Paraneoplastic Syndromes: A Puzzling Piece of Cancer

Cancer is a complex disease. Even more convoluted: its effects on the body. For instance, we health care professionals often take time to carefully educate our patients about symptoms and side effects of cancer and its treatment.

However, the rarer effects are not necessarily discussed upfront. Most likely, it’s a precaution to not overwhelm patients as they are first learning about their disease, but it’s also because a group of rare syndromes triggered by the cancer may never occur in some patients.

Paraneoplastic syndromes are uncommon disorders that can arise with any cancer type but are more common with lung cancer. They can develop when substances released by some cancer cells or an immune reaction disrupt the normal function of surrounding cells and tissue. Paraneoplastic syndromes affect the nervous system, which can cause problems with muscle movement, sensory perception, memory and sleep. Other organ systems, such as hormones, skin, blood and joints, can also be affected.

In this issue of CURE®, a feature story examines how paraneoplastic syndromes play a role in patients with non-small cell and small cell lung cancer. Experts in the field discuss the four main types associated with lung cancer and how they are diagnosed and treated. We also hear from a patient who shares how, after learning of her lung cancer, she began to experience seemingly unrelated symptoms, such as trouble moving her hands and fingers. The diagnosis: hypercalcemia, or excess calcium in the blood. This type of paraneoplastic syndrome occurs in 20%-30% of cases.

Like this patient, others may notice unexpected symptoms; sometimes a routine blood test might produce a concerning result. That’s why it’s crucial to share any new signs or issues with your health care team and get regular follow-up for any type of active cancer.

Diagnosing these diseases has proved challenging over the years because tests, such as physical exams, blood tests and imaging, don’t always reveal the source of the problem. Your doctor will have to first rule out other causes. And then there is the challenge of understanding how these syndromes work biologically, something researchers are still trying to determine.

There is no absolute cure for paraneoplastic syndromes other than successfully addressing the underlying cancer, but medical teams can treat them in a few ways. Options include decreasing the autoimmune response with steroids, high-dose intravenous immunoglobulin or irradiation. For neurological syndromes, anti-seizure medications have been used. Hormonal derangements that lead to high calcium levels can be treated with calcium-lowering hormones or certain bone-protecting drugs used for osteoporosis. Speech and physical therapy can help patients who may be more disabled by a paraneoplastic syndrome regain functions.

Nevertheless, managing these syndromes seems to fall more under the art of oncology, and we hope the science will continue to catch up.