Keyur Mehta

Definition and Impact of Pathologic Complete Response on Prognosis After Neoadjuvant Chemotherapy in Various Intrinsic Breast Cancer Subtypes

PURPOSE The exact definition of pathologic complete response (pCR) and its prognostic impact on survival in intrinsic breast cancer subtypes is uncertain. METHODS Tumor response at surgery and its association with long-term outcome of 6,377 patients with primary breast cancer receiving neoadjuvant anthracycline-taxane-based chemotherapy in seven randomized trials were analyzed. RESULTS Disease-free survival (DFS) was significantly superior in patients with no invasive and no in situ residuals in breast or nodes (n = 955) compared with patients with residual ductal carcinoma in situ only (n = 309), no invasive residuals in breast but involved nodes (n = 186), only focal-invasive disease in the breast (n = 478), and gross invasive residual disease (n = 4,449; P < .001). Hazard ratios for DFS comparing patients with or without pCR were lowest when defined as no invasive and no in situ residuals (0.446) and increased monotonously when in situ residuals (0.523), no invasive breast residuals but involved nodes (0.623), and focal-invasive disease (0.727) were included in the definition. pCR was associated with improved DFS in luminal B/human epidermal growth factor receptor 2 (HER2) -negative (P = .005), HER2-positive/nonluminal (P < .001), and triple-negative (P < .001) tumors but not in luminal A (P = .39) or luminal B/HER2-positive (P = .45) breast cancer. pCR in HER2-positive (nonluminal) and triple-negative tumors was associated with excellent prognosis. CONCLUSION pCR defined as no invasive and no in situ residuals in breast and nodes can best discriminate between patients with favorable and unfavorable outcomes. Patients with noninvasive or focal-invasive residues or involved lymph nodes should not be considered as having achieved pCR. pCR is a suitable surrogate end point for patients with luminal B/HER2-negative, HER2-positive (nonluminal), and triple-negative disease but not for those with luminal B/HER2-positive or luminal A tumors.

Pathological complete response and long-term clinical benefit in breast cancer: the CTNeoBC pooled analysis

BACKGROUND Pathological complete response has been proposed as a surrogate endpoint for prediction of long-term clinical benefit, such as disease-free survival, event-free survival (EFS), and overall survival (OS). We had four key objectives: to establish the association between pathological complete response and EFS and OS, to establish the definition of pathological complete response that correlates best with long-term outcome, to identify the breast cancer subtypes in which pathological complete response is best correlated with long-term outcome, and to assess whether an increase in frequency of pathological complete response between treatment groups predicts improved EFS and OS. METHODS We searched PubMed, Embase, and Medline for clinical trials of neoadjuvant treatment of breast cancer. To be eligible, studies had to meet three inclusion criteria: include at least 200 patients with primary breast cancer treated with preoperative chemotherapy followed by surgery; have available data for pathological complete response, EFS, and OS; and have a median follow-up of at least 3 years. We compared the three most commonly used definitions of pathological complete response--ypT0 ypN0, ypT0/is ypN0, and ypT0/is--for their association with EFS and OS in a responder analysis. We assessed the association between pathological complete response and EFS and OS in various subgroups. Finally, we did a trial-level analysis to assess whether pathological complete response could be used as a surrogate endpoint for EFS or OS. FINDINGS We obtained data from 12 identified international trials and 11 955 patients were included in our responder analysis. Eradication of tumour from both breast and lymph nodes (ypT0 ypN0 or ypT0/is ypN0) was better associated with improved EFS (ypT0 ypN0: hazard ratio [HR] 0·44, 95% CI 0·39-0·51; ypT0/is ypN0: 0·48, 0·43-0·54) and OS (0·36, 0·30-0·44; 0·36, 0·31-0·42) than was tumour eradication from the breast alone (ypT0/is; EFS: HR 0·60, 95% CI 0·55-0·66; OS 0·51, 0·45-0·58). We used the ypT0/is ypN0 definition for all subsequent analyses. The association between pathological complete response and long-term outcomes was strongest in patients with triple-negative breast cancer (EFS: HR 0·24, 95% CI 0·18-0·33; OS: 0·16, 0·11-0·25) and in those with HER2-positive, hormone-receptor-negative tumours who received trastuzumab (EFS: 0·15, 0·09-0·27; OS: 0·08, 0·03, 0·22). In the trial-level analysis, we recorded little association between increases in frequency of pathological complete response and EFS (R(2)=0·03, 95% CI 0·00-0·25) and OS (R(2)=0·24, 0·00-0·70). INTERPRETATION Patients who attain pathological complete response defined as ypT0 ypN0 or ypT0/is ypN0 have improved survival. The prognostic value is greatest in aggressive tumour subtypes. Our pooled analysis could not validate pathological complete response as a surrogate endpoint for improved EFS and OS. FUNDING US Food and Drug Administration.

