Adverse effects of treatment
The intensity of acute adverse reactions to chemotherapy can be quite different from patient to patient. Nausea and vomiting occurring several hours after the administration of chemotherapeutic drugs can be considerably mitigated by antiemetic drugs. Loss of hair (alopecia) is an adverse reaction that affects most patients. However, it is usually a temporary problem, and permanent loss of hair is seen very rarely.
Chemotherapeutic drugs have a damaging effect on the bone marrow, which plays an important role in therapy. The bone marrow impairment causes changes in the blood count and should therefore be monitored at close intervals. If the number of white blood cells (leukocytes) decreases, this is associated with an increased risk for contracting infectious diseases, particularly oral, nasal or pharyngeal infections or pneumonia. New drugs, which are injected subcutaneously, may reduce the time during which the infection risk is increased. In very rare cases, spontaneous bleedings caused by a decrease in platelets (thrombocytes) have been observed. A decrease in red blood cells (erythrocytes) may cause symptoms like general weakness, fatigue and shortness of breath. A blood transfusion may be necessary, depending on the chemotherapeutic regimen used. Before the start of a new chemotherapy cycle, the blood parameters should have recovered.
In all stages of Hodgkin lymphoma but especially in advanced stages, patients experience a reduced quality of life already before the beginning of their treatment. Many patients report physical, emotional and mental exhaustion (fatigue), usually worsening in the initial phase of therapy. Fatigue and other problems causing a reduced quality of life become severe during treatment. The degree of severity is similar in patients across all stages and all current types of treatment. There are many potential causes for cancer-related fatigue including, apart from the cancer disease itself, sleep disorders, existential fears, reduced activity and withdrawal from social life. In many cases, fatigue may be reduced by physical activities, endurance and muscle building training. However, depending on the cause of the problems, other measures and activities may be necessary. If the complaints last extremely long, the patient may benefit from the help of a psycho-oncologist or other therapists to support the care they receive from the medical specialists involved in their cancer treatment. But most Hodgkin lymphoma patients recover by themselves within a period of one to two years after end of treatment. Severe fatigue and greater limitations in quality of life are no longer the rule after this period, but still affect about 20-30% of patients.
Fertility and hormonal balance
Whether male patients become permanently infertile as a consequence of therapy seems to depend on the dose of some of the drugs used. The physician must inform male patients, particularly young patients, about these potential late effects and discuss the option to cryopreserve (freeze) sperm before the start of treatment if the patient wants to have children after treatment.
Female patients have to be informed about a premature onset of the menopause. Whether the ovaries recover and the patient is able to conceive again after treatment depends on the patient’s age and the dose of the administered cytostatic drugs. Even one year after end of treatment a spontaneous return of menstruation is possible. However, to reduce the risk for a premature onset of osteoporosis (reduction in bone density), a female hormone (estrogen) deficiency should be balanced (temporarily or permanently) if corresponding complaints occur. After end of treatment it is recommended to consult a gynecologist and/or endocrinologist regarding these problems.
Before start of treatment a detailed menstruation history and a hormonal analysis should be performed.
Oral contraceptives (the “Pill”) or so-called GnRH analogues may protect the ovaries, and administration should therefore be considered. Both influence the ovarian cycle and inhibit the maturation of oocytes, through which damage to ovaries and oocytes may possibly be prevented. In addition, it is possible to remove mature oocytes and to freeze (cryopreserve) them either fertilized or unfertilized. Cryopreservation of ovarian tissue may also be an option.
It is important to note that there is no evidence for an increased risk of abnormalities in children whose parents were successfully treated with chemo- or radiotherapy, and abnormal developments do not occur more often than in children of healthy parents who did not receive such treatments. So there is no reason why women should be discouraged from becoming pregnant after chemotherapeutic and/or radiotherapeutic treatment.
Heart and lung function
Certain drugs contained in chemotherapy regimens can affect heart and lung function. An impairment of the heart function is usually dose-dependent and is also influenced by other individual factors. It may affect the pump function of the heart and the cardiac rhythm. Besides, changes in the coronary vessels comparable with coronary heart disease may be observed. They may become apparent months or even years after therapy but can usually be treated. Acute symptoms are reversible in almost all cases. However, cardiac symptoms occurring after end of treatment are often persistent.
The lung function may be impaired by inflammation or changes of the lung tissue. The severity of a lung function impairment usually also depends on the dose. Acute inflammations of the pulmonary alveoli occur quite rarely and are not necessarily dose-dependent. After irradiation of the thorax (mediastinal irradiation), a temporary radiation damage of the lung (pulmonary fibrosis) can often be detected, however, in most cases it does not cause any complaints. Radiation-induced, non-infectious inflammations of the lung (radiation pneumonitis) and the heart (myocarditis, pericarditis) are more severe, but have only been observed in very rare cases. Such inflammations may occur weeks or even months after mediastinal irradiation and may cause serious complaints, above all, long-term impairment of the general condition.
Because of the potential adverse effects mentioned above, heart and lung function should be examined at the beginning of therapy and within the scope of follow-up care.
During the cause of chemotherapy, sensation disorders that usually present as tingling sensations or a numb/furry feeling in hands and feet may occur. Depending on the severity of these symptoms, the causative drug can be replaced or its administration can be discontinued.
Some patients who underwent irradiation of the cervical lymph nodes were afterwards diagnosed with dysfunctions of the thyroid gland. These dysfunctions become manifest in a hypofunction of the thyroid gland with relatively unspecific symptoms like general weakness, fatigue, permanent freezing, weight gain or poor concentration. Thyroid gland hypofunction must be treated by substituting thyroid hormone.
Secondary tumors (secondary malignancies)
The most severe late effect of both chemotherapy and radiotherapy is the increased risk for the development of secondary malignancies (non-Hodgkin lymphomas, leukemias, solid tumors). This is why lifelong aftercare and cancer screening examinations are of great importance in Hodgkin lymphoma patients.
Current clinical trials mainly aim to reduce adverse reactions and late effects as well as the risk for secondary tumors without impairing efficacy by optimizing treatment methods.