The breast and the menopause

Spatial variations in optical and physiological properties of healthy breast tissue

Near-infrared (NIR) diffuse optical spectroscopy (DOS) and diffuse optical imaging (DOI) show promise as noninvasive clinical techniques for breast cancer screening and diagnosis. Since NIR methods are based on optical contrast between healthy and diseased tissue, it is essential to characterize the sources of endogenous contrast in normal subjects. We report intra- and inter-subject variation and bilateral asymmetry of the optical and physiological parameters of 31 women using a seven-wavelength NIR frequency-domain photon migration (FDPM) instrument. Wavelength-dependent absorption and reduced scattering parameters (micro(a) and micro(s'), respectively) were measured in four major quadrants and the areolar regions of left and right breasts. These values were used to determine tissue concentrations of oxy-(HbO(2)) and deoxy-(Hb-R) hemoglobin, lipid content, water concentration, and tissue "scatter power." Mean total hemoglobin for premenopausal (PRE) women (20 to 30 microM) is approximately two-fold higher than for postmenopausal (POST) subjects at all positions. POST women have approximately 50% higher lipid content (50 to 60%) than PRE at all positions. Water concentration on average is 1.8-fold higher for PRE subjects (30 to 40%) than POST. These differences are most pronounced when comparing the areolar complex to the other regions of the breast. In premenopausal women, the areolar regions have 40 to 45% increased total hemoglobin concentration (THC), 20 to 25% lower lipid content, and 30 to 60% higher scatter power versus the quadrants. Small-scale (3 cm) changes in optical properties are negligible compared to large-scale variations over all quadrants, where the intrinsic spatial heterogeneity of healthy breast tissue is 20 to 40% for micro(a) and 5 to 12% for micro(s'). Although no consistent right-left differences are observed in the study population, relative differences between symmetric positions ranged from 18 to 30% for THC, 10 to 40% for adipose, 10 to 25% for water, and 4 to 9% for scattering (674 nm) within an individual.

Increase in breast size after menopause: prevalence and determinants

OBJECTIVES

To determine the prevalence and determinants of increases in breast size after menopause.

METHODS

Subjects were 1130 postmenopausal women, aged 54-71, participating in a population based breast cancer screening project, the DOM-project in Utrecht, The Netherlands. Questionnaire data on changes in breast size, parity, age at first childbirth, breast feeding, age at menarche, age at menopause, HRT use and usual weight between age 30 years and age at questionnaire were used. Weight and height were measured at three screening rounds and waist and hip circumference was measured once.

RESULTS

18.6% of the women reported that they had to buy a larger bra because of changes in breast size, whereas 1.7% reported that they had to buy a smaller bra. Weight gain, waist circumference, hip circumference, Quetelet's index at third screening, Quetelet's index at first screening, waist-to-hip ratio and years since menopause were significantly associated with increased breast size (odds ratios between 2.5 and 1.4) (all tests for trend P < 0.05), whereas age at menopause, HRT use, parity and age at menarche were modestly, though not significantly associated with increased breast size. Age, usual Quetelet's index, age at first childbirth and number of months of full breast feeding were not associated with increased breast size.

CONCLUSION

About one in five women experienced an increase in breast size after menopause. The most important factor associated with such an increase was found to be weight gain.

Comparison of physical and emotional side effects of progesterone or medroxyprogesterone in early postmenopausal women

OBJECTIVE

To compare the mood and somatic effects during the initial 2 months of medroxyprogesterone acetate (MPA) or progesterone combined with conjugated equine estrogen (CEE) in early postmenopausal women.

DESIGN

Twenty-three nondepressed, early postmenopausal women (average age, 52.5 years) completed a 91-day, single-blind pilot study with the following sequence of treatments: 1 week of no substance; 2 weeks of placebo; 2 weeks of progestogen only; 1 week of placebo; and 2 months of "standard hormone replacement therapy cycles," which consisted of (in order) 2 weeks of 0.625 mg CEE, 2 weeks of CEE plus progestogen, 2 weeks of CEE, and 2 weeks of CEE plus progestogen. Ten women who completed the study received MPA (5 mg/day) as their progestogen, and 13 who completed the study received micronized, oil-suspended progesterone (200 mg/day) as their progestogen. All participants made daily assessments of mood using the Profile of Mood States and daily recordings of somatic symptoms. All subjects had plasma follicle-stimulating hormone of greater than 35 IU/L and had not had spontaneous vaginal bleeding for more than 1 year.

RESULTS

None of the hormone treatments had a detectable effect on mood. MPA users reported more vaginal bleeding and breast tenderness than progesterone users.

CONCLUSIONS

In contrast with the widely held belief among psychiatrists that progesterone depresses mood, neither of the progestogens we used in normal, nondepressed and nonanxious women showed this effect. Absence of an effect on mood was also found when the results of the two progestogens were combined. The lesser side effects of the micronized progesterone-containing regimen suggest that some women may prefer it to an MPA-containing regimen.

Noninvasive functional optical spectroscopy of human breast tissue

Near infrared diffuse optical spectroscopy and diffuse optical imaging are promising methods that eventually may enhance or replace existing technologies for breast cancer screening and diagnosis. These techniques are based on highly sensitive, quantitative measurements of optical and functional contrast between healthy and diseased tissue. In this study, we examine whether changes in breast physiology caused by exogenous hormones, aging, and fluctuations during the menstrual cycle result in significant alterations in breast tissue optical contrast. A noninvasive quantitative diffuse optical spectroscopy technique, frequency-domain photon migration, was used. Measurements were performed on 14 volunteer subjects by using a hand-held probe. Intrinsic tissue absorption and reduced scattering parameters were calculated from frequency-domain photon migration data. Wavelength-dependent absorption (at 674, 803, 849, and 956 nm) was used to determine tissue concentration of oxyhemoglobin, deoxyhemoglobin, total hemoglobin, tissue hemoglobin oxygen saturation, and bulk water content. Results show significant and dramatic differences in optical properties between menopausal states. Average premenopausal intrinsic tissue absorption and reduced scattering values at each wavelength are 2.5- to 3-fold higher and 16-28 % greater, respectively, than absorption and scattering for postmenopausal subjects. Absorption and scattering properties for women using hormone replacement therapy are intermediate between premenopausal and postmenopausal populations. Physiological properties show differences in mean total hemoglobin (7.0 microM, 11.8 microM, and 19.2 microM) and water concentration relative to pure water (10.9 %, 15.3 %, and 27.3 %) for postmenopausal, hormone replacement therapy, and premenopausal subjects, respectively. Because of their unique, quantitative information content, diffuse optical methods may play an important role in breast diagnostics and improving our understanding of breast disease.