Chemoradiotherapy reduces physical fitness in rectal cancer patients waiting for surgery

This small study investigated the effect of neoadjuvant chemoradiotherapy on whole-body physical fitness.

Locally advanced rectal cancer indicates that the cancer has spread beyond the lining of the rectum or has spread to the nearby lymph nodes. Patients with locally advanced rectal cancer routinely receive neoadjuvant chemoradiotherapy (chemotherapy plus radiotherapy given before surgery). However, the effects of neoadjuvant chemoradiotherapy on physical fitness are unclear.

As poor physical fitness is linked to worse outcomes following surgery it is important to know if any pre-surgery medication is affecting fitness. To get an overall estimate of whole body fitness heart, lung and muscle response at rest and in response to exercise can be investigated.

This small study included 12 patients with rectal cancer.  Patient fitness was assessed using a cardiopulmonary exercise test (measures the impact of exercise on heart and lung function), while patient physical activity was assessed through 72-hour continuous monitoring of activity using an accelerometer (measures the number of steps taken by the wearer). Quadricep muscle (thigh muscle) function was also assessed using an exercise-recovery test. Measurements were made 2 weeks before beginning chemoradiotherapy and within 48 hours of finishing the 5-week treatment.

Neoadjuvant chemoradiotherapy significantly decreased patient fitness without affecting patient weight. The average level of oxygen uptake was decreased both at rest (decreased form 0.9 Lmin^-1 to 0.7 Lmin^-1) and following exercise (decreased form 1.4 Lmin^-1 to 1.1 Lmin^-1).

Average resting heart rate also showed a significant decrease following neoadjuvant treatment (76 beats.min^-1 to 68 beats.min^-1). However, patient heart rate after exercise was not affected following treatment (135 beats.min^-1 to 130 beats.min^-1).

The average number of steps walked over the 72 hour testing period decreased from 5352 to 3725 after neoadjuvant treatment. Muscle recovery after exercise also decreased in patients after neoadjuvant treatment (1.5 to 1.1 min^-1). This decline in muscle recovery function may account for the rapid loss in fitness and activity over the neoadjuvant treatment period.

The authors concluded that neoadjuvant chemotherapy decreased whole-body fitness in patients with rectal cancer. Determining why this occurs could lead to new interventions being developed to prevent the physical decline.

This was a very small study. Further research is required to ensure that the results are generalizable.