Dr. Susan Love's Breast Book

PART ONEPART ONE

THE HEALTHY BREAST AND COMMON PROBLEMSTHE HEALTHY BREAST AND COMMON PROBLEMS

CHAPTER 1CHAPTER 1

The BreastThe Breast

IF YOU’RE READING THIS BOOK, it’s probably because you’ve come to think of the breast in terms of breast cancer: either it has the disease, or you’re worried it might develop. But I think it is important to start your reading with a quick review of just what the breast actually is and does.

Your breast is the only organ in your body that you are not born with. You come into the world with a nipple and lots of potential: some cells behind the nipple that, given the right hormonal stimulation, will grow and become a breast. These are called stem cells. I like to think these stem cells are like those capsules you had as a kid that held collapsed sponge animals. When you added water, a sponge animal appeared. In the breast, what is added to the cells are certain hormones. These hormones cause your nipple to grow, and then a whole breast. When you get pregnant, the hormones take the breast tissue to the next level, making it ready to turn blood into milk to nurse a baby. The breast milk not only nourishes; it also passes on immunity to friendly bacteria and viruses needed to colonize the child’s gut. Once that job is over, the breast cleans up all the milk-making cells and ducts and then makes new ones—to prepare for the next pregnancy. This continues for decades. When menopause comes along, this remarkable organ goes into retirement and just hangs out, literally and figuratively. Men’s breasts develop similarly, but without that crucial role in pregnancy. Finally, despite all their marvels, it’s important to know that you can live without breasts. Men and many women do it all the time. Still, they are pretty great and deserve some praise beyond their outward beauty!

Figure 1.1

Understanding a bit about anatomy will make much of the rest of the book clearer. The breast itself is usually tear shaped (Figures 1.1, 1.2). There’s breast tissue from the collarbone all the way down to the last few ribs, and from the breastbone in the middle of the chest to the back of the armpit. This becomes most obvious when you are pregnant and the tissue responds to the call to action. You suddenly notice parts of the breast you did not know you had. This, however, is also why it is impossible to tell a woman with cancer that you removed all of her breast. Unfortunately, breast tissue does not come in a different color or consistency than the surrounding flesh. Luckily, removing most of the tissue is sufficient most of the time for women seeking prevention or treatment of breast cancer.

Figure 1.2

Often there’s a ridge of fat at the bottom of the breast—the inframammary ridge (Figure 1.3). This ridge is perfectly normal, the result of walking upright: our breasts fold over themselves. Plastic surgeons take great care to reproduce this ridge when reconstructing a breast so that it will actually hang normally.

Figure 1.3

The areola is the darker area of the skin surrounding the nipple (Figure 1.4). Its size and shape vary from woman to woman, and its color varies according to complexion. In most women it gets darker after the first pregnancy. There are hair follicles around the nipple, so most women have at least some nipple hair. It’s perfectly natural, and you can ignore it. If you don’t like it, you can shave it off, pluck it out, use electrolysis, or get rid of it any sensible way you want—it’s just like leg or armpit hair, except softer. You may also notice little bumps around the areola that look like goose pimples. These are the little glands known as Montgomery’s glands. The nipple also has sebaceous glands, which I’ll talk about later in this chapter.

Sometimes nipples are “shy”: when they’re stimulated, instead of becoming erect, they retreat into themselves and become temporarily inverted. This is nothing to worry about; it has no effect on milk supply, breastfeeding, sexual pleasure, or anything else. However, this is different when nipples suddenly become permanently inverted (see Chapter 2).

Inside, the breast tissue is sandwiched between layers of fat, behind which is the chest muscle. The fat has some give to it, which is why we bounce. The breast tissue is firm and rubbery. One of my patients told me while I was operating on her that she thought the breast was constructed like a woman—soft and pliant on the outside and tough underneath. The breast also has its share of the connective tissue that holds the entire body together. This tissue has a solid structure—like gelatin—within which other kinds of tissues are loosely set. Sometimes called the stroma, it is getting more attention as recent studies show its importance in breast cancer.

