Guanabana, known also as Graviola or Annona muricata is a tropical fruit which has been commonly used as complimentary/alternative medicine in Latin American countries. The main compounds in Graviola are the annonaceous acetogenins. These acetogenins have been shown to be selective and toxic against various types of cancer cells in-vitro and in-vivo experimental animal models. In spite of this evidence of anti tumor activity of Graviola, no prospective clinical studies have been carried out to determine if it also has clinical activity.The Investigator have observed two patients at Auxilio Mutuo Cancer Center who experienced significant tumor shrinkage while taking a tea made of Graviola leaves. Neither of these patients were taking any other treatment for their cancer. The investigator propose to conduct a study using guanabana leaves extract in patients with Gastroesophageal junction(GEJ) adenocarcinoma, as well as in Gastric adenocarcinoma, Hepatocellular carcinoma, Pancreatic adenocarcinoma, Low Grade Lymphomas and Colorectal adenocarcinoma.

Patients with relapsed/refractory gastric adenocarcinoma, adenocarcinoma of gastroesophageal junction, hepatocellular carcinoma, colorectal adenocarcinoma will be eligible. Colorectal adenocarcinomas will be eligible after failing second line therapy while the remainder will be eligible after first line therapy depending on the judgment of the treating oncologist. Any patient who refuse to receive chemotherapy will also be eligible even if they have not received chemotherapy. Patients with low grade lymphomas including chronic lymphocytic leukemias whose favorable blood counts and lack of symptoms make the candidates for "watch and wait" approach as well as any patient with low grade lymphoma who because of age or co-morbidity might not be eligible for chemotherapy or who refuse chemotherapy.

Inclusion Criteria:

• Understand and voluntarily sign an informed consent form.
• Age > 18 years at the time of signing the informed consent form.
• Willing and able to adhere to the study visit schedule and other protocol requirements.
• Must have measurable or evaluable disease.
• All previous cancer therapy, including radiation, hormonal therapy and surgery, must have been discontinued at least 2 weeks prior to treatment in this study.
• Performance status of ≤ 2 on the Eastern Cooperative Oncology Group (ECOG) scale at study entry.

Exclusion Criteria:

• Patients actively taking guanabana or guanabana tea daily or who have used it at some point after their diagnosis of cancer.
• Patients with Parkinson's disease.
• Serum Total Bilirubin ≥ 3.0 mg/dL
• Serum Creatinine level ≥ 3.0 mg/dL
• Central Nervous System (CNS) involvement.
• Known human immunodeficiency virus (HIV) infection; Known active hepatitis B or hepatitis C infection.
• Females who are pregnant (positive urine test) or breast-feeding females.
• Any history of a medical condition or a concomitant medical condition that, in the opinion of the investigator, would compromise the subject's ability to safely complete the study.