PANHER study: a 20-year treatment outcome analysis from a multicentre observational study of HER2-positive advanced breast cancer patients from the real-world setting

Background:

The evolution of therapeutic landscape of human epidermal growth factor receptor-2 (HER2)-positive breast cancer (BC) has led to an unprecedented outcome improvement, even if the optimal sequence strategy is still debated. To address this issue and to provide a picture of the advancement of anti-HER2 treatments, we performed a large, multicenter, retrospective study of HER2-positive BC patients.

Methods:

The observational PANHER study included 1,328 HER2-positive advanced BC patients treated with HER2 blocking agents since June 2000 throughout July 2020. Endpoints of efficacy were progression-free survival (PFS) and overall survival (OS).

Results:

Patients who received a first-line pertuzumab-based regimen showed better PFS (p < 0.0001) and OS (p = 0.004) than those receiving other treatments. Median PFS and mOS from second-line starting were 8 and 28 months, without significant differences among various regimens. Pertuzumab-pretreated patients showed a mPFS and a mOS from second-line starting not significantly affected by type of second line, that is, T-DM1 or lapatinib/capecitabine (p = 0.80 and p = 0.45, respectively). Conversely, pertuzumab-naïve patients receiving second-line T-DM1 showed a significantly higher mPFS compared with that of patients treated with lapatinib/capecitabine (p = 0.004). Median OS from metastatic disease diagnosis was higher in patients treated with trastuzumab-based first line followed by second-line T-DM1 in comparison to pertuzumab-based first-line and second-line T-DM1 (p = 0.003), although these data might be partially influenced by more favorable prognostic characteristics of patients in the pre-pertuzumab era. No significant differences emerged when comparing patients treated with ‘old’ or ‘new’ drugs (p = 0.43), even though differences in the length of the follow-up between the two cohorts should be taken into account.

Conclusion:

Our results confirmed a relevant impact of first-line pertuzumab-based treatment and showed lower efficacy of second-line T-DM1 in trastuzumab/pertuzumab pretreated, as compared with pertuzumab-naïve patients. Our findings may help delineate a more appropriate therapeutic strategy in HER2-positive metastatic BC. Prospective randomized trials addressing this topic are awaited.

PONDx: real-life utilization and decision impact of the 21-gene assay on clinical practice in Italy

Clinicopathological prognostic features have limited value to identify with precision newly diagnosed patients with hormone receptor (HR)-positive, HER2-negative breast cancer (BC), who would benefit from chemotherapy (CT) in addition to adjuvant hormonal therapy (HT). The 21-gene Oncotype DX Breast Recurrence Score® (RS) assay has been demonstrated to predict CT benefit, hence supporting personalized decisions on adjuvant CT. The multicenter, prospective, observational study PONDx investigated the real-life use of RS® results in Italy and its impact on treatment decisions. Physicians' treatment recommendations (HT ± CT) were documented before and after availability of RS results, and changes in recommendations were determined. In the HR+ HER2- early BC population studied (N = 1738), physicians recommended CT + HT in 49% of patients pre-RS. RS-guided treatment decisions resulted in 36% reduction of CT recommendations. PONDx confirms that RS results provide clinically relevant information for CT recommendation in early-stage BC, resulting in a reduction of more than a third of CT use.

Impact of BMI on HER2+ metastatic breast cancer patients treated with pertuzumab and/or trastuzumab emtansine. Real-world evidence

