Postoperative radiation therapy did not lower the recurrence rate among patients with ductal carcinoma in situ that was excised with margins of 10 mm or more. Patients in whom the margin width is less than 1 mm can benefit from postoperative radiation therapy.

DCIS patients with VNPI scores of 3 or 4 can be considered for treatment with excision only. Patients with intermediate scores (5, 6, or 7) show a 17% decrease in local recurrence rates with radiation therapy. Patients with VNPI scores of 8 or 9 exhibit extremely high local recurrence rates, regardless of irradiation, and should be considered for mastectomy.

Background. Infiltrating lobular carcinomas (ILC) represent approximately 10% of all breast cancers. The literature is mixed regarding their prognosis when compared with infiltrating duct carcinomas (IDC). There are few data regarding the treatment of ILC with radiation therapy. Methods. The clinical, pathologic, laboratory, and survival data of 161 patients with ILC were compared with the data of 1138 patients with IDC. Results. ILCs were larger, more difficult to excise completely, and more difficult to diagnose clinically. All prognostic factors measured were more favorable for ILC Nodal positivity for ILC was 32%, compared with 37% for IDC (P = 0.22). The 7‐year disease‐free Kaplan‐Meier survival (DFS) was 74% for patients with ILC and 63% for patients with IDC (P < 0.03). The 7‐year breast cancer specific survival (BCSS) was 83% for patients with ILC and 77% for patients with IDC (P < 0.04). Selected patients with smaller lesions were treated with excison and radiation therapy. Patients with ILC treated with radiation therapy had a better DFS and BCSS than did patients with IDC treated with radiation therapy. Conclusions. ILCs often are homogeneous, small cell tumors of low nuclear grade. Their desmoplastic reaction may be absent or less marked than that of IDC, making them more difficult to palpate and to visualize mammographically. Despite this, they can be treated successfully with either mastectomy or excision and radiation therapy.

Background. Axillary dissection has been a routine part of breast cancer treatment for more than 100 years. Axillary node involvement is the single most important prognostic variable in patients with breast cancer. Recently, routine node dissection has been eliminated for intraductal carcinoma because so few patients had positive nodes. With the availability of numerous histologic prognosticators and the development of new immunochemical prognostic indicators, it is time to consider eliminating routine node dissection for lesions more advanced than duct carcinoma in situ (DCIS) but with extremely low likelihood of axillary involvement. Methods. Axillary node positivity, disease‐free survival, and breast cancer‐specific survival were determined for six breast cancer subgroups by T category: Tis (DCIS), T1a, T1b, T1c, T2, and T3. Results. Nodal positivity for DCIS was 0%; for T1a lesions, 3%. A large increase in nodal positivity was seen in lesions larger than 5 mm. (T1b, 17%; T1c, 32%; T2, 44%; T3, 60%). The rate of nodal positivity was statistically different as each T category was compared with the next more advanced T category. The disease‐free survival and breast cancer‐specific survival decreased with every increment in T value. Conclusions. Axillary node positivity increases as the size of the invasive component increases and is an excellent predictor of DSF and breast cancer‐specific survival. Consideration should be given to eliminating axillary node dissection for T1a lesions because of the low yield of positive nodes. Axillary node dissection should be performed routinely for T1b lesions and larger.

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