Neoadjuvant treatment is a treatment method applied as the first step to reduce tumor size before the main treatment method, which is usually planned as surgery. Chemotherapy, radiation therapy and hormone treatments are the main approaches that constitute neoadjuvant treatment. Neoadjuvant therapy is among the types of induction therapy. Induction therapy covers the beginning of the treatment plan and constitutes the first of the chemotherapy stages.
What is Neoadjuvant Therapy?
Neoadjuvant therapy, which can consist of chemotherapy , radiation and hormone treatments, is known as treatment administered before the main treatment phase to achieve success in the main treatment. The word adjuvant means helper. Adjuvant chemotherapy is administered to cancer cells that survive after the primary treatment approach. Neoadjuvant treatment differs from adjuvant treatment because it is applied extra before the primary treatment. However, both treatment methods have similar features. Although neoadjuvant chemotherapy is a frequently preferred method, it includes drug therapy to shrink the tumor structure before moving on to other treatment options such as surgery. It may also be preferred in cases where very large tumors put pressure on vital organs and cause loss of function. Choosing more than one method together instead of a single method in cancer treatment is generally the basis of the approach to conditions such as breast, colon or lung cancer. Adjuvant or neoadjuvant treatment choices generally increase the chance of recovery in most types of cancer. One of the most important advantages of neoadjuvant treatment is that it can reach cancer cells in the circulation and in distant tissues and organs that are overlooked by imaging techniques during the diagnosis process. If cancer cells that are missed at diagnosis are not treated, there is a risk of cancer recurrence and cancer treatment failure. In such cases, neoadjuvant therapy is a very valuable approach for successful cancer treatment. Neoadjuvant chemotherapy allows cancer cells to be targeted more easily and increases the likelihood that treatment will be successful. In some cases, neoadjuvant radiation therapy may also be preferred to shrink the tumor before surgery. Induction chemotherapy is a concept that is often confused with neoadjuvant chemotherapy. If the main treatment approach in cancer treatment planning is only chemotherapy application, it is called induction chemotherapy. Neoadjuvant treatment is the application of a different treatment method before the main treatment. The treatment method applied before surgery is usually chemotherapy.
In Which Situations Is Neoadjuvant Treatment Applied?
The main proven benefits of neoadjuvant chemotherapy are to remove tumors that cannot be removed by surgical operations and to make inoperable tumors operable. Although neoadjuvant chemotherapy is a potentially useful approach, it has not been proven to definitively increase survival or provide definitive treatment. While the response to neoadjuvant chemotherapy is positive in some types of cancer, the application of neoadjuvant chemotherapy in some cancers may not reduce the likelihood of cancer recurrence. Indications for neoadjuvant chemotherapy are not broad. The main reasons for a systemic neoadjuvant treatment approach before definitive cancer treatment are as follows.
- The main reason why neoadjuvant treatment is preferred is to prevent the spread of cancer cells (micrometastases) that are overlooked or very small in the diagnosis of cancer and to complete the treatment at the first opportunity.
- If complications develop after cancer treatment that may prevent the application of additional treatment methods, recovery becomes difficult and the process takes longer. Neoadjuvant treatment has yielded more reliable results in this sense.
- With neoadjuvant treatment, the systemic effects of the disease on the body can be observed more accurately in the long term.
- In some types of cancer, shrinking large tumors improves the course of the cancer. Neoadjuvant therapy, which makes surgery easier by shrinking the tumor, is a promising approach in some cancers that cannot be treated with surgery.
How is Neoadjuvant Therapy Applied?
Neoadjuvant chemotherapy has more than one application method. Neoadjuvant chemotherapy can be administered orally, intravenously and by injection. The reason for the change in application methods can be explained by various factors. The most important of these factors are the type of cancer, its stage and the type of medication deemed appropriate by the specialist doctor. Neoadjuvant chemotherapy is a procedure that can be performed in a doctor’s clinic, hospital or at home, depending on the type of cancer and treatment plan. If there is no regression in the disease after completion of neoadjuvant chemotherapy or in cases of cancer that progresses despite chemotherapy, radiation therapy ( radiotherapy ) may be used. Following surgical removal of the tumor, adjuvant radiotherapy is planned at the most appropriate time based on the patient’s symptoms and the course of the cancer. Hormone therapies or neoadjuvant endocrine therapies may be preferred in patients who do not have features suitable for chemotherapy, but the chance of success in these treatments is much lower than chemotherapy.
How Long Does Neoadjuvant Treatment Last?
When determining the cancer treatment approach, if there is neoadjuvant chemotherapy in the personalized plan, it is recommended to apply chemotherapy without delay so that the surgical operation can be performed quickly. Neoadjuvant treatments are generally administered at intervals, with some rest period following each treatment period. For example, chemotherapy in breast cancer usually continues for 3-6 months. The number of cures can be increased or decreased depending on the characteristics of the patient, the characteristics of the cancer, its progression, and the response to treatment. When the response to treatment is good, the amount of cure is usually reduced and the treatment duration is shortened. The response to neoadjuvant treatment is evaluated by monitoring tumor sizes, shrinking or growing the tumor in images obtained with imaging techniques, and examining pieces taken from the tumor under a microscope.
What are the Side Effects of Neoadjuvant Treatment?
Although the possible side effects of neoadjuvant chemotherapy vary from person to person, the main side effects are seen in almost every patient and disappear after the chemotherapy treatment is completed. There are a number of medications that are appropriate to prescribe to manage milder side effects such as nausea and vomiting. With these drugs, side effects are alleviated and the likelihood of benefit from chemotherapy is expected to increase. Possible side effects can be listed as follows.
- Nausea and vomiting
- Hair loss
- Changes in nails, skin and teeth
- loss of appetite
- Weight loss, weight changes, imbalance of fat, muscle and protein
- Change in bowel habits, such as constipation or diarrhea
- Mouth, tongue and gum sores
- Restlessness, weakness and depressed mood.
In some cases, different effects of neoadjuvant chemotherapy may be observed in the long term. These are mainly heart and nerve damage, stagnation or decline in mental functions, loss of energy, and an increase in the risk of leukemia due to the use of certain medications. In addition to all these effects of chemotherapy, early menopause, menstrual changes and fertility problems are not uncommon in women. The reason for fertility problems in particular is that some drugs used in chemotherapy treatment can cause irreversible damage to the ovaries. The risk of infertility is a condition that can also be seen in men because chemotherapy can affect sperm. Various satisfactory treatments are still widely preferred today in order to protect and maintain reproductive functions. There are some methods that can be applied to preserve fertility before chemotherapy treatment. Embryo , sperm or egg freezing is one of these methods. In this process, working with expert therapists and taking an active role in cancer support groups can be effective in managing stress and overcoming mental problems.
The effectiveness, success rates and necessity of neoadjuvant treatment vary greatly depending on the individual characteristics of the patients, their genetic structure, age and gender. The type of cancer, its stage, whether it recurs, the type and dose of the drug used in the treatment, and the duration of treatment are affected by many factors and therefore change the neoadjuvant treatment process. It is very important to work with an expert team and get support from a healthcare institution for all questions regarding treatment planning.