Neoadjuvant Treatment With Trastuzumab in HER2-Positive Breast Cancer: Results From the GeparQuattro Study

PURPOSE Trastuzumab, a humanized antibody against the human epidermal growth factor receptor type 2 (HER2), has shown high efficacy in breast cancer. We prospectively investigated its efficacy given simultaneously with anthracycline-taxane-based neoadjuvant chemotherapy. PATIENTS AND METHODS Patients with operable or locally advanced, HER2-positive tumors were treated preoperatively with four cycles of epirubicin/cyclophosphamide followed by four cycles of docetaxel with or without capecitabine (EC-T[X]) and trastuzumab 6 mg/kg (with a loading dose of 8 mg/kg) every 3 weeks during all chemotherapy cycles. Patients with HER2-negative tumors treated in the same study with the same chemotherapy but without trastuzumab were used as a reference group. Results Of 1,509 participants, 445 had HER2-positive tumors treated with trastuzumab and chemotherapy. Pathologic complete response (pCR; defined as no invasive or in situ residual tumors in the breast) rate was 31.7%, which was 16% higher than that in the reference group (15.7%). HER2-positive patients without response to the first four cycles of EC showed an unexpectedly high pCR rate of 16.6% (3.3% in the reference group). Breast conservation rate was 63.1% and comparable to that of the reference group (64.7%). EC-T(X) plus trastuzumab was associated with more febrile neutropenia and conjunctivitis, but with a comparable short-term cardiac toxicity profile as the reference group. CONCLUSION This trial confirms that combining trastuzumab with anthracycline-taxane-based neoadjuvant chemotherapy results in a high pCR rate without clinically relevant early toxicity. Combination of chemotherapy with trastuzumab should be considered when neoadjuvant treatment is given to patients with HER2-positive breast cancer.

Tumor-Infiltrating Lymphocytes and Response to Neoadjuvant Chemotherapy With or Without Carboplatin in Human Epidermal Growth Factor Receptor 2–Positive and Triple-Negative Primary Breast Cancers

PURPOSE Modulation of immunologic interactions in cancer tissue is a promising therapeutic strategy. To investigate the immunogenicity of human epidermal growth factor receptor 2 (HER2) -positive and triple-negative (TN) breast cancers (BCs), we evaluated tumor-infiltrating lymphocytes (TILs) and immunologically relevant genes in the neoadjuvant GeparSixto trial. PATIENTS AND METHODS GeparSixto investigated the effect of adding carboplatin (Cb) to an anthracycline-plus-taxane combination (PM) on pathologic complete response (pCR). A total of 580 tumors were evaluated before random assignment for stromal TILs and lymphocyte-predominant BC (LPBC). mRNA expression of immune-activating (CXCL9, CCL5, CD8A, CD80, CXCL13, IGKC, CD21) as well as immunosuppressive factors (IDO1, PD-1, PD-L1, CTLA4, FOXP3) was measured in 481 tumors. RESULTS Increased levels of stromal TILs predicted pCR in univariable (P < .001) and multivariable analyses (P < .001). pCR rate was 59.9% in LPBC and 33.8% for non-LPBC (P < .001). pCR rates ≥ 75% were observed in patients with LPBC tumors treated with PMCb, with a significant test for interaction with therapy in the complete (P = .002) and HER2-positive (P = .006), but not the TNBC, cohorts. Hierarchic clustering of mRNA markers revealed three immune subtypes with different pCR rates (P < .001). All 12 immune mRNA markers were predictive for increased pCR. The highest odds ratios (ORs) were observed for PD-L1 (OR, 1.57; 95% CI, 1.34 to 1.86; P < .001) and CCL5 (OR, 1.41; 95% CI, 1.23 to 1.62; P < .001). CONCLUSION Immunologic factors were highly significant predictors of therapy response in the GeparSixto trial, particularly in patients treated with Cb. After further standardization, they could be included in histopathologic assessment of BC.

