Circulating lipids and lipoproteins in women with metastatic breast carcinoma

Circulating Phospholipids as Biomarkers of Breast Cancer: A Review

Breast cancer is the most common cancer in women and the second leading cause of cancer deaths in women. The key to surviving breast cancer is early detection and treatment. Current technologies rely heavily on imaging of the breast, and although considered the gold standard, they have their limitations. There is a need for a more accurate screening test for women of all ages, which can detect the cancer at a cellular level and before metastasis. There have been extensive studies into markers for breast cancer including protein and nucleic acid biomarkers, but to date, these have been unsuccessful. A growing field of interest is the association between breast cancer (tissue and cells) and lipids, which is documented in the literature, and may be considered as a leading candidate in the breast cancer detection space.

Identification of breast cancer-associated lipids in scalp hair

A correlation between the presence of breast cancer and a change in the synchrotron-generated X-ray diffraction (XRD) pattern of hair has been reported in several publications by different groups, and on average XRD-based assays detect around 75% of breast cancer patients in blinded studies. To date, the molecular mechanisms leading to this alteration are largely unknown. We have determined that the alteration is likely to be due to the presence of one or more breast cancer-associated phospholipids. Further characterization of these lipids could be used to develop a novel, sensitive and specific screening test for breast cancer, based on hair initially, and potentially extendable to other biological samples.

The association between lipid profiles and breast cancer among Taiwanese women

BACKGROUND

Breast cancer incidence increased seven-fold from 1979 to 2002, and it has become the second most common cancer in Taiwanese women. Although the relationship between high-density lipoprotein cholesterol (HDL-C) and breast cancer has been studied, no consistent association has been explicitly confirmed. The aim of this study was to demonstrate the relationship between breast cancer and lipid profiles in Taiwanese women.

METHODS

A total of 150 breast cancer patients before treatment and 71 healthy controls were enrolled. Lipid profiles in fasting serum were measured after participants gave their consent.

RESULTS

The breast cancer patients had significantly lower values for HDL-C and apolipoprotein A-I (apoA-I), lower apoA-I/apoB ratios and higher values for very-low-density lipoprotein cholesterol (VLDL-C) than controls. After logistic regression analysis, the breast cancer patients had significantly higher values for VLDL-C and lower values for apoA-I after controlling for HDL-C and the apoA-I/apoB ratio.

CONCLUSIONS

Our findings demonstrate that higher VLDL-C and lower apoA-I values were significantly associated with breast cancer, with a greater association between apoA-I values and the development of breast cancer than for HDL-C values.

Elevated levels of plasma triglycerides are associated with histologically defined premenopausal breast cancer risk

Lipids and lipoproteins have been associated with breast cancer risk; however, published results have been inconsistent. To clarify these associations, we measured fasting lipids in women undergoing breast biopsies. A case-control study examined the association of fasting levels of lipids with histologically defined breast cancer risk. Four groups of premenopausal women were assembled on the basis of histological appearance of breast tissue: 1) no epithelial proliferation (n = 102), 2) proliferation without atypia (n = 53), 3) atypical hyperplasia or carcinoma in situ (n = 53), and 4) node-negative invasive cancer (n = 102). A postoperative fasting blood specimen was analyzed for cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triglycerides. Demographics, risk factors, diet, physical activity, fasting weight, and skin-fold thickness were measured. Triglyceride levels were significantly higher in women with node-negative invasive cancer (0.94 +/- 1.04 mg/ml) than in those with no epithelial proliferation (0.83 +/- 1.04 mg/ml, p = 0.03). This association persisted after adjustment for age, body size, lipids, reproductive and familial risk factors, and previous benign breast problems (p < 0.01), in keeping with an independent association of elevated triglycerides with breast cancer risk.

Associations between breast cancer, plasma triglycerides, and cholesterol

A case-control study investigating the association between plasma lipids and breast cancer was conducted among women aged 30-80 in Buffalo, NY. All eligible women from a large breast clinic and two area physicians' offices were requested to participate over a one-year period. Subjects completed a health questionnaire and donated a fasting blood sample prior to diagnostic breast biopsies. The 83 women found to have breast cancer (cases) had significantly higher plasma triglyceride values than did the 113 women found not to have breast cancer (controls). Lower plasma beta-carotene values were associated with breast cancer, but only in those women with elevated triglyceride or cholesterol. Plasma cholesterol values were lower in those breast cancer cases presenting with more advanced stages of cancer, suggesting that metabolic effects of clinical and preclinical breast cancer may lower cholesterol levels. Although the limitations of case-control studies are well-recognized, these data suggest an etiologic role for plasma triglycerides and beta-carotene or for related dietary factors.

