Association of PD-L1 expression with driver gene mutations and clinicopathological characteristics in non-small cell lung cancer: A real-world study of 10 441 patients

BACKGROUND

Programmed death ligand-1 (PD-L1) expression is a well-known predictive biomarker of response to immune checkpoint blockade in non-small cell lung cancer (NSCLC). However, there is limited evidence of the relationship between PD-L1 expression, clinicopathological features, and their association with major driver mutations in NSCLC patients in Latin America.

METHODS

This retrospective study included patients from Argentina with advanced NSCLC, and centralized evaluation of PD-L1 expression concurrently with genomic alterations in the driver genes EGFR, ALK, ROS1, BRAF, and/or KRAS G12C in FFPE tissue samples.

RESULTS

A total of 10 441 patients with advanced NSCLC were analyzed. Adenocarcinoma was the most frequent histological subtype (71.1%). PD-L1 expression was categorized as PD-L1 negative (45.1%), PD-L1 positive low-expression 1%-49% (32.3%), and PD-L1 positive high-expression ≥50% (22.6%). Notably, current smokers and males were more likely to have tumors with PD-L1 tumor proportion score (TPS) ≥50% and ≥ 80% expression, respectively (p < 0.001 and p = 0.013). Tumors with non-adenocarcinoma histology had a significantly higher median PD-L1 expression (p < 0.001). Additionally, PD-L1 in distant nodes was more likely ≥50% (OR 1.60 [95% CI: 1.14-2.25, p < 0.01]). In the multivariate analysis, EGFR-positive tumors were more commonly associated with PD-L1 low expression (OR 0.62 [95% CI: 0.51-0.75], p < 0.01), while ALK-positive tumors had a significant risk of being PD-L1 positive (OR 1.81 [95% CI: 1.30-2.52], p < 0.01).

CONCLUSIONS

PD-L1 expression was associated with well-defined clinicopathological and genomic features. These findings provide a comprehensive view of the expression of PD-L1 in patients with advanced NSCLC in a large Latin American cohort.

Overcoming Resistance to Osimertinib by T790M Loss and C797S Acquisition Using Gefitinib in a Patient With EGFR-Mutant NSCLC: A Case Report

Limited strategies are available at disease progression on osimertinib for patients with EGFR-mutant NSCLC. The emergence of the on-target EGFR C797S mutation has been described as one of the most common mechanisms of resistance. In addition, loss of the EGFR T790M mutation has been mainly investigated as a resistance phenomenon to second-line osimertinib exposure. Remarkably, by studying the molecular profile at progression, it has been reported that the presence of the EGFR-sensitizing mutation, concurrently with the T790M, and C797S resulted in resistance to the current available EGFR tyrosine kinase inhibitors. Here, we report the first clinical evidence of gefitinib efficacy at EGFR exon 19 deletion/C797S mutation/T790M loss-mediated resistance to first-line osimertinib. Our findings highlight that dynamic genetic monitoring is a crucial approach in the evolution of EGFR-mutant NSCLC to understand the acquired molecular mechanisms for driving the best treatment strategy.

Implementation of a molecular tumour board in LATAM: the impact on treatment decisions for patients evaluated at Instituto Alexander Fleming, Argentina

BACKGROUND

The role of the molecular tumour board (MTB) is to recommend personalised therapy for patients with cancer beyond standard-of-care treatment. A comprehensive molecular analysis of the tumour in a molecular pathology laboratory is important for all targeted therapies approaches. Here we report the 1-year experience of the Instituto Alexander Fleming Molecular Tumour Board.

PATIENTS AND METHODS

The MTB of the Instituto Alexander Fleming was launched in December 2019 in a monthly meeting. In each interactive monthly session, five cases were presented and discussed by the members. These cases were referred by the treating oncologists. The MTB recommendations were sent to each physician individually, and to the rest of the meeting participants. This was discussed with the patients/families by the treating oncologist. The final decision to choose therapy was left to the treating physicians. Of the 32 patients presented at MTB, 28 (87.5%) had potentially actionable alterations and only 4 (12.5%) had no actionable mutation. Six (19%) patients received a local regulatory agency approved drug recommendation, nine (28%) patients received an off-label approval treatment recommendation and three (9%) patients did not receive the treatment due to access and reimbursement of the drug.

CONCLUSION

In most of the cases evaluated, the MTB was able to provide treatment recommendations based on targetable genetic alterations. Molecular-guided extended personalised patient care is effective for a small but clinically significant proportion of patients in challenging clinical situations. We believe that the implementation of a MTB is feasible in the Latin America (LATAM) region.

Assessment of early response to imatinib 800 mg after 400 mg progression by 18F-fluorodeoxyglucose PET in patients with metastatic gastrointestinal stromal tumors

ABSTRACT 

Introduction: Imatinib is the standard first-line therapy for advanced gastrointestinal stromal tumor. 18F-fluorodeoxyglucose PET computed tomography (FDG PET/CT) shows a faster response than computed tomography in nonpretreated patients. Patients & methods: After disease progression on imatinib 400 mg, 16 patients were exposed to 800 mg. Tumor response was evaluated by FDG PET/CT on days 7 and 37. Primary objective was to correlate early metabolic response (EMR) with progression-free survival (PFS). Results: EMR by FDG PET/CT scan was not predictive of PFS. Median PFS in these patients was 3 months. Overall survival was influenced by gastric primary site (p = 0.05). Conclusion: The assessment of EMR by FDG PET/CT in patients with advanced gastrointestinal stromal tumor exposed to imatinib 800 mg was not predictive of PFS or overall survival.

