When it comes to a topic that individualized medicine walks into a reality, scientists would stress that the current challenge is identifying different subtypes of patients so that treatment can be truly tailored to the individual.

Clinical developments have enabled the classification of patients into various subtypes, based on anatomical and pathological findings. Currently, samples from cancer patients are routinely tested for relevant biomarkers in order to tailor the treatment. The ultimate goal is to get the right drug to the right patient, at the right time.

Genetic testing in breast cancer is becoming common practice to predict each patient’s therapeutic effect and risk of recurrence. Testing for ER positivity enables physicians to determine the likelihood of response to endocrine therapy and provides a variety of treatment options. HER2 presents in around 25% of cases, and is associated with an aggressive form of the disease. The monoclonal antibody trastuzumab targets HER2 and is active in patients expressing this receptor.

“Treatment today is getting much more individualized,” says Dr. Clifford A. Hudis, chief of breast cancer medicine service at Memorial Sloan Kettering Cancer Center in New York. “Depending on the molecular nature of a woman’s tumor, postoperative hormonal treatment or other drug treatments are routinely prescribed to prevent or delay a recurrence of disease.”

Cancer therapy and its environment

Gone is the simplistic notion that cancer is a disease of abnormal cell division, said Dr. Larry Norton, deputy physician-in-chief for breast cancer programs.”It’s a disease of abnormal relationships between the cancer cell and other cells in its environment.”

This new perspective is leading to changes in treatment. Bevacizumab, as the first FDA-approved angiogenesis Inhibitor, slows or blocks the formation of blood vessel to treat cancer. It is based on the discovery that tumour sends out signals to nearly blood vessel causing new capillaries to sprout towards the tumour, thereby effectively hijacking the blood supply. Therefore, this monoclonal antibody blocks cancer cell growth by cutting off supplies from its environment.

In light of this new perspective, current surgery for breast cancer involves removing only a few lymph nodes, rather than a whole, for testing. “We know that in many cases we’re leaving behind nodes that contain cancer cells, but it doesn’t hurt the patient to leave them there. Because cancer cells require other cells in their vicinity to help them grow, it’s not true that if there’s one cancer cell left it will definitely grow and cause trouble.”Dr. Norton said.

Cancer immunotherapy

Instead of waiting for cancer to recur in certain high-risk patients, scientists are now developing techniques to outwit the cancer cell’s aggressive tactics by recruiting the patient’s immune system to launch a continuous attack.

Knowing that the effectiveness of treatment is reduced once cancer has metastasized, researchers are now testing creative ways to prevent such recurrences. One, a specially designed vaccine called NeuVax, is in the final stage of multinational clinical tests.

The vaccine is made from a peptide, a small piece of a cancer protein, that is combined with an immune stimulant. Early results suggest that the vaccine can reduce the risk of recurrence by 50 percent among breast cancer patients whose tumors produce low levels of the protein HER2, a marker for more aggressive breast cancer.

Another approach under study involves destroying the tumor by freezing it with an ice probe, but leaving it in place so that the immune system can be trained to attack it, Dr. Hudis said. The patient then would be given an immune stimulant to help overcome the molecular obstacles that had kept the immune system from recognizing the cancer as foreign tissue.

References:

1. The HER2 peptide nelipepimut-S (E75) vaccine (NeuVax™) in breast cancer patients at risk for recurrence: correlation of immunologic data with clinical response. Immunotherapy. 2014 May;6(5):519-31.

2. Phase II study of weekly intravenous trastuzumab (Herceptin) in patients with HER2/neu-overexpressing metastatic breast cancer. Semin Oncol. 1999 Aug;26(4 Suppl 12):78-83