(All the articles published in past are available at www.shyamhemoncclinic.com)
Question: Dr. Chiragbhai, thank you very much for this complete series on Hemato-Oncology, and a few of related benign hematology topics (thrombocytopenia, pancytopenia, aplastic anemia, eosinophilia) as well. In 49 parts, we have covered all major diagnoses including leukemia-acute and chronic, lymphoma, myeloma, myelodysplastic syndrome, myeloproliferative diseases, as well as some explanation of transplant including for Thalassemia major. Since this has been covered over 4 years, can you summarize this vast topic for us, especially with regard to major advances or major take home points which would ultimately help some patients to be cured or substantially prolong life.
Ans: Yes, indeed this has been a long but very interesting and satisfying journey. And it would be worthwhile summarizing this. Even summarizing this vast topic will need few sessions. We can cover this under Prevention/Etiology, Diagnosis/Prognosis, Treatment, Other.
Without going in to much details, I would say that unlike field of solid tumors where we have better idea of some etiologic factors like tobacco, In the field of Hemato-Oncology, we have hardly any knowledge of what leads to these cancers. There are some cases with genetic predisposition as part of some syndromes OR due to immune suppression OR rarely related to some chemotherapy in the past (such as acute myeloid leukemia secondary to chemotherapy given for some solid tumor in past). But overall these constitute a very small minority. Leukemias etc in children are not related to parents health. There is no relation to tobacco, alcohol, weight, lifestyle, food, infections etc known major causes of solid tumors. This is important to know as most patients ask first about “How did I get it?”. In almost all cases, our answer is “we do not know. But there is a good chance we can get rid of it.”
Que: That clarifies a lot about causes of various blood cancers. What about Diagnosis?
Ans: Huge advances have been made in Diagnosis, Prognosis, and in some cases Predicting what treatment to choose for an individual patient. Remember that in today’s times, even if these tests are not available in your hospital or town, they can be easily sent out to other lab or city/state. Patients come to you for proper diagnosis and treatment, not for what you can do in your hospital. Inaccurate or wrong diagnosis has medicolegal implications as well. In summary:
1. Flow cytometry for immunophenotyping: almost mandatory for diagnosis of acute leukemias, and for chronic lymphocytic leukemia. Morphology alone is misleading in some cases, even for the BEST pathologists in World. Treatment is extremetly different for these diagnoses, hence flow cytometry must be used for nearly all cases of possible acute leukemias, and CLL. Tests like myeloperoxidase, Sudan, PAS stain etc have many limitations.
2. Biopsy: FNAC is NOT sufficient in general. Trucut or excisional biopsy is mandatory for suspected diagnosis of lymphomas, even if clinically or radiologically diagnosis is almost certain. We see Tuberculosis diagnosis made by FNAC frequently enough, where actual diagnosis by proper biopsy turns out to be a Lymphoma. Patients lose valuable months undergoing treatment of tuberculosis.
3. IHC (immunohistochemistry): IHC is mandatory for diagnosis of suspected lymphoma, whether Hodgkin or Non Hodgkin. Some subtypes or some cases have very misleading features on microscopy alone, and treatments are very different. Prognosis is very different. Some tests such as CD 20 positivity is required to prescribe a very important lymphoma drug, Rituximab, as CD 20 is the target for this drug. We frequently see morphological diagnosis of Hodgkin changed to NHL on IHC or vice versa. And also “reactive lymph node” changed to “lymphoma” and vice versa after IHC. Hence one should rarely treat lymphomas without IHC today.
April 14th, 2014.
Dr. Chirag A. Shah; M.D. Oncology/Hematology (USA), 079 26754001. Diplomate American Board of Oncology and Hematology. Ahmedabad. firstname.lastname@example.org Shyam Hem-Onc Clinic. 402 Galaxy, Near Shivranjani, Opp Jhansi ki Rani BRTS, Ahmedabad. www.shyamhemoncclinic.com