What to Know About Leukemia in Older Adults

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Leukemia, a cancer of the blood-forming cells, is often thought of as a condition that affects children and teens—in fact, it’s the most common cancer of childhood. However, leukemia also affects many older adults and people in the over-60 age group, in particular.

While treatment for older adults can be more challenging, today there are an increasing number of options—even if you are old enough to remember Eisenhower and JFK.

New classes of medications are emerging that can help battle disease, even when your body can’t take the collateral damage of intensive chemotherapy. That said, even in modern times, leukemia is a formidable adversary for many.

Leukemia Types in Older Adults

Chronic lymphocytic leukemia (CLL) is the most common leukemia in adults, with the average age at diagnosis of approximately 71 years. Acute myeloid leukemia (AML) ranks a close second in adults, with a median age at diagnosis of 67 years; and more than 60 percent of newly diagnosed patients with AML are over 60. As such, CLL and AML are dealt with more extensively here, however older adults may develop the other two types of leukemia, as well. Age greater than 70 years is a risk factor for adult acute lymphoblastic leukemia (ALL), which is also called adult lymphocytic leukemia. And as for chronic myelogenous leukemia (CML), approximately 50 percent of patients with CML are ages 66 and older.

Older Individuals Diagnosed With Leukemia

CLL and AML are the more common types of leukemia to emerge later in life. Of the two, AML is the more rapidly progressive disease. Estimates for the two malignancies (all age groups) in 2016 are as follow:

  • 18,960 new cases and 4,660 deaths from CLL
  • 19,950 new cases and 10,430 deaths from AML.

    CLL and AML are very different disease, reflecting the significant differences between acute and chronic leukemias, in general. All leukemias starts when cells of the bone marrow—your body’s factory for making new blood cells—begin to produce abnormal white blood cells. Stem cells in the bone marrow normally give rise to all of your blood cells continually, making new cells to replace the old. Acute leukemia involves immature blood-forming cells and tends to progress very rapidly. Chronic leukemia involves blood-forming cells that are somewhat more mature, but still abnormal, and chronic leukemias tend to develop more slowly, over the course of months and years.

    Chronic lymphocytic leukemia (CLL)

    CLL is a cancer of white blood cells in the B-lymphocyte family. The B-lymphocytes, or B-cells, are the lymphocytes that can become activated and lead to antibody production. The other kind of lymphocytes is T-cells, which are more like the immune system’s ‘infantry,’ or soldier cells.

    CLL does not usually cause symptoms early on, and a person will not necessarily know that he or she has CLL at first.

    In fact, very frequently, people are diagnosed after having routine blood tests. When CLL does cause symptoms, some of the more common ones are: feeling very tired and weak; or having swollen lymph nodes in the neck, under the arm or in the groin; or falling ill to infections more easily than normal; or having fevers, or great sweats at night time: or losing weight without trying.

    In CLL, the cancer cells tend to be found mostly in the blood, bone marrow and lymph nodes. A related condition, called small lymphocytic leukemia, or SLL, is a cancer that starts in the B-cell family of cells, just like CLL, however a person with SLL does not have high numbers of white blood cells in their blood.

    The diagnosis of CLL requires blood tests, and the number of B-cells in your blood must be determined. CLL is diagnosed by the presence of at least 5,000 abnormal B-cells per ml of blood, and the B-cells have to be “copies” or clones of the same malignant parent cell. This is called monoclonality. The CLL cells also need to be tested to see what’s on their surface. They may have any number of protein tags or markers. Laboratories refer to these protein tags using the letters CD followed by a numerical expression. In CLL, cells might have markers named CD5, CD19, and CD23 on their surface; some may have CD20, but none have CD10. In some instances, you need to have other tests done in addition to blood tests, such as a lymph node biopsy or a bone marrow biopsy—however, this is not the usual scenario for diagnosis of CLL.

    CLL vs. MBL

    Studies suggest that 3 to 5 percent people over age 40, when tested with sensitive tests, show a clonal population of lymphocytes, like in CLL. This discovery led to creation the diagnosis of MBL, which is considered the precursor state to CLL.

    If you have fewer than 5,000 monoclonal B-cells, no lymph node enlargement and no other signs of CLL, you might be diagnosed with monoclonal B-lymphocytosis (MBL). This is common in older adults, and it is not yet a cancer. Very few people with BML go on to develop CLL; however there is that possibility, and therefore watchful waiting is recommended.

