Case Analysis



Case Analysis

Incidence and epidemiology

Primary lung cancer is the most common malignancy after non-melanocytic skin cancer, and the leading cause of human cancer deaths worldwide [1]. While it has been the most important cause of cancer mortality in men since the 1960s, it has equaled breast cancer as a cause of mortality in women since the 1990s. Lung cancer is still increasing both in prevalence and mortality worldwide. In developed countries, the latter has begun to decline in men, reflecting a decrease in smoking, and is reaching a plateau for women in most European countries and in the United States—where lung cancer death rates in women are approaching those of men. Lung cancer deaths in women are expected to increase (+7%) in the EU in 2012 [2].

Non-small-cell lung cancer (NSCLC) accounts for 80-85% of lung cancers, while small-cell lung cancer has been decreasing in frequency over the last two decades.

Smoking is the main cause of lung cancer, responsible for 80% of cases. The observed variations in lung cancer rates across countries largely reflect differences in the stage and degree of the tobacco epidemic, with reported crude incidence rates between 2/100 000-80/100 000 and 1/100 000-39/100 000 for men and women, respectively. There are several other known risk factors including exposure to asbestos, arsenic, radon, and non-tobacco-related polycyclic aromatic hydrocarbons, and interesting hypotheses about indoor air pollution (e.g. coal-fueled stoves and cooking fumes) suspected to contribute to the relatively high burden of non-smokingrelated lung cancer in women.

Prevalence of lung cancer in females without a history of tobacco smoking is estimated to represent 19% compared with 9% of male lung carcinoma in the United States [3]. Women are overrepresented among younger patients, raising the question of gender-specific differences in the susceptibility to lung carcinogens [4]. In recent times, an increase in the proportion of NSCLC patients who are never smokers has been observed, particularly in Asian countries [5]. These new epidemiological data have resulted in 'non-smoking-associated lung cancer' being considered a distinct disease entity, where specific molecular and genetic tumor characteristics are being recognized.

Literature Review

Lung metastases, also known as secondary lung cancer, are tumours that have spread to the lungs from other parts of the body(Horiuchi et. al. 2011). Lung tissue is a very common site for metastases because all circulating blood passes through the lungs, allowing cancerous cells to be carried into lung tissue from other parts of the body (Hu et. al. 2009). The primary (original) cancers that spread most often to the lungs include cancers of the breast, colon, prostate gland, and kidney (Kaplan 2011).

Metastatic cancer to the lungs is the spread of cancer from another region of the body to the lungs. The place where cancer begins is called the primary cancer. For example, if breast cancer spreads to the lungs, it would be called breast cancer with metastasis (spread) to the lungs. In this case, breast cancer would be considered the “primary” cancer. (Andreoni et. al. 2007)

Secondary lung cancers may not cause ...