[Surgically treated bronchopulmonary carcinoid tumours. Prognostic value of TNM staging 7a edition]

We analyzed 43 women (61%) and 28 men (39%) surgically treated for carcinoid tumors from Jan/1975 to Dec/2011. Median age: 38 years (13-67). Typical carcinoid (TC) appeared in 63 (89%) patients, 8 (11%) suffered from atypical carcinoid (AC). Median follow-up: 4 years (1-24). TC stages were: IA = 33 (52%), IB = 10 (16%), IIA = 2 (3%), IIB = 2 (3%), IIIA = 12 (19%) and IIIB = 2 (3%); AC stages were: IA = 1 (12.5%), IIB = 1 (12.5%), IIIA = 2 (25%) and IIIB = 4 (50%). TNM classification did not show significant differences on 5-years survival period by stage (p = 0.689), even according to histological type (TC: p = 0.547; AC: p = 0.592). The disease-free survival rate was significantly lower (TC: 3 years vs. AC: 2 years, p = 0.000) and relapses were more frequent in AC (AC: 50% vs. TC: 2%, p = 0.000). The 7th TNM staging was not influential in estimating survival from carcinoid tumours in our population. The histological subtype was a better prognostic factor.

High-risk human papilloma virus infection, tumor pathophenotypes, and BRCA1/2 and TP53 status in juvenile breast cancer

Juvenile breast cancer is rare and poorly known. We studied a series of five breast cancer patients diagnosed within 25 years of age that included two adolescents, 12- and 15-years-old, and 3 young women, 21-, 21-, and 25-years-old, respectively. All cases were scanned for germline mutations along the entire BRCA1/2 coding sequences and TP53 exons 4-10, using protein truncation test, denaturing high performance liquid chromatography and direct sequencing. Paraffin-embedded primary tumors (available for 4/5 cases), and a distant metastasis (from the 15-years-old) were characterized for histological and molecular tumor subtype, human papilloma virus (HPV) types 16/18 E6 sequences and tumor-associated mutations in TP53 exons 5-8. A BRCA2 germline mutation (p.Ile2490Thr), previously reported in breast cancer and, as compound heterozygote, in Fanconi anemia, was identified in the 21-year-old patient diagnosed after pregnancy, negative for cancer family history. The tumor was not available for study. Only germline polymorphisms in BRCA1/2 and/or TP53 were detected in the other cases. The tumors of the 15- and 12-years-old were, respectively, classified as glycogen-rich carcinoma with triple negative subtype and as secretory carcinoma with basal subtype. The tumors of the 25-year-old and of the other 21-year-old were, respectively, diagnosed as infiltrating ductal carcinoma with luminal A subtype and as lobular carcinoma with luminal B subtype. No somatic TP53 mutations were found, but tumor-associated HPV 16 E6 sequences were retrieved from the 12- and 25-year-old, while both HPV 16 and HPV 18 E6 sequences were found in the tumor of the 15-year-old and in its associated metastasis. Blood from the 15- and 25-year-old, diagnosed with high-stage disease, resulted positive for HPV 16 E6. All the HPV-positive cases were homozygous for arginine at TP53 codon 72, a genotype associated with HPV-related cancer risk, and the tumors showed p16(INK4A) immunostaining, a marker of HPV-associated cancers. Notably menarche at 11 years was reported for the two adolescents, while the 25-year-old was diagnosed after pregnancy and breast-feeding. Our data suggest that high-risk HPV infection is involved in a subset of histopathologically heterogeneous juvenile breast carcinomas associated with menarche or pregnancy and breast-feeding. Furthermore we implicate BRCA2 in a juvenile breast carcinoma diagnosed at 21 years of age, 4 years after an early full-term pregnancy, in absence of cancer family history.

Surgical and non-surgical treatment of pulmonary metastases of soft tissue sarcomas

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Background: Several reports have shown a prolonged survival after surgery for lung metastases from soft tissue sarcomas (STS). This finding is in contrast with the results from chemotherapy. We performed a retrospective analysis to determine the impact of surgical and non surgical treatment in terms of time to progression (TTP) and disease specific survival (DSS). Methods: A review of 144 patients (pts) with STS treated at a single institution (december 1994-february 2005) was performed. Median age: 45 years old, female 53%. Extremity was the primary site in 54 pts and leiomyosarcoma was the most common histologic type (24%). In 42 pts pulmonary metastases were synchronous. The median disease free interval (DFI) was 11 months. Surgical treatment on the lung lesions was performed in 48 pts (group A), while 96 received medical treatment (group B). Results: Surgery was R0 in 90% of group A pts with only 4 lobectomies and 36 metastasectomies. Nine pts (19%) in this group received neo or adyuvant chemotherapy. The median TTP was 11 months (2–107) and 21 pts (44%) relapse in the lung (8 lung + other site). At the time of this analysis 13 pts (27%) are NED, with a DSS of 24 months for the surgical group. 28% remain alive at 5 years. In a univariate analysis only the number of lung metastases (1 vs 2 or more) was significant for DSS (p=0.05). Group B was treated primarily with chemotherapy being doxorubicin the most common drug used (89%). The RR was 23% with a median TTP of 3 months and a DSS of 12 months (1–98). Conclusions: The present results are similar with previous reports in terms of overall survival. Paliative chemotherapy showed modest activity and surgical treatment remains the only curative treatment modality for pts with lung metastases from STS.

No significant financial relationships to disclose.