Does Polypharmacy Affect Patient’s With Colorectal Cancer?

Colorectal cancer (CRC) is a type of cancer that starts in the rectum or the colon. Itcan be called rectum and colon cancer; however, because both cancers have similar features, and are grouped as colorectal.¹ Colorectal cancer is frequently diagnosed worldwide. There have been 1.9 million cases of colorectal cancer, and has caused 900,000 deaths in the year 2020, making it a significant concern for public health.^2,3 As more than half of the patients with CRC are diagnosed after the age of 70, the five-year survival rate⁴ for all the stages of CRC combined has increased above 60%.⁵ The pharmacological care for older patients with CRC and often those with comorbidities⁶ has proven to be increasingly challenging for physicians. However, it also shows excellent potential for improving the overall health and survival of older patients with CRC. 

Polypharmacy is defined as the concomitant use of five or more medications;⁷ it is incorporated into the geriatric assessment tool to tackle the clinical complications of frail older patients.⁸ In addition, cancer patients are more prone to the unintended consequences associated with polypharmacy as these patients often receive chemotherapy and specific agents to relieve symptoms. This increases the likelihood of drug-to-drug interactions and unwanted adverse drug reactions.⁹ Therefore, this study is aimed to evaluate the association of polypharmacy regarding overall survival of a large group of patients diagnosed with CRC.¹⁰ 

The study involved 3,239 patients, with 1,334 being female, the average age of individuals involved in the study was 75 years. After analysis, the study results showed that men were 46% less likely to be exposed to polypharmacy than females. In addition, it was shown that patients with rectal cancer had significantly higher odds of polypharmacy (21%) than those with colon cancer. Regarding lifestyle factors, participants who used to smoke had a 23% higher odds of polypharmacy, while current smokers had 20% higher odds of polypharmacy.¹⁰ 

Regarding patient comorbidities, patients with; acute coronary syndrome, history of stroke, hypertension, cardiac insufficiency, history of myocardial infarction, chronic obstructive pulmonary disease, atrial fibrillation, diabetes, chronic pain, hypothyroidism and depression had a significantly higher chance of polypharmacy. During the five-year follow-up on overall survival, it was shown that 1,070 participants died over the period of five years, 615 participants died from CRC as the main cause of death, and 296 participants died from other causes other than cancer. Furthermore, the study also found that the patients that were given an increasing number of medications after CRC surgery were associated with poorer overall survival after five years. In addition, the study found that with eight drugs or more, the management of these drugs in patients with CRC becomes more complex. As a result, it increases risks for adverse drug reactions and drug-to-drug interactions.¹⁰

In summary, polypharmacy was common in older patients with CRC. Although the studies showed some links, overall, the use of eight or more drugs was found to be a weak risk factor for colorectal-specific mortality. Therefore, medication reviews need to be conducted for older patients with CRC who are taking eight drugs or more.