Andrew C. Neuschatz

BACKGROUND: A prospectively applied treatment policy for breast‐conserving therapy used margin assessment as the exclusive guide to the intensity of radiation therapy directed at the tumor bed.METHODS: From 1982 to 1994, 498 women with 509 Stage I/II breast carcinomas with a median follow‐up of 121 months were treated. Final margin status (FMS) categories were defined as greater than 5 mm, greater than 2–5 mm, greater than 0–2 mm, and positive. For margins less than or equal to 2 mm or indeterminate, reexcisions were performed if feasible. All patients received whole breast irradiation to 50.0–50.4 Gy. Final tumor bed boosts as a function of FMS were as follows: no residual on reexcision, no boost performed; FMS greater than 5 mm, boost of 10 Gy; FMS greater than 2–5 mm, boost of 14 Gy; FMS greater than 0–2 mm or positive, boost of 20 Gy. Cases were analyzed for local failure with respect to histology, age, tumor size, excision volume, reexcision, and total dose.RESULTS: FMS was positive, greater than 0–2 mm, greater than 2–5 mm, and greater than 5 mm, and no residual tumor on reexcision in 21%, 20%, 17%, 14%, and 28% of cases, respectively. At 12 years, Kaplan–Meier local failure rates were 17% for FMS positive, 9% for FMS greater than 0–2 mm, 5% for FMS greater than 2–5 mm, 0% for FMS greater than 5 mm, and 6% for specimens without evidence of residuum on reexcision (P = 0.009). Patients 45 years old and younger had a 12‐year local failure rate of 15% whereas patients older than 45 years had a 12‐year local failure rate of 6% (P = 0.01). On multivariate analysis, young age (P = 0.03) predicted increased local failure rate, whereas margins that were less than or equal to 2 mm or positive predicted late (> 5 years) but not early (≤ 5 years) recurrence (P = 0.003).CONCLUSIONS: Graded tumor bed dose escalation in response to FMS results in very low rates of local failure over the first 5 years for all FMS categories. However, tumors with close/positive margins have significantly increased local failure rates after 5 years of follow‐up even with increased radiation boost dose. In addition, graded tumor bed dose escalation does not fully overcome the adverse influence of young age. Cancer 2003;97:30–9. © 2003 American Cancer Society.DOI 10.1002/cncr.10981

BACKGROUND: Margin width is considered the most important risk factor for local recurrence in ductal carcinoma in situ (DCIS) of the breast. The purpose of this report is to assess the predictive utility of lumpectomy specimen margin assessment for the presence and extent of residual DCIS.METHODS: Specimens from 253 DCIS cases with lumpectomy and reexcision were studied to determine to the probability of residual DCIS on reexcision. The probability of residual tumor was evaluated with respect to tumor size, margin status, nuclear grade, presence of necrosis, patient age, and the extent of specimen processing (number of sections/volume tissue). Lesions were grouped by size: less than or equal to 2 mm, greater than 2–15 mm, greater than 15–40 mm, or greater than 40 mm. Margin width was recorded as the distance of DCIS to the closest specimen edge or, for positive margins, scored as: extensive (margin involvement in ≥8 sections or >4 low‐power fields [LPFs]), moderate (5–7 sections or 2–4 LPFs), minimal (2–4 sections or 1 LPF), or focal (1 section, single focus). The amount of residual tumor was graded by maximum dimension on a semiquantitative basis.RESULTS: Initial excision margin significantly predicted for the presence of residual tumor on reexcision. Residual tumor was found on reexcision in 85% of extensively positive, 68% of moderately positive, 46% of minimally positive, 30% of focally positive, 41% of greater than 0–1 mm, 31% of greater than 1–2 mm, and 0% of greater than 2 mm margins (P < 0.0001). On univariate analysis, margin width and lesion size of initial excision specimens significantly predicted for the presence of residual DCIS on reexcision. Age, grade, necrosis, and extent of specimen processing were not significant prognostic factors. On multivariate analysis, both initial margin width (P < 0.0001) and lesion size (P = 0.02) significantly predicted for residual DCIS. As for amount of residual tumor, margin width and initial lesion dimension both significantly predicted for medium to large residuum, whereas age 45 years or younger was of borderline significance on univariate analysis. On multivariate analysis, margin width and lesion size on initial excision both remained significant predictors of larger volume residual tumor.CONCLUSIONS: The margin status of a DCIS lumpectomy specimen is the most important predictive factor for both the presence and amount of residual disease. Cancer 2002;94:1917–24. © 2002 American Cancer Society.DOI 10.1002/cncr.10460