Body mass index (BMI) is a main indicator of obesity and its association with breast cancer is well established. However, little is known in the metastatic setting, especially in HER2-positive patients. We assessed the influence of BMI on clinical outcomes of patients treated with pertuzumab and/or trastuzumab emtansine (T-DM1) for HER2+ metastatic breast cancer (mBC). BMI was addressed as a categorical variable, being classified on the basis of the following ranges, that is, 18.5-24.9, 25-29.9, and 30.0-34.9, namely, normal weight, overweight, and Class I obesity. The outcomes chosen were progression-free survival to first-line chemotherapy (PFS1) and overall survival (OS). Overall (N = 709), no impact of BMI was observed on PFS1 (p = .15), while BMI ≥ 30 was associated with worse OS (p = .003). In subjects who progressed to first line (N = 575), analyzing data across PFS1 quartiles and strata of disease burden, BMI predicted lower PFS1 in patients within the I PFS1 quartile and with the lowest disease burden (p = .001). Univariate analysis showed a detrimental effect of BMI ≥ 30 on OS for women within the I PFS1 quartile (p = .03). Results were confirmed in multivariate analysis. According to PFS1 quartiles a higher percentage of patients with high BMI and low disease burden progressed within 6 months of therapy. The effect of BMI on prognosis was also confirmed in multivariate analysis of OS for overall population. In our cohort, a BMI ≥ 30 correlated with worse OS in patients with HER2+ mBC who received pertuzumab and/or T-DM1 but had no impact on PFS to first line. BMI predicted worse I PFS1 quartile.

Palbociclib plus endocrine therapy in HER2 negative, hormonal receptor-positive, advanced breast cancer: A real-world experience

Data from 423 human epidermal growth factor receptor 2-negative (HER2-), hormone receptor-positive (HR+) advanced breast cancer (aBC) patients treated with palbociclib and endocrine therapy (ET) were provided by 35 Italian cancer centers and analyzed for treatment outcomes. Overall, 158 patients were treated in first line and 265 in second/later lines. We observed 19 complete responses and 112 partial responses. The overall response rate (ORR) was 31% (95% confidence interval [CI], 26.6-35.4) and clinical benefit was 52.7% (95% CI, 48-57.5). ORR was negatively affected by prior exposure to everolimus/exemestane ( p = 0.002) and favorably influenced by early line-treatment ( p < 0.0001). At 6 months, median progression-free survival was 12 months (95% CI, 8-16) and median overall survival was 24 months (95% CI, 17-30). More favorable outcomes were associated with palbociclib in early lines, no visceral metastases and no prior everolimus/exemestane. The main toxicity reported was neutropenia. Our results provide further support to the use of palbociclib with ET in HER2-, HR+ aBC. Differences in outcomes across patients subsets remain largely unexplained.

A multicenter REtrospective observational study of first-line treatment with PERtuzumab, trastuzumab and taxanes for advanced HER2 positive breast cancer patients. RePer Study

We carried out a retrospective observational study of 264 HER2-positive advanced breast cancer (ABC) patients to explore the efficacy of first-line treatment with pertuzumab/trastuzumab/taxane in real-world setting. Survival data were analyzed by Kaplan Meier curves and log rank test. Median follow-up, length of pertuzumab/trastuzumab/taxane treatment and of pertuzumab, trastuzumab maintenance were 21, 4 and 15 months, respectively. The response rate was 77.3%, and the clinical benefit rate 93.6%. Median progression-free survival (mPFS) was 21 months, and median overall survival (mOS) was not reached. When comparing patients by trastuzumab-pretreatment, similar PFS were observed, although a longer OS was reached in trastuzumab-naïve patients (p = 0.02). Brain metastases at baseline and their development in course of therapy were associated with significantly shorter PFS (p = 0.0006) and shorter OS, although at a not fully statistically relevant extent (p = 0.06). The addition of maintenance endocrine therapy (ET) to pertuzumab/trastuzumab maintenance was associated with longer PFS (p = 0.0001), although no significant differences were detected in OS (p = 0.31). Results were confirmed by propensity score analysis (p = 0.003 and p = 0.46, respectively). In multivariate models, longer PFS was related to lower Performance Status (PS) (p = 0.07), metastatic stage at diagnosis (p = 0.006) and single metastatic site (p < 0.0001). An OS advantage was observed with lower PS (p < 0.0001), single metastatic site (p = 0.004), no prior exposure to trastuzumab (p = 0.004) and response to pertuzumab-based treatment (p = 0.003). Our results confirm that trastuzumab/pertuzumab/taxane is the standard of care as first-line treatment of patients with HER2-positive ABC even in the real-world setting. Moreover, the double-maintenance therapy (HER2 block and ET) is strongly recommended when feasible.

