W. Zhuang

Comparison of 22C3 PD-L1 Expression between Surgically Resected Specimens and Paired Tissue Microarrays in Non–Small Cell Lung Cancer

Introduction: The extent to which intratumoral heterogeneity of programmed death ligand 1 (PD‐L1) expression causes discordance of PD‐L1 expression between paired samples remains unclear. Here, PD‐L1 status was compared between whole sections from NSCLCs and the corresponding tissue microarrays (TMAs) serving as surrogate biopsy specimens. Methods: PD‐L1 expression was evaluated by 22C3 immunohistochemistry assay on 190 archival surgical specimens and matched to the TMA results. PD‐L1 expression was determined by the tumor proportion score (TPS) and classified as TPS lower than 1%, TPS of 1% to 49%, and TPS of 50% or higher. Agreement statistics were used. Results: The percentage of PD‐L1 expression on tumor cells differed greatly between individual TMAs and matched surgical specimens. When PD‐L1 TPS was adopted, a total of 36 of 190 discordance cases (18.9%) were observed, with a &kgr;‐value of 0.630 between paired samples. The TMAs underestimated or overestimated PD‐L1 status in 19 of 36 (52.8%) and 17 of 36 (47.2%) of the matched surgical specimens, respectively (p = 0.118). The discordance rate was much lower in cases with a PD‐L1 TPS lower than 1% compared with in cases with a TPS of 1% to 49% and TPS of 50% or higher (18.4% versus 56.7% and 43.3%, p < 0.001). When a TPS of 50% or higher was used as the cutoff, the discordance rate of PD‐L1 TPS less than 50% was further reduced to 7.5%. Such discrepancies were due mainly to intratumoral heterogeneity of PD‐L1 expression and nonsignificant association with clinicopathological features. Conclusions: PD‐L1 expression in TMAs correlates moderately well with that in the corresponding surgical specimens, indicating that evaluating PD‐L1 expression in diagnostic biopsy specimens could be misleading in defining sensitivity to pembrolizumab treatment yet may be reliable as a way to exclude patients with a PD‐L1 TPS less than 50% from first‐line pembrolizumab treatment.

Prognostic significance of PD-L1 expression and tumor infiltrating lymphocyte in surgically resectable non-small cell lung cancer

Programmed death ligand 1 (PD-L1) expression is a predictive biomarker of the success of PD-1/PD-L1 inhibitor therapy for patients with advanced non-small cell lung cancer (NSCLC) but its role as a prognostic marker for early stage resectable NSCLC remains unclear. Here, we studied PD-L1 expression and tumor infiltrating lymphocytes (TILs) in surgically resectable NSCLC and correlate the finding with clinicopathological features and patient outcomes. Total of 170 archival samples of resectable NSCLC were probed for PD-L1 expression using the clone 22C3 pharmDx kit. The PD-L1 expression was determined by the Tumor Proportion Score (TPS) and classified into TPS <1%, TPS 1 to 49% and TPS ≥50%. The scoring of TILs was from hematoxylin & eosin stained tissue sections using a system for standardized evaluation of TILs in breast cancer. PD-L1 expression was compared with clinical pathological characteristics and survival outcome. Expression of PD-L1 scores of TPS ≥50%, TPS 1 to 49% and TPS <1% were observed in 10.6%, 24.7% and 64.7% of the 170 archival samples, respectively. Positive PD-L1 expression was significantly higher in patients with squamous carcinoma, in those with higher TNM stage and with the presence of TILs. Neither the PD-L1 expression, TIL status, nor their combination was an independent prognosis biomarker of survival when the data was subjected to either univariate or multivariate analysis. The incidence of PDL1 expression appears to be lower in patient with early stage resectable lung cancer. PD-L1 expression and TILs are not prognostic indicators of survival outcome in this population.

