as per tumor molecular status, particularly EGFR‐mutated tumors, have a favorable response to radiotherapy, contrary to KRAS‐mutated tumors.

KRAS-specific Amino Acid Substitutions are Associated With Different Responses to Chemotherapy in Advanced Non-small-cell Lung Cancer

BACKGROUND

Emerging data highlight different clinical behaviors according to KRAS amino acid substitutions (AASs) in patients with non-small-cell lung cancer (NSCLC). We aimed to evaluate whether different KRAS AASs were associated with different responses to chemotherapy.

PATIENTS AND METHODS

We retrospectively reviewed data from 1190 patients with KRAS mutations who underwent first-line platinum-based chemotherapy for stage IV NSCLC. The response to different chemotherapy regimens was evaluated using the Response Evaluation Criteria In Solid Tumors criteria (v 1.1). Overall survival and time to progression (TTP) were secondary endpoints.

RESULTS

Taxane was associated with the best response in the entire cohort (odds ratio, 2.52; 95% confidence interval [CI], 1.82-3.48; P < .001), especially in G12V patients (odds ratio, 2.15; 95% CI, 1.05-4.41; P = .036). Taxane was associated with improved TTP in the entire cohort (hazard ratio [HR], 0.31; 95% CI, 0.26-0.38; P < .001), especially in G13D patients (HR, 0.47; 95% CI, 0.22-1.01; P = .054). Pemetrexed was associated with the worst TTP in the entire cohort, particularly in G12V patients, who had the worst response rates (HR, 0.55; 95% CI, 0.30-0.99; P = .049). No impact on overall survival was observed according to different chemotherapy regimens and AASs.

CONCLUSION

KRAS-specific AAS appears to induce different responses to chemotherapy regimens after first-line platinum-based chemotherapy in advanced NSCLC.

Prognostic value of tumor mutations in radically treated locally advanced non-small cell lung cancer patients

Introduction

Chemo-radiation is standard treatment in locally advanced non-small cell lung cancers (NSCLC). The prognostic value of mutations has been poorly explored in this population.

RESULTS

Clinical data were collected from 190 patients and mutational profiles were obtained in 78 of them; 58 (74%) were males, 31 (40%) current smokers, 47/31 stage IIIA/IIIB and 40 (51%) adenocarcinoma. The following mutations were identified: EGFR 12% (9/78), KRAS 15% (12/78), BRAF 5% (3/65), PI3KCA 2% (1/57), NRAS 3% (1/32), and ALK+ (FISH) 4% (2/51). HER2 was not detected. Median follow-up was 3.1 years. Overall survival was evaluated by group; no significant differences were identified in median overall survival (p = 0.21), with 29.4 months for the EGFR/ALK group (n = 11), 12.8 months for other mutations (n = 17), and 23.4 months for wild-type (n = 50). The EGFR/ALK and other mutations groups had poorer median progression-free survival (9.6 and 6.0 months) compared to the wild-type group (12.0 months; multivariate hazard ratio 2.0 [95% CI, 0.9–4.2] and 2.8 [95% CI, 1.5–5.2] respectively, p = 0.003).

Materials and Methods

We retrospectively reviewed all patients receiving radical treatment for locally advanced NSCLC in a single institution between January 2002 and June 2013. Next generation sequencing was performed on DNA from paraffin-embedded tissue. ALK rearrangements were detected by immunohistochemistry and/or FISH. Mutational prognostic value for Kaplan-Meier survival parameters was determined by log-rank tests and Cox proportional hazards models.

Conclusions

Selected gene alterations may be associated with poorer progression-free survival in locally advanced radically treated NSCLC and their prognostic and/or predictive value merits further evaluation in a larger population.

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.

KRAS-mutation incidence and prognostic value are metastatic site-specific in lung adenocarcinoma: poor prognosis in patients with KRAS mutation and bone metastasis

Current guidelines lack comprehensive information on the metastatic site-specific role of KRAS mutation in lung adenocarcinoma (LADC). We investigated the effect of KRAS mutation on overall survival (OS) in this setting. In our retrospective study, 500 consecutive Caucasian metastatic LADC patients with known KRAS mutational status were analyzed after excluding 32 patients with EGFR mutations. KRAS mutation incidence was 28.6%. The most frequent metastatic sites were lung (45.6%), bone (26.2%), adrenal gland (17.4%), brain (16.8%), pleura (15.6%) and liver (11%). Patients with intrapulmonary metastasis had significantly increased KRAS mutation frequency compared to those with extrapulmonary metastases (35% vs 26.5%, p = 0.0125). In contrast, pleural dissemination and liver involvement were associated with significantly decreased KRAS mutation incidence (vs all other metastatic sites; 17% (p < 0.001) and 16% (p = 0.02) vs 33%, respectively). Strikingly, we found a significant prognostic effect of KRAS status only in the bone metastatic subcohort (KRAS-wild-type vs KRAS-mutant; median OS 9.7 v 3.7 months; HR, 0.49; 95% CI, 0.31 to 0.79; p  = 0.003). Our study suggests that KRAS mutation frequency in LADC patients shows a metastatic site dependent variation and, moreover, that the presence of KRAS mutation is associated with significantly worse outcome in bone metastatic cases.

