Introduction

So stark a chapter title befits the subject. Even today, with the outlook for many malignancies dramatically improved, the word ‘cancer’ can strike fear into many hearts. Any attempt to over-simplify the subject would be facile, but there are a few basic rules. Cancer implies a malignant growth or tumour, although the word ‘tumour’ actually means a swelling or lump, and many tumours are benign, the majority (but not all) remaining so. For a tumour to be malignant (cancerous) its method of cell division and replication becomes disordered and goes out of control, a cellular Sorcerer's Apprentice. Human tissues are living and shed old cells to replace them with new ones but in an orderly, even pre-ordained, fashion.

Two definitive features of cancer are, firstly, that it invades neighbouring tissues and structures and, secondly, that it spreads to remote organs by the blood or the lymphatic systems to cause secondary deposits (metastases). The detailed classification of malignant tumours is complex. It is reasonable to simplify it. Malignant tumours arising from lining surfaces are carcinomas, and those from connective tissues such as fat or bone are sarcomas. To subdivide again, lining tissues are the epithelium (e.g. skin, mouth, gullet) and endothelium, including the lining of the gastrointestinal tract from stomach to rectum. Then there are cancers arising from more specialised tissues, particularly the nervous system. A survival rate is the percentage of patients still alive years after treatment for that growth. Achieving these benchmarks often reassures patients enormously. There are sarcomas for which a survival of two years after therapy almost behoves a cure. For other tumours that may be achieved within five.

Treatment can readily be classified. Surgery may involve just a local excision, or removal of part or all of an organ and lastly of the total structure, plus a more extensive dissection, removing surrounding tissues. Modern scanning techniques (e.g. CT, MRI and PET) now enable doctors to accurately define the edges of a growth and plan treatment accordingly. Surgery is often supplemented or even supplanted by radiation (radiotherapy) and/or by anti-cancer drugs (chemotherapy). These are sometimes given in conjunction with one another.