Cervical cancer. Light micrograph through a squamous cell (or epidermoid) carcinoma tumour of the cervix (red). This is a fairly common form of cancer. Risk factors are smoking, early age of first sexual intercourse and exposure to human papilloma virus (HPV), a common virus that can cause genital warts. Smear tests are used to check for pre-cancerous changes in the cervix. Cervical cancer is treatable with surgery, chemotherapy and radiotherapy. Sample stained with papanicolaou.