KRAS exon 2 codon 13 mutation is associated with a better prognosis than codon 12 mutation following lung metastasectomy in colorectal cancer

Introduction

The utilization of molecular markers as routinely used biomarkers is steadily increasing. We aimed to evaluate the potential different prognostic values of KRAS exon 2 codons 12 and 13 after lung metastasectomy in colorectal cancer (CRC).

Results

KRAS codon 12 mutations were observed in 116 patients (77%), whereas codon 13 mutations were observed in 34 patients (23%). KRAS codon 13 mutations were associated with both longer time to pulmonary recurrence (TTPR) (median TTPR: 78 months (95% CI: 50.61–82.56) vs 56 months (95% CI: 68.71–127.51), P = 0.008) and improved overall survival (OS) (median OS: 82 months vs 54 months (95% CI: 48.93–59.07), P = 0.009). Multivariate analysis confirmed that codon 13 mutations were associated with better outcomes (TTPR: HR: 0.40 (95% CI: 0.17–0.93), P = 0.033); OS: HR: 0.39 (95% CI: 0.14–1.07), P = 0.07). Otherwise, no significant difference in OS (P = 0.78) or TTPR (P = 0.72) based on the type of amino-acid substitutions was observed among KRAS codon 12 mutations.

Materials and Methods

We retrospectively reviewed data from 525 patients who underwent a lung metastasectomy for CRC in two departments of thoracic surgery from 1998 to 2015 and focused on 150 patients that had KRAS exon 2 codon 12/13 mutations.

Conclusions

N2-IIIA non-small cell lung cancer: a plea for surgery!

Management of stage IIIA-N2 non-small cell lung cancer is still matter of ongoing controversy. The debate is flawed by the heterogeneity of this group of patients, lack of strong evidence from controlled trials, diverging treatment strategies, and hesitating estimation of prognosis. Surgery is credited a survival advantage in a trimodality setting. For many teams, N2 is by principle managed with induction chemotherapy, followed by surgery if the patient is down-staged. However, surgery remains a suitable option even in case of persistent N2. On the other hand, outcomes are comparable, regardless whether chemotherapy has been given as induction or adjuvant treatment. Hence, upfront surgery without invasive staging, followed by adjuvant therapies, appears reasonable in resectable single station N2 disease, simplifying patient care and reducing cost. We expect that molecular biomarkers will improve estimation of prognosis and patient selection in the future.

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.

Radiotherapy plus EGFR TKIs in non-small cell lung cancer patients with brain metastases: an update meta-analysis

Brain metastasis (BM) is the common complication of non‐small cell lung cancer (NSCLC) with a poor prognosis and dismal survival rate. This update meta‐analysis aimed to derive a more precise estimation of radiotherapy plus epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) in NSCLC patients with BM. PubMed, EMBASE, Web of Science, Google Scholar, and Cochrane Library were searched to identify any relevant publications. After screening the literature and undertaking quality assessment and data extraction, the meta‐analysis was performed using STATA Version 12.0. In total, 15 studies involving 1552 participants were included. The results indicated that radiotherapy plus EGFR TKIs was more effective at improving response rate and disease control rate (DCR) (risk ratio (RR) = 1.48, 95% confidence interval [CI]: 1.12–1.96, P = 0.005; RR = 1.29, 95% CI: 1.02–1.60, P = 0.035; respectively) than radiotherapy alone or plus chemotherapy. Moreover, radiotherapy plus EGFR TKIs significantly prolonged the time to central nervous system progression (CNS‐TTP) (HR = 0.56, 95% CI [0.33, 0.80]; P = 0.000) and median overall survival (OS) (HR = 0.58, 95% CI [0.42, 0.74]; P = 0.000) but significantly increased adverse events (any grade) (RR = 1.25, 95% CI [1.01, 1.57]; P = 0.009), especially rash and dry skin. These results suggested that radiotherapy plus EGFR TKIs produced superior response rate and DCR and markedly prolonged the CNS‐TTP and OS of NSCLC patients with BM. However, combined groups had the higher rate of incidence of overall adverse effects, especially rash and dry skin.