The expression of PD-1 ligand 1 on macrophages and its clinical impacts and mechanisms in lung adenocarcinoma.

Programmed cell death-1 (PD-1) and PD-1 ligand 1 (PD-L1) are target molecules for immunotherapy in non-small cell lung cancer. PD-L1 is expressed not only in cancer cells, but also on macrophages, and has been suggested to contribute to macrophage-mediated immune suppression. We examined the clinical significance of PD-L1 expression on macrophages in human lung adenocarcinoma. The mechanism of PD-L1 overexpression on macrophages was investigated by means of cell culture studies and animal studies. The results showed that high PD-L1 expression on macrophages was correlated with the presence of EGFR mutation, a lower cancer grade, and a shorter cancer-specific overall survival. In an in vitro study using lung cancer cell lines and human monocyte-derived macrophages, the conditioned medium from cancer cells was found to up-regulate PD-L1 expression on macrophages via STAT3 activation, and a cytokine array revealed that granulocyte-macrophage colony-stimulating factor (GM-CSF) was a candidate factor that induced PD-L1 expression. Culture studies using recombinant GM-CSF, neutralizing antibody, and inhibitors indicated that PD-L1 overexpression was induced via STAT3 activation by GM-CSF derived from cancer cells. In a murine Lewis lung carcinoma model, anti-GM-CSF therapy inhibited cancer development via the suppression of macrophage infiltration and the promotion of lymphocyte infiltration into cancer tissue; however, the PD-L1 expression on macrophages remained unchanged. PD-L1 overexpression on macrophages via the GM-CSF/STAT3 pathway was suggested to promote cancer progression in lung adenocarcinoma. Cancer cell-derived GM-CSF might be a promising target for anti-lung cancer therapy.

SPP1 Derived from Macrophages Is Associated with a Worse Clinical Course and Chemo-Resistance in Lung Adenocarcinoma.

Osteopontin, also called secreted phosphoprotein 1 (SPP1), is a multifunctional secreted phosphorylated glycoprotein. SPP1 is also expressed in tumor cells, and many studies demonstrated that a high level of circulating SPP1 is correlated with a poor prognosis in various cancers. SPP1 is expressed not only by tumor cells but also by stromal cells, such as macrophages. However, there have been no studies distinguishing the SPP1 expression of cancer cells and tumor-associated macrophages (TAMs). Thus, in this study, we tried to accurately evaluate the SPP1 expression status on cancer cells and TAMs separately in patients with non-small cell lung cancer by using double immunohistochemistry. We demonstrated that high SPP1 expression on TAMs predicted a poor prognosis in lung adenocarcinoma patients. Additionally, we investigated the expression mechanisms related to SPP1 using human-monocyte-derived macrophages and revealed that the SPP1 expression level increased in macrophage differentiation mediated by granulocyte-macrophage colony-stimulating factor. Furthermore, SPP1 contributed to anti-cancer drug resistance in lung cancer cell lines. In conclusion, SPP1 production on TAMs predicted a poor prognosis in lung adenocarcinoma patients, and TAM-derived SPP1's involvement in the chemo-resistance of cancer cells was suggested.

Association of Probiotic Clostridium butyricum Therapy with Survival and Response to Immune Checkpoint Blockade in Patients with Lung Cancer.

Gut dysbiosis caused by antibiotics impairs response to immune checkpoint blockade (ICB). Gut microbiota is becoming an attractive therapeutic target for cancer. The Clostridium butyricum MIYAIRI 588 strain is a probiotic therapy used to improve symptoms related to antibiotic-induced dysbiosis in Japan. We hypothesized that probiotic Clostridium butyricum therapy (CBT) may affect the therapeutic efficacy of ICBs. We retrospectively evaluated 118 patients with advanced non-small cell lung cancer treated with ICBs at Kumamoto University Hospital (Kumamoto-shi, Kumamoto, Japan). Survival analysis comparing patients given CBT before and/or after ICB was conducted using univariate analyses and Cox proportional hazards regression models using propensity score. Propensity score analyses confirmed that probiotic CBT significantly prolonged progression-free survival (PFS) and overall survival (OS). Probiotic CBT significantly associated with longer PFS and OS even in patients who received antibiotic therapy. This study suggests that probiotic CBT may have a positive impact on therapeutic efficacy of ICB in patients with cancer.See articles by Hakozaki et al., p. 1243, and Peng et al., p. 1251.

Non-small-cell Lung Cancer with Severe Skin Manifestations Related to Radiation Recall Dermatitis after Atezolizumab Treatment.

Radiation recall dermatitis (RRD) is an inflammatory reaction that occurs at previously irradiated skin regions after drug administration. We herein report a patient with non-small-cell lung cancer treated previously with thoracic radiotherapy who developed severe RRD induced by atezolizumab [anti-programmed death 1 ligand 1 (PD-L1) antibody]. Immunohistochemistry of the skin biopsy showed dermatitis with infiltration of CD8+ lymphocytes, suggesting that atezolizumab might provoke an immune-related inflammatory reaction at previously irradiated skin regions. When administering anti-PD-L1 antibody to patients who have undergone radiotherapy previously, physicians should carefully monitor the irradiated skin for the potential occurrence of RRD.

