If Chemotherapy Before Surgery Destroys All Breast Cancer in Lymph Nodes, Survival Is Better, Especially for Women With HER2-Positive Disease
A study suggests that lymph node pathologic complete response is associated with better survival in women diagnosed with HER2-positive, stage II or stage III breast cancer.
Treatments given to weaken and destroy breast cancer before surgery are called neoadjuvant treatments. Most neoadjuvant treatments involve one or more chemotherapy medicines. Targeted therapy medicines, hormonal therapy, or radiation therapy also are sometimes used as neoadjuvant treatments.
Treatment before surgery isn’t routinely used to treat early-stage breast cancer, but may be used if the cancer is large or aggressive.
One way doctors judge the effectiveness of neoadjuvant chemotherapy is to look at the tissue removed during surgery to see if any actively growing cancer cells are present. If no active cancer cells are present, doctors call it a “pathologic complete response” or pCR.
Several studies have shown an association between pCR to neoadjuvant chemotherapy for breast cancer and better disease-free survival, as well as better overall survival.
Disease-free survival is how long a woman lives without the breast cancer coming back. Overall survival is how long a woman lives, with or without the breast cancer coming back.
The link between pCR and survival is strongest when the pCR includes both the breast and the lymph nodes. This means that if no actively growing cancer cells are found in the breast area where the cancer was and in the lymph nodes where the cancer was, survival is likely to be better than if there is no pCR in both areas.
While many studies have looked at pCR in the breast, as well as pCR in the breast AND the lymph nodes, no large studies have looked at pCR in just the lymph nodes and how this might affect survival.
A study suggests that lymph node pCR is associated with better disease-free survival and overall survival in women diagnosed with HER2-positive, stage II or stage III breast cancer that has spread to the lymph nodes under the arm.
The study was published online on Dec. 30, 2015 by JAMA Oncology. Read the abstract of “Ten-Year Outcomes of Patients With Breast Cancer With Cytologically Confirmed Axillary Lymph Node Metastases and Pathologic Complete Response After Primary Systemic Chemotherapy.”
In the study, the researchers looked at the records of 1,600 women diagnosed with stage II or stage III breast cancer that had spread to the lymph nodes under the arm. The women were diagnosed between 1989 and 2007 and all received chemotherapy before breast cancer surgery. The women ranged in age from 21 to 86 years old.
The researchers found that 454 of the women (28.4%) had lymph node pCR. Women who had lymph node pCR were more likely to have been diagnosed with:
- HER2-positive breast cancer
- triple-negative breast cancer (HER2-negative, estrogen-receptor-negative, and progesterone-receptor-negative)
- cancers that were higher-grade
These characteristics make a cancer more aggressive.
After 10 years, overall survival rates were:
- 84% for women with lymph node pCR
- 57% for women without lymph node pCR
Recurrence-free survival rates were:
- 79% for women with lymph node pCR
- 50% for women without lymph node pCR
Overall survival rates for women with lymph node pCR were:
- 90% for women who also had breast pCR
- 72% for women who didn’t have breast pCR
Overall survival rates for women without lymph node pCR were:
- 66% for women who had breast pCR
- 56% for women without breast pCR
The researchers also looked only at women who were diagnosed with HER2-positive breast cancer who were treated with a medicine such as Herceptin (chemical name: trastuzumab) that targets HER2 receptors -- 67.1% (100 of 149 women) had lymph node pCR.
Ten-year overall survival rates for women treated with an HER2-targeted medicine were:
- 92% for women with lymph node pCR
- 57% for women without lymph node pCR
Ten-year recurrence-free survival rates for this same group of women were:
- 89% for women with lymph node pCR
- 44% for women without lymph node pCR
All these survival differences were statistically significant, which means they were likely due to the difference in lymph node pCR and not just because of chance.
If you’ve been diagnosed with stage II or stage III breast cancer, the results of this study are encouraging, especially if the cancer is HER2-positive. It’s important to know that not having a pathologic complete response to chemotherapy before surgery doesn’t mean you won’t do well. Most women don’t have a pCR to neoadjuvant chemotherapy.
After your diagnosis, you and your doctor will develop a treatment plan that will likely include chemotherapy and possibly targeted therapy medicines. No matter which treatments are recommended for you, you may want to talk to your doctor about:
- why each treatment is recommended (including any combinations)
- treatment timing and sequence
- the expected benefits, risks, and side effects of each treatment
For more information on neoadjuvant chemotherapy, visit the Breastcancer.org Chemotherapy section.
— Last updated on February 22, 2022, 9:55 PM
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