Blood Cancer (Leukaemia, Lymphoma, Myeloma) — Causes, Types & Treatment Guide — Symptoms, Causes & Treatment | MyMedicPlus

Blood cancers are malignant diseases of the blood, bone marrow, and lymphatic system, encompassing three major groups: leukaemia (malignant proliferation of white blood cells in the bone marrow and blood), lymphoma (malignancy of the lymphatic system — lymph nodes, spleen), and multiple myeloma (malignant plasma cell proliferation in the bone marrow). Together they account for approximately 10% of all cancer diagnoses globally — around 1.3 million new cases annually. Leukaemia is classified by cell type and clinical course: acute leukaemia (ALL — acute lymphoblastic; AML — acute myeloid) progresses rapidly without treatment, while chronic leukaemia (CLL — chronic lymphocytic; CML — chronic myeloid) may smoulder for years. Lymphomas are divided into Hodgkin lymphoma (HL) — predominantly young adults, Reed-Sternberg cells, highly curable — and non-Hodgkin lymphomas (NHL) — heterogeneous group of over 60 subtypes including diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma. Multiple myeloma, a plasma cell neoplasm, affects predominantly older adults, causing bone destruction, renal failure, and immunosuppression. Revolutionary advances — CAR-T cell therapy, novel targeted agents — have dramatically improved outcomes across blood cancer subtypes.

Most blood cancers arise from acquired somatic mutations in haematopoietic stem cells, though the precise triggers are usually unclear. Established risk factors vary by type. Leukaemia: ionising radiation (atomic bomb survivors, prior radiotherapy); chemotherapy exposure (alkylating agents, topoisomerase II inhibitors cause therapy-related AML); benzene and petrochemical exposure; Down syndrome (21-trisomy — 20x risk of ALL/AML); HTLV-1 infection (adult T-cell leukaemia); genetic syndromes (Fanconi anaemia, Diamond-Blackfan). CML is driven by the Philadelphia chromosome — BCR-ABL1 fusion (t(9;22) translocation) — in 95% of cases. Lymphoma: Epstein-Barr virus (Burkitt lymphoma, EBV-associated DLBCL); HIV infection (dramatically increases NHL risk); Helicobacter pylori (MALT gastric lymphoma); immunosuppression (post-transplant lymphoproliferative disorder); autoimmune diseases (Sjogren's, coeliac disease — MALT, enteropathy-associated T-cell lymphoma). Multiple myeloma: advancing age (median diagnosis 70), male sex, Black ethnicity (2-3x higher risk), obesity, and monoclonal gammopathy of undetermined significance (MGUS — precursor lesion progressing to myeloma at 1% per year).

Acute leukaemia (ALL/AML): rapid onset over days-weeks; bone marrow failure symptoms — fatigue and pallor (anaemia), bruising and petechiae (thrombocytopaenia), recurrent infections or fever (neutropaenia); bone pain (marrow infiltration); splenomegaly and lymphadenopathy. CNS involvement in ALL: headache, neck stiffness, cranial nerve palsy. Chronic leukaemia (CLL/CML): often asymptomatic — incidental diagnosis on FBC. CLL: painless lymphadenopathy, fatigue, night sweats, weight loss, recurrent infections (hypogammaglobulinaemia). CML: abdominal discomfort from massive splenomegaly, fatigue, weight loss — blast crisis mimics AML. Lymphoma: painless cervical, axillary, or inguinal lymphadenopathy; B symptoms (fever above 38 degrees, drenching night sweats, weight loss more than 10% in 6 months — indicate advanced stage and worse prognosis); mediastinal mass causing cough or superior vena cava obstruction; extranodal disease (bone marrow, CNS, GI tract). Multiple myeloma: CRAB criteria — hyperCalcaemia, Renal failure (creatinine elevation), Anaemia, Bone lesions (lytic lesions, pathological fractures, bone pain); hyperviscosity (visual blurring, confusion in IgM myeloma); recurrent infections; amyloidosis in some cases.

Full blood count and differential: leukaemia — elevated WBC with blast cells (acute leukaemia); lymphocytosis (CLL). Peripheral blood film: morphology of abnormal cells. Bone marrow aspirate and trephine biopsy: essential for leukaemia and myeloma — cellularity, blast percentage (AML if more than 20% blasts), cytogenetics (FISH for Philadelphia chromosome, MLL, FLT3/NPM1 mutations), flow cytometry (immunophenotyping). Lymph node biopsy (excision preferred over core): histology, immunohistochemistry, flow cytometry, cytogenetics — essential for lymphoma classification. CT neck/chest/abdomen/pelvis: staging of lymphoma and assessment of lymphadenopathy. PET-CT: gold standard for Hodgkin lymphoma and aggressive NHL staging and response assessment — replaces CT in most HL cases. MRI spine and whole body MRI: myeloma bone disease staging. Serum protein electrophoresis (SPEP), immunofixation, serum free light chains (kFLC): myeloma diagnosis and monitoring. FISH cytogenetics (del(17p), t(4;14) in myeloma) guide prognosis and treatment choice.

