BOSTONNeither the presence nor the extent of lobular carcinoma in
situ (LCIS) is related to risk of local recurrence in patients with invasive
breast cancer treated with conservative surgery and radiotherapy, a retrospective
study from the Joint Center for Radiation Therapy has shown.
"This is very different from the situation with associated DCIS,"
Stuart Schnitt, MD, said at a general session. Joint Center data show that
infiltrating ductal carcinoma with a large amount of associated DCIS has
a five-year local recurrence rate of 24% vs 6% when there is little or
The LCIS study included 858 patients with clinical stage I or II infiltrating
ductal carcinoma (782 patients), infiltrating lobular carcinoma (44 patients),
or infiltrating carcinoma with mixed ductal and lobular features (32 patients),
treated with conservative surgery and radiotherapy.
Overall, neither local recurrence nor the incidence of distant failure
was related to histologic type. In terms of LCIS, 4% of patients with infiltrating
ductal cancer had associated LCIS. Not surprisingly, the vast majority
(93%) of patients with infiltrating lobular carcinoma had associated LCIS.
Of the patients with mixed ductal/lobular features, 59% had associated
Other prognostic factors for local recurrence were equally distributed
among the three groups and among those with and without LCIS. The most
important prognostic factor, margin status, was unknown in most patients.
The investigators then looked at the 10-year crude rate of local recurrence
among patients with and without LCIS. Patients with infiltrating ductal
carcinoma and no LCIS had a local recurrence rate of 14% vs 10% for those
few patients in whom LCIS was present. Among infiltrating lobular carcinomas,
there were no local recurrences in the three patients without LCIS, and
five (12%) among the patients with LCIS.
For patients with mixed features, local recurrence was 15% with no LCIS,
and 16% with LCIS. None of these differences were significant. Similarly,
the extent of LCIS was not associated with the risk of local recurrence
in any group. Based on these results, Dr. Schnitt suggests that the presence
of associated LCIS should not influence local management of infiltrating
ductal, lobular, or mixed carcinoma.