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| Breast Cancer |
Breast cancer, the most common cancer among women (excluding skin cancers), accounts for one in every three cancer diagnoses in the United States. As the leading cause of death in women age 35-50 in the US, breast cancer is a major public health problem with 1 in 8 women are expected to be diagnosed sometime during their lives. Only 5-6% of breast cancers are associated with heritable genetic mutations and such mutations are rare (0.1% of the general population). Therefore, most individuals or families with breast cancer do not have heritable mutations but such mutations do increase an individuals lifetime risk of breast cancer. Breast cancer in males is a very rare occurrence.
The National Cancer Institute has designated breast cancer as a top research priority. Early detection and treatment are key to survival. Monthly breast self exams and yearly mammograms (after age 40) are recommended.
Risk factors associated with breast cancer are:
The National Cancer Institute has designated breast cancer as a top research priority. Early detection and treatment are key to survival. Monthly breast self exams and yearly mammograms (after age 40) are recommended.
Risk factors associated with breast cancer are:
- Beginning menstruation early &/or late menopause.
- No children or children born after age 30.
- History of fibrocystic disease.
- Ethnic background; highest incidence in caucasians
- Family history of breast cancer.
- Hormone replacement therapy for 5 or more years after menopause.
Estrogen is clearly permissive in the induction of breast cancer. Inconclusive data suggests that oral contraceptives do not contribute to the induction of breast cancer. However, prudence suggests limiting the dose and duration of use. Obesity correlates positively with an increased risk of breast cancer. A history of fibrocystic disease of the breast, ovarian or endometrial cancer and exposure to ionizing radiation are also risk factors.
Breast cancer is usually detected by self exam where the woman finds a lump that is painless, non tender and movable. In more advanced cases the lump becomes anchored to the underlying muscle. The skin may show signs of the cancer by dimpling or retraction. Mammography, thermography, and ultrasound may be used for diagnosis. Breast biopsy is used for confirmation of diagnosis. Treatment can include surgery in the form of lumpectomy or mastectomy, sometimes followed by radiation, chemotherapy or endocrine therapy.
Breast cancer is usually detected by self exam where the woman finds a lump that is painless, non tender and movable. In more advanced cases the lump becomes anchored to the underlying muscle. The skin may show signs of the cancer by dimpling or retraction. Mammography, thermography, and ultrasound may be used for diagnosis. Breast biopsy is used for confirmation of diagnosis. Treatment can include surgery in the form of lumpectomy or mastectomy, sometimes followed by radiation, chemotherapy or endocrine therapy.
Breast Self-Exams.
Many medical personnel can provide instruction for performing a breast self exam. This procedure should be done monthly shortly after the menstrual period because the changes induced in the breast by progesterone may confuse results. The procedure should also be done monthly after menopause. If any abnormality is discovered, a physician should be contacted.
A physician will generally palpate the breasts in a similar manner during a physical exam. The basic steps include:
- Lie down with one hand behind your head.
- With the other hand, gently feel the extended breast, pressing lightly, with flattened fingers. Begin at the outer axillary portion (near arm pit) and move in a circular clockwise pattern inwardly toward the nipple. Gently feel for lumps or thickenings. Remember to feel all parts of the breast, including the underarm area.
- Repeat the same procedure sitting up with the hand still behind your head.
- Repeat the above steps for the other breast.
Mammographic screening.
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| Breast Cancer Symptoms |
Increased use of mammographic screening has resulted in breast cancers being detected earlier in development, with a concomitant decrease in mortality. A fundamental measure of the quality of all mammography systems is the capability to resolve microcalcifications. Clustered microcalcifications are the single most common sign of early breast cancer and very often are the only sign. Those that are indicative of cancer vary in shape and size from 100 to 300 mm. Currently, x-ray mammography is the only breast imaging technique suitable for screening. Screening requires highly sensitive imaging techniques because the detection of microcalcifications and subtle changes in soft tissue architecture are dependent on excellent spatial and contrast resolution. Differential x-ray attenuation of breast tumors, microcalcifications and distortions as compared to normal breast tissue can be properly visualized with film-screen techniques, thus providing an effective screening tool for breast cancer. Among available imaging modalities, conventional film-screen mammography allows for high-quality images at low radiation doses in the majority of patients. As a result, the overwhelming majority of mammograms are obtained via traditional film-screen techniques and read from conventional X-ray film. However, suspected cancerous lesions detected by mammography are not necessarily cancerous. Indeed, up to 75% of lesions detected by mammography prove to be false positives (non-cancerous).
