Facts and Hopes on Cancer Immunotherapy for Small Cell Lung Cancer.

Platinum-based chemotherapy plus PD1 axis blockade is the standard of care in the first-line treatment of extensive-stage small cell lung cancer (SCLC). Despite the robust and consistent increase in long-term survival with PD1 axis inhibition, the magnitude of the benefit from immunotherapy seems lower than that for other solid tumors. Several immune evasive mechanisms have been shown to be prominently altered in human SCLC, including T-cell exclusion, downregulation of components of the MHC class I antigen processing and presentation machinery, or upregulation of macrophage inhibitory checkpoints, among others. New immunotherapies aiming to target some of these dominant immune suppressive features are being intensively evaluated preclinically and clinically in SCLC. They include strategies to enhance the efficacy and/or reverse features that promote intrinsic resistance to PD1 axis inhibition (e.g., restoring MHC class I deficiency and targeting DNA damage response) and novel immunomodulatory agents beyond T-cell checkpoint blockers (e.g., T cell-redirecting strategies, antibody-drug conjugates, or macrophage checkpoint blockers). Among them, delta-like ligand 3-targeted bispecific T-cell engagers have shown the most compelling preliminary evidence of clinical efficacy and hold promise as therapies that might contribute to further improve patient outcomes in this disease. In this study, we first provide a brief overview of key tumor microenvironment features of human SCLC. Then, we update the current clinical evidence with immune checkpoint blockade and review other emerging immunotherapy strategies that are gaining increasing attention in SCLC. We finally summarize our future perspective on immunotherapy and precision oncology for this disease.

Tumor-to-Tumor Metastasis: Lung Adenocarcinoma as a Recipient of Metastasis from Renal Cell Carcinoma: A Case Report.

BACKGROUND The occurrence of metastasis from one neoplasm to another is known as tumor-to-tumor metastasis (TTM). It is a rare phenomenon in the natural history of any neoplasm, with approximately 100 cases reported in the literature to date. The lungs are the most frequent metastatic tumor donors and kidney cancer is the most common recipient. However, the opposite phenomenon (lung adenocarcinoma as a recipient of metastasis from renal carcinoma) has not been previously reported in the literature. CASE REPORT We present the case of a man with a history of multiple neoplasms. He had a diffuse large B-cell lymphoma in 2006, a left papillary renal cell carcinoma (RCC) type 2 in 2006, and an acinar adenocarcinoma of the prostate in 2011. A follow-up computed tomography scan in July 2019 showed a suspicious lung nodule on the left upper lobe and a retroperitoneal hypermetabolic mass on the positron emission tomography scan. The lung nodule and retroperitoneal mass biopsies were consistent with a primary lung adenocarcinoma with a lepidic pattern and a metastatic RCC, respectively. In January 2020, he underwent a thoracoscopic left upper lobectomy and a mediastinal lymph node dissection. Histopathological evaluation revealed a 2-cm nodule composed of a lung adenocarcinoma with an intratumoral metastasis from a papillary RCC. To date, the patient has stable renal neoplastic metastatic disease and no locoregional recurrences of the lung adenocarcinoma. CONCLUSIONS Metastasis from one primary tumor to another primary tumor is an extremely unusual event. We report one of the first cases of an RCC metastasis to a primary lung adenocarcinoma.