Figure 1.4

Like the rest of the body, the breast has arteries, veins, and nerves. There is another, almost parallel, network called the lymphatic system, which consists of lymph vessels and lymph nodes. These recycle and filter lymph to help the body fight infection. The job of the lymphatic network is to collect the debris from the cells and strain it through the lymph nodes found scattered in nests throughout the body; it then sends the filtered fluid back into the bloodstream to be reused (Figure 1.5). This system does more than just recycle, however. In the process of filtering the unnecessary fluid, the lymph nodes record what is in it. If there is anything threatening—a bacterial cell, a bit of material foreign to the body, or a virus—they hold on to it and use it to develop an immune response (see Chapter 3). They send cells to identify the invader and make antibodies to fight it. The lymph nodes are important later in the book when we talk about the way breast cancer spreads. It is crucial to identify which lymph vessels and which lymph nodes drain a particular area of the breast so that these nodes can be removed and examined for signs of cancer.

Figure 1.5

THE BREAST: AN INTERACTIVE COMMUNITY

During most of my career the critical component of the breast has been thought to be the system of milk ducts, with everything else just along for the ride. Yet there has been little research on the actual anatomy of the breast ducts. So I have devoted much of my own research to the subject.

Over the years my studies¹ have confirmed the findings of other researchers.² When we try to insert a tube (called a cannula) into openings of the milk duct on the surface of the nipple, we find that there are between five and eight openings (Figure 1.6).³ But this may be deceiving. When we examine a breast that has been removed and cut horizontally across the nipple, more ducts appear to exist—between fifteen and twenty-two duct-like structures.⁴ This puzzle has still not been completely resolved, but recent work suggests that some of the ducts meet together inside the breast before they exit the nipple, thus sharing an opening, while others exit the nipple separately. In addition, some of what appear to be ducts may be something else: little glands that make a sebaceous material—a white, oily substance—and join with the milk duct. These sebaceous glands are found all over the body. We don’t know what they’re for or why there are so many around the nipple. My own theory is that they provide a coating that protects the skin—your own little skincare system. The nipple, designed to be sucked on, is especially vulnerable to getting chapped and sore, so having a lot of these glands makes sense.

Figure 1.6

My colleagues and I studied the anatomy of the breast beyond the nipple, using both autopsies and breasts removed by mastectomy (with the patients’ permission). We learned that the duct opening in the nipple leads into the breast in a straight line for a very short distance—only about a centimeter (less than one-half inch). There’s a little sphincter muscle here that prevents milk from squirting out when a breastfeeding woman is not nursing her baby. Behind that is a little antechamber called the lactiferous sinus. From there the ductal system, like a tree, breaks up into little branches that go to the back of the breast. These branches are the ducts. Leafing out at the end of each branch are the lobules, which make the breast milk and then send it through the ducts to the nipple (Figure 1.7). Each ductal system is independent of all the others; each creates milk separately. They coexist, but they don’t connect with one another. Each ductal system is completely lined or “tiled” by a single layer of small cells that completely coat the inside of the whole structure from nipple to the very last branch closest to the chest wall. Breast cancer was thought to arise from changes in these lining cells, as we will see later. Initially we believed that if we could selectively remove these lining cells from the inside of the ductal system when it is no longer needed for breastfeeding, we would be able to eliminate breast cancer. But recent studies have since shown that it isn’t quite so simple. It turns out that the cells living around the ducts and lobules—fat cells, fibrous cells, and white blood cells—are as specialized and important as the cells lining the inside of the ducts and lobules. The cells all influence each other in a complex community that creates the breast’s versatility, allowing it to go from the resting state to pregnancy and milk production and back to the resting state (Figure 1.8). What we do know is that when this interaction goes awry, it probably produces the environment that promotes cancer development and growth (see Chapter 3).

