The investigators have already proven that Mitotic Activity Index (MAI)is the most robust measure of proliferation in breast cancer tissue.

The purpose was to study whether 18 and 2-4 hours pre-operative per-oral carbohydrate loading (often given in gastrointestinal surgery i.e. enhanced recovery after surgery=ERAS) influences proliferation in the tumor, serum insulin characteristics, metabolic profile and survival.

It has been postulated that a "Western-style" diet, rich in carbohydrates (especially high glycemic carbohydrates) may have an effect on the incidence of breast cancer, and perhaps also prognosis. This may be mediated through the insulin-related pathways in breast cells which may show insulin-dependent proliferation, which may alter outcome.

Aims:

To study:

1. The inter-patient variation in insulin and insulin-related characteristics in the blood taken just before the operation from breast cancer patients, on a usual pre-operative fasting schedule;
2. The influence of the variation in insulin and insulin-related characteristics on proliferation and other cell biological features in the breast cancers of these patients;
3. Whether 4 and 18-hours pre-operative hyperglycaemic glucose loading (to reduce postoperative insulin resistance) influences proliferation (Mitotic Activity Index (MAI) and other cell biological features in breast cancer*
4. The influence of the short-term effect of a pre-operative low-glycaemic carbohydrate isocaloric diet on proliferation and other cell biological features of the primary breast cancer cells (Low-glycemic isocaloric diet intervention study);
5. Epidemiological risk factors: The correlation between epidemiological risk factors, insulin and insulin-related characteristics, proliferation, cell biological features and other biomarkers in breast cancer patients.
6. Estrogen Receptor positive tumors will be analyses separately.
7. Relapse free survival
8. Breast Cancer Specific Survival.

The Short-term effect of carbohydrates will be assessed in a randomized intervention study, where 30 patients receive oral carbohydrates 18 and 4 hours before surgery and 30 patients receive fasting procedure/water.

Primary Outcome

1. Proliferation in the tumor as measured by MAI.

Secondary Outcomes:

1. Serum insulin characteristics (S-insulin, S- insulin c-peptide, S-IGF and S-IGFBP3) will be measured at various peri-surgical timepoints

2. Changes in metabolic profile* in the tumor and in serum samples

3. Patient Reported Outcome Measures (PROM) on well being

4. Relapse free survival

5. Breast Cancer Specific Survival

   • Metabolic profile assessed by High Resolution Magnetic Resonance Spectroscopy (HR-MRS) in the tumor and in serum samples.

Inclusion Criteria:

• All consecutive operable patients in 2009-2010, with a clinical and/or radiologic and/or cytologic diagnosis of primary breast cancer, unless the exclusion criteria apply.

Exclusion Criteria:

1. Non-operable patients (i.e" patients with T3-4 (>5 cm) disease or distant metastases at the time of operation).
2. All patients who refuse to participate.
3. All patients with DCIS, micro-invasive cancer < 2mm diameter or tumors with histologic poor-quality material.
4. Co-morbidity (Insulin dependent Diabetes Mellitus, Cushing syndrome, previous or concurrent cancers except CIN and non-melanomatous skin cancer.
5. Mental inability to participate.
6. Persons allergic to one of the compounds in any of the two diets.

Breast cancer is 100 x more frequent in women than in men.

All data will be available to all researches involved in the study included the statistician allocated to the study.