Key Questions - Cancer Care
Dion Smyth is lecturer practitioner in cancer and palliative care, University of Central England.
Will human papilloma virus (HPV) vaccination prevent cervical cancer?
Recurrent or persistent infections with strains of HPV that cause changes to the lining of the cervix can increase the risk of developing pre-cancerous lesions or cancer. Two recently developed vaccines have been shown to protect against the two strains most commonly associated with cervical cancer (type 16 and 18). These strains are implicated in over 70% of cases, so it is hoped vaccination will prevent many of the cases developing. However, vaccination will not replace screening, as other strains of HPV are still implicated and it is still not clear how long the immunity conferred by inoculation will last.
What are tumour markers?
Tumour markers, such as cancer antigen 125 (CA-125), are substances, usually proteins, which are produced either directly by the malignant growth or by the body’s tissue reaction to the presence of cancer. Many are not specific to cancer or even to particular types of cancer so they cannot be used as a diagnostic test. However, raised levels may signify the existence or recurrence of cancer, so they may be used to monitor response to treatment.
How is lymphoma staged?
Hodgkin’s disease and non-Hodgkin’s lymphoma use the Ann Arbor system for classifying the extent of the spread of the disease.
Stage 1 disease is limited to one group of lymph nodes above or below the diaphragm, or disease that is confined to one organ or site other than the lymph nodes. Stage 2 is where two or more groups of lymph nodes are affected, or an organ and one or more groups of lymph nodes are involved, but both of these instances are still on only one side of the diaphragm. Stage 3 involves disease above and below the diaphragm, while stage 4 lymphoma is diffuse, involving other organs such as the bone marrow and liver.
What are the signs and symptoms of malignant superior vena cava obstruction (SVCO)?
The thin-walled great vein is surrounded by relatively rigid structures in the thorax and has low intravascular pressure as the blood returns to the heart. As such, it is easy to compress by primary tumours and enlarged lymph nodes or become blocked by clots forming in the lumen, particularly around structures such as central venous catheters. The most common cause in patients with cancer is a primary lung tumour in the region adjacent to the trachea but any cancer spreading to the mediastinal nodes, particularly lymphomas, may cause SVCO. The patient presents with a flushed, swollen face, neck and arms, and complains of headache, feeling of fullness in the head and visual disturbances. Dyspnoea may occur but is usually associated with the underlying condition. Jugular veins may be engorged and collateral veins will be visible on the chest wall.
What is the WHO analgesic ladder?
Pain occurs in about a third of all patients receiving anti-cancer treatment and two-thirds of those receiving palliative care. The World Health Organization (WHO) described a sequential and systematic order of drug use for the management of cancer pain. This suggests the initial use of non-opioid analgesia, with or without adjuvant drugs as indicated (such as steroids to reduce swelling). If this is inadequate, an opioid for mild to moderate pain should be tried in conjunction with the non-opioid drug (+/- the adjuvant drug). Where this is insufficient, an opioid for moderate to severe pain should be substituted.