1. To assess the fatty acid composition of plasma and neutrophil phospholipids (PL)of advanced cancer and to compare this with other patient groups of healthy subjects.

2. To assess n-6 and n-3 fatty acid content and extent of incorporation of supplemented oils into plasma and neutrophil phospholipids in pateints with advanced cancer.

3.To identify relationships among n-6 and n-3 fatty acids in plasma and cell phospholipids and some selected parameters of nutritional status.

• Presence of anorexia,defined as >3 on a visual analog scale.
• Loss of 50% or more of their pre-illness body weight.
• The ability to maintain oral intake.
• Normal cognition,defined as a normal Mini-Mental State Exam(Periera et al,1998) for age and level of education.
• Ability and willingness to give written ,informed consent

Recruitment : In the absence of a large base of reference data,the  patients groups,which represent a wide range of patient groups from critically ill to healthy subjects were used to obtain a context for the range of plasma phospholipids(PL) fatty acids observed in advanced cancer patients in this study. This study collected data in healthy subjects (n=6), advanced cancer (n=23), burn injury (n=18), and high dose chemotherapy with SCT (n=6) on a total of 53 subjects.

1. Advanced cancer patients were a cohort of subjects participating in a larger study. A random sub-sample of 14 subjects per treatment arm were assigned to receive more detailed measures of fatty acid as described in the present study.

2. Burn injury patients- recruitment methods were not detailed.

3. High dose chemotherapy patients-recruitment methods were not detailed.

4. Healthy subjects-recruitment methods were not identified.

Design : 

Eligible participants were randomised using a computer generated sequence to receive identical gelatin capsules containing fish oil or placebo(olive oil) for 14 days. The two treatment arms did not differ in age ,weight,presence of metastasis or mean number of capsules per day.

Due to the limited reference data for fatty acid composition of plasma in advanced cancer patients,multiple subject groups were selected for comparison. Each group of subjects had plasma and cellular level PL compostion assessed using the same laboratory as as the advanced cancer group.

 Participants were provided one of the following:

• 1 gram fish oil - 18 capsules/day x 14 days
• 1 olive oil - 18 capsules/day x 14 days (PLACEBO)

The following measures were taken:

• Blood for plasma and Neutrophil phospholipid: Day 0 & 14
• Weight: Day 1 & 14
• 3 Day Food Record: Beginning & End of 14d period (days not specified)

Blinding used -all investigators and health care workers were blinded to the treatment received throughout the trial.

Intervention : Advanced cancer patients

• Eligible participants were allocated to receive identical 1 gram gelatin capsules containing fish oil(180 mg EPA and 120 mg DHA Banner Pharmacaps,Olds,AB,Canada) or placebo (olive oil).
• Olive oil was was selected as the placebo ,as it was not expected to alter plasma lipids or essential fatty acid metabolism.
• Subjects were instructed to take 18 capsules orally each day for 14 days.

^a Includes 20:1(11),20:1(9),20:1(7) ^bIncludes 22.1(11),20:1(9),20:1(7). Fatty acid composition of fish oil and olive oil capsules was determined by gas liquid chromatography.

 Statistical Analysis:

• Power Calculation: N based on the ability to detect a change at 5% significance level in n-3 fatty acids in plasma after 2 weeks of supplementation with  fish oil.
• Chemotherapy and burn patients were not compared statistically to the advanced cancer patients because they were not controlled cohorts for sex,age or body composition.     
• T-test (differences between the high BMI and low BMI groups)
• Correltation analysis (BMI,kcal kg^-1 BW intake against plasma lipids)
• Paired t-test (changes in fatty acids composition within a supplemental group)
• Repeat measures ANOVA (Differences between groups and timepoints)
• Least squared means (differences between treatments and day 0 and 14)
• Data are reported as mean±s.e.m
• P<0.05 

Timing of Measurements:

1. Advanced cancer patients:

• Patients were instructed by a research assistant to keep a three day food record during three consecutive days both at the beginning and end of the 14 day supplemntation period .
• On day 0 and day 14 of supplementation,a non-fasting sample of peripheral blood(16 ml)was drawn by a registered nurse during in-home visits or in the clinic.

2. Burn injury patients:

• A non-fasting wenous blood sample (10 mL) was collected within the first 12 days(n=10) and after 50 days(n=8) following the burn injury. Timepoints were compared using a repeated measures ANOVA.

 3. High dose chemotherapy patients:

• Blood (16 ML0 was collected into heparinsed tubes at stem cell harvest(~ 2 weeks post induction chemotherapy) and on the day of disharge( ~ 2 weeks post-HDCT). A paired t-test was used to compare pre-and post chemotherapy values.    

