We will need a detailed history of your symptoms and clinical examination for the same. Also will need to know about your family history related to cancer. Few investigations will be needed to perform and to judge if you need any endoscopy procedure or radiological test for diagnosis.
As far as weight loss is concerned cancer cachexia is associated with loss of appetite and is fairly rapid depending on stage of cancer.
Next Steps
Visit a surgical oncologist , do the required tests to diagnose objectively.
Health Tips
Kindly do not ignore the symptoms if they last more than a month.