What is the treatment and prognosis for double positive invasive ductal carcinoma (IDC) of the breast?

From the Guidelines

Double positive invasive ductal carcinoma of the breast, which is HER2-positive, should be treated with neoadjuvant therapy or upfront surgery followed by targeted therapies, with the goal of achieving a total pathological complete response (tpCR) to improve survival endpoints. The treatment approach for HER2-positive early breast cancer continues to evolve, with a focus on risk-based decision-making 1. Patients with high-risk HER2-positive disease (tumour diameter ≥2 cm, and/or node-positive disease) are candidates for neoadjuvant chemotherapy (NACT) plus pertuzumab–trastuzumab, while those with node-negative disease and tumour diameter <2 cm may undergo upfront surgery followed by paclitaxel for 12 weeks plus 18 cycles of trastuzumab, with the option to add pertuzumab (if pN+) 1.

Key considerations in the treatment of double positive invasive ductal carcinoma of the breast include:

• Achieving a total pathological complete response (tpCR) after neoadjuvant therapy, which is associated with improved survival endpoints 1
• Continuing pertuzumab–trastuzumab in the adjuvant setting to complete 1 year (18 cycles) of treatment for patients who achieve tpCR 1
• Using post-neoadjuvant trastuzumab emtansine (T-DM1) therapy for patients with invasive residual disease, which significantly increases invasive-DFS compared with trastuzumab 1
• Considering extended adjuvant therapy with neratinib in selected patients (HER2-positive and oestrogen receptor [ER]-positive) who have completed adjuvant trastuzumab-based therapy 1

The prognosis for double positive invasive ductal carcinoma of the breast is generally favorable, with a focus on minimizing recurrence risk and optimizing treatment outcomes 1. Treatment recommendations should be consistent with local and international guidelines, and further studies will guide optimization of treatment for patients with HER2-positive early breast cancer according to the risk of disease recurrence 1.

From the FDA Drug Label

For patients with carcinoma of the breast, the following is recommended (see CLINICAL STUDIES: Breast Carcinoma section):

1. For the adjuvant treatment of node-positive breast cancer, the recommended regimen is paclitaxel, at a dose of 175 mg/m2 intravenously over 3 hours every 3 weeks for 4 courses administered sequentially to doxorubicin-containing combination chemotherapy
2. After failure of initial chemotherapy for metastatic disease or relapse within 6 months of adjuvant chemotherapy, paclitaxel at a dose of 175 mg/m2 administered intravenously over 3 hours every 3 weeks has been shown to be effective

The treatment for double positive invasive ductal carcinoma of breast may involve paclitaxel as part of the adjuvant treatment regimen, specifically for node-positive breast cancer. The recommended dose is 175 mg/m2 administered intravenously over 3 hours every 3 weeks for 4 courses, given sequentially to doxorubicin-containing combination chemotherapy. Additionally, tamoxifen may be used to lower the chance of getting invasive breast cancer in women with ductal carcinoma in situ (DCIS) who have been treated with surgery and radiation therapy. However, the provided drug labels do not directly address the prognosis of double positive invasive ductal carcinoma of breast. Key points to consider:

• Paclitaxel is used in the treatment of breast cancer, specifically for node-positive disease.
• Tamoxifen is used to lower the chance of getting invasive breast cancer in women with DCIS.
• The prognosis and treatment outcomes may vary depending on individual patient factors and the specific characteristics of the cancer. 2 3

From the Research

Double Positive Invasive Ductal Carcinoma of Breast Treatment and Prognosis

• The treatment and prognosis of double positive invasive ductal carcinoma of the breast is a complex topic, with various studies providing insights into the optimal approach 4, 5, 6.
• Invasive ductal carcinoma (IDC) is the most common type of breast cancer, and its treatment depends on various factors, including tumor stage, grade, and hormone receptor status 4.
• The presence of ductal carcinoma in situ (DCIS) accompanying IDC is associated with improved local recurrence-free survival, suggesting a less aggressive phenotype than IDC alone 5.
• A study found that patients with IDC-DCIS were significantly younger, had smaller tumors, and less lymph node involvement compared to those with pure IDC 5.
• The optimal treatment of synchronous bilateral breast cancers with differing histological subtypes, such as IDC and invasive lobular carcinoma (ILC), remains uncertain and requires further research 6.
• A case report highlighted the importance of multidisciplinary collaboration and patient-centered decision-making in managing synchronous bilateral breast cancers with distinct histological subtypes 6.
• The use of radiotherapy in patients with DCIS has been shown to reduce the risk of breast cancer mortality, suggesting a potential benefit in patients with IDC as well 7.
• However, the choice of treatment between mastectomy and lumpectomy with radiation depends on various factors, including patient preferences, tumor characteristics, and surgeon expertise 8.

Treatment Options

• Mastectomy and lumpectomy with radiation are both viable treatment options for breast cancer, with similar survival outcomes 8.
• A study found that mastectomy patients experienced less chronic pain and post-surgical side effects compared to lumpectomy patients, but had lower cosmetic satisfaction 8.
• Lumpectomy patients reported higher chronic pain frequency and radiation side effects, but were more satisfied with cosmetic outcomes 8.
• The overall surgical treatment satisfaction was similar between mastectomy and lumpectomy patients 8.

Prognosis

• The prognosis of double positive invasive ductal carcinoma of the breast depends on various factors, including tumor stage, grade, and hormone receptor status 4, 5.
• Patients with IDC-DCIS have a better prognosis compared to those with pure IDC, with improved local recurrence-free survival and reduced risk of distant metastases 5.
• However, the presence of synchronous bilateral breast cancers with distinct histological subtypes poses a significant clinical challenge, requiring individualized treatment approaches and further research to establish optimal treatment strategies 6.