[Results of the conservative surgical and irradiation treatment of 132 nonpalpable ductal carcinomas in situ of the breast]

[Ductal in situ carcinoma: is it ethical to consider the breast conserving therapy as a standard?]

The increasing incidence of DCIS during the past 20 years needs a continuous evaluation of the treatment strategies and a multidisciplinary decision process. The management of the DCIS remains a challenging issue in 2003. Mastectomy should still be considered as the reference treatment which is able to guarantee cure in almost all cases, whereas breast conserving surgery followed by radiation therapy is associated with 7-10% of local recurrence. However, the increasing knowledge of the predictive factors of the local recurrence allows to propose a conservative treatment strategy to a large amount of patients, without negative impact on their prognosis. This review presents the arguments that permit to justify the reasoned choice of the different therapeutic options according to the clinico-pathological situations.

Carcinome canalaire in situ du sein

OBJECTIVE

This study assesses the results of "current clinical practice" among 882 women treated in nine French Cancer Centers from 1985 to 1995 for pure ductal carcinoma in situ (DCIS) of the breast.

METHOD

Median age was 53 years (range 21-87); 177 (20%) patients underwent mastectomy (M), 190 (22%) conservative surgery alone (CS) and 515 (58%) conservative surgery with radiotherapy (CS + RT).

RESULTS

The crude 7-year local relapse (LR) rates were 2%, 31% and 13% among the M, CS and CS+RT subgroups (p<0.0001). All four LR after M were invasive as well as 31 (52%) out of 59 and 40 (61%) out of 66 in the CS and CS+RT groups. Distant metastases occurred in 1%, 3% and 1% of the three treatment groups. No LR factors were found in the M group. Among women treated with CS, the 7-year LR rates were 36%, 31% and 30% among women aged 40 or less, 41 to 60 and 61 or more (NS). For women treated by CS+RT, the LR rates in these age subgroups were 33%, 13% and 8%, respectively (p<0.0001). Patients with negative, positive or uncertain margins had 7-year LR rates of 26%, 56% and 29% respectively if treated with CS (p=0.02) and 11%, 23% and 9% if treated with CS+RT (p=0.0008). RT reduced LR rates by 65% in all histological subgroups, but more particularly in comedocarcinoma and mixed cribriform/papillary subgroups. The 7-year rate of contralateral breast cancer was 7%, identical in all subgroups.

CONCLUSION

Mastectomy remains the safest treatment for women with DCIS, with a 98% 7-year control rate. After conservative surgery, RT reduces very significantly LR rates, according to the NSABP B-17 and EORTC 10853 randomized trial results. The RT benefit is present in all clinical/histological subgroups, but its magnitude varies. Young age (<40 years) and incomplete excision are the most important LR risk factors.

Breast-conserving therapy for ductal carcinoma in situ of the breast: the French Cancer Centers' experience

PURPOSE

To assess the long-term outcome for women with ductal carcinoma in situ of the breast treated in current clinical practice by conservative surgery with or without definitive breast irradiation.

METHODS AND MATERIALS

We analyzed 705 cases of ductal carcinoma in situ treated between 1985 and 1995 in nine French regional cancer centers; 515 underwent conservative surgery and radiotherapy (CS+RT) and 190 CS alone. The median follow-up was 7 years.

RESULTS

The 7-year crude local recurrence (LR) rate was 12.6% (95% confidence interval [CI] 9.4-15.8) and 32.4% (95% CI 25-39.7) for the CS+RT and CS groups, respectively (p <0.0001). The respective 10-year results were 18.2% (95% CI 13.3-23) and 43.8% (95% CI 30-57.7). A total of 125 LRs occurred, 66 and 59 in the CS+RT and CS groups, respectively. Invasive or microinvasive LRs occurred in 60.6% and 52% of the cases in the same respective groups. The median time to LR development was 55 and 41 months. Nine (1.7%) and 6 (3.1%) nodal recurrences occurred in the CS+RT and CS groups, respectively. Distant metastases occurred in 1.4% and 3% of the respective groups. Patient age and excision quality (final margin status) were both significantly associated with LR risk in the CS+RT group: the LR rate was 29%, 13%, and 8% among women aged < or =40, 41-60, and > or =61 years (p <0.001). Even in the case of complete excision, we observed a 24% rate of LR (6 of 25) in women <40 years. Patients with negative, positive, or uncertain margins had a 7-year crude LR rate of 9.7%, 25.2%, and 12.2%, respectively (p = 0.008). RT reduced the LR rate in all subgroups, especially in those with comedocarcinoma (17% vs. 59% in the CS+RT and CS groups, respectively, p <0.0001) and mixed cribriform/papillary tumors (9% vs. 31%, p <0.0001). In the multivariate Cox regression model, young age and positive margins remained significant in the CS+RT group (p = 0.00012 and p = 0.016). Finally, the relative LR risk in the CS+RT group compared with the CS group was 0.35 (95% CI 0.25-0.51, p = 0.0001). Subsequent contralateral breast cancer occurred in 7.1% and 7.5% of the patients in the CS+RT and CS groups, respectively.

CONCLUSION

Despite the absence of randomization, our results are extremely consistent with the updated National Surgical Adjuvant Breast Project B17 and European Organization for Research and Treatment of Cancer 10853 trials. We also noted that the LR risk was very high in women <40 years and/or in the case of incomplete excision.