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The number of new cancer cases is increasing, also in Poland. However, mortality from breast cancer is declining. This has to do with early screening and later with combination therapy. Dr. Barbara Radecka from Opole Oncology Center for them talks about the treatment of early breast cancer. prof. Tadeusz Koszarowski.
- Malignant neoplasms are the second most common cause of death in women and men in Poland (heart disease is in the first place)
- Women are most often diagnosed with malignant neoplasms of the breast (22,5%), colon (9,9%) and lung (9,4%).
- The data of the Organization for Economic Co-operation and Development (OECD) show that on average 41,8 per 100 thousand people Polish women died in 2020 from breast cancer
- You can find more such stories on the TvoiLokony home page
How can early breast cancer be treated?
Iwona Schymalla, Medexpress: Doctor, what are the treatment options for early breast cancer?
Barbara Radecka, MD, PhD, Opole Oncology Center prof. Tadeusz Koszarowski: Over the past 30-40 years, many developed countries have seen a decrease in mortality from breast cancer, despite the steadily increasing incidence. We have seen such trends in Poland since the beginning of the XNUMXst century. It is a huge success of oncology and several elements contribute to this success. First, the introduction of screening tests to detect the disease at an early stage, when it can be effectively treated. Secondly – we commonly introduce knowledge in the field of dynamically developing basic sciences, such as cell biology, biotechnology, into clinical practice, and thanks to this we treat more precisely. And finally, thirdly and very important – we use combined treatment, i.e. combining various local methods, such as surgery and irradiation, and systemic ones – chemotherapy, hormone therapy, biological treatment in appropriate sequences.
Such combined treatment is the basis of treatment of patients with early breast cancer and is recommended by all oncological scientific societies in the world. It is also the standard of conduct in Poland. Treatment should be carried out in specialized centers and therapeutic decisions should be made by a multidisciplinary council. Difficult decisions about the treatment plan should be made with the active participation of the patient, after giving her full information, presenting possible options for treatment, and giving her consent.
Treatment of early breast cancer depends on the type of cancer involved. We define subtypes based on biomarkers, including hormone receptors and the HER2 receptor. The most extensive algorithms concern the so-called aggressive subtypes – triple negative and HER2 positive breast cancer. Currently, the preferred treatment is the initial systemic treatment of such patients – chemotherapy (and in the case of HER2-positive cancer, also additionally one or two anti-HER2 antibodies), followed by optimal surgical treatment and, possibly, additional radiotherapy. The aim of systemic treatment is to destroy micrometastases that may be present at the time of cancer diagnosis, even though we cannot detect them with commonly available tests. Systemic treatment used in such a situation is reimbursed in Poland from public funds. Treatment with anti-HER2 antibodies is carried out as part of a drug program, i.e. a special procedure for reimbursement of modern therapies.
What is the intention to treat in early breast cancer?
Radical treatment is used in patients with early breast cancer. His intention is to heal. We intend to protect the patient from relapse and premature death. Speaking a bit more figuratively, we want cancer disease not to shorten human life.
Preoperative treatment may even lead to the disappearance of the tumor
What are the benefits of neoadjuvant treatment and why should it be used in patients with early breast cancer?
As I mentioned, the goal of systemic treatment is to destroy micrometastases that may be present at the time of cancer diagnosis. Such a goal can be achieved with both pre- and post-breast surgery treatments.
In contrast, preoperative (called neoadjuvant) treatment aims to shrink the tumor. This improves the possibilities of surgical treatment, also sparing the mammary gland. This procedure has been recognized for several decades.
In some situations, preoperative systemic treatment may even lead to the disappearance of the tumor. In such a situation, no invasive cancer cells are found in the microscopic examination of the removed part of the breast containing the tumor and in the axillary lymph nodes. This is called pathological complete response (pCR). Obtaining a pCR improves prognosis and increases the chances of living without relapse. The more effective pre-operative treatment and the more susceptible the disease is to it, the greater the chance of obtaining pCR. The sensitivity of the disease depends on various factors, e.g. in HER2-positive cancer it is the presence of estrogen and progesterone receptors and the size of the tumor – the larger the tumor, the worse it responds to treatment and the more difficult it is to destroy it completely. A pathomorphological complete response is achieved in about half of these patients, but not all. The diagnosis of invasive cancer in microscopic examination after initial systemic treatment and surgery is called a residual disease.
