When a cancerous tumor is diagnosed in the early stages – before the tumor has a chance to metastasize, or colonize, other healthy organs and tissues – patients typically have a very good chance of survival. Unfortunately, when noticeable symptoms first occur for many common tumors, these cancers are well beyond the early stages of development and have already begun to spread.
Lung cancer, ovarian cancer, colorectal and cervical cancers, as well as breast cancer, can all go unnoticed by patients until they are very advanced, stage 3 or stage 4 tumors. These tumors are often defined as “late stage” cancers.
It’s no coincidence that these are some of the most fatal forms of cancer.
According to the Centers for Disease Control and Prevention, half of all colorectal and cervical cancers in the U.S. are not diagnosed until stage 3 or stage 4, which means the tumors have already migrated to other organs and tissues.
Despite great strides in awareness and screening, a third of all breast cancers in the U.S. are not diagnosed until the late stages.
Treatment of ovarian cancer has a 90 percent success rate if diagnosed early. Unfortunately, ovarian cancers are extremely silent and almost always go undetected until it is too late. Noticeable symptoms of ovarian cancer typically occur only after the tumor has spread throughout the abdomen and beyond. According to the Ovarian Cancer Research Fund, 51% of ovarian cancer patients are not diagnosed until stage 3. The 5-year survival rate for these women is only 34%.
According to the American Cancer Society (ACS), Lung cancer is the leading cause of cancer deaths among both American men and women. Lung cancer is responsible for 28% of all cancer fatalities in the U.S. each year. There were approximately 228,190 new cases of lung cancer diagnosed in the U.S. in 2013. According to the ACS, the 1-year survival rate for lung cancer is 44%. However, when all stages of lung cancer are combined, the 5-year survival rate drops to 16%. Only 15% of lung cancers are diagnosed at the localized stage.
It is not necessarily true to say these silent tumors are difficult to treat. Many could be eradicated with standard therapies if diagnosed in State 1 or 2. However, once a tumor has spread to nearby and distant organs and tissues, it becomes much more difficult to treat.
Tomorrow: Sentinel cells, the early clues to silent tumors