Patients harboring ALK rearrangement adenocarcinoma after acquired resistance to crizotinib and transformation to small-cell lung cancer: a case report

Anaplastic lymphoma kinase (ALK) rearrangement responds to ALK tyrosine kinase inhibitors (TKIs) in lung cancer. Many cases ultimately acquire resistance to crizotinib. Resistance, including ALK-dominant or ALK non-dominant, mechanisms have been described. Transformation to small-cell lung cancer is rare. Herein, we report a 49-year-old man diagnosed with adenocarcinoma, who was negative for EGFR and ALK genes as detected by reverse transcription polymerase chain reaction, and was treated with crizotinib. A new biopsy showed a small-cell lung cancer after disease progression. Then, next-generation sequencing (NGS) was carried out and detected a TP53 gene mutation, an ALK rearrangement, and no loss of the retinoblastoma gene (RB). Although a regimen for small-cell lung cancer may be one treatment option, a heterogeneous tumor may exist at the time of diagnosis and manifest during the course of disease.

CEP72-ROS1: A novel ROS1 oncogenic fusion variant in lung adenocarcinoma identified by next-generation sequencing: CEP72-ROS1 in ADC identified by NGS

ROS1 rearrangement is a validated therapeutic driver gene in non‐small cell lung cancer (NSCLC) and represents a small subset (1–2%) of NSCLC. A total of 17 different fusion partner genes of ROS1 in NSCLC have been reported. The multi‐targeted MET/ALK/ROS1 tyrosine kinase inhibitor (TKI) crizotinib has demonstrated remarkable efficacy in ROS1‐rearranged NSCLC. Consequently, ROS1 detection assays include fluorescence in situ hybridization, immunohistochemistry, and real‐time PCR. Next‐generation sequencing (NGS) assay covers a range of fusion genes and approaches to discover novel receptor‐kinase rearrangements in lung cancer. A 63‐year‐old male smoker with stage IV NSCLC (TxNxM1) was detected with a novel ROS1 fusion. Histological examination of the tumor showed lung adenocarcinoma. NGS analysis of the hydrothorax cellblocks revealed a novel CEP72‐ROS1 rearrangement. This novel CEP72‐ROS1 fusion variant is generated by the fusion of exons 1–11 of CEP72 on chromosome 5p15 to exons 23–43 of ROS1 on chromosome 6q22. The predicted CEP72‐ROS1 protein product contains 1202 amino acids comprising the N‐terminal amino acids 594–647 of CEP72 and C‐terminal amino acid 1‐1148 of ROS1. CEP72‐ROS1 is a novel ROS1 fusion variant in NSCLC discovered by NGS and could be included in ROS1 detection assay, such as reverse transcription PCR. Pleural effusion samples show good diagnostic performance in clinical practice.

Comparison of the c-MET gene amplification between primary tumor and metastatic lymph nodes in non-small cell lung cancer

c‐MET has recently been identified as a promising novel target in non‐small cell lung cancer (NSCLC). We detected the consistency of c‐MET gene amplification in metastatic lymph nodes and tumor tissues of NSCLC patients and discuss the clinical application value of c‐MET gene amplification in metastatic lymph nodes.

Dual drive coexistence of EML4-ALK and TPM3-ROS1 fusion in advanced lung adenocarcinoma: ALK and ROS1 fusion in ADC

We report a case of concomitant EML4‐ALK and TPM3‐ROS1 fusion in non‐small cell lung cancer (NSCLC) in a 47‐year‐old Chinese man and review the clinical characteristics of this type double of fusion. The patient presented with a local tumor of the left upper lobe and underwent thoracoscopy. Postoperative surgical pathologic staging revealed T1aN0M0 stage IA. Histological examination of the tumor showed lung adenocarcinoma. Ventana ALK (D5F3) assay of the left lung tissue was ALK negative; however, immunohistochemical assay was positive for ROS1 protein. Using next generation sequencing, we found that the tumor had concomitant EML4‐ALK and TPM3‐ROS1 fusion. No recurrence was observed during seven months of follow‐up. Precise diagnostic techniques allow the detection of concomitant ROS1 fusion and other driver genes, including ALK or EGFR; therefore oncologists should consider this rare double mutation in NSCLC patients. Further exploration of treatment models is required to provide additional therapeutic options.