Fasting glucose and body mass index as predictors of activity in breast cancer patients treated with everolimus-exemestane: The EverExt study

Evidence on everolimus in breast cancer has placed hyperglycemia among the most common high grade adverse events. Anthropometrics and biomarkers of glucose metabolism were investigated in a observational study of 102 postmenopausal, HR + HER2- metastatic breast cancer patients treated with everolimus-exemestane in first and subsequent lines. Best overall response (BR) and clinical benefit rate (CBR) were assessed across subgroups defined upon fasting glucose (FG) and body mass index (BMI). Survival was estimated by Kaplan-Meier method and log-rank test. Survival predictors were tested in Cox models. Median follow up was 12.4 months (1.0–41.0). The overall cohort showed increasing levels of FG and decreasing BMI (p < 0.001). Lower FG fasting glucose at BR was more commonly associated with C/PR or SD compared with PD (p < 0.001). We also observed a somewhat higher BMI associated with better response (p = 0.052). More patients in the lowest FG category achieved clinical benefit compared to the highest (p < 0.001), while no relevant differences emerged for BMI. Fasting glucose at re-assessment was also predictive of PFS (p = 0.037), as confirmed in models including BMI and line of therapy (p = 0.049). Treatment discontinuation was significantly associated with changes in FG (p = 0.014). Further research is warranted to corroborate these findings and clarify the underlying mechanisms.

A retrospective multicentric observational study of trastuzumab emtansine in HER2 positive metastatic breast cancer: a real-world experience

We addressed trastuzumab emtansine (T-DM1) efficacy in HER2+ metastatic breast cancer patients treated in real-world practice, and its activity in pertuzumab-pretreated patients. We conducted a retrospective, observational study involving 23 cancer centres, and 250 patients. Survival data were analyzed by Kaplan Meier curves and log rank test. Factors testing significant in univariate analysis were tested in multivariate models. Median follow-up was 15 months and median T-DM1 treatment-length 4 months. Response rate was 41.6%, clinical benefit 60.9%. Median progression-free and median overall survival were 6 and 20 months, respectively. Overall, no differences emerged by pertuzumab pretreatment, with median progression-free and median overall survival of 4 and 17 months in pertuzumab-pretreated (p=0.13), and 6 and 22 months in pertuzumab-naïve patients (p=0.27). Patients who received second-line T-DM1 had median progression-free and median overall survival of 3 and 12 months (p=0.0001) if pertuzumab-pretreated, and 8 and 26 months if pertuzumab-naïve (p=0.06). In contrast, in third-line and beyond, median progression-free and median overall survival were 16 and 18 months in pertuzumab-pretreated (p=0.05) and 6 and 17 months in pertuzumab-naïve patients (p=0.30). In multivariate analysis, lower ECOG performance status was associated with progression-free survival benefit (p<0.0001), while overall survival was positively affected by lower ECOG PS (p<0.0001), absence of brain metastases (p 0.05), and clinical benefit (p<0.0001). Our results are comparable with those from randomized trials. Further studies are warranted to confirm and interpret our data on apparently lower T-DM1 efficacy when given as second-line treatment after pertuzumab, and on the optimal sequence order.

