This is a multi-center, two-arm, parallel-group, triple-blind, phase 2-3 randomised controlled trial. All patients over the age TRANS of 15 from 5 types of cancer, acute lymphoid and myeloid leukemias MESHD myeloid leukemias HP, non-Hodgkin's lymphoma MESHD lymphoma HP, breast and colon cancer HP will enter the study. Patients are randomly assigned to two groups. During two months of treatment, the two groups are treated with either hydroxychloroquine or placebo. Patients will be monitored for COVID-19 symptoms. The primary end point of the study is to investigate the incidence of COVID-19 in patients.Randomisation will be performed using randomly permuted blocks. The allocation ratio in two groups is 1:1. Participants, caregivers, outcome assessor and the data analyst are blinded to group assignment.The calculated total sample size is 60 patients, with 30 patients in each group. The trial began on April 14, 2020 and recruitment is ongoing. Recruitment is anticipated to be completed by June 14, 2020. This trial has been registered on the Iranian Registry of Clinical Trials (IRCT) with the registration number of IRCT20200405046958N1.