Breast cancer treatment neoadjuvant chemotherapy can cause tumor evolution, Russian researchers reveal

Neoadjuvant chemotherapy treatment can spur tumor evolution in breast cancer patients, according to Russian researchers.

Chemotherapy is a well-known cancer treatment and has been used to extend survival, but the research headed by Nicholay Litvyakov, head of the Tumor Virology Laboratory at the Cancer Research Institute, and Tomsk State University (TSU) researcher Marina Ibragimova tells otherwise.

The researchers looked at various biopsies of women with breast cancer and taking note of chromosomal abnormalities. The breast cancer patients all received at least 2 to 4 doses of neoadjuvant chemotherapy (NAC) before having surgery. The women were observed again after the surgery to determine the effect of the therapy. While the chemical therapy treatment partially or fully worked on most of the patients, 23 percent of women grew new tumors. The findings were published in the Siberian Journal of Oncology.

"We have preliminary results indicating that chemotherapy may cause the appearance of mutations which had not been observed before in the form of amplifications of chromosomal regions. In some cases it was a reason for an occurrence of hematogenous metastasis," Ibragimova said in a statement, as reported by EurekAlert. "We should find out the causes and methods for anticipating tumor development. Thus, there is no doubt that chemotherapy shall have strictly personalized character, depending on the properties of tumor and patient."

The researchers are working on how chemotherapy may encourage the growth of tumors. According to News Medical, chemotherapy drugs are "mutagens" which means it increases the frequency of mutations in genes which may lead to genetic disorders which makes tumor cells act strangely.

"Now we are extending our samples in order to check these observations. If we succeed we would create a technology allowing to predict the development of tumor in a specific patient and to define whether this patient needs chemotherapy and which medicines should be prescribed," Ibragimova said, as reported by Economic Times. This could help women with breast cancer get the utmost care.

Breast cancer is considered to be one of the most fatal cancers in the US. It is also considered to be the most commonly diagnosed cancer in women. According to Breast Cancer Org, more than 220,000 new cases of invasive breast cancer will be diagnosed in 2015; while there will be more than 60,000 new cases for non-invasive breast cancer. White women over 45 years old are more susceptible to the disease than African American. However, African-American women under than 45 are more likely to get diagnosed that whites.