The overall incidence of Leukemia from SEER data is 12.3/100,000 men and women. This further subdivided into 3.6/100,000 for AML, 1.6/100,000 ALL, 1.5/100,000 CML, and 4/100,000 CLL. The median age of diagnosis is 67 years and the median age of death is 74 years. The major focus of post-therapy follow-up remains the detection of relapse. The specifics regarding this should be found in the disease specific guidelines and will not be discussed here. The surveillance for some of the complications of therapy and suggestions for follow-up are discussed in this section.
Cardiac function compromise can be seen secondary to anthracycline use and is often manifested during therapy. Routine testing is done prior to cycles of chemotherapy. The role of routine testing post therapy completion is less clear. The potential for toxicity should however be kept in mind and monitored for in terms of history and physical examination during follow up visits. Focused testing (e.g. Echocardiogram) can then be done based on clinical concern. For young adults treated on the ALL 13-01 protocol, periodic cardiac evaluation by echocardiography is recommended.
Renal or liver function derangement is most commonly seen secondary to nephrotoxic agents used in supportive therapy (e.g. aminoglycosides, anti-fungals). This should be followed up as warranted by the degree of dysfunction and appropriate specialist referral made as deemed appropriate. Iron overload and viral hepatitis should be kept in mind as causes of liver function derangement.
Secondary MDS/AML can occur following the chemotherapy for Leukemia. Topoisomerase 2 inhibitors are associated with a shorter latency period (~2 years) to development of secondary MDS/AML. Recurrent cytogenetic abnormalities (e.g. 11q23 abnormalities) are often detected on analysis. The average time to development of secondary MDS/AML with the other chemotherapy agents is often longer at 4-7 years and complex/adverse markers (e.g. -7) are often noted on cytogenetic analysis. Regardless, this type of leukemia is often extremely refractory to therapy and the prognosis is poor.
Sub-fertility is often an issue post therapy. In men pre-chemotherapy sperm banking with subsequent assisted fertility techniques should be recommended. In women embryo cryopreservation prior to receipt of chemotherapy is the only technique proven to be beneficial. However, as this requires a treatment delay of several weeks and a willing partner, it may not be suitable in a number of patients. In women there is also a risk of development of hypergonadotrophic hypogonadism and this should be kept in mind during follow-up and HRT instituted as deemed appropriate.
Cranial radiotherapy can be associated with some exposure of the thyroid gland and therefore yearly TSH, T4 should be considered. Thyroid malignancy can also occur high index of suspicion should be maintained. Young patients (<20 years) can develop secondary benign and malignant brain tumors post cranial radiotherapy with a latency period of 15-20 years. Again a high index of suspicion needs to be maintained.
Ophthalmology assessment should be completed every 2-3 years for young adults treated on the ALL 13-01 protocol.
Drug Toxicity Surveillance
Not including acute toxicity during therapy.
The following table summarizes some of the common drug related toxicity seen in the follow-up of patients treated for Leukemia.
Click table to open as a PDF.