Comprehensive analysis of blood-based biomarkers for predicting immunotherapy benefits in patients with advanced non-small cell lung cancer

Background

This study aimed to investigate the feasibility of using circulating tumor cells (CTCs), peripheral blood cells (PBCs), and circulating cell-free DNA (cfDNA) as biomarkers of immune checkpoint inhibitor treatment response in patients with advanced non-small cell lung cancer (NSCLC).

Methods

We recruited patients diagnosed with advanced NSCLC who received pembrolizumab or atezolizumab between July 2019 and June 2020. Blood was collected before each treatment cycle (C1–C4) to calculate absolute neutrophil count (ANC), neutrophil-to-lymphocyte ratio (NLR), derived NLR (dNLR), and platelet-to-lymphocyte ratio (PLR). CTCs, isolated using the CD-PRIME^TM system, exhibited EpCAM/CK+/CD45− phenotype in BioViewCCBS^TM. The cfDNA was extracted from plasma at the beginning of C1 and C4.

Results

The durable clinical benefit (DCB) rate among 83 response-evaluable patients was 34%. CTC, PBC, and cfDNA levels at baseline (C1) were not significantly correlated with treatment response, although patients with DCB had lower CTC counts from C2 to C4. However, patients with low NLR, dNLR, PLR, and cfDNA levels at C1 had improved progression-free survival (PFS) and overall survival (OS). Patients with decreased CTC counts from C1 to C2 had higher median PFS (6.2 vs. 2.3 months; P=0.078) and OS (not reached vs. 6.8 months, P=0.021) than those with increased CTC counts. Low dNLR (≤2.0) at C1 and decreased CTC counts were independent factors for predicting survival.

Conclusions

Comprehensive analysis of CTC, PBC, and cfDNA levels at baseline and during treatment demonstrated they might be biomarkers for predicting survival benefit. This finding could aid in risk stratification of patients with advanced NSCLC who are undergoing immune checkpoint inhibitor treatment.

Hypersensitivity reactions to multiple anti-tuberculosis drugs

Objective

This study aimed to evaluate hypersensitivity reactions to anti-tuberculosis (TB) drugs.

Methods

We retrospectively compared the clinical manifestations and treatment outcomes of single and multiple drug hypersensitivity reactions (DHRs).

Results

Twenty-eight patients were diagnosed with anti-TB DHRs using oral drug provocation tests. Of these 28 patients, 17 patients (60.7%) had DHRs to a single drug and 11 (39.3%) had multiple DHRs. The median age of patients was 57.5 years (interquartile range [IQR], 39.2–73.2). Of the total patients, 18 patients (64.3%) were men. The median number of anti-TB drugs causing multiple DHRs was 2.0 (IQR 2.0–3.0). Rifampin was the most common drug that caused DHRs in both the single and multiple DHR groups (n = 8 [47.1%] and n = 9 [52.9%], respectively). The treatment success rate was lower in the multiple DHR group than in the single DHR group; however, the difference was not statistically significant (81.8% vs. 94.1%; P = 0.543).

Conclusions

Multiple anti-TB DHRs were common in all patients who experienced DHRs, and rifampin was the most common causative drug. The treatment outcomes appeared to be poorer in patients with multiple DHRs than in those with single DHRs.

Potentially fatal complications of systemic air embolism after computed tomography-guided transthoracic needle biopsy in lung cancer harboring epithelial growth factor receptor mutation: A case report

Air embolism is a rare, fatal complication of computed tomography (CT)‐guided transthoracic needle biopsy (TTNB) of the lung. Here, we report a patient who developed an air embolism after CT‐guided TTNB, which led to ST‐elevation myocardial infarction and acute cerebral ischemia. The patient recovered completely without critical sequelae and was diagnosed with adenocarcinoma harboring activating epidermal growth factor receptor (EGFR) mutation. The patient responded to subsequent treatment with gefitinib.

Key points

Signficant findings of the study

Air embolism is a rare, fatal complication of CT‐guided transthoracic lung biopsy. Only a few cases have been previously reported where myocardial and cerebral infarction occurred after TTNB, demonstrated not only on CT scan, but also electrocardiogram and electroencephalogram.

What this study adds

Detection of driver gene mutation is crucial for planning lung cancer treatment. Despite the need for tissue biopsy, air embolism propagation to vital organs could result in severe end‐organ damage and multidisciplinary approaches are needed to improve initial outcomes.

Abstract 5373: Circulating tumor cell as a predictive marker for immunotherapy in advnaced non-small cell lung cancer

Background: Circulating tumor cells (CTCs) have potential to provide minimally invasive way for the response monitoring of various cancer. This study aimed to investigate the feasibility of CTCs as a predictive marker for anti-PD-L1 immunotherapy in patients with advanced non-small cell lung cancer (NSCLC).

Methods: This study included 37 patients with advanced NSCLC receiving atezolizumab monotherapy as second-line or more from July to November 2019. Blood was collected in a K2-EDTA tube and CTCs were isolated and enriched by using CD-PRIMETM system which is antibody-independent size-based isolation method. By Bioview CCBS system, total CTCs (tCTCs) were identified by a sum of single EpCAM/CK-positive (sCTCs) and double EpCAM/CK-CD45-positive cells (dCTCs).

Results: Among 26 response-evaluable patients, objective response rate (ORR) and disease control rate (DCR) were 11.5% (3/26) and 57.7% (15/26), respectively. At cycle 1 (C1), patients with progression (PD) showed higher sCTC count (median, 8.6 vs. 4.3, p=0.065) and sCTC-to-tCTC ratio (median %, 35.9 vs. 9.8, p=0.024) than those without PD. During treatment, tCTC and sCTC count showed significant increase from C1 to C2 (p=0.019 and p=0.022). The subgroup with high sCTC increase from C1 to C2 (more than 2-folds) showed higher DCR than subgroup with low sCTC increase (less than 2-folds) (88.9% vs. 44.4%, p=0.066). Patients with high sCTC-to-tCTC ratio at C1 showed worse progression-free survival (median, 2.1 months) than those with low sCTC-to-tCTC ratio (not reached, hazard ratio 2.87, 95% confidence interval: 1.06-7.75, p=0.082).

Conclusion: The baseline sCTC count and sCTC increase (more than 2-folds) at the first 3-week after atezolizumab could be potential biomarkers to predict the disease progression and poor survival in advanced NSCLC.

Citation Format: Cheol-Kyu Park, Joon-Young Yoon, Min-Suk Kim, Bo-Gun Koh, Hyun-Ju Cho, In-Jae Oh, Young-Chul Kim. Circulating tumor cell as a predictive marker for immunotherapy in advnaced non-small cell lung cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5373.