Immunological modifications following chemotherapy are associated with delayed recurrence of ovarian cancer.

Introduction: Ovarian cancer recurs in most High Grade Serous Ovarian Cancer (HGSOC) patients, including initial responders, after standard of care. To improve patient survival, we need to identify and understand the factors contributing to early or late recurrence and therapeutically target these mechanisms. We hypothesized that in HGSOC, the response to chemotherapy is associated with a specific gene expression signature determined by the tumor microenvironment. In this study, we sought to determine the differences in gene expression and the tumor immune microenvironment between patients who show early recurrence (within 6 months) compared to those who show late recurrence following chemotherapy. Methods: Paired tumor samples were obtained before and after Carboplatin and Taxol chemotherapy from 24 patients with HGSOC. Bioinformatic transcriptomic analysis was performed on the tumor samples to determine the gene expression signature associated with differences in recurrence pattern. Gene Ontology and Pathway analysis was performed using AdvaitaBio's iPathwayGuide software. Tumor immune cell fractions were imputed using CIBERSORTx. Results were compared between late recurrence and early recurrence patients, and between paired pre-chemotherapy and post-chemotherapy samples. Results: There was no statistically significant difference between early recurrence or late recurrence ovarian tumors pre-chemotherapy. However, chemotherapy induced significant immunological changes in tumors from late recurrence patients but had no impact on tumors from early recurrence patients. The key immunological change induced by chemotherapy in late recurrence patients was the reversal of pro-tumor immune signature. Discussion: We report for the first time, the association between immunological modifications in response to chemotherapy and the time of recurrence. Our findings provide novel opportunities to ultimately improve ovarian cancer patient survival.

A Case Report on Pearson Syndrome With Emphasis on Genetic Screening in Patients Presenting With Sideroblastic Anemia and Lactic Acidosis.

Pearson marrow-pancreas syndrome is a rare multisystem mitochondrial disease that is a result of defective oxidative phosphorylation caused by mitochondrial DNA mutations. The average prognosis of infants diagnosed with this disease is death within four years of age. The disease often carries an atypical presentation during the neonatal period causing this rare syndrome to be frequently misdiagnosed. The current report details the diagnosis of Pearson syndrome in a three-month-old male with a history of pancytopenia.