Inflammatory breast cancer: is it really a separate entity?

BACKGROUND Inflammatory breast cancer (IBC) is the most aggressive form of primary breast carcinoma and is associated with a dismal outcome despite the availability of multi-modality treatment options. PATIENTS AND METHODS This is a prospective case control study comparing two groups of newly diagnosed patients; the first with inflammatory breast cancer (IBC) and the second with locally advanced non inflammatory breast cancer (LABC). In both groups MIB1, ER, PR, Her2neu were assessed. Neo-adjuvant chemotherapy consisted of four cycles of FEC100 followed by modified radical mastectomy according to clinical response, postoperative chemotherapy with two courses of the same regimen followed by radiotherapy. Tamoxifen 20 mg po daily for 5 years in ER and/or PR positive tumours, starting after the completion of radiotherapy. Primary end points were a) comparison of MIB-1 score in both groups, b) comparison of clinical and pathological responses in both groups. Secondary endpoints were comparison of progression free survival and overall survival. RESULTS From a total of 42 patients, 21 were stage III B (T4d, N0-2 M0) IBC and 21 were stage III B (T4a-c, N0-2, M0) LABC. Patients in the age range from 28 to 68 were included and followed from November 2007 until February 2010 with a median follow-up period of 22.5 months. Toxicity of both arms, mainly haematologic, nausea and vomiting, was in general acceptable with no treatment-related deaths. Of the patients with IBC 81.3% had a high MIB-1 score as compared with 43.8% of patients with LABC (P-value = 0.028). Objective clinical response to neo-adjuvant chemotherapy in the IBC arm was 57.1% (4.8% complete response (CR)) as compared with 81% (9.5% CR) in LABC (P-value = 0.09). Overall pathological response (complete pathological response (pCR)+partial pathological response (pPR)) was 35.3% in the IBC arm compared with 40% in LABC arm (P-value = 0.618). One year, 2 year and median progression free survival (PFS) were 55.87%, 37.71% and 21.7 months, respectively in the IBC arm compared with 85.71%, 66.67% in LABC (median PFS was not reached) (P-value = 0.072). One and 2 year overall survival (OS) were 69.82% and 51.20%, respectively in the IBC arm compared with 95.24% and 95.24% in LABC arm (P-value = 0.0038). CONCLUSIONS IBC should be considered as a separate entity. A high MIB-1 score is a potential molecular marker for IBC.