Clonally-related primary ALK rearranged adenocarcinoma and associated metastatic lesions: Primary and metastatic ADC: A case study

ALK rearrangement is a driver gene in non‐small cell lung cancer (NSCLC). ALK‐positive tumors are sensitive to ALK‐tyrosine kinase inhibitors (TKIs). The detection of key driver genes is crucial to enable personalized treatment. Different histomorphological patterns have different driver genes. Herein, we report the case of a 42‐year‐old male patient diagnosed with adenocarcinoma with different histomorphologies in the primary lung site (mucinous type) and lymph node metastasis (solid type), of the same genotype, both presenting with ALK rearrangement but negative for EGFR mutation. This histological heterogeneity did not necessarily indicate a genomic difference. Genomic analysis may be a supplement to the histological features of ALK‐rearranged tumors. These gene alterations could aid the choice of an appropriate TKI and predict therapeutic response.

Lung adenocarcinoma patient with EGFR 19 exon insert mutation and its response to icotinib

Non-small cell lung cancer (NSCLC) is still the leading cause of cancer-related deaths worldwide [1]. Epidermal growth factor receptor (EGFR) gene mutations as driver oncogenes were first identified in NSCLC in 2004 and common mutations are associated with benefits from tyrosine kinase inhibitors (TKIs) [2–6]. Therefore, EGFR mutation detection is a standard method in the management of NSCLC and it is crucial in the management of cases with common or unexpected genotyping results. Approximately 50% of Asian NSCLC patients have EGFR mutations [7]. The most common EGFR mutations are in-frame deletions of exon 19 (45% of all EGFR mutations) and point mutations in exon 21 p.L858R (35% of all EGFR mutations) [3,4]. Clinical trials have indicated that mutations involving exons 18–21, especially for sensitive EGFR mutations, benefit from EGFR-TKI therapy [3,5,6]. A study that explored the efficacy of EGFR-TKIs in patients with uncommon point mutations in exon 21 (at L861) and exon 18 (at G719) showed that the response rate was 57% [8]. Exon 19 insertion has been reported as a sensitive mutation in some studies [9–12]. Its prevalence is rare and it accounts for only 0.5–1% of all EGFR mutations [9,12]. Therefore, the clinical efficacy of EGFR-TKIs in patients with exon 19 insertion had never been reported in a large cohort. Also, the clinical responsiveness to EGFR-TKIs in Chinese patients is not clear. Due to the limitations of first-generation testing techniques, not all types of uncommon EGFR mutations are detected. Some EGFR-mutation-negative patients might be false negative and these patients could have poor prognosis because of not receiving EGFR-TKI treatment. With the development of accurate detection technologies, more uncommon EGFR mutations have been detected. Next-generation sequencing (NGS) technology is potentially eligible for emerging molecular therapeutics in NSCLC. Here, we report a case to indicate that advanced NSCLC harboring the EGFR exon 19 insertion (p.I740_K745insIPVAIK) is sensitive to icotinib. In February 2016, a 74-year-old Chinese male smoker presented to our hospital with cough and sputum for> 2 weeks. Computed tomography (CT) showed a mass in the right lower lung with right mediastinal lymph node metastasis more likely. Brain enhanced magnetic resonance imaging and abdominal CT. The patient underwent surgery and postoperative pathology showing invasive adenocarcinoma (Fig. 1). Immunohistochemical staining was positive for expression of thyroid transcription factor-1, NapsinA, and cytokeratin 7. Lymph node dissection showed first, second, third, fourth, and seventh group lymph node metastasis. According to the 7th edition of TNM staging, the patient was classified as stage IIIA (T3N2M0). So, he received the postoperative chemotherapy with six cycles of a TP regimen (paclitaxel 135mg/m on day 1; cisplatin 25mg/m on days 1–3). Unfortunately, during routine examination, we detected recurrence in the mediastinal and right supraclavicular lymph node metastasis on CT images indicated cancer progression (Fig. 2A), in January 2017. Wild-type variants of EGFR were detected by RT-PCR in tumor tissue. NGS showed that the EGFR gene was p.I740_K745insIPVAIK (Fig. 3) and BRCA2 p.C315S. Because of the rare occurrence, it might be related to response to EGFR-TKI therapy in January 2017. The patient received icotinib therapy, and CT assessment revealed partial response according to the Response Evaluation Criteria 1.1 in Solid Tumors (Fig. 2B). During icotinib therapy, he was 1 ° of liver dysfunction and there were no other treatment-related adverse events, including rash, gastrointestinal reactions, renal function, and cordis damage. After 13 months, the disease was stable and treatment was continued with icotinib. To the best of our knowledge, this was the first report of EGFR 19 insertion mutation and the effect of EGFR-TKI in Mainland China. Considering this rare type of EGFR mutation and having a good response to TKI therapy, we concluded the incidence of this EGFR gene rare mutation in NSCLC patients was reported before (Table 1 and Fig. 4). To ascertain the structure of EGFR exon 19 insertion, He et al. [9] performed a structural analysis that suggested that the substitution of a Pro for Leu at position 747 underlies the activating effect of the different exon 19 insertions. According to other reports, all patients with an exon 19 insertion had amino acid changes causing substitution of Leu at residue 747 by Pro [10,11,13]. Furthermore, the common exon 19 deletion mutation indicates that it also results in non-conservative substitutions of L747, often to Pro, Thr, or Ser. In addition, the exon 19 insertion might work the same as the exon 19 deletion and could explain the inhibitor sensitivity of these different alterations. In the Caucasian population, p.I744_K745insKIPVAI and p.K745_E746insVPVAIK were the most common types of EGFR exon 19 insertions according to these studies. Our case is the first indicating that p.I740_K745insIPVAIK has been found in a non-Caucasian patient. Due to the rarity of EGFR exon 19 insertions in the Chinese population, a larger sample size is needed to explore whether the types of EGFR 19 insertions differ between Chinese and Caucasian NSCLC patients. Our patient is believed to be the first EGFR 19 exon insert mutation to be treated with icotinib in China. A randomized, double-blind, multicenter, phase III study showed that icotinib, a potent and selective EGFR-TKI, was not inferior to gefitinib as second-line or third-line therapy for patients with advanced NSCLC, particularly in those with EGFR mutations [14,15]. Hence, some patients with uncommon EGFR mutations, such as exon 19 insertion, may show a good response to icotinib. However, this effect needs to be clarified in a large number of lung cancer patients with EGFR 19 insertions. We observed a good clinical response in a Chinese patient with EGFR exon 19 insertion. With the development of detection techniques, more uncommon EGFR mutations will be found and EGFR-TKI therapy should be considered in these rare populations.