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Postoperative treatment in patients with residual disease
What post-operative treatment can be used in patients with residual disease?
The prognosis of patients with residual disease compared to patients with pCR is significantly worse. Although we cannot say precisely in individual patients whether the disease will return and when it will come back, we know that in patients with residual disease the risk of relapse is high, and most relapses in triple negative and HER2 positive cancers occur in the first 2-3 years after primary treatment.
To reduce this risk, additional systemic treatment after surgery is worthwhile. In triple-negative cancer, in justified clinical situations, we additionally use oral chemotherapy. In Her2-positive cancer, we continue the treatment with trastzumab – anti-HER2 antibody (without chemotherapy) as standard. However, we now know that trastuzumab alone is not optimal in patients with residual disease. We can protect such patients more effectively against relapse by using trastuzumab emtansine in postoperative treatment.
This is a new drug from the group of so-called Trojan horses. It is a combination of trastuzumab with the cytostatics – emtansine in one molecule. Trastuzumab binds to the HER2 receptor, inhibiting important life processes in the cancer cell and additionally introducing its “load” into the cell, i.e. emtansine. It is this insidious and sophisticated mechanism of introducing a cytostatic into a cell that has caused drugs that bind antibodies and cytostatics together to be called “Trojan horses”. Importantly, emtansine introduced into the cell with trastuzumab can be used in much lower doses than if it were used alone. And it goes primarily to cells with the HER2 receptor, to which trastuzumab must attach.
It is worth noting that currently in oncology there are more and more such conjugates of various antibodies and various cytostatics.
Post-operative use of trastuzumab emtansine in patients with residual disease causes a prolongation of the clinical relapse compared to classic trastuzumab.
What role does trastuzumab emtansine play in patient prognosis?
Post-operative use of trastuzumab emtansine in patients with residual disease causes a delay in the occurrence of clinically overt disease recurrence compared to classic trastuzumab. We say it extends the time to cancer-free survival. This parameter, abbreviated as DFS from the English name (disease free survival) is a measure of the drug’s effectiveness that we are assessing because patients do not receive any other treatment at that time. Therefore, by using trastuzumab emtansine, we can postpone the relapse of the disease and prevent some patients from relapse. It is of colossal importance for patients, because the cancer is under control, it does not give them any ailments, women have a good quality of life, they can function normally and gain further years of well-being.
In the treatment of cancer patients, we also have another very important parameter of treatment effectiveness – overall survival. The assessment of this parameter requires much longer observation, especially if it concerns a disease in which the expected survival time may be many years. We do not have such data for trastuzumab emtansine at present.
What is the safety profile of trastuzumab emtansine?
Trastuzumab emtansine is generally a well-tolerated drug. Importantly – it is well known to Polish oncologists because we use it with great success in the treatment of patients with advanced breast cancer as another line of anti-HER2 treatment. Of course, it has side effects that include nausea, fatigue, neurotoxicity, muscle or joint pain, thrombocytopenia, increased liver enzymes, headache and constipation. The drug may also cause serious, life-threatening birth defects for the child and therefore must not be used during pregnancy and in women of childbearing potential, a potential pregnancy should be ruled out before starting treatment with trastuzumab emtansine.
Is the drug currently available to Polish patients?
The drug is reimbursed in Poland from public funds, but only in the treatment of patients with advanced breast cancer. It is not reimbursed in the treatment of early cancer. As far as I know, the reimbursement process is ongoing. We are waiting – we as the community, but most of all our patients – for the successful completion of this process.
Author: Iwona Schymalla
Also read:
- What do Polish women die most often? New report
- They know they are dying. How do I talk to cancer patients?
- Polish women die of breast cancer. Money from the government is not helping
- WHO: Breast cancer is the most commonly diagnosed cancer in the world. Not lung cancer anymore
- Poland: more and more malignant tumors