Figure 1.7

Figure 1.8

Supporting Cast

Besides the breast itself, there are two other organs that play an important role in breast cancer. These are the ovaries and the adrenal glands. These produce hormones that come into play in our current understanding of breast cancer and its treatment.

The Role of the Ovary

The Menstruating Years. From puberty onward the ovary produces the key hormones—estrogen and progesterone—needed to prepare for a pregnancy each month (Figure 1.9). This monthly process includes the breast. As the hormones stimulate the breast, we experience a familiar cyclical pattern of swelling, lumpiness, pain, and tenderness. This pattern, which involves over forty years of our reproductive lives, gives ample opportunity for minor changes in the breast to occur, resulting in many of the benign problems that women frequently experience (see Chapter 2).

Menopause. We used to assume that after menopause, when the ovaries are no longer capable of releasing eggs, they shrivel up, dry out, and become completely useless. This resulted in part from the fact that we could not detect estrogen levels in the blood. Now we understand that with menopause, the ovary shifts from production of hormones to making the precursors of hormones and letting the organs themselves produce the final product. This is done by the stroma, or background tissue, in which eggs are embedded. In youth you have more eggs and less stroma. As time goes on, you have fewer and fewer eggs and more and more stroma. The stroma gives up the cyclical rhythm of the menstruating years and produces testosterone and androstenedione, which are then converted into estrogen and progesterone in the breasts as well as in the bones, liver, and brain. This is why no estrogen was found in the blood—it is only the precursors of estrogen that circulate after menopause.⁵ The hormonal dance doesn’t end; the band just strikes up a different tune (see Figure 1.10).

Testosterone, of course, is a male hormone. But don’t panic: you’re not going to grow a beard, though you may find a few hairs on your chin. Much of a woman’s testosterone and androstenedione is converted throughout the body to estrone, a form of estrogen, by an enzyme called aromatase. This continued production of hormones varies somewhat from one woman to the next and may well explain some of the individual differences in symptoms after menopause. It also explains why women who have both ovaries removed surgically, losing all of these hormones, often have worse symptoms of menopause and increased vulnerability to cardiovascular disease and osteoporosis.⁶

Figure 1.9

Figure 1.10

What all this means is that the ovaries have more than one function. Reproduction is their most dramatic task, but it isn’t the only one. These organs have as much to do with the maintenance of the woman’s own life as they do with her role in bringing other lives into the world. A former medical colleague of mine, Bill Parker, confirmed the important role of the ovary postmenopausally when he demonstrated that women who had their ovaries removed preventatively during hysterectomy had an overall increase in mortality compared to women who kept their ovaries. This was even though they had less breast and ovarian cancer.⁷ The menopausal ovary is neither failing nor useless; it’s simply beginning to shift from a reproductive function to a maintenance one. It’s doing in midlife exactly what many people do—changing careers.

And what about the breasts? Clearly menopause is the ultimate involution—the breasts get the message that they will not be called into active duty again and can finally rest. But nothing is ever that simple. Different women have different levels of hormones after menopause, depending on several factors. If a woman has reached menopause through surgery such as hysterectomy or through chemotherapy, her hormone levels will change more dramatically than if she goes through it naturally. Even in the latter case, however, some women naturally have higher levels of estrogen or testosterone, which will cause higher rates of vulnerability to breast cancer. We have observed, for example, that women with osteoporosis have 60 percent less breast cancer than women with normal bone density, and we believe this is probably due to natural estrogen levels. If you have relatively high levels of estrogen in your body postmenopausally, you will have good bones and bad breasts; however, if your estrogen levels are lower, you will have good breasts and bad bones. These differences in residual hormonal stimulation may be seen on a mammogram. A person’s hormone levels may make the stroma appear denser than that of a woman whose breasts have totally gone into retirement and become mostly ducts suspended in fat.

