Complete and Partial Breast Cancer Remission

How the absence or reduction of cancer directs treatment and care

By Brandi Jones, MSN-ED RN-BC 

Medically reviewed by Doru Paul, MD

Updated on June 22, 2022

• How Remission Is Determined

• Complete Remission

• Partial Remission

• Treatment

• Frequently Asked Questions

Breast cancer treatment may result in complete or partial remission. Complete remission is when physical exams, blood tests, and imaging do not show any signs of cancer in your body. Partial remission occurs when the tumor is still present, but it is substantially reduced.

Healthcare providers use the term remission rather than cure because there remains a possibility that breast cancer may return after it's treated. This is called a recurrence.

This article reviews the different types of remission and the approach to their treatment and management.

How Remission Is Determined

Breast cancer remission is determined in multiple ways including the following: 

• Physical examination 
• Blood tests 
• Tissue evaluation
• Imaging studies (such as a breast MRI or PET/CT scan)

As valuable as these tests are, they have their limitations.

Complete Remission

Complete remission, also known as a complete response, means that cancer appears to be gone after treatment.

Even after complete remission has been declared, there may still be cancer cells below the detection levels of these tests. Some cancer cells may lie dormant indefinitely; others may suddenly multiply months or years later, resulting in a recurrence.2

Because of the potential for recurrence, many healthcare providers will refer to complete remission as no evidence of disease, or NED.

Partial Remission

If breast cancer is in partial remission, also known as a partial response, it means that the solid tumor has shrunk. Partial remission is usually declared when there is at least a 50% reduction in the tumor size or the number of cancer cells from the baseline value.3

Partial remission is not the usual goal of breast cancer treatment. It is only when a tumor is inoperable or has metastasized (spread to other organs) that an oncologist will aim to control the tumor rather than eradicate it.4

In all but stage IV breast cancer, efforts will be made to remove the tumor and use radiation and/or chemotherapy to get rid of all remaining cancer cells.

To qualify as a complete or partial remission, the absence or reduction of cancer must last for at least one month. The absence of symptoms is neither a measure nor an indication of remission.

Treatment

For those in complete remission, your healthcare providers will continue to monitor you closely so they can quickly identify and treat a recurrence if needed. You may also require maintenance therapy after the initial treatment. 

The goal of maintenance therapy for those in complete remission is to prevent or delay recurrence. For those in partial remission, the goal is to slow the growth or to lengthen a person’s life. In advanced-stage cancer, it may decrease symptoms or increase quality of life.

Maintenance medication may include a lower dose of chemotherapy, targeted therapy, or endocrine (hormone) therapy.2 

Chemotherapy 

One of the most common types of maintenance therapy often involves traditional chemotherapy drugs. Often, they are given in a lower dose and as a single medication rather than in combination to help decrease side effects.2

Targeted Therapy

Targeted therapy includes kinase inhibitors, monoclonal antibodies, or antibody-drug conjugates.5

Kinase inhibitors block a protein that keeps cancer cells from growing and include:

• Tykerb (lapatinib)
• Nerlynx (neratinib)
• Tukysa (tucatinib)

Monoclonal antibodies help boost the immune system. Examples include:

• Herpecitin (trastuzumab)
• Perjeta (pertuzumab)
• Margenza (margetuximab)
• Phesgo (trastuzumab, pertuzumab, and hyaluronidase)

Antibody-drug conjugates combine monoclonal antibodies and chemotherapy and include medications such as:

• Kadcyla (ado-trastuzumab emtansine)
• Enhertu (fam-trastuzumab deruxtecan)

Endocrine or Hormone Therapy 

Hormone receptor-positive tumors feed off hormones and typically require endocrine therapy that blocks or stops estrogen production. While this is not a complete list, some common hormone therapy medications include:6

• Nolvadex or Soltamox (tamoxifen) 
• Toremifene (Fareston)
• Arimidex (anastrozole) 
• Femara (letrozole)
• Faslodex (fulvestrant)
• Zoladex (goserelin) 
• Lupron (leuprolide)

 Tumor Grades and Breast Cancer

Early-Stage Breast Cancer

If you've been diagnosed with early-stage breast cancer, you would receive local treatment that's intended to completely eradicate the disease.

Partial remission is a term that is usually used to describe stage IV metastatic breast cancer treatment response, but, sometimes, partial remission may also apply to earlier stages.

Even if you are in complete remission, you may still need to take medication to keep your cancer from returning. Known as adjuvant therapy, the drugs are primarily for estrogen receptor-positive breast cancer.7 This is a type of cancer whose growth is directly influenced by the hormone estrogen.

To reduce the risk of recurrence, your healthcare provider may prescribe drugs that suppress either the production of estrogen or the stimulation of estrogen-sensitive cells.

If you have estrogen-sensitive cancer, your practitioner may prescribe tamoxifen, which binds to the estrogen receptors on cells. After three to five years, you may be switched to another class of drug known as aromatase inhibitors (AIs).

For post-menopausal women, you may be prescribed an aromatase inhibitor for an additional five years. Your healthcare provider may make this change to avoid the long-term side effects of tamoxifen. Aromatase inhibitors block estrogen production in the liver, pancreas, breasts, brain, and other tissues.

Unlike tamoxifen, aromatase inhibitors are only effective in postmenopausal women or women whose ovaries are suppressed.

If your breast cancer is estrogen-receptor-negative, you may not need any medications. 

Metastatic Breast Cancer

If you have stage IV breast cancer, you will be prescribed medications to better control the disease. While treatable, metastatic breast cancer cannot be cured.4 

With that being said, recent advances in chemotherapy and immunotherapy have allowed people with stage IV cancer to live longer without symptoms of the disease. This includes experimental adoptive cell therapy (ACT) in which your body's own cancer-fighting cells are harvested and cultured for use as immunotherapy.

 How Immunotherapy Works in Cancer

Summary

When breast cancer is treated, it may result in complete or partial remission. Complete remission occurs when physical exams, blood tests, and imaging do not show any signs of cancer. Partial remission is when the tumor is still present but reduced.

Those with breast cancer will be monitored by their healthcare team for years to come. Maintenance or continued treatment depends on the type of cancer, stage, and size. Some require targeted therapy while others need endocrine (hormone) therapy or continued chemotherapy.

A Word From Verywell

After any breast cancer diagnosis, you will need to see an oncologist on an ongoing basis to monitor your condition. This typically involves a healthcare provider's visit every few months for the first five years, after which you may only need yearly appointments. You will also need an annual mammogram and possibly a breast MRI unless you've had a bilateral mastectomy.

Although there is no way to definitively prevent breast cancer recurrence, there are preventive medications that reduce the risk of a recurrence for some types of breast cancer. By remaining linked to medical care, you will increase the chances that a recurrence will be caught early when it is most treatable.

Posted in: Post Treatment, Recurrence