Lung adenocarcinoma patient with an EGFR kinase domain duplication (KDD) and the response to icotinib

Non-small cell lung cancer (NSCLC) is the leading cause of cancer-related morbidity and mortality worldwide (1). Epidermal growth factor receptor ( EGFR ) mutations, as driver oncogenes, were first identified in NSCLC in 2004 (2).

TP53 mutations predict for poor survival in ALK rearrangement lung adenocarcinoma patients treated with crizotinib

Background Advanced non-small cell lung cancer (NSCLC) patients who harbor anaplastic lymphoma kinase (ALK) rearrangement are sensitive to an ALK inhibitor (crizotinib), but not all ALK-positive patients benefit equally from crizotinib treatment. We analyze the impact of TP53 mutations on response to crizotinib in patients with ALK rearrangement NSCLC. Methods Sixty-six ALK rearrangement NSCLC patients receiving crizotinib were analyzed. 21 cases were detected successfully by the next generation sequencing validation FFPE before crizotinib. TP53 mutations were evaluated in 8 patients in relation to disease control rate (DCR), objective response rate (ORR), progression-free survival (PFS) and overall survival (OS). Results TP53 mutations were observed in 2 (25.00%), 1 (12.50%), 1 (12.50%) and 4 (50.00%) patients in exons 5, 6, 7 and 8, respectively. The majority of patients were male (75.00%, 6/8), less than 65 years old (62.50%, 5/8) and never smokers (75.00%, 6/8). ORR and DCR for crizotinib in the entire case series were 61.90% and 71.43%, respectively. Statistically significant difference was observed in terms of PFS and OS between TP53 gene wild group and mutation group patients (P=0.038, P=0.021, respectively). Conclusions TP53 mutations reduce responsiveness to crizotinib and worsen prognosis in ALK rearrangement NSCLC patients.