Diabetes and hypertension linked to colon cancer recurrence and survival
By all accounts, combining colon cancer, diabetes, and high blood pressure can be a recipe for medical disaster. A new study has shown just how deadly this mix can be. This retrospective analysis of more than 36,000 patients with colon cancer found that those with early stage disease and diabetes or high blood pressure—two components of metabolic syndrome—have a greater risk for recurrence after treatment and of dying compared with patients with colon cancer who do not have either condition.
Metabolic syndrome is a cluster of conditions that affects one in five American adults. It can include diabetes, obesity, high blood pressure, low levels of good cholesterol, and high amounts of lipid in the blood.
“Although metabolic syndrome has been linked to colon cancer, the third leading cause of cancer death in the United States, previous work looking at its effect on mortality has not adequately accounted for cancer stage or treatment,” said senior author Nestor Esnaola, MD, MPH, MBA, of Temple University School of Medicine. “Our results suggest that patients with early stage colon cancer who also have diabetes or hypertension may need to be followed more closely for recurrence and could potentially benefit from broader use of adjuvant chemotherapy.”
To better understand the effect of metabolic syndrome on colon cancer outcomes, Esnaola and his team linked data from the National Cancer Institute's Surveillance, Epidemiology and End Results (SEER) program, a large population-based database, to Medicare data from 1998 to 2006 on 36,079 patients with colon cancer, including 7,024 patients (19.5%) who were identified as having metabolic syndrome. They analyzed the effect of metabolic syndrome and its components on colon cancer recurrence and overall survival.
The researchers found that among patients with early stage disease, patients with diabetes or high blood pressure had a significantly greater risk of cancer recurrence and death after treatment. For example, 47.7% of patients who did not have diabetes were still alive 5 years after diagnosis compared to only 41.3% of patients with diabetes. When the researchers looked more closely, they also found that cancer recurrence rate at 5 years was approximately 8% higher in patients with diabetes or hypertension.
In contrast, the analysis showed that patients with abnormally high levels of lipids in the blood had a lower risk of recurrence and death from colon cancer. Overall, 39% of patients with normal lipid levels were still alive after 5 years, compared to 52.7% of patients with abnormal levels. Cancer recurrence rate was approximately 11 percentage points lower in patients with abnormal lipid levels.
“We suspect that the higher survival and lower recurrence rates observed in patients with high lipid levels in our study group were likely due to the protective effects of statins,” Esnaola said. Statins are widely used to lower cholesterol and lipid levels and have been shown to lower the risk of developing colon cancer.
This study was published in Cancer (2012; doi:10.1002/cncr.27923).