PRIMARY OBJECTIVES:~I. Atezolizumab in combination with oxaliplatin and fluorouracil (5-FU) (modified fluorouracil/leucovorin calcium/oxaliplatin [FOLFOX]) therapy in the neoadjuvant setting will achieve a pathological complete response of approximately 20% in patients with localized esophageal and gastroesophageal (gastroesophageal junction [GEJ]) adenocarcinoma.~SECONDARY OBJECTIVES:~I. To evaluate safety and toxicity profile of intravenous atezolizumab in combination with oxaliplatin and 5-FU therapy.~II. To assess the efficacy of the combination by tumor regression grade scoring in the surgical specimen.~III. To assess the overall safety and tolerability of adjuvant atezolizumab in subjects with resected esophageal and GEJ cancer.~IV. To evaluate disease free survival (DFS) and overall survival (OS). V. To explore changes in tumor stroma profile before and after immunotherapy in combination with chemotherapy.~OUTLINE:~Patients receive oxaliplatin intravenously (IV) over 2 hours, fluorouracil IV continuously over 48 hours, and atezolizumab IV over 30-60 minutes on days 1 and 15. Treatment repeats every 28 days for 3 courses in the absence of disease progression or unacceptable toxicity. Within 4-6 weeks of treatment completion, patients undergo surgical resection. Beginning 6 weeks after surgery, patients continue to receive oxaliplatin IV over 2 hours, fluorouracil IV continuously over 48 hours, and atezolizumab IV over 30-60 minutes on days 1 and 15. Treatment repeats every 28 days for 3 courses in the absence of disease progression or unacceptable toxicity. Patients then receive atezolizumab monotherapy IV over 30-60 minutes on day 1. Treatment repeats every 21 days for up to 4 courses in the absence of disease progression or unacceptable toxicity.~After completion of study treatment, patients are followed up for 90 days and then every 3 months thereafter.
This early phase I trial studies how well atezolizumab in combination with oxaliplatin and fluorouracil works in treating patients with esophageal or gastroesophageal cancer. Immunotherapy with monoclonal antibodies, such as atezolizumab, may help the body's immune system attack the cancer, and may interfere with the ability of tumor cells to grow and spread. Drugs used in chemotherapy, such as oxaliplatin and fluorouracil, work in different ways to stop the growth of tumor cells, either by killing the cells, by stopping them from dividing, or by stopping them from spreading. Giving atezolizumab, oxaliplatin, and fluorouracil may work better in treating patients with esophageal or gastroesophageal cancer.