Neoadjuvant carboplatin in patients with triple-negative and HER2-positive early breast cancer (GeparSixto; GBG 66): a randomised phase 2 trial

BACKGROUND Preclinical data suggest that triple-negative breast cancers are sensitive to interstrand crosslinking agents, and that synergy may exist for the combination of a taxane, trastuzumab, and a platinum salt for HER2-positive breast cancer. We therefore aimed to assess the efficacy of the addition of carboplatin to neoadjuvant therapy for triple-negative and HER2-positive breast cancer. METHODS Patients with previously untreated, non-metastatic, stage II-III, triple-negative breast cancer and HER2-positive breast cancer were enrolled. Patients were treated for 18 weeks with paclitaxel (80 mg/m(2) once a week) and non-pegylated liposomal doxorubicin (20 mg/m(2) once a week). Patients with triple-negative breast cancer received simultaneous bevacizumab (15 mg/kg intravenously every 3 weeks). Patients with HER2-positive disease received simultaneous trastuzumab (8 mg/kg initial dose with subsequent doses of 6 mg/kg intravenously every 3 weeks) and lapatinib (750 mg daily). Patients were randomly assigned in a 1:1 ratio with dynamic allocation and minimisation, stratified by biological subtype and Ki-67 level to receive, at the same time as the backbone regimens, either carboplatin (AUC 1·5 [2·0 for the first 329 patients] once a week) or no carboplatin. The primary endpoint the proportion of patients who achieved a pathological complete response (defined as ypT0 ypN0), analysed for all patients who started treatment; a p value of less than 0·2 was deemed significant for the primary endpoint. This trial is registered with ClinicalTrials.gov, number NCT01426880. FINDINGS 296 patients were randomly assigned to receive carboplatin and 299 to no additional carboplatin, of whom 295 and 293 started treatment, respectively. In this final analysis, 129 patients (43·7%, 95% CI 38·1-49·4) in the carboplatin group achieved a pathological complete response, compared with 108 patients (36·9%, 31·3-42·4) without carboplatin (odds ratio 1·33, 95% CI 0·96-1·85; p=0·107). Of the patients with triple-negative breast cancer, 84 (53·2%, 54·4-60·9) of 158 patients achieved a pathological complete response with carboplatin, compared with 58 (36·9%, 29·4-44·5) of 157 without (p=0·005). Of the patients with HER2-positive tumours, 45 (32·8%, 25·0-40·7) of 137 patients achieved a pathological complete response with carboplatin compared with 50 (36·8%, 28·7-44·9) of 136 without (p=0·581; test for interaction p=0·015). Haematological and non-haematological toxic effects that were significantly more common in the carboplatin group than in the no-carboplatin group included grade 3 or 4 neutropenia (192 [65%] vs 79 [27%]), grade 3 or 4 anaemia (45 [15%] vs one [<1%]), grade 3 or 4 thrombocytopenia (42 [14%] vs one [<1%]), and grade 3 or 4 diarrhoea (51 [17%] vs 32 [11%]); carboplatin was more often associated with dose discontinuations (141 [48%] with carboplatin and 114 [39%] without carboplatin; p=0·031). The frequency of grade 3 or 4 haematological events decreased from 82% (n=135) to 70% (n=92) and grade 3 or 4 non-haematological events from 78% (n=128) to 59% (n=77) in the carboplatin arm when the dose of carboplatin was reduced from AUC 2·0 to 1·5. INTERPRETATION The addition of neoadjuvant carboplatin to a regimen of a taxane, an anthracycline, and targeted therapy significantly increases the proportion of patients achieving a pathological complete response. This regimen seems to increase responses in patients with triple-negative breast cancer, but not in those with HER2-positive breast cancer. FUNDING GlaxoSmithKline, Roche, and Teva.

