What makes a cancer "common"? According to the National Cancer Institute, a common cancer has an estimated annual incidence of at least 40,000 cases. Here we look at the facts and stats surrouding four of the most common cancers in the United States—cancers that affect the breasts, prostate, colon, and lungs.
Breast Cancer
With more than 234,000 new cases expected this year alone, breast cancer is the second most common cancer in the US; only skin cancer is more prevalent. Your health care provider will advise you on when you should schedule a mammogram (breast X-ray), as opinions vary on when to start screening (and how frequently to screen). "When and how often you get screened may depend on your family history," says Stephanie Bernik, MD, chief of surgical oncology at Lenox Hill Hospital in New York City.” For instance, "If you have a first-degree relative (such as a mother or sister) with breast cancer, your chances of getting the disease are increased and, as with many cancers, early detection generally means better outcomes." Mammograms detect about 80 to 85 percent of breast cancers, Bernik notes.
In addition to a mammogram, you may also be advised to have an ultrasound (in which high-energy sound waves are bounced off internal tissues and make echoes to form an image of the breast tissue), or an MRI (magnetic resonance imaging, which uses a computer, a magnet, and radio waves to create a series of pictures of your breasts). "When there is a palpable mass or dense breast tissue on a mammogram, breast ultrasound is very useful," says Bernik. "These will pick up three to five percent of the cancers missed by a mammogram."
If cancer is found, several tests can predict how quickly it will likely be to grow, how well certain treatments will work, and whether it's likely to recur. For instance, breast cancer patients may take the human epidermal growth factor type 2 receptor (HER2/neu) test, which measures how many HER2/neu genes there are in a cancer tissue sample, along with how much HER2/neu protein is has been made. If the levels are abnormally high, the cancer is labeled HER2/neu positive.
HER2/neu positive breast cancer can grow more quickly and is more likely to spread than other types, and patients with this form of the disease may be given drugs that specifically target the HER2/neu protein.
Breast cancer patients may also be familiar with the estrogen and progesterone receptor tests, in which the amounts of estrogen and progesterone hormone receptors in cancerous tissues are measured. If there are more receptors than normal, the cancer is labeled estrogen and/or progesterone receptor positive. Since these tests can show if a treatment to block estrogen and progesterone could halt the cancer, the results can be especially valuable.
Then there are multigene tests like Oncotype Dx™ and Mammaprint™, which estimate the risk of the cancer spreading or recurring in some women with early-stage breast cancer by studying samples of breast tissue to view the activity of various genes associated with breast cancer.
Colon and Rectal Cancers
Often referred to as colorectal cancers, colon and rectal cancers will account for an estimated 132,700 new cases (93,090 colon cancers, and 39,610 rectal cancers), and 49,700 deaths this year. While colon cancer deaths make up 8.4 percent of all cancer deaths, close to 65 percent of people diagnosed with the disease survive for at least five years, according to the National Cancer Institute.
Adenocarcinoma is the most common type of colorectal cancer, says David Samadi, MD, chief of urology at Lenox Hill Hospital in New York City. As with other types of cancer, the stage colorectal cancer is at when detected (how far advanced it is) helps determine treatment. Treatment ranges from a local excision, or tumor removal, for Stage 0 cancers to surgery, chemotherapy, and radiation therapy for more advanced cancers.
It’s recommended that men and women have a colonoscopy (a type of screening that can reduce colorectal cancer deaths by an estimated 60 to 70 percent) starting at age 50, says Samir Abraksia, MD, an oncologist at the Cleveland Clinic. "Some people should be screened using a different schedule because of their personal or family history," he adds. "Patients should talk with their doctor about their history to help determine which colorectal cancer screening is best for them."
Prostate Cancer
An estimated 220,800 new cases of prostate cancer are expected in 2015, and this very common cancer will kill some 27,540 men this year alone. The most common type of prostate cancer, responsible for some 90 percent of diagnoses, is acinar adenocarcinoma.
When should men get screened? Men should speak with their doctor, Abraksia says, and "If the person is African American or has a father or brother who had prostate cancer before age 65, have this talk with your doctor starting at age 45." Prostate screening involves a digital rectal exam (DRE), in which the doctor can feel the prostate through the rectal wall for any abnormalities, and a prostate-specific antigen (PSA) test. PSA, which is made in the prostate, is found in high levels in the blood of men with prostate cancer, though PSA levels can be also elevated in men with a prostate infection. One study that men who had PSA tests were 20% less likely to die of prostate cancer.
The good news about prostate cancer is that many of these tumors are slow growing and may not require treatment, Abraksia says. Surgery to remove the prostate gland, hormone therapy, and radiation are used to treat prostate cancer.
Lung Cancer
More people die from lung cancer than any other type of cancer in the U.S. There will be an estimated 221,000 new cases this year, and some 158,040 individuals will die of it. This high death rate may be in part because typically, lung cancer symptoms aren’t apparent until the cancer is already in an advanced and non-curable stage, according to the American Cancer Society. In addition, many people mistake their symptoms for less serious problems, like an infection.
There are two types of lung cancer: non-small cell and small cell. Non-small cell lung cancer is the more common, Samadi says; it accounts for about 85 percent of diagnoses.
Smoking is a huge risk factor for lung cancer, but being exposed to second hand smoke, having a family history of lung cancer, and living in an area where there is air pollution also increases risk.
If you are 55 to 74 years old and smoke 30 packs a year, or quit smoking in the last 15 years, you may be a candidate for a lung cancer screening with a low-dose spiral CT scan, Abraksia says. This technique makes detailed pictures of the lung area, employing an X-ray machine that scans the body in a spiral path. In people who fit the profile above, the procedure has been shown to decrease the risk of dying from lung cancer by 20 percent, according to the National Cancer Institute.
There are several other lung cancer screening tests, including chest x-rays and sputum cytology, in which a sample of the mucus coughed up from the lungs is checked for the presence of cancer cells. However, researchers have found these do not decrease the risk of dying from lung cancer in heavy smokers.
Can Cancer Be Prevented?
Approximately one quarter to one third of the cancer cases expected that will be diagnosed in 2015 can be attributed to poor nutrition, physical inactivity, being overweight, and obesity, Abraksia says. So yes, some cancers can be prevented by lifestyle changes.
In addition, "Early detection of cancer greatly increases the chance of successful treatment," he adds. "Education to promote early diagnosis and screening is important." To maximize your chances of preventing cancer—or catching it in an early, more treatable stage, go for recommended screenings, eat a healthy diet, and if you smoke, quit.
Samir Abraksia, MD, reviewed this article.
Sources
Samir Abraksia, MD. Email interview April 30, 2015.
Stephanie Bernik, MD. Email interview April 30, 2015.
Samadi, David, MD. Email interview May 1, 2015.
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