ABSTRACT
Background and Objective: Immune checkpoint inhibition has shed light on a new era in cancer therapy, and randomized clinical trials have demonstrated that a meaningful portion of the overall population of metastatic gastric cancer (GC) patients may derive clinical benefit from immunotherapy, which raises the relevance in identifying predictive biomarkers. Programmed cell death-ligand 1 (PD-L1) expression has demonstrated a significant association between level of expression and the magnitude of benefit derived from immune checkpoint inhibition in GC. Nevertheless, this biomarker shows several pitfalls that must be considered in the therapeutic decision to incorporate immune checkpoint inhibition as the standard of care of GC, such as spatial and temporal heterogeneity, interobserver variability, immunohistochemistry (IHC) assay, and influence by chemotherapy or radiation therapy. Methods: In the present comprehensive review, we revised the main studies regarding PD-L1 evaluation in GC. Key Content and Findings: Here we describe the molecular characteristics of the tumor microenvironment in GC, the obstacles in the interpretation of PD-L1 expression and present the data of the clinical trials that have evaluated the efficacy and safety of immune checkpoint inhibition and the association with the biomarker expression, both in first-line and later lines of therapy. Conclusions: From the emerging predictive biomarkers for immune checkpoint inhibition, PD-L1 has demonstrated a meaningful association between level of expression in tumor microenvironment and the magnitude of benefit derived from immune checkpoint inhibition in GC.
ABSTRACT
BACKGROUND: Uterine carcinosarcoma is well known for its aggressive behavior. There is little evidence regarding the gold standard combination chemotherapy in metastatic or locally advanced carcinosarcoma, due to poor survival outcomes obtained with conventional scheduled chemotherapy. This case report represents the first-ever reported objective response to a metronomic chemotherapy regimen and adds to the current literature. CASE PRESENTATION: We describe a case of a Caucasian woman diagnosed with metastatic carcinosarcoma that had already been treated with multiple lines of conventional chemotherapy, with progressive disease. This patient had a surprising clinical and imaging response when treated with oral metronomic cyclophosphamide. CONCLUSIONS: We reviewed the mechanism of action implicated in metronomic chemotherapy, and correlated it with the biology of disease in carcinosarcoma. This information may add to the current literature, providing important insights to future clinical trials in this patient population.
Subject(s)
Antineoplastic Agents, Alkylating/administration & dosage , Antineoplastic Combined Chemotherapy Protocols , Carcinosarcoma/drug therapy , Cyclophosphamide/administration & dosage , Neoplasm Recurrence, Local/drug therapy , Peritoneal Neoplasms/drug therapy , Sarcoma, Endometrial Stromal/drug therapy , Uterine Neoplasms/drug therapy , Administration, Metronomic , Antineoplastic Agents, Alkylating/toxicity , Carcinosarcoma/pathology , Cyclophosphamide/toxicity , Drug Administration Schedule , Female , Humans , Middle Aged , Neoplasm Recurrence, Local/pathology , Peritoneal Neoplasms/secondary , Sarcoma, Endometrial Stromal/pathology , Treatment Outcome , Uterine Neoplasms/psychologyABSTRACT
Background. Neurofibromatosis type 1 is a genetic disorder caused by loss-of-function mutations in a tumor suppressor gene (NF1) which codifies the protein neurofibromin. The frequent genetic alterations that modify neurofibromin function are deletions and insertions. Duplications are rare and phenotype in patients bearing duplication of NF1 gene is thought to be restricted to developmental abnormalities, with no reference to cancer susceptibility in these patients. We evaluated a patient who presented with few clinical signs of neurofibromatosis type 1 and a conspicuous personal and familiar history of different types of cancer, especially lymphoproliferative malignancies. The coding region of the NF-1 gene was analyzed by real-time polymerase chain reaction and direct sequencing. Multiplex ligation-dependent probe amplification was performed to detect the number of mutant copies. The NF1 gene analysis showed the following alterations: mosaic duplication of NF1, TRAF4, and MYO1D. Fluorescence in situ hybridization using probes (RP5-1002G3 and RP5-92689) flanking NF1 gene in 17q11.2 and CEP17 for 17q11.11.1 was performed. There were three signals (RP5-1002G3conRP5-92689) in the interphases analyzed and two signals (RP5-1002G3conRP5-92689) in 93% of cells. These findings show a tandem duplication of 17q11.2. Conclusion. The case suggests the possibility that NF1 gene duplication may be associated with a phenotype characterized by lymphoproliferative disorders.
