Long-Term Complete Response with Single-Agent Capecitabine in Her-2-neu-Positive Metastatic Breast Cancer—A Rare Case Report

Abstract

The standard treatment approach for metastatic breast cancer with HR- and Her-2-neu + disease is trastuzumab with systemic therapy. But in patients having severe cardiac dysfunction, trastuzumab is avoided. Various combination regimens are available in that setting, but no study has shown better efficacy of capecitabine monotherapy in this setting. We hereby present a case report of using capecitabine monotherapy in first-line setting, and the patient had complete resolution of lung metastasis from the last 2 years. A 64-year-old postmenopausal lady with a known case of breast carcinoma in the left side diagnosed in the year 2016 with hormone receptor–positive, Her2-negative disease completed chemoradiation and on is aromatase inhibitor from the last 5 years. She complained of breathlessness and fatigue lasting for 1 month in July 2021. On evaluation, chest CT scan revealed multiple bilateral lung metastases along with 3×3 cm right-sided breast lump with no metastasis elsewhere in the body. Core needle biopsy of breast lump and CT-guided left lung nodule biopsy were performed which revealed infiltrating carcinoma with immunohistochemical markers showing tumor cells positive for Her-2-neu with hormone receptor–negative disease. PET-CT scan was done which revealed FDG avidity in bilateral lung fields and right breast lump with no disease elsewhere. Her echocardiography showed ejection fraction of 40% owing to which injection trastuzumab was deferred and the plan to start tablet capecitabine 1000 mg twice BD days 1–14 cycles every 21 days was made. She showed improvement in symptoms with PET-CT scan revealing resolution of lung metastasis from the last 2 years. Trastuzumab in combination with pertuzumab and taxane is the standard of care for metastatic breast carcinoma with hormone receptor–negative and Her2-positive disease. But in patients who are elderly, frail with severe cardiac dysfunction, trastuzumab-based regimen is contraindicated. No study demonstrated efficacy of capecitabine monotherapy in this subset of disease. More prospective studies are required to identify patients who can benefit from capecitabine monotherapy in first-line setting in this subset of disease. Also capecitabine usage has several advantages mainly low cost and availability in oral form, and patients can be followed up on OPD basis.

Objectives

The standard treatment approach for metastatic breast cancer with HR- and Her-2-neu + disease is trastuzumab with systemic therapy [1, 2]. But in patients having severe cardiac dysfunction, trastuzumab is avoided. Various combination regimens are available in that setting, but no study has shown better efficacy of capecitabine monotherapy in this setting. We hereby present a case report of using capecitabine monotherapy in first-line setting, and the patient had complete resolution of lung metastasis from the last 2 years.

Case Report

A 64-year-old postmenopausal lady, performance status 1 with known case of breast carcinoma in the left side, was operated for modified radical mastectomy in the left side in the year 2016 with final histopathology report of pT3N2M0 and hormone receptor–positive, Her2-negative disease. She received eight cycles of standard dose of adjuvant chemotherapy with four cycles of cyclophosphamide and adriamycin followed by four cycles of paclitaxel. Later, she received standard-dose local radiation. She was initiated on aromatase inhibitors with tablet letrozole 2.5 mg OD and continued the same for 5 years when she complained of breathlessness and fatigue lasting for 1 month in July 2021. On evaluation, chest CT scan revealed multiple bilateral lung metastases along with 3×3 cm right-sided breast lump (Fig. 1). Abdominal CT scan did not reveal any other metastases. Core needle biopsy of breast lump and CT-guided left lung nodule biopsy were performed which revealed infiltrating carcinoma with immunohistochemical markers showing tumor cells positive for Her-2-neu with hormone receptor–negative disease. PET-CT scan was done which revealed FDG avidity in bilateral lung fields and right breast lump with no disease elsewhere. This case was discussed in the multidisciplinary tumor board, where the plan to start trastuzumab-based therapy was made. On evaluation, she was found to have ECG changes of right-sided axis deviation and, echocardiography showed ejection fraction of 40%. Injection trastuzumab was deferred, and the plan to start tablet capecitabine 1000 mg twice BD days 1–14 cycles every 21 days was made.

Fig. 1.

A CT thorax revealing multiple bilateral lung metastasis—July 2021. B CT thorax and abdomen showing right-sided breast lump—July 2021

Results

She was initiated on capecitabine monotherapy which she tolerated well, and there was symptomatic improvement after 1 month of initiation of the drug. She was continued on the same dose and schedule of capecitabine and was kept on regular follow-up after every 3 months. After 6 months of capecitabine initiation, PET-CT scan showed no FDG avidity in the lungs. She was continued on the same regimen to date. The last PET-CT scan was done in February 2023 which again showed complete response to lungs but reduction in FDG avidity over right breast lump with partial reduction in lump size (Fig. 2). Now, she is on a regular follow-up with us from the last 2 years, and capecitabine dose has been reduced to 800 mg twice daily.

Fig. 2.

PET-CT scan showing resolution of lung metastasis—Feb 2023

Discussion and Conclusion

Trastuzumab in combination with pertuzumab and taxane is the standard of care for metastatic breast carcinoma with hormone receptor–negative and Her2-positive disease [1, 2]. Other options include first-line trastuzumab in combination with selected chemotherapy like paclitaxel with or without carboplatin, docetaxel, and vinorelbine for patients with HER2-positive metastatic disease [3–5]. In addition, the combination of trastuzumab and capecitabine has also shown efficacy as a first-line trastuzumab-containing regimen in this setting [6–8]. Treatment mainly depends upon previously administered therapies in the adjuvant setting, patient’s relapse-free interval, benefit obtained from previous therapies in the advanced setting, amount of tumor burden, patients’ preferences and quality of life, as well as drug availability. In the second-line setting, lapatinib with capecitabine was considered the standard regimen before T-DM1 was available [9]. Also the current role of capecitabine usage in combination with other agents in third-line setting and beyond in previously heavily treated Her2-positive metastatic breast carcinoma has shown efficacy as shown by various studies [10–12]. But no study has shown good efficacy of capecitabine monotherapy in first-line setting of these patients. But in patients who are elderly, frail with severe cardiac dysfunction, trastuzumab -based regimen is contraindicated. In our case report, patient had moderate cardiac dysfunction with echocardiography showing ejection fraction of 40% owing to which trastuzumab-based regimen was not initiated. We offered option of capecitabine with lapatinib combination to our patient. But patient could not afford lapatinib due to financial constraints owing to which she was initiated on capecitabine monotherapy at a dose of 1000 m g twice daily day 1–14 cycles every 21 days. Capecitabine was freely available at our institute under state government health schemes. She showed improvement in respiratory symptoms gradually and tolerated the drug well. Repeat PET-CT scan showed resolution of lung metastasis and now she is free from lung metastasis from the last 2 years.

Our aim from this case report is to lay emphasis on the fact that more prospective studies are required to identify subset of patients who can benefit from capecitabine monotherapy in first-line setting of Her-2-neu-positive breast cancer. Capecitabine monotherapy was never considered the standard of care in first-line setting of Her2-positive metastatic breast carcinoma as shown by studies mentioned above. But here in this case report, the patient has shown good response to capecitabine alone in the first-line setting itself. Also capecitabine usage has several advantages mainly low cost and availability in oral form, and patients can be followed up on OPD basis.

Declarations

This study has been done with ethical standards.

Ethics Approval

Ethical approval was waived by the local ethics committee as it is part of a routine care.

Informed Consent

Taken from the patient.

Competing Interests

The authors declare no competing interests.