Prolonged complete response after treatment withdrawal in HER2-overexpressed, hormone receptor-negative breast cancer with liver metastases: the prospect of disappearance of an incurable disease

A remarkable response to palliative treatment in metastatic breast cancer: A case report and comprehensive literature review

The case report describes a patient with stage IV breast cancer which metastasized to the lungs. The patient's initial computed tomography (CT) scan revealed a malignant lesion in the upper outer quadrant of the left breast and multiple pulmonary nodules, suggesting pulmonary metastasis. After starting palliative chemotherapy with intravenous paclitaxel and subcutaneous injections of Herceptin, a follow-up CT scan 3 months after the initiation of treatment showed the disappearance of metastasis, and her cancer regressed to stage II breast cancer that could be surgically resected. This case report highlights the importance of timely and appropriate palliative treatment measures, which can lead to unexpected outcomes, such as the regression of metastatic lesions and the possibility of curative treatment in such advanced cancer.

No evidence of disease versus residual disease in long-term responders to first-line HER2-targeted therapy for metastatic breast cancer

BACKGROUND

Long-term response to HER2-targeted therapies is infrequent in metastatic breast cancer (MBC). We evaluated clinical characteristics of HER2-positive MBC patients with no evidence of disease (NED) vs residual disease (RES) experiencing long-term response to first-line HER2-targeted therapy.

METHODS

Patients receiving first-line chemotherapy-trastuzumab (CT) or taxane-trastuzumab-pertuzumab (THP) with response duration ≥2-fold higher than in phase II/III trials (CT [18.2 months]; THP [40.4 months]) were included. Clinical characteristics and radiographic review for NED or RES was evaluated by Cox-regression (hazard ratio; HR) or Kaplan-Meier (log-rank). Characteristics associated with NED were evaluated by logistic regression (Odds; OR).

RESULTS

From 01/2005-01/2016, N = 103 (4.6%) patients were identified. In multivariate analyses, NED (N = 46) showed improved progression-free (PFS) and overall survival (OS) [p < 0.001] versus RES (N = 57), with high 5-year PFS/OS for NED (93.2%/97.4%) relative to RES (10.6%/61.3%). Premenopausal status (p = 0.006), de-novo metastases (p = 0.002), and no palliative radiotherapy (p = 0.01) were associated with NED. Overall, 6/7 (85.7%) patients with NED were alive and disease-free after discontinuing HER2 treatment (≥1 year) versus 1/17 (5.9%) with RES.

CONCLUSIONS

Long-term responders with NED have better survival compared to RES. Premenopausal status and de novo metastatic disease are associated with NED. Prospective studies of HER2 therapy discontinuation with NED in MBC are warranted.

Treatment-free remission in CML: who, how, and why?

Chronic myeloid leukemia (CML) is the best example of successful targeted therapy. Today, the overall survival of patients with CML treated by using tyrosine kinase inhibitors (TKIs) is very close to that of the healthy population. The current question is: how can we further ameliorate the clinical outcome of patients with CML? Clinical trials have shown that some patients with CML in the chronic phase who achieve sustained deep molecular responses on TKI therapy can safely suspend therapy with no evidence of relapse. The long follow-up studies and the number of eligible patients have now validated the concept of treatment-free remission (ie, the ability to maintain a molecular response after stopping therapy). It should be considered as the future criterion to evaluate the success of clinical trials, especially if we want to take into account the quality of life of patients in addition to the economic aspect. Because post-TKI discontinuation follow-ups have been increasing over time with no evidence of relapse in some patients, the next step for the coming decade will be to address the topic of CML cure.

Treatment-free remission in CML: who, how, and why?

Chronic myeloid leukemia (CML) is the best example of successful targeted therapy. Today, the overall survival of patients with CML treated by using tyrosine kinase inhibitors (TKIs) is very close to that of the healthy population. The current question is: how can we further ameliorate the clinical outcome of patients with CML? Clinical trials have shown that some patients with CML in the chronic phase who achieve sustained deep molecular responses on TKI therapy can safely suspend therapy with no evidence of relapse. The long follow-up studies and the number of eligible patients have now validated the concept of treatment-free remission (ie, the ability to maintain a molecular response after stopping therapy). It should be considered as the future criterion to evaluate the success of clinical trials, especially if we want to take into account the quality of life of patients in addition to the economic aspect. Because post-TKI discontinuation follow-ups have been increasing over time with no evidence of relapse in some patients, the next step for the coming decade will be to address the topic of CML cure.

