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By Jenn Sinrich, Reader's Digest
Even with the significant advances in cancer screening and treatment, there are still many cancers that are hard to detect. Here are the ones you need to know about.
Pancreatic cancer
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This rare disease makes up only 2 percent of all new cancer cases in the country, but it recently surpassed breast cancer as the third-most common cancer killer in the United States. So it’s safe to say cancer screening strategies are desperately needed. “The hopeful news is that there are new technologies emerging, such as molecular blood tests and other novel approaches, that could expand early detection efforts to these historically unscreened tumor types,” says David A. Ahlquist, MD, gastroenterologist and professor of medicine at the Mayo Clinic College of Medicine. The reason pancreatic cancer is so difficult to detect is because it’s internal, initially painless, and not generally connected to anything that would lead to symptoms. “The exception is if it happens to occur close to the bile duct, which leads to blockage and jaundice relatively early in the course of the disease,” explains Mark Faries, MD, surgical oncologist and director of the Donald L. Morton, MD, Melanoma Research Program and director of therapeutic immunology at the John Wayne Cancer Institute at Providence Saint John’s Health Center in Santa Monica, California. “Treatment in a fortunate minority is a very large operation, and in those whose cancer is detected later, treatment is largely based on chemotherapy and is temporarily relieving at most.
Kidney cancer
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Kidney cancer can be hard to detect because patients aren’t usually tested unless they show the symptoms, which often include lower back pain, chronic fatigue, unexplained weight loss, and blood in urine. “Because the kidneys are so deep inside the body, small kidney tumors cannot be seen or felt during an annual physical exam,” explains Chris Fikry, MD, vice president of oncology at Quest Diagnostics. “Additionally, there are no recommended screening tests for kidney cancer in people who are not at increased risk.” Patients who have certain inherited conditions, such as Von Hippel-Lindau syndrome (VHL), hereditary papillary renal cell carcinoma (HPRCC), and Birt-Hogg-Dubé syndrome (BHD) have a higher risk of kidney cancer. Doctors may choose to recommend that these patients get regular imaging tests such as computerized tomography (CT) scan or magnetic resonance imaging (MRI) to look for kidney tumors.
Non-small cell lung cancer
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Three-quarters of lung cancers are diagnosed after they’ve already spread. And often patients do not become symptomatic until the cancer has already grown to a size that causes lung cancer symptoms such as cough, pneumonia, shortness of breath, and has already made its way through the bloodstream and lymph system. Non-small cell lung cancer (NSCL) is the most common type of lung cancer, yet it’s difficult to detect early on because early-stage lung cancer often has no symptoms and is not detected with a chest X-ray. “Positron emission tomography (PET) and CT scans can be helpful in diagnosing lung cancer. A doctor may also take cancer cells from lung secretions, fluid around the lungs, or through a biopsy for a confirmatory diagnosis, which typically happens in a later stage,” says Dr. Fikry. NSCL has very low survival rates if diagnosed in a late state, so people with a long history of smoking may want to talk to their doctor about the possible value of CT screening to aid the detection of lung cancer in an early, more treatable stage.
Ovarian cancer
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While ovarian cancer only accounts for about 3 percent of cancers among women, it’s the fifth-deadliest cancer, accounting for more deaths than any other cancer of the female reproductive system. According to cancer.org, an estimated 22,280 women will receive a new diagnosis of ovarian cancer this year alone, and approximately 14,240 of those women will die from it. Like other cancers, the earlier the diagnosis, the better the outcome, but only about 20 percent of ovarian cancers are found at an early stage.”This is mainly because of the size and distensibility of the abdominal cavity and the fact that there are no symptoms from small, early-stage ovarian cancer,” says Joe O’Connell, MD, vice president of oncology and hematology at inVentiv Health. “It’s most often diagnosed at stages three or four.”
Sarcoma
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These tumors of body tissues, such as fat, muscle, deep skin tissues, bone or cartilage, do not produce early symptoms. While it’s an extremely rare form of cancer to have in adulthood, with only about 1 percent of all adult cancer being sarcoma, it’s much more common in children, compensating for about 15 to 20 percent of all children’s cancers. “Because they’re not connected to the surface in most cases, sarcoma tumors can get quite large before they become symptomatic,” explains Dr. Faries. “They also don’t produce blood markers that can be detected and are generally uncommon with no high-risk populations, making them not ideal for screening.” Biopsy is the only diagnostic tool and treatment generally consists of surgery if possible, as most of the currently available systemic therapies are not very effective.
Brain cancer
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Cancers of the brain and spinal cord tumors are often found because of signs and symptoms the person may be having, however these are often experienced at later stages. “If a tumor were to arise in the motor cortex, for example, (the area of the brain involved in controlling voluntary movement), it would cause a noticeable deficit such as weakness in the arm or leg,” explains David Poulad, MD, board certified neurosurgeon in Union, New Jersey. “However, these tumors may often arise in neighboring areas where they would cause somewhat vague symptoms to a patient such as clumsiness of the hand in performing fine motor tasks, as opposed to frank weakness or subtle difficulties with speech.” Patients may also exhibit very subtle changes in personality that may only be noticed by their closest family members. Another big roadblock in the way of detection is that the most common symptom of a brain tumor is headache, which is so common that it’s often ignored by patients and even some primary care physicians. To date, there’s no cancer screening available for brain cancer, short of an imaging study of the brain such as an MRI or a CT scan, and the prognosis is very poor. “Without no cure currently available, the goal of a neuro-oncology team is to preserve neurological functioning for as long as possible and manage the growth of the cancer,” says Dr. Poulad.
Liver cancer
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Because no symptoms are present until later stages, liver cancer is another hard-to-detect cancer. “If the tumor is small, it’s especially hard to detect on a physical exam because most of the organ is covered by the right rib cage,” explains Dr. Fikry. “By the time the liver is large, the tumors has likely spread throughout the organ, beyond the point of being totally removed surgically, but leaving enough healthy liver intact.” While there are no widely recommended cancer screening tests for liver cancer in those not at risk, your doctor may recommend testing if you have a family history of the disease or have been previously diagnosed with the human papillomavirus (HPV). Many patients who are alcoholics develop liver cancer after long-standing cirrhosis, or liver disease.