Small Cell Lung Cancer Derived from Adenocarcinoma with Mutant Epidermal Growth Factor Receptor Provides a Signature of Transcriptional Alteration in Tumor Cells.

Small cell lung cancer (SCLC) transformation of epidermal growth factor receptor (EGFR) mutant adenocarcinoma (ADC) during EGFR tyrosine kinase inhibitor (TKI) treatment is an example of a rare subset of acquired drug resistance. We herein report the case of a 75-year-old man treated with afatinib who was then diagnosed with SCLC transformation. After two years of successful treatment with afatinib, the tumor relapsed, and a re-biopsy revealed SCLC harboring EGFR exon 19 deletion. We encountered a case of transcriptional alteration, potentially important for SCLC transformation of EGFR mutant lung ADC, that was recognized via the expression of NOTCH, ASCL1 and RB1 on immunohistochemical staining.

Disorder of Coagulation-Fibrinolysis System: An Emerging Toxicity of Anti-PD-1/PD-L1 Monoclonal Antibodies.

A disruption of immune checkpoints leads to imbalances in immune homeostasis, resulting in immune-related adverse events. Recent case studies have suggested the association between immune checkpoint inhibitors (ICIs) and the disorders of the coagulation-fibrinolysis system, implying that systemic immune activation may impact a balance between clotting and bleeding. However, little is known about the association of coagulation-fibrinolysis system disorder with the efficacy of ICIs. We retrospectively evaluated 83 lung cancer patients who received ICI at Kumamoto University Hospital. The association between clinical outcome and diseases associated with disorders of the coagulation-fibrinolysis system was assessed along with tumor PD-L1 expression. Among 83 NSCLC patients, total 10 patients (12%) developed diseases associated with the disorder of coagulation-fibrinolysis system. We found that disorders of the coagulation-fibrinolysis system occurred in patients with high PD-L1 expression and in the early period of ICI initiation. In addition, high tumor responses (72%) were observed, including two complete responses among these patients. Furthermore, we demonstrate T-cell activation strongly induces production of a primary initiator of coagulation, tissue factor in peripheral PD-L1high monocytes, in vitro. This study suggests a previously unrecognized pivotal role for immune activation in triggering disorders of the coagulation-fibrinolysis system in cancer patients during treatment with ICI.

Reversible Restrictive Lung Disease in Pseudomesotheliomatous Carcinoma in a Lung Harboring a HER2-mutation.

Pseudomesotheliomatous carcinoma of the lung is very rare, and reversible restrictive lung disease with pseudomesotheliomatous carcinoma has not yet been previously reported. We herein report a patient with HER2-positive non-small-cell lung cancer (NSCLC) showing pseudomesotheliomatous carcinoma who was successfully treated with bevacizumab combination chemotherapy. A 56-year-old Japanese woman with advanced NSCLC presented with dyspnea. We administered chemotherapy with cisplatin (75 mg/m2) plus pemetrexed (500 mg/m2) plus bevacizumab (15 mg/kg), followed by pemetrexed plus bevacizumab. After eight cycles of maintenance chemotherapy, chest CT demonstrated a marked tumor reduction and an improvement of the right lung volume. The vital capacity was thereafter found to have significantly increased according to pulmonary function tests.

Successful treatment by pembrolizumab in a patient with end-stage renal disease with advanced non-small cell lung cancer and high PD-L1 expression.

We report a 66-year-old Japanese male with end-stage renal disease (ESRD) and advanced non-small cell lung cancer (NSCLC) who was on hemodialysis. The patient harbored high programmed death ligand 1 (PD-L1) expression and was successfully treated with pembrolizumab. Laboratory examination upon diagnosis showed elevated serum creatinine (6.58 mg/dL). We administered pembrolizumab (200 mg/body) and repeated every 3 weeks. His renal dysfunction gradually progressed, hemodialysis was initiated after eight courses of pembrolizumab, and the antitumor effect was maintained at five months after hemodialysis initiation. Therefore, pembrolizumab can be administered for patients with ESRD and advanced NSCLC, who harbor high PD-L1 expression, during preparation for hemodialysis.

Long-term complete response to carboplatin plus paclitaxel combined with bevacizumab in a patient with metastatic spindle cell carcinoma.

We report the case of a 62-year-old Japanese male with metastatic spindle cell carcinoma (SpCC) who showed a long-term complete response (CR) to bevacizumab combination chemotherapy. We performed chemotherapy with carboplatin (AUC 6, day 1) plus paclitaxel (200mg/m2, day 1) plus bevacizumab (15mg/kg, day 1) for four cycles. After the chemotherapy, CT imaging demonstrated a CR. We subsequently administered bevacizumab (15mg/kg) repeated every 3 weeks as maintenance therapy for 12 cycles. The patient discontinued maintenance chemotherapy because of grade 3 proteinuria, but the anti-tumor effect of CR was maintained at 35 months after the discontinuation of chemotherapy.