Synthetic Hormones

Giving women hormones (estrogen and usually progestins) can result in hormone-sensitive breast tumors (see Chapter 6). Also, women on postmenopausal hormones often—but not always—experience an increase in breast density, known to be a risk factor for breast cancer (see Chapter 5). Yet not every woman who takes postmenopausal hormones gets breast cancer. It is likely that some women are more sensitive to postmenopausal hormones than others. Which ones and why remains a subject of much research. Recent studies suggest that mammographic breast density (see Chapter 7) may give us a hint. Karla Kerlikowske showed that postmenopausal women who still had dense breasts on a mammogram had a higher risk of cancer than those with fatty breasts.⁸

In addition, recent studies have shown that breast tissue itself has the enzyme aromatase, as noted earlier, which can convert testosterone and androstenedione into estrogen. This means that estrogen levels in the breast may indeed be higher than in the rest of the body after menopause and may explain the estrogen-sensitive cancers that can occur at this age. Our increasing understanding of the postmenopausal breast’s response to hormones will give us further insight into the cause of breast cancer after menopause.

Getting Acquainted

All this information can be intriguing and may lead you to a desire to get acquainted with your own breasts. This is a good idea, whether you are newly diagnosed or just worried. Those newly diagnosed may want to pay attention to how their breasts look and what is important to them as they try to figure out what surgical treatments are best for them. Those who have not been diagnosed will want to get to know what is normal for them so they will recognize a change. And those who have had breast cancer will need to become acquainted with their new normal.

To start this process, look at your breasts. Stand in front of a mirror and look at yourself. See how your breasts hang, and get a sense of how they project. If you’re young, they’ll tend to stick out; if you’re older, they’ll tend to be droopier. Feel the inframammary ridge, where the breast folds over itself, and the underlying muscles, the pectorals. Look at your nipple—what color is it? Does it have hairs or little bumps on it? If so, that’s perfectly normal. You might want to swing your arms around and watch how your breasts move—or don’t move—with the motion. Put your hands on your hips, flex your muscles, and stretch your arms up. How do your breasts look with each change of position?

It’s important to do this without judging your appearance. You’re not trying out for a Playboy centerfold; you’re learning about your body. Forget everything you’ve learned about what breasts are supposed to look like. These are your breasts, and they look fine.

The next step is to feel your breasts. It’s best to do this soaped up in the shower or bath so your hands can slip very easily over your skin. Put the hand of the side you want to explore behind your head. This shifts the breast tissue that’s beneath your armpit to over your chest wall. Because the tissue is sandwiched between your skin and your chest bones, you have good access to it. If you’re very large-breasted, you may want to do this lying down, in the bathtub or even in bed. You can then roll on one side and then the other to shift the breast closer to your chest wall so you can get a better feel for it.

Breast tissue generally has a texture that is finely nodular or granular, like large seeds. A lot of this more or less bumpy feeling is caused by the normal fat that intermingles with the breast tissue. Lumpy breasts have inspired some of the most unfortunate misconceptions about our bodies. Often this lumpiness gets confused with actual breast lumps, as discussed in Chapter 2. But lumpiness itself often gets bad press. Women have been told their lumpy breasts are symptoms of “fibrocystic disease” (see Chapter 2) and have suffered from needless anxiety, fear, and even disfiguring surgery.

Lumpy breasts are caused by the way the breast tissue forms itself. In some women the breast tissue is fairly fine and thus not perceived as “lumpy.” Others clearly have lumpy breasts, which can feel somewhat like cobblestone paving. Still others are somewhere between the extremes—just a bit nodular. There’s nothing unusual about this—breasts vary as much as any other part of the body. Just as some women are tall and some short and some are fair skinned and some dark, some have lumpier breasts and some have smoother breasts. There can even be differences within the same woman’s breasts. Your breasts might be a little more nodular near your armpit or at the top, for example, and the pattern may be the same in both breasts or may occur only in one. You’ll find if you explore your breasts that there’s a general, fairly consistent pattern. It’s important to get a sense of what your pattern is.