ALL: induction chemotherapy (vincristine, daunorubicin, L-asparaginase, dexamethasone — VDAD); CNS prophylaxis (intrathecal methotrexate); consolidation and maintenance (2-3 years). Philadelphia-positive ALL: imatinib or dasatinib added to chemotherapy dramatically improves outcomes. Allogeneic stem cell transplant (alloSCT) for high-risk or relapsed disease. CAR-T cell therapy (tisagenlecleucel — Kymriah) for relapsed/refractory B-cell ALL. AML: intensive '7+3' induction (cytarabine 7 days + daunorubicin 3 days). FLT3 mutation: midostaurin (Rydapt) added. IDH1/2 mutation: enasidenib/ivosidenib. Post-remission: alloSCT for high/intermediate risk; consolidation chemotherapy for favourable risk. Venetoclax + azacitidine for elderly/unfit patients. CML: imatinib mesylate (Gleevec/Glivec — first BCR-ABL1 TKI; revolutionary — transformed CML from rapidly fatal to near-normal life expectancy); second-generation TKIs (dasatinib, nilotinib) for resistance. Hodgkin Lymphoma: ABVD chemotherapy (doxorubicin, bleomycin, vinblastine, dacarbazine) ± radiotherapy — 80-90% cure rate in early stage. Brentuximab vedotin (anti-CD30 ADC) + AVD for advanced HL. DLBCL: R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisolone) — curative in 60-70%. Relapsed/refractory: R-ICE salvage, autoSCT, or CAR-T (axicabtagene ciloleucel, lisocabtagene maraleucel). Multiple myeloma: VRd induction (bortezomib/proteasome inhibitor + lenalidomide/IMiD + dexamethasone); high-dose melphalan + autoSCT for eligible patients; daratumumab (anti-CD38 mAb) combination regimens; maintenance lenalidomide. Not curative but highly effective — median survival now exceeds 5-8 years.

Bone marrow failure from haematological cancers causes severe anaemia (fatigue, cardiac strain), thrombocytopenia (spontaneous bleeding when platelets fall below 10 x10⁹/L), and neutropenia (life-threatening bacterial and fungal infections including Aspergillus). Tumour lysis syndrome — massive release of intracellular contents when chemotherapy rapidly destroys cancer cells — causes acute kidney failure, hyperuricaemia, hyperkalaemia, and cardiac arrhythmias, requiring preventive allopurinol and aggressive IV hydration. Central nervous system infiltration by leukaemia causes meningeal leukaemia requiring intrathecal chemotherapy. Untreated acute leukaemia is universally fatal within weeks to months. Five-year survival ranges from 20-30% for AML to over 85% for ALL in children with modern treatment protocols.

Most blood cancers cannot be specifically prevented. However, modifiable risk factors should be addressed: avoid unnecessary ionising radiation exposure; minimise benzene and petrochemical exposure (wear PPE if occupational risk). HIV prevention (condoms, PrEP) reduces HIV-associated lymphoma risk. H. pylori treatment cures MALT gastric lymphoma — a rare but important example of infection-driven cancer cured by antibiotics. Maintain a healthy BMI — obesity increases multiple myeloma risk. Screening: MGUS surveillance (annual serum immunofixation and free light chains) identifies progression to myeloma; MGUS patients should avoid contrast nephropathy, bisphosphonate without monitoring, and NSAIDs. Blood cancer is often not preventable but early diagnosis — seeking medical attention for unexplained lymphadenopathy, persistent fatigue, or B symptoms — significantly improves treatment outcomes.

Seek emergency medical care immediately for: severe infection or fever with known or suspected blood cancer (neutropenic fever — potentially fatal); acute collapse or haemorrhage with thrombocytopaenia; neurological symptoms (headache, confusion, visual changes) in any haematological malignancy. Seek urgent GP or haematology assessment (within days) for: unexplained painless lymph node enlargement lasting more than 2-4 weeks; any lymph node more than 1 cm not resolved after 4 weeks; B symptoms (fever, drenching night sweats, weight loss); unexplained severe fatigue with bruising or petechiae; pallor and anaemia with unexplained leucocytosis or leucopaenia. Routine haematology referral for: incidentally discovered lymphocytosis on FBC; raised protein on blood tests with suspected myeloma (bone pain, fatigue, renal impairment in an older adult).