What Is Adjuvant Therapy?

Adjuvant therapy

is treatment after primary cancer therapy to reduce recurrence (return). Considering tumor size, characteristics and spread, protective methods such as chemotherapy, hormones, smart drugs and radiotherapy aim to lower the chance of cancer returning.

One of the Most Frequently Asked Medical Terms

Cancer diagnosis and treatment are extremely difficult to manage for patients, relatives and sometimes physicians. Doctors are accustomed to using medical terminology in everyday practice, sometimes English and sometimes Latin. These habitual terms can impair patient communication. Patients follow instructions but remain full of unanswered questions. Facing cancer for the first time, a lack of knowledge about anatomy and commonly used terminology creates further confusion. Patients and families may not fully understand the disease or many details of the proposed treatment. It is therefore necessary to explain vital cancer-related terms and expressions to them from time to time.

Today I explain adjuvant therapy, frequently used by doctors and difficult for patients to understand.

What is it?

When and for whom is it used?

Adjuvant therapy supports the main cancer treatment. For example, surgery is primary in breast cancer. If detected before spread to other body areas, surgery removes part or all of the breast and underarm nodes. The surgeon refers the patient to a medical oncologist to assess future recurrence and whether treatment can reduce it. After surgery, the oncologist calculates risk from tumor size, characteristics, behavior and nodal spread. Recurrence reflects invisible cells traveling during tumor formation to distant sites such as lungs, liver and bones. Stage does not mean every cancer will return, but generally patients with recurrence risk of %10 or more receive hormonal therapy if sensitive, chemotherapy and smart drugs are added. Tumor characteristics matter greatly: sensitivity to female hormones or certain smart drugs determines postoperative supporting treatment. These features inform risk calculations. If the tumor exceeds 1 cm, reaches underarm nodes or has unfavorable characteristics, recurrence risk may be %10 or more. Particularly over the next 5 years, risk above %10 leads us to offer protective chemotherapy, or adjuvant treatment. Cancer has developed over 3-5 years; a sufficiently large tumor may reach lymph nodes, and cells can travel through blood to other organs. Imaging cannot detect a tumor until larger than 1-3 mm, so the presence of invisible cells can only be estimated as a probability.

For example, a recurrence estimate of %30 means among 100 similar untreated postoperative patients, 30 recur over 5 years and 70 remain disease-free. Since we cannot identify those 30, all 100 receive adjuvant treatment to save some of the 30. Each of chemotherapy, hormones and smart drugs reduces recurrence approximately %20-30. After colon, lung or stomach surgery, high-risk patients similarly receive adjuvant chemotherapy supporting the main treatment.

Protective chemotherapy, hormones and smart drugs are systemic, affecting the whole body. Adjuvant radiotherapy reduces local recurrence at the tumor site in high-risk patients.

Side effects

Depend on method: nausea, vomiting, hair loss, reduced blood counts and infection are common. Ovarian function can be damaged in fertile women or young children, so fertility preservation is essential for those wanting children. Blood-supporting and anti-nausea drugs reduce effects. Scalp cooling can preserve hair, while wigs or scarves address loss. Hormones and targeted drugs have specific effects depending on the medicine.

For example, Hormonal therapy may cause hot flashes, increased osteoporosis and muscle/joint pain. Patients should consult physicians for treatment of these effects.

Patients and families struggle to understand why, after surgery and assurance of complete removal, chemotherapy, hormones or smart drugs are needed. This is difficult to grasp when first facing cancer. Explain thoroughly why adjuvant therapy is necessary, discussing advantages and disadvantages if possible. Better understanding of the goal makes addressing problems and preventing future difficulties easier.