Inclusion Criteria:
1. Age 18 years and above. There will be no upper age restriction. Because no dosing or adverse event data are currently available on the use of intraperitoneal paclitaxel in patients \<18 years of age, children are excluded from this study.
2. ECOG performance status ≤ 2 (Karnofsky ≥60%). Appendices 1 and 2.
3. Cytologic or histologic proof of adenocarcinoma of the stomach or gastroesophageal junction.
4. Adequate renal, and bone marrow function:
1. Leukocytes \>= 3,000/uL
2. Absolute neutrophil count \>= 1,500/uL
3. Platelets \>= 60,000/Ul
4. Serum creatinine \<= 1.6 mg/dL
5. Distant Metastatic Disease of peritoneum:
1. Positive peritoneal cytology, or
2. Carcinomatosis on diagnostic laparoscopy or laparotomy.
6. Completion of preoperative systemic cytotoxic chemotherapy. Targeted therapy, such as HER2 directed therapy, and immunotherapy, such as PD-1 inhibitors, may be continued.
7. English and non-English speaking patients are eligible.
Exclusion Criteria:
1. Distant metastatic disease not limited to the peritoneum such as solid organ metastases to the liver, central nervous system, or lung.
2. Infections such as pneumonia or wound infections that would preclude protocol therapy.
3. Women with a positive urine or serum pregnancy test are excluded from this study; women of childbearing potential (defined as those who are not postmenopausal defined as no menses in greater than or equal to 12 months, have not had a hysterectomy or bilateral salpingo-oophorectomy, do not have ovarian failure, or have not had a surgical sterilization procedure) must agree to refrain from breast-feeding and practice adequate contraception as specified in the informed consent. Adequate contraception consists of oral contraceptive, implantable contraceptives, injectable contraceptives, a double barrier method, or abstinence. Men with reproductive potential must agree to an appropriate method of birth control, including abstinence or double barrier method (diaphragm plus condom).
4. Subjects with unstable angina or New York Heart Association Grade II or greater congestive heart failure.
5. Subjects, such as those with cognitive impairment, deemed unable to comply with study and/or follow-up procedures.
6. Subjects with a known hypersensitivity to protocol systemic chemotherapy that was life-threatening, required hospitalization or prolongation of existing hospitalization, or resulted in persistent or significant disability or incapacity.
7. Previous surgery that would preclude safe cytoreduction and intraperitoneal port placement.
