As the population ages, patients diagnosed with cancer often are already dealing with other chronic medical conditions, such as heart disease, chronic obstructive pulmonary disease, diabetes and hypertension.
Scientific journals recently have published papers evaluating data collected from other studies to determine the impact of comorbidities on cancer care. A study published in JMIR Cancer in October 2021 concluded there is an adverse effect of comorbidity on treatment and survival, and this increases with age. The Journal of the National Cancer Institute published a study in July 2024 concluding that the cancer patient who is otherwise healthy and free of disease other than cancer, “is rapidly becoming an enigma” when dealing with the older population.
“The incidence of cancer increases with age, which is true of almost all cancers, with the exception of cancers seen in childhood,” said Vincent Grzywacz II, M.D., a radiation oncologist at Trident Cancer Center in Charleston. “There are things that increase a person’s risk for cancer that also increase the risk for other conditions. For example, smoking is obviously going to increase your risk for things like vascular disease, heart disease, lung disease, COPD, etc. And that’s obviously the number one risk factor for lung cancer as well.”
These comorbidities also impact the treatment plan for cancer. While the three main cancer treatments – surgery, radiation and chemotherapy – have their own side effects, they can also exacerbate symptoms that exist from the comorbidity.
Dr. Grzywacz cited a patient with a kidney condition who receives a diagnosis of pelvic cancer. Testing with contrast and radiation therapy can cause issues with diarrhea or urinary retention. Some chemotherapeutic agents also affect the kidneys and the bladder, and, if there are already symptoms, that can increase their severity as well.
Some chemotherapy drugs used to treat breast cancer are more toxic to the heart, Dr. Grzywacz noted, while others affect lung function. Radiation to the lungs and heart can exacerbate pre-existing medical conditions, he said.
It’s important for cancer patients to share their complete health history with their oncologists and every member of their medical team. “[We make] sure we have a good idea of the patient’s overall health picture, what comorbid issues they’re dealing with and ensuring that they have consistent routine follow-up with the specialists who need to be involved in their care,” Dr. Grzywacz said. “If a patient has a significant heart history [and has] a pacemaker, we’ll make sure that that cardiologist is tied in with the patient’s plan of care.”
For a patient with breast cancer who also has a heart condition, there may be adjustments to the radiation dose; research has linked radiation exposure to the heart during breast cancer treatment to an increased risk for cardiac events long-term. Similarly, medical oncologists may choose an alternate chemotherapy drug to alleviate impact on cardiac function. With bladder cancer, radiation oncologists may use a rectal spacer to decrease the dose of radiation to the rectum. This is particularly beneficial for patients with inflammatory bowel disease who cannot or choose not to have surgery due to concerns over exacerbating this condition.
Regardless of the patient’s age, cancers are being detected earlier, and they are more treatable and curable. That emphasizes the importance of keeping chronic conditions in mind for all patients.
By Linda L. Esterson
