Defining Complete Remission

I have been searching for the scientific definition of complete remission (CR) of this disease. These defining criteria are discussed by a leading specialist, Dr. Hamblin, on his blog:

Now CR needs all the following criteria as assessed at least three months after the completion of treatment:

1. No clonal lymphocytes. This is more stringent than before – all you needed then was fewer than 4000 lymphocytes.

2. No significantly enlarged lymph nodes. In clinical trials CT scanning is now positively encouraged. So we are talking about the largest diameter of lymph nodes anywhere in the body, not being greater than 1.5 cm.

3. No hepatomegaly or splenomegaly by physical examination. We have now reverted to physical examination even though a CT scan will have been done to look for enlarged lymph nodes. The guidelines advise that if liver or spleen were found to be abnormal before treatment then a scan should be performed at evaluation; this should also be done if the evaluation was inconclusive by physical examination.

4. No constitutional symptoms.

5. Neutrophils >1500 / cu mm, platelets >100,000 /. Cu mm Hb >11 g/dL (untransfused). For more than 20 years I have been protesting that to choose the same Hb level for men and women is insane.

6. If all these points have been achieved a bone marrow aspirate and trephine biopsy should be performed. The marrow should be examined by flow cytometry and immunohistochemistry to look for clonal B cells. If clonal cells are found then the case is demoted to PR. It must be stressed here that the flow cytometry is not the powerful 4-color flow used to detect MRD, but the simpler 2-color flow that detects one cell in 100.If lymphoid nodules are found in the trephine, then immunohistochemistry should distinguish between CLL and reactive nodules. The nPR category therefore disappears. If the marrow is hypercellular, then it should be repeated in 4-6 weeks, provided the blood counts have recovered. In some cases it is necessary to continue to postpone the marrow, but this time interval should not exceed 6 months.

7. The question of apparent CR with a failure to recover the bone marrow also seems to have been resolved. Those who fulfill all the criteria for a CR including the marrow examination, but who have a persistent anemia, thrombocytopenia or neutropenia unrelated to CLL but related to drug toxicity are designated CRi (‘i’ stands for incomplete marrow recovery). In view of the fact that a PR still requires recovery of at least one of the marrow lineages, I am not clear whether CRi can be applied to a patient with complete pancytopenia.