Quality of Life, Exercise Behaviour and Baseline Dietary Intake of Women Undergoing Neoadjuvant Chemotherapy in the DHA WIN Randomized Controlled Trial

• Author / Creator

  Douglas, Claire

• Breast cancer is the second most common cancer in Canada. It is estimated that one in eight Canadian women will be diagnosed with the disease in their lifetime. Neoadjuvant chemotherapy is often prescribed to improve surgical resection outcomes and reduce micrometastases. Achieving a pathological complete response (pCR) after neoadjuvant chemotherapy is associated with an improved prognosis. However, chemotherapy has been associated with side effects that undermine quality of life (QoL) and inhibit physical activity. Both exercise and supplementation of omega-3 polyunsaturated fatty acids during chemotherapy have been associated with reduced side effects and improved QoL in breast cancer patients. There are mixed findings regarding the relationship between exercise and pCR in patients with breast cancer. The current study analyzes secondary outcomes from the DHA WIN phase II randomized controlled trial which was designed to evaluate docosahexaenoic acid (DHA) supplementation (4.4 g/day) on tumour growth and metabolism in women with breast cancer undergoing six cycles of neoadjuvant chemotherapy (3 weeks/cycle) (n = 49). QoL questionnaires were completed at baseline and at the end of chemotherapy treatment (n = 47). Exercise questionnaires were completed at baseline, the start of cycles 2 to 6 and the end of cycle 6 (n = 42). A food frequency questionnaire was completed at baseline (n = 46) and pCR was assessed after surgery (n = 49). Estimated daily dietary intake of macronutrients, cholesterol, sodium, sugar and dietary fiber were not statistically significantly different between the DHA and placebo groups. Compared to Albertan women that completed the 2015 Canadian Community Health Survey (CCHS), the estimated daily intake of the DHA WIN cohort was greater for protein, total fat, total monounsaturated fatty acids, sodium and dietary fiber (all p ≤ 0.05). Compared to the CCHS cohort, a greater percentage of the DHA WIN cohort was above the acceptable macronutrient distribution range for fat (52.2% versus 32.9%, p = 0.008) and carbohydrate (8.7% versus < 3%, p = 0.008). All subscales of the Functional Assessment of Cancer Therapy (FACT) questionnaire (except emotional well-being), the fatigue subscale and the State-Trait Anxiety Inventory (STAI) score decreased over time in both the DHA and control groups (p-time ≤ 0.03). Emotional well-being and the Fordyce Emotions Combination score increased over time in both groups (p-time ≤ 0.03). DHA supplementation did not significantly mitigate the change in any QoL indicator over time. A change over time was observed for mean weekly aerobic exercise (p-time < 0.001) and resistance training frequency (p-time = 0.01). However, the DHA treatment did not significantly affect mean weekly aerobic exercise (p-interaction = 0.56) or resistance training frequency (p-interaction = 0.28) over time. Participants that met WHO’s aerobic exercise recommendation at baseline experienced a smaller decline in their FACT-General (FACT-G) total score, a greater decline in their Perceived Stress Scale and STAI scores, as well as a greater increase in their emotional well-being score over time (p-interactions ≤ 0.05). Similarly, participants that met WHO’s aerobic exercise recommendation at the end of cycle 6 experienced a smaller decline over time in their FACT-G total score and functional well-being (p-interactions = 0.01). Participants that met WHO’s resistance training recommendation at baseline experienced a smaller decline in their FACT-G total score and FACT-Breast (FACT-B) total score over time (p-interactions ≤ 0.06). Similarly, participants that met WHO’s resistance training exercise recommendation at the end of cycle 6 experienced a smaller decline in their functional well-being and FACT-B trial outcome indices (p-interactions ≤ 0.07). Meeting WHO’s aerobic or resistance training exercise recommendation at baseline or the end of cycle 6 was not associated with achieving a pCR. These findings suggest that aerobic and resistance training exercise before and during treatment have the potential to mitigate the negative effect of chemotherapy on various QoL indicators in patients with breast cancer. DHA did not appear to mitigate the change in participants’ QoL over time. Further research is needed to determine the role of exercise in achieving a pCR in this population.

• Subjects / Keywords

  • Breast cancer
  • Quality of life
  • Exercise
  • Dietary intake
  • Docosahexaenoic acid

• Graduation date

  Spring 2024

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/r3-6gqs-6439

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.