4. Healthy subjects: information not detailed.

Dependent Variables

Initial N:

• Advanced Cancer: n=23 [Fish Oil: n=13 (8 male, 5 female); Control: n=10 (10 male, 0 female)]
  • The patients with advanced cancer were a cohort of subjects participating in a larger study. A random sub-sample of 14 subjects per treatment arm were assigned to receive more detail measures of fatty acid as described in this study. Characteristics are in Table 2.
• Burn Injury: n=18 (details not described)
• High Dose Chemotherapy w/ SCT: n=6 (0 male, 6 female) (details not described
•  Healthy subjects: n=6, details not described   

Attrition (final N): n=23 [Fish Oil: n=13 (8 male, 5 female); Control: n=10 (10 male, 0 female)]

• Reasons for not completing the study including failure to maintain intake of the oil capsules,complications due to cancer progression , and death(n=4).

Ethnicity: Not detailed.

Other relevant demographics: Groups did not differ significantly in age,or the presence of metastasis. The primary site of the cancer varied widely among subjects in both groups(See Table 2).

Anthropometrics :Groups did not differ significantly in body weight

Location: University of Alberta, Canada 

• Advanced Cancer Patients
  • Total plasma PL and most individual fatty acids in the PL lowest of all groups studied. 
  • Measure of EFAD elevated (0.3±0.04)
• Chemotherapy patients
  • Decreased level of long chain FA
  • All PUFA (except EPA & DHA) below limit of detection
  • Post high dose chemotherapy:
    • DHA undetectable
    • EPA fell to 7% of control values (0.1 µg/ml)

^a nil=<0.04; Abbreviations:PUFA polyunsaturated fatty acids, MUFA monounsaturated fatty acids,SFA saturated fatty acids.

• Advanced Cancer Patients
  • Baseline PL FA coincentrations different
  • Higher  levels of 20:4 n-6 in all PL classes of neutrophils led to higher n-6/n-3 FA ratio
    • +80% in PI,+ 80% in PC,+22% in PE and 100% in PS
  • Average levels EPA & DHA in neutrophil PL highly variable
  • • EPA levels range: undetectable to 4%
  • Highest levels of n-6 FA in neutrophil PL
• Chemotherapy Patients:
  • Undectable levels of n-3 FA in neutrophil PL post induction

^bnil=<0.04%. N/A=Not applicable. Data are expressed as means±s.e.m.  Abbreviations:PUFA polyunsaturated fatty acids, MUFA monounsaturated fatty acids,SFA saturated fatty acids.

• Advanced Cancer Patients:
  • Significant reduction in 20:4 n-6 content in the PI fraction to levels similar to control subjects.
  • Total n-3 FA content of neutrophil PC directly related to plasma PL n-3 FAcontent (r 0.78, p0.001)
  • n-6/n-3 ration of plasma PL directly relatd to n-6/n-3 ratio of neutrophil PC (r 0.67, p 0.007)
  • No significant increase in plasma PL concentration

 Data are expressed as means±s.e.m.(n=13).^ab Within a column grouping(i.e pre vs post FO) are significantly different.

Other Findings:

Advanced cancer patients

• Caloric intake 488-2152 Kcal/day
  • 1/3 patient with intake < 1,000 Kcal/d
  • Mean percentage of calories derived from fat was 31±7%.
• Caloric intake and total fat were highly correlated (r=0.97,P=0.0001).
• Average BMI ± 20.7 kg/m² (range 15-28)
  • Seperated into 2 groups (low BMI & high BMI)
  • No difference in caloric intake by BMI
• Both BMI and caloric intake varied over a broad range and were not significantly correlated(P=0.14).

• At baseline,patients with advanced cancer exhibited low levels(<30% of normal values of plasma phospholipids and constituent fatty acids and elevated 20:4 n-6 content in neutrophil phospholipids.
• High n-6 /n-3 fatty acid ratios in neutrophil and plasma phospholipids were inversely related to body mass index.
• Fish oil supplementation raised eicosapentaenoic acid and docosahexaenoic acid content in plasma but not neutrophil phospholipids.
• 20:4 n-6 content was related directly to increases in eicosapentaenoic acid in plasma 
• Limitations: The results presented here represent an initial approach and it is necessary to employ caution in comparing the data obtained from cancer patients with other patient groups which serve mainly to place the advanced cancer patiens in a context for discussion.  

• "Double -blinding"  procedure was not utilized.
• Advanced cancer group consisted of both hospital and outpatient subjects. Because the study also included outpatients, problems with patient compliance may have impacted the results of the study.
• Limitations noted by the authors are very relevant in evaluating the study design employed. True  experiments assume that individuals in the experimental and control groups are equivalent,so that the only reason they might differ on the outcome of interest is the program or intervention itself. 
• Power analysis goals were met for advanced cancer patients. "The number of patients entered into the study was based on the ability to detect a change at 5% significance level in n-3 fatty acids in plasma after 2 weeks of supplementation with  fish oil." 
• Article confusing, data included on non-cancer patients included