Direct Digital Mammography.
Although direct digital mammography is an attractive alternative to conventional mammography, this technology has several well-known drawbacks related to equipment cost, object-contrast ratio, and inadequate spatial resolution. However, a recent publication on full-field direct digital mammography declares a spatial resolution approaching that of film-screen mammography. As this technology will undoubtedly progress, the future most probably includes screening by direct digital mammography which may eventually replace conventional film mammography.
Ultrasound.
Tumors or cysts of the breast are easily visualized using ultrasound. Solid masses can be distinguished from fluid filled cysts based the density dependent differential reflection of ultrasound waves. The procedure is quick, painless and does not expose tissues to radiation.
Treatment.
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| Signs of Breast Cancer |
Cancers of the breast are treated by several measures dependent on the patients' age, clinical status, the type and size of the tumor, the degree of spread, and the estrogen responsiveness of the tumor. Some 35% of cancer of the breast in women of childbearing age are estrogen-dependent, meaning that their continued growth is dependent on the presence of estrogen. Symptoms are often dramatically decreased by the removal of the ovaries, the major source of estrogen. Endocrine therapy using antiestrogens, such as tamoxifen, has response rates from 30-60%. Aromatase inhibitors that inhibit the conversion of precursors to estrogens is effective in hormone receptor-positive breast cancers.
Some 25 to 30% of breast tumors have more growth factor receptor protein (HER2) on the cells than is normal. These tumors can be treated with a monoclonal antibody that blocks the receptors and prevents activation of genes that induce cell division thereby slowing the growth of the tumor. This drug, trastuzumab (Herceptin® Genentech) is an antineoplastic drug that has the reported side effects of chills, diarrhea, nausea, weakness, headache and vomiting and possibly damage of the heart muscle, anemia, and nerve pain. Trastuzumab can be used alone or in combination with paclitaxel and is prescribed for metastatic breast cancer.
A low tumor burden and a good general condition of the patient have much to do with the effectiveness of hormonal treatment. Receptor positive (estrogen and/or progesterone) tumors are more prevalent in postmenopausal women. Therefore, hormonal treatment is more likely to be effective in postmenopausal women. Side effects include, edema, weight gain, uterine bleeding, depression, nausea, vomiting, breast tenderness and anorexia.
Early stage breast lesions (prior to lymph node involvement) have an 80% chance of cure with surgery alone. Conservative surgery is preferred rather than the more radical mastectomies of the past. When cancer has spread to the lymph nodes, the chances of recurrence are about 90% over 10 years when treated with surgery alone. Therefore, if the cancer has spread to involve 3 or fewer nodes, chemotherapy might be beneficial. More advanced cancers are difficult to treat and treatment is mostly palliative. Some successful remissions have been produced by the use of combination chemotherapy. Remissions have an average length of 10-15 months. Only 10-20% of metastatic breast cancer patients experience complete remission under chemotherapy.
Some 25 to 30% of breast tumors have more growth factor receptor protein (HER2) on the cells than is normal. These tumors can be treated with a monoclonal antibody that blocks the receptors and prevents activation of genes that induce cell division thereby slowing the growth of the tumor. This drug, trastuzumab (Herceptin® Genentech) is an antineoplastic drug that has the reported side effects of chills, diarrhea, nausea, weakness, headache and vomiting and possibly damage of the heart muscle, anemia, and nerve pain. Trastuzumab can be used alone or in combination with paclitaxel and is prescribed for metastatic breast cancer.
A low tumor burden and a good general condition of the patient have much to do with the effectiveness of hormonal treatment. Receptor positive (estrogen and/or progesterone) tumors are more prevalent in postmenopausal women. Therefore, hormonal treatment is more likely to be effective in postmenopausal women. Side effects include, edema, weight gain, uterine bleeding, depression, nausea, vomiting, breast tenderness and anorexia.
Early stage breast lesions (prior to lymph node involvement) have an 80% chance of cure with surgery alone. Conservative surgery is preferred rather than the more radical mastectomies of the past. When cancer has spread to the lymph nodes, the chances of recurrence are about 90% over 10 years when treated with surgery alone. Therefore, if the cancer has spread to involve 3 or fewer nodes, chemotherapy might be beneficial. More advanced cancers are difficult to treat and treatment is mostly palliative. Some successful remissions have been produced by the use of combination chemotherapy. Remissions have an average length of 10-15 months. Only 10-20% of metastatic breast cancer patients experience complete remission under chemotherapy.
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