Plasma lipids in premenopausal women with mammographic dysplasia

Epidemiological evidence indicates that mammographic dysplasia is associated with an increased risk of breast cancer, particularly in premenopausal women. To examine biochemical associations with mammographic dysplasia we have compared premenopausal women with different patterns of the breast parenchyma on mammography. One group had extensive radiological dysplasia (n = 30) and the other no dysplasia (n = 16). Both groups were recruited from mammographic units in the same way and then compared according to epidemiological risk factors, anthropometric measures, nutrient intake and plasma levels of oestradiol, progesterone and prolactin obtained in both follicular and luteal phases of the menstrual cycle as well as total plasma cholesterol and lipid fractions. Women with mammographic dysplasia were found to be leaner, more often nulliparous and to consume more alcohol than women without these radiological changes. Mammographic dysplasia and a family history of breast cancer were found to be independently associated with significantly higher levels of high density lipoprotein cholesterol (HDL-C) after taking into account the possible confounding effects of percentage body fat, parity and consumption of alcohol and dietary fat. Triglyceride levels were also independently associated with a family history of breast cancer. We conclude that further investigation is warranted of the role of plasma lipids in relation to breast cancer risk.

Plasma lipids and prolactin in patients with breast cancer

In a comparative study of pre- and postmenopausal women with benign and malignant breast disease, a number of differences were observed in circulating plasma prolactin and lipid concentrations. Plasma lipids, phospholipids, triglycerides, cholesterol and free fatty acids were all higher in blood obtained from breast cancer patients prior to surgery. HDL-Cholesterol levels were significantly lower in these patients. These differences remained when the patient groups were sub-divided according to menopausal status. Plasma prolactin concentrations were also found to be higher in cancer compared with non-cancer patients, this effect being more marked in premenopausal than in postmenopausal patients. Premenopausal patients with invasive or poorly differentiated disease had significantly higher prolactin levels than those with non-invasive disease. No correlations were found between plasma prolactin and any of the lipid fractions.

Peculiarities of hyperlipidaemia in tumour patients

The study group included 684 cases: 258 patients with breast carcinoma, 113 males with lung cancer, 42 patients with rectal tumours, 42 patients with stomach tumours, 59 patients with fibroadenomatosis, and 170 healthy subjects of varying age (male and female). A relatively high blood triglyceride level was found in patients with breast, lung, rectal (females), and stomach (female) tumours. The blood concentration of high-density lipoprotein-cholesterol in patients with breast, lung, and stomach (female) tumours was relatively low. The elimination of tumour (breast carcinoma) did not lead to significant changes in lipid metabolism. There was no correlation between degree of lipidaemia and stage of tumour progression except in the cases of rectal cancer. Preliminary results are presented on the tentative classification of hyperlipoproteinaemia in tumour patients, using the lipid concentration threshold values advocated by Carlson et al. (1977); an increased frequency of Type IV hyperlipoproteinaemia proved to be the most characteristic feature of tumour patients. The results are discussed in terms of the concept of the importance of lipid metabolic disturbances, primarily those due to ageing, in the genesis of the syndrome of "cancerophilia" (predisposition to cancer).

Response of serum cholesterol and triglycerides to hormone treatment and the relation of pretreatment values to mortality in patients with prostatic cancer

Cholesterol and triglycerides were measured in plasma samples from patient with cancer of the prostate before and after 3 months treatment with either Premarin, Provera, Provera and diethylstilbestrol, or diethylstilbestrol alone. Cholesterol was also measured before and after one of three doses of diethylstilbestrol or placebo. Pretreatment cholesterol levels at 196 +/- 1.3 mg per 100 ml (X +/- SE, N = 1093) were significantly lower than these reported for similar age group noncancer controls. Significant increases occurred with some of the estrogen treatments. Pretreatment cholesterol levels showed a significant negative correlation with age in Stage III and IV patients of both studies and a positive correlation with hemoglobin in Stage III patients of both studies. Pretreatment triglyceride levels at 120 +/- 1.9 mg per 100 ml (X +/- SE, N = 1089) were similar to levels reported for noncancer controls of similar age. Estrogen treatment produced a significant increase in triglyceride levels. Serum triglycerides were significantly correlated with hemoglobin, weight, and cholesterol and negatively correlated with age, Analysis of covariance for both cholesterol and triglycerides showed highly significant treatment effects, but no stage effects and no stage-treatment interactions. It showed that the pretreatment value is of extreme importance for predicting or explaining the 3-month value. Death rates were calculated by level of pretreatment cholesterol or pretreatment triglycerides for all Stage II and IV patients, all treatments combined, and for Study 2 and Study 3 separately. No consistent trends were evident for cholesterol. Spearman correlation coefficients between category of initial triglyceride value and rank of death rate were computed to test for a quadratic effect. When the absolute values of the initial triglyceride values minus the overall mean were correlated with the death rate, a significant negative correlation was found for all causes of death and for deaths due to cardiovascular disease and prostatic cancer. These results indicate that the death rate is highest near the overal mean for initial triglyceride values and decreases as the initial values deviate above or below the mean. Initial triglyceride levels appear to have potential as indicators of risk of death in patients with prostatic cancer. The percentage of patients dead at 1 year by initial triglyceride levels, measured only in Study 3, revealed a pattern similar to that observed for the death rate, that is, the highest percentages were associated with values near the overall mean.