Variations in Breast Development

Healthy breasts come in many different shapes and sizes. There’s nothing “abnormal” about large, small, or asymmetrical breasts or about extra nipples (Figure 1.11).

Common variations in breast development fall into one of two categories: those that are obvious from birth and those that don’t show themselves until puberty. The latter are far more frequent. (There are also variations due to accident or illness, the surgical remedies for which are essentially the same as those used for genetic variations.)

Figure 1.11

Variations Apparent at Birth. The most common variation to appear at birth is polymastia—an extra nipple or nipples. These can appear anywhere along the milk ridge (see Figure 1.12). Usually the milk ridge—a throwback to the days when we were animals with many nipples—regresses before birth, but in some people it remains throughout life. Between 1 and 5 percent of extra nipples are on women whose mothers also had extra nipples. Usually they’re below the breast, and often women don’t even know they’re there, as they look like moles. When I would point out an extra nipple to a patient, it was usually the first time she’d been aware of it.

Extra nipples cause no problems and usually don’t appear cosmetically unattractive. One patient was actually fond of her extra nipple: she told me that her husband had one too, and that’s how they knew they were meant for each other! Men sometimes do have extra nipples, though as far as we know, they have them less frequently than women do. This may be due to some biological factor we don’t yet know about, or it may simply be that men and their doctors don’t notice the nipples because they’re covered by chest hair.

Figure 1.12

Extra nipples don’t cause any problems, though they may lactate if you breastfeed. There’s nothing wrong with this, unless it causes you discomfort.

A variation of the extra nipple is extra breast tissue without a nipple, most often under the armpit. It may feel like hard, cyst-like lumps that swell and hurt when you menstruate the way your breasts do. Like extra nipples, this extra breast tissue is often unnoticed by doctor and patient. One of my patients found that she had swelling under both armpits during her second pregnancy. It was probably caused by extra breast tissue, and it went down after she finished lactating. The extra tissue is subject to all the problems of normally situated tissue. I have had patients with cysts, fibroadenomas, or even cancers in such tissue.

Unless the extra nipple or breast tissue causes you extreme physical discomfort or psychological distress, there’s no need to worry about it. If it does bother you, it’s easy to get rid of surgically. The nipple can be removed under local anesthetic in your doctor’s office, and the extra breast tissue can be removed under either local or general anesthetic.

A much rarer condition is amastia—being born with a breast that has breast tissue but no nipple. It’s usually associated with problems in the development of the chest bone and muscles, like scoliosis and rib deformities. Aside from whatever medical procedures you may need because of the associated problems, you might want to have a fake nipple created by a plastic surgeon, in the same way a nipple is created during reconstruction after a mastectomy (see Chapter 13). The nipple can be created using skin from the breast, and the areola can be tattooed on or created using a skin graft, commonly from the inner thigh. Though this artificial nipple will look real, it won’t feel completely like a real nipple; its advantages are wholly cosmetic.

Some women have an underdeveloped breast on one side. This condition is sometimes called Poland’s syndrome, and it involves not just the breast but also the pectoralis muscle and the ribs as well as, in some cases, abnormalities of the hand. A woman with Poland’s syndrome may have a small but very deformed breast.

There is another condition in which women have permanently inverted nipples—they grow in instead of out—a congenital condition that usually won’t manifest until puberty.

Various injuries can affect breast development. This may happen surgically or with trauma. If the nipple and breast bud are seriously injured before puberty, the potential adult breast is destroyed as well. Sometimes injuring the skin can limit future breast development. Most commonly this occurs as a result of a severe burn. The resulting scars are so tight that breast tissue cannot develop. In the past some congenital conditions such as hemangiomas (birthmarks) were treated with radiation, which damaged the nipple and breast bud and prevented later growth. Any serious injury to the breast bud can cause such arrested development.

Variations Appearing at Puberty. Three basic variations appear when the breasts begin to develop: extremely large breasts, extremely small breasts, and asymmetrical breasts.

Very Large Breasts.