Although some studies have focused on the role of exercise on inflammation and cytokine expression in cancer patients undergoing treatment and survivors, to our knowledge none have investigated the effect of exercise during neoadjuvant treatment as a complementary therapy to 1) modulate inflammation which may have a positive influence on chemotherapy response and 2) preserve or improve skeletal muscle, thus preventing cancer cachexia. Furthermore, we believe that the neoadjuvant treatment period could be a window of opportunity to optimize patient's nutritional status before surgery, which until now has been under used.

Bearing in mind that nutritional interventions may also influence IL-6, our hypothesis is that a Combined Exercise and Dietary Intervention (CEDI) may induce positive alterations in cytokine profile and increase NK cell infiltration of the tumor in gastric and pancreatic cancer patients submitted to neo-adjuvant therapy.

Inclusion Criteria:

• gastric or pancreatic cancer stage II/III, eligible for neoadjuvant chemotherapy,
• age higher than 40 years and lower than 80 years,
• ECOG (Eastern Cooperative Oncology Group) functional status: 0-2,
• sedentary/low physical activity level.

Exclusion Criteria:

• life expectancy less than 12 months at inclusion,
• chemotherapy regimen other than 5-Fluorouracil, Folinic acid, Oxaliplatin, Docetaxel (FLOT) for gastric and 5-Fluorouracil, Irinotecan and Oxaliplatin (FOLFIRINOX) or gemcitabine for pancreatic cancer,
• metastatic disease,
• chronic anti-inflammatory medication use,
• known inflammatory condition (rheumatoid arthritis, ankylosing spondylitis or chronic active hepatitis)
• cardiovascular, respiratory or musculoskeletal or joint problems that preclude moderate physical activity.