Pathologic Complete Response After Neoadjuvant Chemotherapy Plus Trastuzumab Predicts Favorable Survival in Human Epidermal Growth Factor Receptor 2–Overexpressing Breast Cancer: Results From the TECHNO Trial of the AGO and GBG Study Groups

PURPOSE To evaluate efficacy and safety of epirubicin and cyclophosphamide followed by paclitaxel and trastuzumab as neoadjuvant treatment in patients with human epidermal growth factor receptor 2 (HER2)-overexpressing breast cancer. PATIENTS AND METHODS Patients with centrally confirmed HER2-overexpressing breast cancer (≥ 2 cm or inflammatory) received four 3-week cycles epirubicin and cyclophosphamide (90/600 mg/m(2)) followed by four 3-week cycles paclitaxel (175 mg/m(2)) and trastuzumab (6 mg/kg) before surgery. Trastuzumab was continued after surgery to complete 1 year of treatment. Primary end point was pathologic complete response (pCR) defined as no residual invasive tumor in breast and lymphatic tissue. RESULTS Thirty-nine percent of 217 enrolled patients achieved a pCR. Breast conservation was possible in 64% of patients. Three-year disease-free survival (DFS) was 88% in patients with pCR compared to 73% in patients without pCR (P = .01). Three-year overall survival (OS) was 96% in patients with pCR compared to 86% in patients without pCR (P = .025). pCR was the only significant prognostic factor for DFS (hazard ratio [HR] 2.5; 95% CI, 1.2 to 5.1; P = .013) and OS (HR, 4.9; 95% CI, 1.4 to 17.4; P = .012) in multivariable analysis. Cardiac toxicity was reported in eight patients (3.7%) of whom six presented with an asymptomatic left ventricular ejection fraction decrease and two with symptomatic chronic heart failure. CONCLUSION Neoadjuvant combination of trastuzumab and chemotherapy resulted in a high pCR rate in HER2-overexpressing primary breast cancer. Patients with a pCR after neoadjuvant anti-HER2 therapy in combination with chemotherapy followed by maintenance trastuzumab have an improved long-term outcome. Patients without a pCR had an increased risk for relapse and death.

Neoadjuvant Vinorelbine–Capecitabine Versus Docetaxel–Doxorubicin–Cyclophosphamide in Early Nonresponsive Breast Cancer: Phase III Randomized GeparTrio Trial

