What is Comorbidity?

September 15, 2022

Comorbidity can be summed up in a simple question: “In addition to cancer, what else is wrong with you?” A comorbidity is an existing and unrelated diagnosis at the time of a cancer diagnosis. Common comorbidities include heart disease, diabetes, hypertension, and obesity. Nearly 30 such comorbid conditions occur frequently enough and contribute to treatment decision-making and prognosis enough to warrant consideration at the time of a cancer diagnosis.

Physicians have recognized the importance of comorbidity for many years. Several tools have been developed to aid in collecting comorbid health conditions at the time of diagnosis. For example, using the Adult Comorbidity Examination-27 (ACE-27) to capture comorbid health is quite easy.

Comorbidity is an important factor for patients with cancer.

Surprisingly, coexisting medical conditions can contribute heavily to prognosis. It is also an important factor in proper treatment selection for at least 70% of adults with newly diagnosed cancers.

Comorbidity is a crucial component for women with breast cancer because the overall survival rate is good, just as it is for men with prostate cancer. Among men with prostate cancer, for instance, comorbidity is far and away more important than tumor size or spread, the usual factors doctors look for.

The combination of comorbid conditions in a patient can determine how the patient will respond to a given therapy, or whether the patient should a particular treatment course. In short, these other medical conditions can be crucial factors in selecting the right treatment.

Physicians must consider the patient’s comorbidies when recommending cancer treatment. For instance, one patient may be bedridden from congestive heart failure, making the most aggressive treatment inappropriate. Treating this patient with aggressive chemotherapy or surgery could be fatal because of the comorbidities. But another young and otherwise healthy patient, could tolerate aggressive medical or surgical treatment appropriate and beneficial.

In some cases, such as with cancers that are not aggressive, it may make more sense to adopt a “watchful- waiting approach.” In these situations, some studies suggest treatment may worsen matters, and people may have a better quality of life by forgoing cancer treatment altogether. Doctors and patients need to understand that aggressive “all-out” treatment can be a mistake for some patients.

In this way, the exclusion of comorbid health factors has hindered accurate assessment of prognosis and treatment effectiveness in cancer patients. Data analysis from large cancer registries, including comorbid health information, allows for more accurate descriptions of patients, creating better survival estimates.


Data analysis from large cancer registries, including comorbid health information, allows for more accurate descriptions of patients, creating better survival estimates.

How MyCancerJourney incorporates comorbid factors:

MyCancerJourney merges the support of a navigator with data and analytics to provide personalized survival estimates based on the outcomes of people like me. MyCancerJourney pulls data from millions of patients with similar underlying health conditions. The prognostic estimates are precise, but the whole idea of personalized prediction is challenging. We see survival curves as a discussion point to help newly diagnosed patients understand what a cancer prognosis means for them individually and provide insight into the possible results of different treatment options. This information allows patients to become more informed about outcomes of patients with similar health conditions, so they are empowered to discuss these options with their physicians. When coupled with a supportive community web portal like MyCancerJourney, comorbid health information can be considered the “new” factor to personalize cancer care.


A cancer diagnosis is an overwhelming and frightening time. MyCancerJourney is here to help. Our board-certified navigators are here to help guide you through the overwhelming and confusing process and help you make treatment decisions that are right for you. We harness the power of AI to create a plan for you and your specific factors and preferences based on the data of others with your exact diagnosis and health factors, not just a one-size-fits-all guideline. To start today, fill out an intake form here or call us at 737.307.0077.

MyCancerJourney is a comprehensive patient navigation service paired with a proprietary data and analytics platform that powers treatment decision support for patients.
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