Prognosis and survival for chronic lymphocytic leukemia
People with chronic lymphocytic leukemia (CLL) may have questions about their prognosis and survival. Prognosis and survival depend on many factors. Only a doctor familiar with a person’s medical history, type of cancer, stage, characteristics of the cancer, treatments chosen and response to treatment can put all of this information together with survival statistics to arrive at a prognosis.
A prognosis is the doctor’s best estimate of how cancer will affect a person, and how it will respond to treatment. A prognostic factor is an aspect of the cancer or a characteristic of the person that the doctor will consider when making a prognosis. A predictive factor influences how a cancer will respond to a certain treatment. Prognostic and predictive factors are often discussed together and they both play a part in deciding on a treatment plan and a prognosis.
The following are prognostic and predictive factors for CLL.
A lower stage at the time of diagnosis is a more favourable prognostic factor.
Leukemia cells in the bone marrow
Abnormal blood cells (called leukemia cells) can form different patterns in the bone marrow. When the leukemia cells are more spread out (called a diffuse pattern) it is a less favourable prognostic factor. Leukemia cells that are in small clumps (called a nodular pattern) or leukemia cells between normal cells (called an interstitial pattern) are more favourable prognostic factors.
Elderly people have a less favourable prognosis.
Men have a less favourable prognosis than women.
Deletion of part of chromosome 13, with no other chromosome abnormalities, is a more favourable prognostic factor. Deletion of parts of chromosome 11 or 17 is a less favourable prognostic factor.
A prolymophocyte is an early form of a lymphocyte. A higher number of prolymphocytes in the blood is called prolymphocytic transformation. It has a less favourable prognosis.
Lymphocyte doubling time
Lymphocyte doubling time is the time it takes for the lymphocyte count to double. A lymphocyte doubling time of more than 6 months is a more favourable prognostic factor.
Areas of lymphatic tissue affected
The areas of lymphatic tissue are the spleen, liver and lymph nodes in the neck, underarm area and groin. Having fewer areas of lymphatic tissue areas affected by CLL is a more favourable prognostic factor.
The following protein levels mean a more favourable prognosis:
- a low blood level of beta-2-microglobulin
- a low number of CLL cells have the proteins CD38 (cluster of differentiation 38) or ZAP-70 (zeta-associated protein 70)
IGHV gene mutation
CLL cells with a changed, or mutated, gene for IGHV (immunoglobulin heavy chain variable region) have a more favourable prognosis.
Richter’s syndrome, or a Richter transformation, occurs when CLL develops into an aggressive non-Hodgkin lymphoma, usually a diffuse large B-cell lymphoma (DLBCL). Richter’s syndrome is a less favourable prognostic factor.
People with a good performance status at the time of diagnosis have a more favourable prognosis.
The measure of how well a person is able to perform ordinary tasks and carry out daily activities.
Examples of scales used to evaluate performance status include the Eastern Cooperative Oncology Group (ECOG), World Health Organization (WHO) and the Karnofsky performance status scale.