"Triple positive" early breast cancer: an observational multicenter retrospective analysis of outcome

We recently found that trastuzumab benefit may be lower in a small subset of early breast cancer (BC) patients (pts) with tumors expressing high levels of both hormonal receptors (HRs), i.e. triple positive (TP). To better investigate the role of HRs in HER2 positive BC, we retrospectively identified 872 TP BC pts treated with adjuvant chemotherapy alone (cohort A-366 pts), or plus trastuzumab (cohort B-506 pts). Relapse-free-survival (RFS) and breast-cancer-specific-survival (BCSS) were evaluated. Trastuzumab improved RFS and BCSS in all the subsets analyzed, but the effect on BCSS in tumors expressing both HRs in >30% of cells (TP30), and even on RFS in tumors with both HRs expressed in >50% of cells (TP50) was not significant. Distinct patterns of relapse were observed in TP50 and no-TP50 tumors, the former showing low and constant risk in the first 5 years, a late increase beyond 5 years and modest trastuzumab effect. Trastuzumab effect tended to disappear in pts whose tumors expressed ER in >50% of cells. Multivariate analysis of RFS confirmed a significant interaction between trastuzumab and ER expression, with benefit confined to pts whose tumors expressed ER in ≤50% of cells. Our data suggest that the pattern of relapse of TP tumors with high HRs is similar to that of "luminal", HER2 negative tumors, without clear benefit from adjuvant trastuzumab, which remains the standard treatment even in TP tumors. Confirmatory findings on the extent to which quantitative expression of HRs may impact clinical behavior of HER2 positive BC are warranted.

Ifosfamide, cisplatin and etoposide combination in locally advanced inoperable non-small-cell lung cancer: a phase II study

From March 1993 to February 1997, 43 eligible patients with inoperable stage IIIA (ten patients) and stage IIIB (33 patients), histologically confirmed NSCLC received 3 courses of the ICE combination (ifosfamide 1.5 g m(-2) and mesna 750 mg m(-2) two times a day, cisplatin 25 mg m(-2) and etoposide 100 mg m(-2), all administered intravenously (i.v.) on days 1-3 every 3 weeks) with G-CSF support. After three cycles, patients were submitted to radical surgery or received two additional courses of the ICE regimen and/or curative radiotherapy. Grade 3-4 neutropenia occurred in 21% of 114 evaluable courses, but was of short duration, leading to neutropenic fever in 5% of the courses. Severe thrombocytopenia and anaemia were observed in 13% and 3% of the courses respectively. Non-haematological toxicity was generally mild with only two episodes of reversible renal impairment. The overall response rate after three chemotherapy courses was 69% (28 partial responses, one complete response). Ten patients (8/10 patients in stage IIIA, 2/33 patients in stage IIIB) underwent radical surgery. Median TTP for patients not undergoing surgery (n = 33) was 8 months (range 3-34+); median DFS for patients rendered NED by surgery (n = 10) was 26 months (range 1-54+). Median OS for the entire group was 12.5 months (range 2-57+). The ICE regimen is active in locally advanced NSCLC with acceptable toxicity and warrants further exploration as induction chemotherapy in larger series.

Mitomycin C plus vindesine plus etoposide (MEV) versus mitomycin C plus vindesine plus cisplatin (MVP) in stage IV non-small-cell lung cancer: A phase III multicentre randomised trial. The "Gruppo Oncologico Centro-Sud-Isole' (G.O.C.S.I.)

PURPOSE

To compare mitomycin C plus vindesine plus etoposide (MEV) vs. mitomycin C plus vindesine plus cisplatin (MVP) in the treatment of stage IV non-small-cell lung cancer.

PATIENTS AND METHODS

204 patients were entered in a phase III multicentre randomised trial from June 1990 to December 1994 and stratified according to the ECOG performance status (0-1 vs. 2). MVP was given in the following dosages: mitomycin C 8 mg/m2+vindesine 3 mg/m2+cisplatin 100 mg/m2 i.v. day 1 and vindesine 3 mg/m2 i.v. day 8 with cycles repeated every 4 weeks. MEV was given in the following dosages: mitomycin C 8 mg/m2+vindesine 3 mg/ m2 i.v. day 1 and etoposide 100 mg/m2 i.v. days 1 to 3 with cycles repeated every 3 weeks. For both treatments a maximum of 6 cycles was planned. Response and toxicity were evaluated according to WHO. Subjective responses were assessed by numerical scales. Analyses were made on the basis of intent to treat.

