6 RESEARCH ARTICLES
Original Investigation | May 16, 2016; JAMA Intern Med. Published online May 16, 201
– Leisure-time physical activity has been associated with lower risk of heart-disease and all-cause mortality, but its association with risk of cancer is not well understood.
– Determine association of leisure-time physical activity with incidence of common types of cancer and whether associations vary by body size and/or smoking
– We pooled data from 12 prospective US and European cohorts with self-reported physical activity (baseline 1987-2004).
– Looked for associations of leisure-time physical activity with incidence of 26 types of cancer.
– Exposures – Leisure-time physical activity of a moderate to vigorous intensity.
– A total of 1.44 million participants (median [range] age, 59 [19-98] years; 57% female) and 186 932 cancers were included.
(1) High vs low levels of leisure-time physical activity were associated with lower risks of 13 cancers: esophageal adenocarcinoma, liver, lung, kidney, gastric cardia, endometrial, myeloid leukemia, myeloma, colon, head and neck, rectal, bladder, and breast
(2) Body mass index adjustment modestly attenuated associations for several cancers, but 10 of 13 inverse associations remained statistically significant after this adjustment.
(3) Leisure-time physical activity was associated with higher risks of malignant melanoma and prostate cancer.
(4) Associations were generally similar between overweight/obese and normal-weight individuals.
(5) Smoking status modified the association for lung cancer but not other smoking-related cancers.
Santa Mina D1, Clarke H2, Ritvo P3, Leung YW2, Matthew AG4, Katz J5, Trachtenberg J4, Alibhai SM2.
– Review evidence of pre-operative exercise, known as ‘prehabilitation’, on peri- and postoperative outcomes in adult surgical populations
– Two reviewers examined the effects of pre-operative total-body exercise with peri- and postoperative outcome analysis.
– Given the nascence of this field, controlled and uncontrolled trials were included.
– 21 studies were included. Trials were generally small (median=54 participants) and of moderate to poor methodological quality.
(1) The majority of studies found that total-body prehabilitation improved postoperative pain, length of stay and physical function, but it was not consistently effective in improving health-related quality of life or aerobic fitness in the studies that examined these outcomes.
(2) Prehabilitation reduced postoperative length of stay with a small to moderate effect size
(3) Intervention-related adverse events were reported in two of 669 exercising participants.
(1) The literature provides early evidence that prehabilitation may reduce length of stay and possibly provide postoperative physical benefits.
(2) Cautious interpretation of these findings is warranted given modest methodological quality and significant risk of bias.
Gillis C1, Li C, Lee L, Awasthi R, Augustin B, Gamsa A, Liberman AS, Stein B, Charlebois P, Feldman LS, Carli F.
– The preoperative period (prehabilitation) may represent a more appropriate time than the postoperative period to implement an intervention.
– The impact of prehabilitation on recovery of functional exercise capacity was thus studied in patients undergoing colorectal resection for cancer.
– A parallel-arm single-blind superiority randomized controlled trial was conducted. 77 patients were randomized to receive either
(1) prehabilitation (n = 38)
(2) or rehabilitation (n = 39).
– Both groups received a home-based intervention of moderate aerobic and resistance exercises, nutritional counseling with protein supplementation, and relaxation exercises initiated either 4 wks before surgery (prehabilitation) or immediately after surgery (rehabilitation), and continued for 8 wks after surgery.
– Primary outcome was functional exercise capacity measured using the validated 6-min walk test.
(1) Median duration of prehabilitation was 24.5 days.
(2) While awaiting surgery, functional walking capacity increased (≥ 20 m) in a higher proportion of the prehab group compared with rehab group (53 vs. 15%)
(2) Complication rates and duration of hospital stay were similar.
(3) The difference between baseline and 8-week 6-min walking test was significantly higher in the prehab compared with the rehab group
(4) A higher proportion of the prehab group recovered to or above baseline exercise capacity at 8 wks compared with the rehab group (84 vs. 62%)
– Meaningful changes in postoperative functional exercise capacity can be achieved with a prehabilitation program.
By Melissa Walker Published March 2014 Reviewed by Lillie Shockney, RN, BS, MAS
– A study in BMJ (British Medical Journal) showed less fatigue, increased strength and greater aerobic capacity in chemo patients who participated in a 6 wk exercise program; To break a sweat safely, even when you’re in your most fragile state
– Clear any exercise program with your oncologist and then follow these guidelines:
(1) Know your limits. Exercising is more risky during chemotherapy because chemo weakens the body’s ability to make [oxygen-carrying] red and [infection-fighting] white blood cells, and exercise can also slow the formation of new blood cells. Choose an activity that’s gentle and balancing for the body, like stretching or walking slowly—not something that will weaken you. If you feel tired, take a break or stop for the day. Your goal is to do movements that make your body feel good.
(2) Redefine “exercise.” Any physical activity that’s healing for your body counts—think meditation, acupuncture and massage. These can be your workouts when you’re feeling weakened or would like to choose a more passive physical experience.
(3) Dodge germs and injury. Fitness clubs, yoga studios and other frequently traveled workout locations are a breeding ground for germs. “When your immunities are low, find a private space to exercise. Also, be sure to avoid contact sports, such as football and soccer, which are more likely to result in injury. Your immune system is weak, so it may take your body longer to heal from even mild cuts, bumps and bruises.
(4) Walk. Taking a stroll is a good thing, and it can easily turn into an opportunity for meditation.
Sanchis-Gomar F1, Berger NA11. et al
– Sedentary lifestyle is associated with elevated cancer risk whereas regular physical activity (PA) and high cardiorespiratory fitness (CRF) have the opposite effect, with several biological mechanisms mediating such associations
– There is a need for lifestyle interventions aimed at increasing PA levels and CRF of general population and particularly cancer survivors
– Further, provocative data suggest a dose-dependent benefit of increasing levels of PA and/or CRF against cancer risk or mortality
– Current PA guidelines (≥150 min/wk of moderate-to-vigorous PA) may not be sufficiently rigorous for preventing cancer nor for extending cancer survivorship
Helene Rundqvist,1,* and Arne Östman1
– Physical activity is associated with reduced risk of several cancers, including aggressive prostate cancer.
– The mechanisms mediating the effects are not yet understood; among the candidates are modifications of endogenous hormone levels.
– Long-term exercise is known to reduce serum levels of growth stimulating hormones.
– In contrast, the endocrine effects of acute endurance exercise include increased levels of mitogenic factors such as GH and IGF-1.
– It can be speculated that the elevation of serum growth factors may be detrimental to prostate cancer progression into malignancy.
– The incentive of the current study is to evaluate the effect of acute exercise serum on prostate cancer cell growth.
– 10 male individuals performed 60 minutes of bicycle exercise at increasing intensity.
– Serum samples were obtained before (rest serum) and after completed exercise (exercise serum).
– The established prostate cancer cell line LNCaP was exposed to exercise or rest serum.
(1) Exercise serum from 9 out of 10 individuals had a growth inhibitory effect on LNCaP cells.
(2) Incubation with pooled exercise serum resulted in a 31% inhibition of LNCaP growth and pre-incubation before subcutaneous injection into SCID mice caused a delay in tumor formation.
(3) Serum analyses indicated two possible candidates for the effect; increased levels of IGFBP-1 and reduced levels of EGF
– Despite the fear of possible detrimental effects of acute exercise serum on tumor cell growth, we show that even the short-term effects seem to add to the overall beneficial influence of exercise on neoplasia.