-IBIS-1.7.0-
tx
reproductive system
breast cancer
Diagnoses

definition and etiology

definition:

Malignancy of the breast.

etiology:

The risk of an American woman developing breast cancer during her lifetime is approximately 11%, or 1 in 8 women, with approximately 3-4% dying of the disease. Breast cancer accounts for 27% of all cancers in women. It is rare in women under 30, and greatly increases in incidence after menopause.

Factors known to increase the risk of breast cancer include a diet high in fats, alcohol consumption, radiation of the breast, and unopposed estrogen stimulus. Several factors appear to increase the risk of developing breast cancer, including family history, reproductive history, diet high in fats, alcohol consumption, radiation exposure, and hormone usage, especially unopposed estrogen stimulus. Despite the recognition of these risk factors, approximately 70% of the women who develop breast carcinomas do not have any of these identifable risk factors.

A study published in the New England Journal of Medicine tracked 1,300 women for 25 years, they found those who had the densest bones were 3.5 times more likely to develop breast cancer than those with the least dense bones. It is important to note that the researchers acknowledge that it may be a woman's lifetime exposure to estrogen that could increase her chances of developing breast cancer -- not necessarily estrogen taken during and after menopause. (Zhang Y, et al. N Engl J Med 1997 Feb 27;336(9):611-617. )

signs and symptoms

signs and symptoms:

Painless lump.

Skin dimpling.

Nipple retraction.

Bleeding from the nipple.

Peau d'orange skin with discoloration from lymph blockage.

Axillary, supraclavicular or infraclavicular lymphadenopathy.

Attachment of the mass to the surrounding tissues.

Symptoms of an infection (in inflammatory carcinoma and Paget's disease of the breast): skin over the tumor becomes red, warm, painful, hardened, and edematous.

lab findings:

(+) Mammography.

(+) Biopsy.

course and prognosis

Breast cancer accounts for 18% of all cancer deaths in women. Five-year survival rates vary significantly based on size of tumor and extent of metastasis:

tumor was smaller than 2 cm with no metastases (80%)

tumor was larger than 2 cm with no metastases (65%)

tumor was greater than 5 cm with no metastases though nodes are palpable (40%)

there are distant metastases (10%).

Conventional treatment includes lumpectomy, mastectomy (nowadays mainly partial), radiation therapy, chemotherapy, and hormonal therapy.

differential diagnosis

Fibrocystic breast disease.

Fibroadenoma.

Intraductal papillomas.

Lipomas.

footnotes

O'Brien K, Caballero B. High bone mass as a marker for breast cancer risk. Nutr Rev 1997 Jul;55(7):284-286. (Review)

Abstract: Postmenopausal women in the highest quartile for metacarpal bone mass were found to have an increased risk of

developing breast cancer, after adjusting for age and other variables known to influence breast cancer risk. Although the

mechanisms responsible for this relationship have not been identified, postmenopausal bone mass may serve as an indicator

of cumulative estrogen exposure.

Smith-Warner S, et al. Alcohol and Breast Cancer in Women A Pooled Analysis of Cohort Studies. JAMA. 1998;279:535-540.

Abstract: Combining analyses from 6 prospective studies that included a total of 322,647 women evaluated for up to 11 years, cconcluded that alcohol consumption is associated with a linear increase in breast cancer incidence in women over the range of consumption reported by most women. For alcohol intakes less than 60 g/d (reported by >99% of participants), risk increased linearly with increasing intake. Limited data suggested that alcohol intakes of at least 60 g/d were not associated with further increased risk. The specific type of alcoholic beverage did not strongly influence risk estimates. The association between alcohol intake and breast cancer was not modified by other factors. Among women who consume alcohol regularly, reducing alcohol consumption is a potential means to reduce breast cancer risk.

Zhang Y, Kiel DP, Kreger BE, Cupples LA, Ellison RC, Dorgan JF, Schatzkin A, Levy D, Felson DT. Bone mass and the risk of breast cancer among postmenopausal women. N Engl J Med 1997 Feb 27;336(9):611-617.

Abstract: BACKGROUND: Recent studies have shown a direct relation between serum estrogen levels assessed at a single point in time and the risk of breast cancer, but no evidence links estrogen levels assessed repeatedly over an extended interval to the risk of breast cancer. Bone mass has been proposed as a marker of cumulative exposure to estrogen in women. We therefore studied the association between bone mass and the incidence of breast cancer. METHODS: Between 1967 and 1970, 1373 women who were 47 to 80 years old and had no history of breast cancer underwent posteroanterior hand radiography in the Framingham Study. We used radiogrametry to measure the cortical width of each woman's second metacarpal. Participants were followed until the end of 1993. All incident cases of breast cancer were confirmed by pathological reports. We used a Cox proportional-hazards model to examine the relation of metacarpal bone mass to the

risk of postmenopausal breast cancer. RESULTS: Postmenopausal breast cancer developed in 91 subjects. Incidence rates per 1000 person-years increased from 2.0 among the women in the lowest age-specific quartile of metacarpal bone mass to 2.6, 2.7, and 7.0 among the women in the second, third, and highest quartiles, respectively. After adjustments for age and other potential confounding factors, the rate ratios for the risk of breast cancer were 1.0, 1.3, 1.3, and 3.5 from the lowest quartile to the highest (P for trend, <0.001). CONCLUSIONS: Women in the highest quartile of bone mass are at higher risk for postmenopausal breast cancer than those in the lowest quartile. The mechanisms underlying this relation are not understood, but cumulative exposure to estrogen may play a part.