Retrospective analysis of HER2 therapy interruption in patients responding to the treatment in metastatic HER2+ breast cancer

Introduction

Human epidermal growth factor receptor 2 (HER2)-targeted-therapy regimens can lead to prolonged tumour responses in metastatic HER2+ breast cancer. Clinical trials have concerned use of HER2-targeted agents until disease progression, but it is unknown whether the therapy can be interrupted in cases of a good response.

Methods

Single institute, retrospective collection of data on patients with HER2+ metastatic breast cancer (n=68) was carried out through a pharmacy search for patients who had received trastuzumab in 2006–2014. Clinical and pathological factors, treatment history and survival data were collected from patient records.

Results

Median survival in metastatic disease (all patients) was 32 months and survival times were dramatically different in patients with and without trastuzumab as adjuvant or primary metastatic disease (median 16, 77 and 35 months, respectively; p=0.0004). More importantly, HER2 therapy was intentionally interrupted in 21 responding patients, and these patients experienced long HER2-therapy-free intervals (median 51 months), with excellent long-term survival. A lack of previous adjuvant trastuzumab was the only statistically significant factor predictive of HER2 therapy interruption.

Conclusions

These results from our retrospective study show that HER2 therapy interruption in patients with metastatic HER2+ breast cancer, who have responded to the therapy, is associated with low risk of rapid disease progression. Study suggests that therapy interruption in cases of response and reinitiation in progression is feasible.

Deep molecular responses for treatment-free remission in chronic myeloid leukemia

Several clinical trials have demonstrated that some patients with chronic myeloid leukemia in chronic phase (CML-CP) who achieve sustained deep molecular responses on tyrosine kinase inhibitor (TKI) therapy can safely suspend therapy and attempt treatment-free remission (TFR). Many TFR studies to date have enrolled imatinib-treated patients; however, the feasibility of TFR following nilotinib or dasatinib has also been demonstrated. In this review, we discuss available data from TFR trials and what these data reveal about the molecular biology of TFR. With an increasing number of ongoing TFR clinical trials, TFR may become an achievable goal for patients with CML-CP.

Duration of trastuzumab in patients with HER2-positive metastatic breast cancer in prolonged remission

BACKGROUND

Outcomes in metastatic breast cancer (mbc) positive for her2 (human epidermal growth factor receptor 2) are generally unfavourable. Trastuzumab has revolutionized the prognosis of her2-positive mbc. Some her2-positive mbc patients go into prolonged remission, and a few patients remain in remission even after discontinuation of trastuzumab, suggesting the possibility of a cure. In our practice, 4 her2-positive mbc patients treated with chemotherapy and trastuzumab have remained in remission on maintenance therapy for 5 years or more. Of those 4 patients, 2 have continued in remission after discontinuation of trastuzumab for more than 1 year. The objective of the present paper was therefore to address the duration of trastuzumab therapy in her2-positive mbc patients in prolonged remission.

METHODS

We conducted a literature review of the duration of trastuzumab in her2-positive mbc patients in remission. We also conducted an online survey of oncologists in Ontario to determine their treatment practices in her2-positive mbc patients.

RESULTS

The literature search found no specific evidence about the optimal duration of trastuzumab maintenance therapy in her2-positive mbc in prolonged remission. However, retrospective studies suggest predictive markers of good prognosis in patients in complete remission taking maintenance trastuzumab. Identifying those markers could lead to more personalized treatment. Our survey of oncologists about their treatment practices in her2-positive mbc patients revealed that 82.93% of respondents (n = 34) follow the currently available guidelines.

CONCLUSIONS

With the emergence of patients in prolonged remission, duration of trastuzumab in her2-positive mbc has become an important and relevant clinical question worldwide. Collaborative efforts are needed for the further study of this topic.