ÜDS-Sağlık 2008-1 Soru=71

It is made clear in the passage that oral cancers ----.

Oral cancers develop in 30,000 Americans and cause
8,000 deaths each year, mostly in people over age
40. This represents about 2.5 per cent of cancer
cases and 1.5 per cent of all cancer-related deaths.
Clearly this is a high rate considering the small size
of the mouth in relation to the rest of the body. Along
with cancers of the lung and skin, cancers of the
mouth are more preventable than most other
cancers. Non-cancerous and cancerous growths can
originate in any type of tissue in and around the
mouth, including bone, muscle, and nerve. Rarely,
cancers found in the mouth region have spread there
from other parts of the body – most commonly the
lung, breast and prostate. Screening for oral cancer
should be an integral part of medical and dental
examinations because early detection is critical.
Cancers less than a half inch across can usually be
cured easily. Unfortunately, most oral cancers aren't
diagnosed until they've spread to the lymph nodes of
the jaw and neck. Because of delayed detection, 25
per cent of oral cancers are fatal.