Textbook of Medical-Surgical Nursing 3e

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Unit 3   Applying concepts from the nursing process

(18,560 cases), bowel cancer (15,840), breast cancer (14,680), melanoma of the skin (12,510) and lung cancer (11,280) (Australian Institute of Health Welfare [AIHW], 2012). The most commonly registered cancer in 2009 in New Zealand was prostate cancer (16.1%), followed by colorectal and cancer of the breast. Among males, prostate cancer was the most commonly registered cancer (30.2% of male registrations), and among females, breast cancer was the most commonly regis- tered cancer (28.4% of all female registrations (New Zealand Ministry of Health, 2009). The Australian Institute of Health Welfare [AIHW] (2012) reported that in 2003 the risk of a cancer diagnosis for men before the age of 75 was 1 in 3 and before 85 was 1 in 2. For women, the risk was 1 in 4 before the age of 75 and a 1 in 3 risk before the age of 85. The cancer death rate among Indigenous Australians was estimated to be 40% higher than the total non-Indigenous population. In New Zealand, Ma¯ori have a disproportionate risk of cancer (Cancer Control New Zealand [CCNZ], 2005). In 2005, 1377 cancer registrations (598 males and 779 females) and 760 deaths (369 males and 391 females) from cancer were Ma¯ori and for Pacific peoples, there were 575 registrations (267 males and 308 females) and 244 deaths (115 males and 129 females). Ma¯ori males have a cancer death rate that is 53.2% higher than the non-Ma¯ori male rate, while the Ma¯ori female rate is 70% higher than the non-Ma¯ori female rate. With global population rates for ageing increasing, it is estimated that by 2020 there will be between 15–20 million new cases of cancer per year and 10–12 million deaths (World Health Organization [WHO], 2003). However, in the devel- oped world, cancer incidence and death rates stabilised during the 1990s and have continued to fall as improvements in health promotion, diagnosis and treatment are made. This trend has been seen in the Australian statistics with the death rate for all cancers falling from 210 persons per 100,000 in 1986 to 181 persons per 100,000 in 2004 (AIHW, 2012). Cancer is a disease process that begins when an abnormal cell is transformed by the genetic mutation of the cellular DNA. This abnormal cell forms a clone and begins to proliferate abnor- mally, ignoring growth-regulating signals in the environment surrounding the cell. The cells acquire invasive characteristics and changes occur in surrounding tissues. The cells infiltrate these tissues and gain access to lymph and blood vessels, which carry the cells to other areas of the body. This phenomenon is called metastasis (cancer spread to other parts of the body). Proliferative patterns During the lifespan, various body tissues normally experience periods of rapid or proliferative growth that must be distin- guished from malignant growth activity. Several patterns of cell growth exist: hyperplasia , metaplasia , dysplasia , ana­plasia , and neoplasia (see Glossary). Cancerous cells are described as malignant neoplasms. They demonstrate uncontrolled cell growth that follows no physiological demand. Benign (causing little or no harm) and malignant growths are classified and named by tissue of origin, as described in Table 11-1. Pathophysiology of the malignant process

Table 11-1  Tumours and Tissue Types Tissue type

Benign tumours Malignant tumours

Epithelial Surface Glandular Connective Fibrous Adipose Cartilage Bone Blood vessels Lymph vessels Lymph tissue Muscle Smooth Striated Neural tissue

Papilloma Adenoma

Squamous cell carcinoma Adenocarcinoma

Fibroma Lipoma Chondroma Osteoma

Fibrosarcoma Liposarcoma Chondrosarcoma Osteosarcoma Haemangiosarcoma Lymphangiosarcoma Lymphosarcoma

Haemangioma Lymphangioma

Leiomyoma Rhabdomyoma

Leiomyosarcoma Rhabdomyosarcoma

Nerve cell Glial tissue

Neuroma Glioma (benign)

Neuroblastoma Glioblastoma, astrocytoma,  

  medulloblastoma,   oligodendroglioma Neurilemmal sarcoma Meningeal sarcoma

Nerve sheaths Meninges Haematological

Neurilemmoma Meningioma

Granulocytic Erythrocytic Plasma cells Lymphocytic

Myelocytic leukaemia Erythrocytic leukaemia Multiple myeloma Lymphocytic leukaemia or   lymphoma Monocytic leukaemia

Monocytic Endothelial tissue

Blood vessels Lymph vessels

Haemangioma Lymphangioma

Haemangiosarcoma Lymphangiosarcoma

Reproduced with permission from Porth, C. M. & Matfin, G. (2009). Pathophysio­logy: Concepts of altered health states (8th ed.). Philadelphia: Lippincott Williams & Wilkins.

Benign and malignant cells differ in many cellular growth characteristics, including the method and rate of growth, ability to metastasise or spread, general effects, destruction of tissue and ability to cause death. These differences are sum- marised in Table 11-2. The degree of anaplasia (cells that lack normal cellular characteristics and differ in shape and organi- sation with respect to their cells of origin, i.e. lack of differen- tiation of cells) ultimately determines the malignant potential. Characteristics of malignant cells Despite their individual differences, all cancer cells share some common cellular characteristics in relation to the cell membrane, special proteins, the nuclei, chromosomal abnor- malities, and the rate of mitosis and growth. The cell mem- branes are altered in cancer cells, which affects fluid movement in and out of the cell. The cell membrane of malignant cells also contains proteins called tumour-specific antigens (TSA) (e.g. carcinoembryonic antigen [CEA] and prostate-specific antigen [PSA]), which develop as they become less differenti- ated (mature) over time. These proteins distinguish the malig- nant cell from a benign cell of the same tissue type. They may be useful in measuring the extent of disease in a person and in tracking the course of illness during treatment or relapse. Malignant cellular membranes also contain less fibronectin, a cellular cement. They are therefore less cohesive and do not adhere to adjacent cells readily.