RESULTS

The objective response rate was 21.4% (1 CR + 21 PR among 103 patients) in the MEV and 28.7% (1 CR + 28 PR among 101 patients) in the MVP arm (P = 0.48). Symptoms were similar in the two arms. 196 patients progressed and 182 died. The median times to progression were 10 weeks (95% CI 9-12) and 12 weeks (95% CI 10-15) and median survivals were 29 weeks (95% CI 25-36) and 28 weeks (95% CI 25-35) in the MEV and MVP arms, respectively. The relative risks of progressing and of dying were 0.89 (95% CL 0.66-1.20) and 0.96 (95% CL 0.71-1.30), respectively, for patients receiving MVP as compared with those receiving MEV at multivariate analysis adjusted by sex, age, histologic type, number of metastatic sites, performance status at entry, and centre.

CONCLUSIONS

In the present study, no significant differences were observed in response rate, survival or palliation of symptoms between the MEV and MVP regimens, while toxicity was significantly more frequent and severe with MVP. Thus, MEV should be considered a reasonable alternative to the MVP regimen in the treatment of stage IV NSCLC.

Accelerated chemotherapy with high-dose epirubicin and cyclophosphamide plus r-met-HUG-CSF in locally advanced and metastatic breast cancer

BACKGROUND

This study evaluated the toxicity of high-dose epirubicin and cyclophosphamide plus r-met-HUG-CSF (G-CSF) given every 2 weeks and compared the dose-intensity achieved with this schedule with that obtained in a previous study we conducted in which the same regimen was given every 3 weeks without G-SCF (EC 21). The secondary objective was to explore the activity of this regimen.

PATIENTS AND METHODS

Between December 1991 and March 1994, 41 patients (pts), 19 with locally advanced breast cancer (LABC) and 22 with metastatic breast cancer (MBC), were given high-dose epirubicin (Hd-Epi) (120 mg/m2) and cyclophosphamide (CTX) (600 mg/m2) on day 1 every 14 days (EC 14) plus granulocyte colony-stimulating factor (G-CSF) (5 mcg/kg/d s.c. on days 2-12). A total of 8 cycles in LABC pts (4 pre- and post-surgery), and 6-8 cycles in MCB pts were administered. The results were compared with those obtained in the previous study.

RESULTS

The incidence of WHO grade 3-4 neutropenia was significantly reduced in the EC 14 + G-CSF regimen (25.2% vs. 46.8% in 214 and 250 evaluable cycles, respectively, p<0.0001), as well as the incidence of neutropenic fever (7% vs. 3%, p=0.05). Grade 3-4 anemia (36.6% vs. 8% pts, p=0.001) and grade 3-4 thrombocytopenia (17.1% vs. 0 pts, p=0.002), were significantly more frequent in EC 14 + G-CSF. No significant differences in the other side effects were found. A total of 17 of 207 of the cycles (8.2%) were delayed in the EC 14 + G-CSF vs. 58/271 (21.4%) in the EC 21 (p<0.0001). The main reasons for these treatment delays were neutropenia (1% vs. 15%), anemia (3% vs. 0) and thrombocytopenia (1% vs. 0). As a result of treatment acceleration and differences in dose delays, the patients on EC 14 + G-CSF received a higher dose-intensity (Epi 58.51 mg/m2/wk vs. 36.8 mg/m2/wk; CTX 292.52 mg/m2/wk vs. 182.9 mg/m2/wk). A complete response at surgery was obtained in 9/19 (47.4%) LABC pts. An objective CR was obtained in 11/22 MBC pts (50%) and a partial response in 8/22 (36.4%), yielding an overall response rate of 86.4%.

