Chapter 086. Breast Cancer (Part 6)

Breast Cancer: TreatmentPrimary Breast CancerBreast-conserving treatments, consisting of the removal of the primary tumor by some form of lumpectomy with or without irradiating the breast, result in a survival that is as good as (or slightly superior to) that after extensive surgical procedures, such as mastectomy or modified radical mastectomy, with or without further irradiation. Postlumpectomy breast irradiation greatly reduces the risk of recurrence in the breast. While breast conservation is associated with a possibility of recurrence in the breast, 10-year survival is at least as good as that after more radical surgery. Postoperative radiation to regional nodes following...
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Chapter 086. Breast Cancer (Part 6) Chapter 086. Breast Cancer (Part 6) Breast Cancer: Treatment Primary Breast Cancer Breast-conserving treatments, consisting of the removal of the primarytumor by some form of lumpectomy with or without irradiating the breast, result ina survival that is as good as (or slightly superior to) that after extensive surgicalprocedures, such as mastectomy or modified radical mastectomy, with or withoutfurther irradiation. Postlumpectomy breast irradiation greatly reduces the risk ofrecurrence in the breast. While breast conservation is associated with a possibilityof recurrence in the breast, 10-year survival is at least as good as that after moreradical surgery. Postoperative radiation to regional nodes following mastectomy isalso associated with an improvement in survival. Since radiation therapy can alsoreduce the rate of local or regional recurrence, it should be strongly consideredfollowing mastectomy for women with high-risk primary tumors (i.e., T2 in size,positive margins, positive nodes). At present, nearly one-third of women in theUnited States are managed by lumpectomy. Breast-conserving surgery is notsuitable for all patients: it is not generally suitable for tumors >5 cm (or forsmaller tumors if the breast is small), for tumors involving the nipple areolacomplex, for tumors with extensive intraductal disease involving multiplequadrants of the breast, for women with a history of collagen-vascular disease, andfor women who either do not have the motivation for breast conservation or do nothave convenient access to radiation therapy. However, these groups probably donot account for more than one-third of patients who are treated with mastectomy.Thus, a great many women still undergo mastectomy who could safely avoid thisprocedure and probably would if appropriately counseled. An extensive intraductal component is a predictor of recurrence in thebreast, and so are several clinical variables. Both axillary lymph node involvementand involvement of vascular or lymphatic channels by metastatic tumor in thebreast are associated with a higher risk of relapse in the breast but are notcontraindications to breast-conserving treatment. When these patients areexcluded, and when lumpectomy with negative tumor margins is achieved, breastconservation is associated with a recurrence rate in the breast of substantiallyworse than that of women who do not. Thus, recurrence in the breast is a negativeprognostic variable for long-term survival. However, recurrence in the breast isnot the cause of distant metastasis. If recurrence in the breast caused metastaticdisease, then women treated with lumpectomy, who have a higher rate ofrecurrence in the breast, should have poorer survival than women treated withmastectomy, and they do not. Most patients should consult with a radiationoncologist before making a final decision concerning local therapy. However, amultimodality clinic in which the surgeon, radiation oncologist, medicaloncologist, and other caregivers cooperate to evaluate the patient and develop atreatment is usually considered a major advantage by patients. Adjuvant Therapy The use of systemic therapy after local management of breast cancersubstantially improves survival. More than one-third of the women who wouldotherwise die of metastatic breast cancer remain disease-free when treated with theappropriate systemic regimen. Prognostic Variables The most important prognostic variables are provided by tumor staging.The size of the tumor and the status of the axillary lymph nodes providereasonably accurate information on the likelihood of tumor relapse. The relation ofpathologic stage to 5-year survival is shown in Table 86-2. For most women, theneed for adjuvant therapy can be readily defined on this basis alone. In the absenceof lymph node involvement, involvement of microvessels (either capillaries orlymphatic channels) in tumors is nearly equivalent to lymph node involvement.The greatest controversy concerns women with intermediate prognoses. There is rarely justification for adjuvant chemotherapy in most womenwith tumors