Colorectal cancer (CRC) survivor rates are improving, which means people are living long enough after the cancer to have other chronic conditions. CRC is the third most commonly diagnosed cancer among users of the US Department of Veterans Affairs (VA) health care system, according to VA researchers, and there is a high prevalence of cardiovascular disease (CVD). The researchers also say emerging evidence suggests that survivors of CRC may be more likely to develop diabetes mellitus (DM) in the 5 years following their cancer diagnosis. But they add that there is a paucity of research about control of CVD-related chronic conditions among survivors of CRC.
In a retrospective study, the researchers compared 9,758 nonmetastatic patients with CRC with 29,066 people who had not had cancer. At baseline, 69% of the survivors of CRC and the matched controls were diagnosed with hypertension, 52% with hyperlipidemia, and 37% with DM.
But somewhat contrary to expectations, the researchers found no significant differences between the 2 groups for DM in the year following the baseline assessment. The researchers point to the VA’s “strong history” of DM risk reduction research and 2 national programs targeting DM, although they do not know whether the people in their study participated in those.
The survivors of CRC also had half the odds of being diagnosed with hyperlipidemia. However, they did have 57% higher odds of being diagnosed with hypertension.
Although the researchers acknowledge that hypertension is a transient adverse effect of certain chemotherapy regimens, they found only 7 survivors of CRC and 11 controls were treated with bevacizumab during their first year postanchor date.
The relationship between nonmetastatic CRC and CVD risk-related chronic conditions is complex, the researchers say. But they share risk factors, including obesity, physical inactivity, and diet.
The researchers call behavioral change interventions that improve survivors of CRC physical activity, dietary habits, and body mass index a “promising beginning” but call for other similar interventions, particularly those targeting blood pressure management and adherence to antihypertensive medications (which was significantly lower among the survivors).
While the magnitude of the effect regarding hypertension seems relatively small, the researchers say, they believe it is still an important difference when considered from a population health perspective—and one that should be addressed. The researchers also note that nonmetastatic survivors of CRC and controls had very similar rates of primary care visits in the 3 years postanchor date and as a result similar opportunities to receive a hypertension diagnosis.