Young women with complete response to neoadjuvant chemotherapy show improved survival

A study in the Journal of the National Comprehensive Cancer Network found that survival rates improved in women younger than 40 years old with breast cancer that completely responded to neoadjuvant chemotherapy.

Background

Though breast cancer is rare in women younger than 40 years old, it still represents a large portion of cancers diagnosed before age 40.   Because doctors often don’t recommend young women have breast cancer screenings, those who are diagnosed are more likely to have a later stage of disease.  Younger women also often have a more aggressive subtype of breast cancer.  Both of these factors can lead to a higher risk of recurrence or death from breast cancer.

Neoadjuvant chemotherapy, chemotherapy given before surgery, is often offered for larger cancers or those with more aggressive features. Its goal is to shrink the tumor, help get rid of cancer cells, and possibly lower the risk of recurrence.  Neoadjuvant chemotherapy may

• shrink the tumor before surgery, allowing you to have lumpectomy instead of mastectomy
• allow the doctor to see whether the treatment is working before a surgeon removes the tumor
• allow you to avoid more chemotherapy, and its side effects, after surgery

Doctors assess the effect of neoadjuvant chemotherapy during treatment and after surgery.  If the cancer has disappeared from the breast and lymph nodes at the time of surgery after neoadjuvant chemotherapy, that is called a pathologic complete response. This study’s researchers wanted to see how response to neoadjuvant chemotherapy was associated with survival rates in young women with breast cancer, and if cancer subtype or genetic mutations play a role in predicting the impact of the neoadjuvant treatment.

Design

The researchers collected data from past medical and death records of 170 women who were diagnosed with stage II or III invasive breast cancer at age 40 or younger. All of the women were treated with neoadjuvant chemotherapy followed by surgery between 1998 and 2014 at Massachusetts General Hospital in Boston. Women with HER2-positive breast cancer also received trastuzumab (Herceptin). The median length of follow-up for the group was 5.2 years.

Of the 170 young women:

• 39 percent had hormone receptor-positive breast cancer
• 32 percent had HER2-positive breast cancer
• 28 percent had triple-negative breast cancer

Of those who chose to have genetic testing, 18 percent were positive for an inherited breast cancer-related gene mutation, such as BRCA1.

The researchers looked at disease-free survival, the length of time from the start of treatment until cancer returns, and overall survival, the length of time from the date of diagnosis until death.

Results

Overall, the research team found that in young women, seeing pathologic complete response after neoadjuvant chemotherapy was associated with longer disease-free survival and overall survival, compared with peers who did not have pathologic complete response.

About a third (31.2 percent) of the women in the study saw pathologic complete response. This result was seen in more women with HER2-positive and triple-negative breast cancer than in women with hormone receptor-positive breast cancer. Of the 25 participants who tested positive for genetic mutations, 56 percent responded completely to neoadjuvant chemotherapy.

Disease-free survival

Over an average of 5.2 years of follow-up, 29.4 percent of the women had the breast cancer return. Women who had pathologic complete response were much less likely to have a recurrence. This was true regardless of the cancer subtype.

• 91 percent of women  were disease-free after 5 years when they had pathologic complete response to neoadjuvant chemotherapy
• 60 percent of women were disease-free after 5 years when they did not have pathologic complete response

Overall survival

Over the follow-up period, 22.9 percent of the total study participants died. But young women who saw pathologic complete response were much less likely to die than young women who did not.

• 95 percent of those who had pathologic complete response to neoadjuvant chemotherapy were alive after 5 years
• 75 percent of those who did not have pathologic complete response to neoadjuvant chemotherapy were alive after 5 years

Across all cancer subtypes, participants with pathologic complete response had higher rates of overall survival than those who did not have pathologic complete response.

Limitations

This study was retrospective, meaning the researchers looked back at old medical records and treatments that took place in the past. The study is from one hospital and researchers did not compare the women there with women from other institutions or with women who were 40 years or older. The researchers also studied people over an average of 5.2 years, and a longer time period would strengthen the results.

What This Means for You

This study shows that reaching pathologic complete response after neoadjuvant chemotherapy is a marker of better disease-free and overall survival rates for young women. You may be interested in getting chemotherapy treatment before surgery if you have HER2-positive or triple-negative breast cancer because it works especially well in those subtypes, and these are often people in whom neoadjuvant therapy is recommended.

For young women who get chemotherapy before surgery, whether cancer is present at the time of surgery can help predict the risk of the cancer coming back. Neoadjuvant chemotherapy may also provide your doctors with more information than chemotherapy after surgery (called adjuvant chemotherapy).  It can also be used to shrink tumors and allow for less extensive surgeries – such as lumpectomy instead of mastectomy – in some cases.

Talk to your doctor about this study and whether neoadjuvant chemotherapy is right for you.

 

Spring L, Greenup R, Niemierko A. Pathologic Complete Response After Neoadjuvant Chemotherapy and Long-Term Outcomes Among Young Women With Breast Cancer. Journal of the National Comprehensive Cancer Network. 2017;15(10):1216-1223;doi: 10.6004/jnccn.2017.0158.

This article was supported by the Grant or Cooperative Agreement Number 1 U58 DP005403, funded by the Centers for Disease Control and Prevention. Its contents are solely the responsibility of the authors and do not necessarily represent the official views of the Centers for Disease Control and Prevention or the Department of Health and Human Services.