Differences in the pathologic features of ductal carcinoma in situ of the breast based on patient age.

BACKGROUND: Young patient age at diagnosis has been reported as a risk factor for recurrence in patients with ductal carcinoma in situ (DCIS) of the breast treated with breast-conserving therapy (BCT). The authors examined pathologic features of DCIS in three different age groups of patients to identify differences that might explain why young patient age at the time of diagnosis is a risk factor for recurrence.

METHODS: Excised specimens from 177 breasts of 172 patients with DCIS treated with BCT were studied. All slides from all specimens were reviewed. Patients were divided into 3 age groups: those age < 45 years, those ages 45-59 years, and those age >/= 60 years. The histologic features that were quantified included most common and highest nuclear grades, DCIS architectural pattern, amount of central necrosis (quartiles), calcifications, amount of DCIS, and number of terminal duct lobular units (TDLUs) with cancerization of lobules (COL) within 0.42 cm of the margin, margin status, and size and volume of excision specimens.

RESULTS: Patients age < 45 years at the time of diagnosis more frequently had higher nuclear grade DCIS (highest nuclear Grade 3: 69%, 60%, and 39%; P = 0.003), respectively and central necrosis (72%, 62%, and 44%; P = 0. 01), respectively. Although not statistically significant, younger patients tended to have comedo subtype DCIS more often (31%, 23%, and 19%; P = 0.35), respectively. Younger patients also more often had smaller initial biopsy specimen maximum dimensions (4.3 cm, 5.2 cm, and 5.7 cm; P = 0.004), respectively, with close or positive margins (89%, 61%, and 64%; P = 0.03), and more TDLUs with COL in the 0.42-cm rim of tissue adjacent to the margin (5.2, 3.6, and 1.9; P = 0.23), respectively. No other features including the amount of DCIS when classified as > 50% or > 75% of ducts, calcifications within DCIS ducts, pattern of DCIS involvement, number of slides examined, number of slides with DCIS, and mean number of DCIS ducts near the margin were found to occur more frequently in younger patients.

CONCLUSIONS: Younger patients with DCIS may have an increased risk of local recurrence when treated with BCT due to smaller initial excision volumes, a greater proportion of high nuclear grade DCIS, and central necrosis.