Preoperative twice-weekly paclitaxel with concurrent radiation therapy followed by surgery and postoperative doxorubicin-based chemotherapy in locally advanced breast cancer: a phase I/II trial.

PURPOSE: Preoperative chemotherapy is the conventional primary treatment in locally advanced breast cancer (LABC). We investigated the safety and efficacy of primary twice-weekly paclitaxel and concurrent radiation (RT) before modified radical mastectomy followed by adjuvant doxorubicin-based chemotherapy. PATIENTS AND METHODS: Stage IIB (T3N0) to III LABC patients were eligible. Primary chemoradiation consisted of paclitaxel, 30 mg/m(2) delivered intravenously for 1 hour twice weekly for a total of 8 to 10 weeks, and concurrent RT (45 Gy at 1.8 Gy/fraction). Modified radical mastectomy was performed at least 2 weeks after completion of chemoradiation or on recovery of skin toxicity. Postoperatively, patients who responded to paclitaxel and RT received four cycles of doxorubicin/paclitaxel, whereas patients who did not respond received doxorubicin/cytoxan. RESULTS: Forty-four patients were accrued. Toxicity from paclitaxel/RT included grade 3 skin desquamation (7%), hypersensitivity (2%), and stomatitis (2%). Postsurgery complications occurred in six patients (14%). The only grade 4 toxicity of postmastectomy chemotherapy was hematologic (10%). Grade 3 toxicities were leukopenia (24%), infection (22%), peripheral neuropathy (17%), arthralgia and pain (17%), stomatitis (12%), fatigue (10%), esophagitis (5%), and nausea (2%). Overall clinical response rate to preoperative paclitaxel and RT was 91%. Thirty-four percent of patients achieved a pathologic response in the mastectomy specimen: 16% pathologic complete responses (clearance of invasive cancer in the breast and axillary contents) and 18% pathologic partial responses (< 10 residual microscopic foci of invasive breast cancer). CONCLUSION: Twice-weekly paclitaxel with concurrent RT is a feasible and effective primary treatment for LABC. Future studies should compare primary chemoradiation to chemotherapy in LABC.

Low HER2/neu gene expression is associated with pathological response to concurrent paclitaxel and radiation therapy in locally advanced breast cancer.

PURPOSE: The objective of this study was twofold: first, to identify patients with locally advanced breast cancer (LABC) who will achieve a pathological response to a preoperative regimen of concurrent paclitaxel and radiation; and second, to explore associations between molecular markers from the original tumors and pathological response. METHODS AND MATERIALS: Patients with previously untreated LABC were eligible to receive a regimen of preoperative concurrent paclitaxel, 30 mg/m(2) twice a week for a total of 8 weeks, and radiation delivered Weeks 2--6, 45 Gy at 1.8 Gy per fraction to the breast, ipsilateral axilla, and supraclavicular nodes. At mastectomy, pathologic findings were classified as pathological complete response (pCR) = no residual invasive cells in the breast and axillary contents; pathological partial response (pPR) = presence of < or = 10 microscopic foci of invasive cells; no pathological response (pNR) = pathological persistence of tumor. For each patient, pretreatment breast cancer biopsies were prospectively analyzed by immunohistochemistry (IHC) for estrogen and progesterone (ER/PR) hormonal receptors, HER2/neu and p53 overexpression. Estrogen receptor (ER), HER2/neu, metablastin, beta-tubulin III and IV, microtubule-associated protein-4 (MAP-4), bcl-2, bax, and cyclooxygenase-2 (COX-2) gene expression were measured using real-time quantitative polymerase chain reaction (PCR). RESULTS: A total of 36 patients had pretreatment biopsies and were evaluable for the analysis of the association of molecular markers with pathological response. Pathological response in the mastectomy specimen was achieved in 12 of these 36 patients (33%). Only HER2/neu and ER gene expression were found to be significantly associated with the extent of pathological response to the regimen, i.e., tumors with low HER2/neu gene expression and negative estrogen receptors were more likely to respond to the tested regimen (p = 0.009 and p = 0.006, respectively). Conversely, p53 protein expression measured by IHC did not appear to be associated with pathological response (p = 0.67). CONCLUSION: Further studies in LABC should assess whether patient selection for treatment based on the original tumor molecular characteristics could affect their chance to achieve a pathological response.