Result card

  • CUR4: What is the natural course of the condition?

What is the natural course of the condition?

Authors: Sarah Baggaley, Massimo Gion

Internal reviewers: Luciana Ballini, Aurora Llanos, Antonio Migliore, Claudia Wild

The information used for this section was from an evidence-based guideline and cancer research charity websites.

Cancer begins when a cell or a group of cells start to grow and divide uncontrollably. This abnormal cell growth can occur when there are mutations in genes that are involved in cell growth or cell repair. Genes are segments of genetic code that provide the basic instructions that influence a cell’s behaviour. In healthy cells, when there is a gene mutation the cell repairs the mutation or dies. In cancer, cell repair and cell death do not occur so, as the cancer cell divides, the gene mutation(s) are passed on to the cell progeny. Some mutated genes are inherited (e.g. BRCA gene) but most mutations occur when cells divide or are created by environmental factors such as cigarette smoke {2}.

The natural progression of breast cancer differs greatly between patients. The two main categories of early breast cancer are in situ disease and invasive cancer. Breast cancer that is in situ is typically confined to the lobules (milk-producing glands) or ducts (tubes that carry the milk from the lobule to the nipple) of the breast. However, breast cancer in situ can progress from non-invasive (in situ) to invasive breast cancer and spread from the ducts or lobules, invading the surrounding tissues in the breast or other parts of the body {15}.

The main ways in which breast cancer can spread are by local spread to nearby tissues, or by regional or distant spread through the circulatory system or through the lymphatic system. In order for cancer to spread, cancer cells must become detached from the main tumour and be carried in the lymph to the lymph nodes or travel in the circulating blood until they get stuck in a capillary and invade the nearby tissue. When cancer cells spread and start to grow elsewhere in the body, the tumours are known as secondary tumours.

Circulating cancer cells can go undetected until a tumour starts to form and this is one of the reasons cancer can recur after the initial treatment. Another reason for cancer recurring is if cancer cells remain after the primary tumour has been removed.

The degree to which cancer has spread determines the stage of the disease and subsequent treatment. Typically, the more extensive the spread of cancer in the body then the more aggressive the treatment and the worse the patient’s prognosis {16}.

Baggaley S, Gion M Result Card CUR4 In: Baggaley S, Gion M Health Problem and Current Use of the Technology In: Jefferson T, Vicari N, Raatz H [eds.]. Prognostic tests for breast cancer recurrence (uPA/PAI-1 [FEMTELLE], MammaPrint, Oncotype DX ) [Core HTA], Agenzia nationale per i servizi sanitari regionali (, Italy ; 2013. [cited 7 February 2023]. Available from: