Cancer describes a class of diseases characterized by the uncontrolled growth of aberrant cells. Cancers kill by the destructive invasion of normal organs through direct extension and spread to distant sites via the blood, lymph, or serosal surfaces. The abnormal clinical behaviour of cancer cells is often mirrored by biologic aberrations such as genetic mutations, chromosomal translocations, expression of fetal or other discordant ontologic characteristics, and the inappropriate secretion of hormones or enzymes. All cancers invade or metastasize but each specific type has unique biologic and clinical features that must be appreciated for proper diagnosis, treatment and study. About 1.2 million new cases of invasive cancer are diagnosed each year in the United States, and about 500,000 people die annually of the disease. Cancer is the second most deadly disease and is expected to surpass heart disease early in the twenty-first century to top that vicious list. Over the past half century, the frequency of most cancers has been stable, but some dramatic changes have taken place. Steady declines in stomach and uterine cancer have occurred, the latter undoubtedly due to routine cytologic screening for cervical cancer. The cause of the decline in stomach cancer is unknown. The most striking change has been the increases in lung cancer in both men and women, undoubtedly related to smoking.
It is pointed out in the passage that, over the next few decades, mortality due to cancer ____.
will start to decline as new methods of treatment are introduced
will be higher than the mortality caused by heart disease
will start to threaten younger people
will be greatly reduced through an increase in early diagnosis
will increase at an alarming rate as very many more people are starting to smoke
As it is pointed out in the passage, cancer ____.
has been on a steady increase since the mid-twentieth century
has caused much higher mortality in the United States than anywhere else in the world
is a disease with a great deal of variety, which requires different treatments and studies
is still a disease much deadlier than heart disease
of the stomach is the one that causes the most problems
We learn from the passage that, among the different cancers, lung cancer ____.
shows a downward trend in the United States
is the one that most needs to be dealt with immediately
is the one that most readily yields to treatment
has appeared with increasing frequency over the years
affects as many non-smokers as smokers
We learn from the passage that cancer cells ____.
all present the same clinical features
can be carried by the blood and spread to distant organs