BACKGROUND Among breast cancer patients, nonresponse to initial neoadjuvant chemotherapy is associated with unfavorable outcome. We compared the response of nonresponding patients who continued the same treatment with that of patients who switched to a well-tolerated non-cross-resistant regimen. METHODS Previously untreated breast cancer patients received two 3-week cycles of docetaxel at 75 mg/m(2), doxorubicin at 50 mg/m(2), and cyclophosphamide at 500 mg/m(2) per day (TAC). Patients whose tumors did not decrease in size by at least 50% were randomly assigned to four additional cycles of TAC or to four cycles of vinorelbine at 25 mg/m(2) and capecitabine at 2000 mg/m(2) (NX). The outcome was sonographic response, defined as a reduction in the product of the two largest perpendicular diameters by at least 50%. A difference of 10% or less in the sonographic response qualified as noninferiority of the NX treatment. Pathological complete response was defined as no invasive or in situ residual tumor masses in the breast and lymph nodes. Toxic effects were assessed. All statistical tests were two-sided. RESULTS Of 2090 patients enrolled in the GeparTrio study, 622 (29.8%) who did not respond to two initial cycles of TAC were randomly assigned to an additional four cycles of TAC (n = 321) or to four cycles of NX (n = 301). Sonographic response rate was 50.5% for the TAC arm and 51.2% for the NX arm. The difference of 0.7% (95% confidence interval = -7.1% to 8.5%) demonstrated noninferiority of NX (P = .008). Similar numbers of patients in both arms received breast-conserving surgery (184 [57.3%] in the TAC arm vs 180 [59.8%] in the NX arm) and had a pathological complete response (5.3% vs 6.0%). Fewer patients in the NX arm than in the TAC arm had hematologic toxic effects, mucositis, infections, and nail changes, but more had hand-foot syndrome and sensory neuropathy. CONCLUSION Pathological complete responses to both regimens were marginal. Among patients who did not respond to the initial neoadjuvant TAC treatment, similar efficacy but better tolerability was observed by switching to NX than continuing with TAC.

Intensified Neoadjuvant Chemotherapy in Early-Responding Breast Cancer: Phase III Randomized GeparTrio Study

BACKGROUND Patients with an early response to neoadjuvant chemotherapy have chemosensitive tumors and a high probability for a pathological complete response at surgery. The relationship between extended chemotherapy and pathological complete response at surgery was investigated in a clinical trial. METHODS Untreated breast cancer patients received two 3-week cycles of docetaxel at 75 mg/m(2), doxorubicin at 50 mg/m(2), and cyclophosphamide at 500 mg/m(2) (TAC). Those whose tumor size decreased by 50% or more by sonographic measurement (ie, reduction in the product of the two largest perpendicular diameters by at least 50%) were classified as responders and randomly assigned to receive four or six more cycles of TAC, for a total of six or eight TAC cycles. The primary aim was to increase the rate of a pathological complete response (defined as no invasive or in situ residual tumor masses in the breast and lymph nodes) from 20% to 26%. Sonographic response rates and rates of breast-conserving surgery and adverse effects were also assessed. All statistical tests were two-sided. RESULTS Of the 2090 patients in the GeparTrio trial, 1390 (66.5%) were randomly assigned as responders after two initial TAC cycles to receive an additional four (n = 704) or six (n = 686) TAC cycles. Rates of pathological complete response were not statistically significantly different between the arms (21.0% with six TAC cycles and 23.5% with eight TAC cycles; difference = 2.5%, 95% confidence interval [CI] = -1.8% to 6.8%; P = .27). More clinical (48.2% vs 52.9%, difference = 4.7%; 95% CI = -0.55% to 9.95%; P = .08) and sonographic (22.6% vs 27.6%, difference = 5%; 95% CI = 0.45% to 9.55%; P = .033) complete responses at surgery were observed with eight TAC cycles than with six TAC cycles. The rate of breast-conserving surgery was similar in both arms (67.5% vs 68.5%, respectively, P = .68). Grade 3 or 4 leukopenia and edema and various grade 1 or 2 adverse events were more frequent in patients receiving eight TAC cycles than in those receiving six cycles. CONCLUSION Patients receiving eight TAC cycles had statistically significantly higher sonographic response rates but not pathological complete response rates than those receiving six TAC cycles. However, they also had more toxic effects. So far, eight cycles of TAC cannot be recommended for the whole group of patients responding to two initial cycles of TAC.