CONCLUSIONS

Hd-Epi + CTX is very active against both LABC and MBC. The administration of G-CSF allows dose intensification of both drugs (a 59.5% increase of the actual dose intensity) with acceptable clinical tolerance (a lower incidence of neutropenia but a higher incidence of anemia and thrombocytopenia). Only a specifically designed phase III trial will lead to definitive conclusions regarding the greater antitumor activity of accelerated CSF-including regimens as compared to standard chemotherapy for advanced breast cancer.

Prognostic value of lymph node metastases after neoadjuvant chemotherapy for large-sized operable carcinoma of the breast

BACKGROUND

Neoadjuvant chemotherapy followed by surgery or radiation therapy, or both, has become the treatment of choice for patients with large-sized resectable carcinoma of the breast in whom mastectomy is the conventional option. Since tumor regression before surgery is considered a favorable prognostic factor, there is still controversy regarding the need to perform an axillary dissection after a good response to systemic induction treatment.

STUDY DESIGN

Between February 1990 and December 1993, we conducted a prospective study of 56 consecutive patients receiving high-dose anthracycline-based preoperative chemotherapy for large but potentially resectable carcinoma of the breast. Patients who had a good clinical response to induction systemic treatment received the same chemotherapy in the adjuvant phase, while those whose response was less than optimal received alternative adjuvant chemotherapy regimens. A multivariate analysis was made to evaluate the relative influence on disease-free survival rates of 11 clinicopathologic and treatment-related variables, including clinical response to primary chemotherapy, primary pathological (p-T) staging, and the number of metastatic lymph nodes.

RESULTS

At a median follow-up period of 36 months, only the number of metastatic lymph nodes was found to be an independent predictor of relapse. Clinical response to systemic induction treatment and p-T staging did not correlate with prognosis. In the group of patients with axillary lymph node involvement, those who did not respond to preoperative chemotherapy showed a lower relapse rate compared with those who achieved an objective response.

CONCLUSIONS

These findings suggest that axillary lymphadenectomy should be considered an important component of the combined modality therapy for patients with large-sized resectable carcinoma of the breast in order to identify subgroups of patients that may benefit from alternative treatments in the adjuvant setting.

Phase II trial of high-dose epirubicin and cyclophosphamide in advanced breast cancer

Between February 1990 and December 1991 high-dose epirubicin (Epi)(120 mg/m2) plus cyclophosphamide (CTX)(600 mg/m2) were given every 3 weeks to 52 patients with locally advanced and metastatic breast cancer. 26 patients with locally advanced disease received four courses of this regimen before and after local treatments. 26 patients had metastatic disease: they received eight courses unless progression or unacceptable toxicity occurred. Responses were seen in 37/48 (77%) evaluable patients including 14 complete responses (CR), 23 partial responses (PR), nine stable disease, two progressive disease. Among the 25 evaluable patients with locally advanced disease, 9 had a CR and 11 a > 80% decrease in tumour volume. 6 patients (24%) had a pathologically confirmed complete response. 18 patients (72%) had a tumour reduction to 0-2 cm. The 3-year disease-free survival was 60%. Of the 23 evaluable patients with metastatic disease, 5 obtained a CR and 10 a PR, yielding an overall response rate of 65%. Myelosuppression was substantial with a grade 3-4 leucopenia in 76% of the patients even if neutropenic fever occurred in only 7% of the courses. A clinical congestive heart failure occurred in 1 patient following a total Epi dose of 960 mg/m2 and a bilateral quadrantectomy and radiotherapy. We conclude that (1) high-dose Epi + CTX is a very active regimen, in particular for the patients with locally advanced breast cancer; (2) breast conservation after this regimen in some of these patients may be considered; (3) neutropenia is the dose-limiting toxicity. Currently, a phase II study using the same combination given every 2 weeks together with r-methuG-CSF is ongoing.