Physical exercise and immune system function in cancer survivors

Abstract

BACKGROUNDThere are a limited number of interventions for cancer survivors following completion of primary therapy that might reduce the risk of cancer recurrence and/or secondary malignancies and increase survival times. It has been proposed that physical exercise may be beneficial by enhancing the anticancer immune system response. The purpose of the current article is to: 1) briefly describe the immune system response to tumors, 2) discuss the impact of anticancer therapy on immune system function in cancer survivors, 3) provide a systematic and comprehensive review of the extant literature examining physical exercise and immune system function in cancer survivors, and 4) offer a critical analysis of this literature and outline directions for future research.METHODSA comprehensive literature search up to March 2001 identified empirical articles that examined the effects of physical exercise training on immune system function in cancer survivors from CD‐ROM database searches and manual searches.RESULTSTo the authors' knowledge, six empirical studies published between 1994 and 2000 have examined physical exercise and immune system function in cancer survivors. Overall, four out of six studies reported statistically significant improvements in a number of cancer‐related immune system components as a result of exercise. However, there are several limitations that must be considered when interpreting the findings of these studies. These limitations involve the samples, designs, physical exercise interventions, physical fitness assessments, and immunologic assessments.CONCLUSIONSAdditional research is needed to determine if physical exercise in cancer survivors may reduce the risk of cancer recurrence and secondary malignancies and increase survival times. Cancer 2002;94:539–51. © 2002 American Cancer Society.

Inactividad Física y Ausentismo en el Ámbito Laboral

“…Como factores explicativos de la asociación encontrada se puede considerar también el aporte del ejercicio moderado en la función inmunitaria de hombres y mujeres, aspecto que contribuye a explicar en cierta medida la menor frecuencia de incapacidad por causas médicas presentada en el grupo de personas activas (14).…”

Exercise therapy across the prostate cancer continuum

“…[64][65][66][67] One possible underlying mechanism responsible for the age-associated increase in PC incidence is oxidative damage from ROS, such as superoxide, hydroxyl radical and hydrogen peroxide; 72,73 therefore, exercise could have a negative effect on PC by reducing these free radicals. Exercise has also been shown to improve innate immune function and surveillance, [68][69][70] and previous studies have demonstrated the importance of innate immune function on PC pathogenesis. [74][75][76][77][78] Exercise therapy and prostate cancer J Antonelli et al…”

“…[64][65][66][67] Exercise may also improve innate immune function and surveillance. [68][69][70] In addition, the reductions in systemic inflammation and pro-inflammatory factors seen with exercise have been postulated to decreased cancer risk. 71 Investigators in our group are beginning to explore alterations in angiogenesis as a potential molecular mechanism to explain the effect of exercise on PC pathogenesis.…”

Posibles mecanismos de acción biológica de la actividad física en el cáncer de mama

“…En cuanto al componente celular, los mecanismos implicados comprenden: las células (NK) activadas por linfoquinas (LAK); los macrófagos que constituyen una defensa de primera línea contra el CA y son capaces de disminuir la incidencia, progresión y metástasis de algunos tumores; los neutrófilos y células asesinas naturales, y nivel de los factores solubles la proteína C-reactiva, la interleucina 1 (IL-1), el factor de necrosis tumoral (TNF-α) y el interferón (IFN) (Fairey, Courneya, Field y Mackey, 2002b).…”

“…Por el contrario, estudios realizados en animales con ejercicio de alta intensidad demuestran un mejor efecto de este tipo de ejercicio que el de baja y moderada intensidad sobre el sistema inmune innato (Fairey et al, 2002b).…”