    Even if you have a diagnosis of CLL, the decision to treat may not be a forgone conclusion. In the past, physicians told patients with CLL that a “watchful waiting” period should follow diagnosis, until the disease progressed, at which time therapy would be initiated. While this still may be the case in many instances, there is an increasing understanding that different cases of CLL may behave differently, and some cases of CLL might call for more prompt therapy.

    Part of the planning that you and your doctor will undertake is to determine when treatment for your CLL should begin. The decision is made based on CLL symptoms, results from lab tests and an assessment of staging. For CLL, the Rai staging system is in use, ranging from Stage I to Stage IV. There is also a Binet staging system for CLL that classifies stages A, B and C, but it is not as useful for deciding on when to start treatment.

    Doctors separate the Rai stages into low-, intermediate-, and high-risk groups when determining treatment options.

    Stage 0 is considered low risk.
    Stages I and II are considered intermediate risk.
    Stages III and IV are considered high risk.

    For people with CLL of RAI stages 0, I and II, it is possible that treatment may not be needed right away. However, for a person with early stage disease and active CLL—for instance with the presence of symptoms of CLL such as severe fatigue or fever, night sweats or unintentional weight loss— treatment is advised.

    Other factors along with stage are sometimes taken into account when looking at treatment options. Factors associated with shorter survival times are called adverse prognostic factors, while factors linked to longer survival are favorable prognostic factors.

    Certain factors related to the leukemia cells’ genetic profile and surface markers are also used: ZAP-70, CD38, and a mutated gene for IGHV help divide cases of CLL into 2 groups, slow growing and fast growing. People with the slower growing kind of CLL tend to live longer and may be able to delay treatment longer as well.

    Available treatments for CLL generally fall into broad categories of therapy such as chemotherapy, targeted therapy, immunotherapy, immunomodulators, and steroids. Not every treatment is appropriate for all individuals with CLL. The more doctors learn about the different varieties of CLL, the more specific therapies may be appropriate for some CLL cases but not others.

    Some therapies are investigational and may only be accessible if you enter a clinical trial. Based on clinical trials, once a therapy is determined to be safe and effective for CLL, the drug is approved by the FDA and becomes more widely available.

    Age and general health also become important considerations when deciding on treatment. For example, some first-time treatments for CLL might be designated as more appropriate for younger and fairly healthy individuals with CLL; some other first-time treatments or regimens may be deemed better for those who are older or in poor health.

    Supportive care is treatment that will not cure the cancer but aims to make life with CLL much better for you. Supportive care includes things like vaccines, transfusions, preventive medications, and even help with coordinating care when there are many different doctors involved.

    Older People With AML

    According to the American Cancer Society, acute myeloid leukemia is generally a disease of older people and is uncommon before the age of 45. The average age of a patient with AML is about 67 years.

    The symptoms of AML are often related to a person’s low blood counts. When the leukemia cells take over the bone marrow, they crowd out the normal blood forming cells, resulting in shortages in your bloodstream. A shortage of red blood cells leads to anemia and symptoms like weakness and becoming excessively tired. A shortage of white blood cells leads to neutropenia, potentially with symptoms such as fever and infection. A shortage of platelets leads to thrombocytopenia and symptoms such as unusual bleeding or bruising. And combinations of these symptoms are common.

    In the diagnosis of AML, there are irregularities in blood tests; however, unlike the diagnosis of CLL, bone marrow aspiration/biopsy is usually required to diagnose and evaluate AML. Many different subtypes of AML are now known to exist.

    After an AML diagnosis, together with your health care team, you develop a sense of the goals of therapy, as well as the side effects of treatments. About half of older AML patients go into remission after initial treatment, according to the American Cancer Society. People who achieve a complete remission have an improved quality of life compared with those patients who receive palliative therapy, possibly due to fewer hospitalizations, transfusions and antibiotics. Long-term AML survivors are represented in all age groups; however, relapse after initial therapy is very common. Often, patients with AML are encouraged to enroll in clinical trials to avail themselves of newer therapies and combinations in hopes of improving their outcomes.

    For older patients who are frail or generally otherwise very sick, or have poor physical function, sometimes supportive care and/or less intensive chemotherapy is chosen. Supportive care includes transfusions, antibiotics, and other medications that help a person’s health but do not get rid of the cancer.

    Sources:

    Chiorazzi N, Rai K, Ferrarini M. Chronic Lymhocytic Leukemia. N Engl J Med. 2005;352:804-15.

    NCCN Guidelines. Chronic Lymphocytic Leukemia. Version 1. 2016.

    American Society of Hematology. Treatment of elderly patients with acute myeloid leukemia. http://www.hematology.org/Thehematologist/Ask/3615.aspx.

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