A recent study by Zielinski et al compared two bevacizumab-containing drug regimens as first-line treatment for HER2-negative metastatic breast cancer and found one — bevacizumab plus capecitabine — to be more tolerable and suitable without affecting survival rate, and the other — bevacizumab plus paclitaxel — to offer more progression-free survival among patients. The researchers of the trial (TURANDOT) recommend bevacizumab+capecitabine as a valid first-line treatment for breast cancer.
It was an open labelled, randomized phase 3 TURANDO trial study that consisted of total 564 subjects aged 18 or older. 266 members were included in bevacizumab plus paclitaxel group and 265 in bevacizumab plus capecitabine group.
The participants were administered bevacizumab plus paclitaxel (bevacizumab 10 mg/kg on days 1 and 15 plus paclitaxel 90 mg/m2 on days 1, 8, and 15 every 4 weeks) or bevacizumab plus capecitabine (bevacizumab 15 mg/kg on day 1 plus capecitabine 1000 mg/m2 twice daily on days 1–14 every 3 weeks until any sign of disease progression, toxicity or any withdrawal from the consent.
During the study, the scientist also noted that no treatment-related deaths appeared in the bevacizumab plus capecitabine group, which proved more tolerable treatment with uncompromised survival rate. However, two casualties in bevacizumab plus paclitaxel group were reported. Additionally, both groups experienced some adverse events such as a drop in white blood cells count (neutropenia and leucopenia), hand food syndrome, peripheral neuropathy, and hypertension in multiple ratios.
Bevacizumab works by blocking the protein called vascular endothelial growth factor (VEGF).
VEGF is the lifeline of cancerous tumors i.e., it provides blood and oxygen to the rapidly dividing cancerous cells. When bevacizumab suppresses this protein, the cancerous cells choke to death.
Although drug bevacizumab (Avastin) has already been used in the treatment of multiple cancers such as cervical cancer, colorectal cancer, glioblastoma, non-small cell lung cancer, ovarian epithelial, fallopian or primary peritoneal cancer as well as renal cancer, it was not approved as a treatment for breast cancer due to its less reliability and effectiveness noted against metastatic breast cancer.
The trial outcomes presented by Genentech, the drug sponsor, failed at providing sufficient and satisfying evidence of breast cancer treatment and earning an approval by the US Food and Drug Administration (FDA).
However, on February 22, 2008, the FDA approved to escalate the use of bevacizumab in combination with paclitaxel against HER2-negative metastatic breast cancer in people who haven’t been administered any chemotherapy treatment earlier.
About 1 in 8 US women are at risk of developing invasive breast cancer over the course of her lifetime – making it the second most common type of cancer among US population. Human breast is made of different regions . These regions can have their own cancer type such as the ductal carcinoma or cancer of the lobules. Cancer is an uncontrollable division of cells, can be both localized or advanced. Localized cancers do not progress, hence they are associated with a specific region. However, advanced form of breast cancer (called metastatic cancer) spreads to other parts of the body such as bone, lungs, liver or brain, but no matter how much and wherever it spreads in the body, it will generally be treated as breast cancer.
Additionally, genes encode the recipe of proteins, the latter of which are essential for a cell to survive and perform normal functions. Each protein performs a specific function, for instance, a protein coded by the human epidermal growth factor receptor 2 (HER2) gene has a role in the development of breast cancer. HER2 gene encodes HER2 proteins, the receptors of which are present on the surface of breast cells and control the healthy growth of breast. But sometimes, HER2 genes fails to work properly and start producing copies of itself which leads to the uncontrollable production of HER2 protein which eventually leads to the birth of breast cancer cells. Cancer associated with the overproduction and overexpression of HER2 protein is known as HER2 positive breast cancer and the reverse is observed in the case of HER2 negative breast cancer.
While findings of this multinational, phase 3 trial study may seem to provide a pathway for HER2-negative breast cancer, it is still advisable to doctors that before prescribing this conjunct drug for treatment for breast cancer, consider the predictive risk factors associated with it. The treatment might be a source of hope for breast cancer patients, it still is recommended to consider patient’s concerns about the treatment as well as varied safety profiles.