Effect of Luteinizing Hormone–Releasing Hormone Agonist on Ovarian Function After Modern Adjuvant Breast Cancer Chemotherapy: The GBG 37 ZORO Study

PURPOSE Observational studies suggested that luteinizing hormone-releasing hormone agonists (LHRHa) might prevent premature ovarian failure resulting from adjuvant chemotherapy in premenopausal patients. We aimed to test the efficacy of ovarian function preservation with the LHRHa goserelin in patients with breast cancer. PATIENTS AND METHODS In a prospective, randomized, open-label, controlled multicenter study, 60 patients younger than age 46 years with hormone-insensitive breast cancer were allocated to receive anthracycline/cyclophosphamide (with or without taxane) -based neoadjuvant chemotherapy with or without goserelin. The first goserelin injection was administered at least 2 weeks before the first chemotherapy cycle, continuing at 3.6 mg subcutaneously every 4 weeks until the end of the last cycle. The primary objective was the reappearance of normal ovarian function, defined as two consecutive menstrual periods within 21 to 35 days at 6 months after end of chemotherapy. RESULTS Fifty-three patients (88.3%) experienced temporary amenorrhea (93.3% with v 83.3% without goserelin). No significant difference was observed regarding the reappearance of menstruation at 6 months after chemotherapy (70.0% with v 56.7% without goserelin; difference of 13.3%; 95% CI, -10.85 to 37.45; P = .284). All but one evaluable patient reported regular menses at 2 years after chemotherapy. Time to restoration of menstruation was 6.8 months (95% CI, 5.2 to 8.4) with goserelin and 6.1 months (95% CI, 5.3 to 6.8) without goserelin (P = .304). Chemotherapy resulted in a decreased ovarian reserve measured by inhibin B and anti-Müllerian hormone during follow-up, supporting the other findings. CONCLUSION Premenopausal patients with breast cancer receiving goserelin simultaneously with modern neoadjuvant chemotherapy did not experience statistically significantly less amenorrhea 6 months after end of chemotherapy compared with those receiving chemotherapy alone.

Capecitabine in Addition to Anthracycline- and Taxane-Based Neoadjuvant Treatment in Patients With Primary Breast Cancer: Phase III GeparQuattro Study

PURPOSE Capecitabine can be integrated either concomitantly or sequentially to anthracycline-plus-taxane-based regimens. PATIENTS AND METHODS Patients with large operable or locally advanced tumors, with hormone receptor-negative tumors, or with receptor-positive tumors but also clinically node-positive disease were recruited to receive preoperatively four cycles of epirubicin plus cyclophosphamide (EC; epirubicin 90 mg/m(2) and cyclophosphamide 600 mg/m(2)). Patients were then randomly assigned to four cycles of docetaxel (100 mg/m(2)), four cycles of docetaxel + capecitabine (TX; docetaxel 75 mg/m(2) plus capecitabine 1,800 mg/m(2)), or four cycles of docetaxel (75 mg/m(2)) followed by four cycles of capecitabine (1,800 mg/m(2); T-X). Patients with human epidermal growth factor receptor 2 (HER-2) -positive tumors received trastuzumab concomitantly with all cycles. Primary objectives were to assess the effect of docetaxel by comparing EC plus docetaxel versus EC plus TX and to assess the effect of duration by comparing EC plus TX versus EC plus T-X on pathologic complete response (pCR, without invasive/noninvasive breast tumor, regardless of nodal status) at surgery, irrespective of trastuzumab treatment. Results Of 1,509 patients starting EC, 1,421 were randomly assigned to docetaxel (n = 471), TX (n = 471), or T-X (n = 479). At surgery, pCR rates were 22.3%, 19.5%, and 22.3%, respectively; the difference for docetaxel (EC plus docetaxel v EC plus TX) was 2.8% (95% CI, -2.4% to 8.0%; P = .298).The difference for duration was -2.8% (95% CI, -8.0% to 2.4%; P = .298). Breast conservation rates were 70.1%, 68.4%, and 65.3%, respectively (P = .781 for docetaxel; P = .270 for duration). Concomitant but not sequential treatment with docetaxel was associated with more diarrhea; nail changes, and hand-foot-syndrome, but it was associated with less edema. CONCLUSION Adding capecitabine to or prolonging duration of neoadjuvant EC plus docetaxel does not result in higher efficacy at surgery.