ONCOLOGIST: An oncologist is a physician who specializes in the study and treatment of neoplastic diseases,particularly cancer.
1 surgical oncology
it provides definitive surgical treatment of localized malignancies, lnowledge of and ability to consult with other modalities in the choosing adjustment therapy preoperatively and postop,reconstruction and rehabil9itation for resected organs,provides debulking of residual cancers.
2 Radiation oncology
radiation therapy is used for local tunor control, an approach shared with suirgeru. Ot mau also vbe used in a locoregional approach. Effedrtivelu srerulizing the tumor within a field, including first station lunphnodes. In lukenias and lumphomas, radiarion can also ve used as a sustemic control.
3medical oncology:chemotherapu is curative for lukemiads, lumphomas,hodgkins disease,choriocarcinomas, some pediatric malignancies and especially testicular cancers.
An oncologist must have the following qualification
-graduation fron an approved medical school
completion of acgme accredited internal medicine residency program, which isw minimum of therr in length ,.
Completion of subspeciality fellowship in oncologym which must be three years
Peadiatric solid tumors
Lukemias are clonal disorders characterized by uncontrolled proliferation of cells..typed of lukemias
Acutemyeloid leukemia,chronic myeloid leukemia,chronic lymphocytic leukemia,acutelymphocytic leukemia
Acute myeloid lukemia
Signs and symptoms
Weakness,fatigue reflecting anemia,dyspnoea on exercise,pustules and pyogenic skin infection,excessive bleeding following minor injuries,easy bruising,fever in about 50% patients,malaise and anorexia
Diagnostic testing diagnosis done based on signs and symptoms,physical examination,peripheral blood findings,bone marrow findings
Physical examination gingival hyperplasia,lymphadenopathy,hepatospleenomegaly,skin infiltration,painful red brown nodules
Peripheral blood findings presence of blast form cells,50%patients will have lukopenia and absolute neutropenia,5-20%will have elevated WBC counts,anemia,thrombocytopenia
Bone marrow findings bone marrow hypercellular,megacaryocytes are decreased or absent,monotonous infiltration of blast cellsbone marrow findings done by cytochemistry,cytogenesis,immunotyping
Risk factors environmental factors-eg.benzene
Potential treatments of the disease induction chemotherapyinduction regimen ara-c plus continous infusion of ara-c at 100mg/m square/day for 7 days used with bolus infusion of daunorubicin at 45mg/m square/day for 3 days
Analogus bine marrow transplant
Allogenic bone marrow transplantation
Low dose maintainence chemotherapy following induction can prolong complete remission duration compared with no further therapy.
Patients entering remission following standard induction are randomized to receive four cycles of consolidation of three doses of ara-c:
100mg/m square * 5 doses
400mg/m square * 5 doses
3g/m square * 6doses
For patients younger than 60 , with favorable cytogenetics,consolidation using repetitive cycles of heavy dose ara-c yields best disease free survival results.
Autologus bone marrow transplantation
In auto bone marrow transplantation,haemopoetic recovery from high dosechemoradiation is provided by an infusion of patients own bone marrow
Allogenic bone marrow transplantation
Patientsw are rescued from consequences of marrow ablation by infusion of normal haemopoetic cells from allogenic donor.
Most trials consistently show higher relapse rates in patients undergoing autologous bone marrow transplant . chemotherapy results in complete remission rates of 50-90%
The transpolant related mortality for patients undergoing autologus bone marrow transplantation is less than 10%.mortality rate for allgenic bone marrow transplant .
Acute myeloid lukemisa is belived to result from malignant transformation of a single hemopoetic stem cell.clonal proliferation and a block in normal differentiation and maturation are characteristic features. Aml is a mukltistep process,with an initial transformation event in a haemopoetic stem cell followed by additional genetic abnormalities in descendents of clonally derived cells. Oncogenes and antioncogenes are believed to have a critical role in pathogenesis of acute leukemia.
Signs and symptoms
Painless lymph node enlargement
Constitutional symptoms-unexplained fevers,drenching night sweats,significant weight loss,pruritis,malaise,alcohol intolerance
History and physical examination
-abdomen ct scan-abdominal and pelvic nodes-nodes larget then 1 cm in short acis dianeter is considered abnornmal
gallium imaging with single photon emission computerized tomography-helpful for staging and monitoring respinse to therapyu
complete blood cell count
differential wbc count
showing neutrophilic leukocytosis,mild normocytic,normochromic anemia and eosinophilia may occur
elevated alkaline phosphatase level reflects involvement of liver, bone marroe or bone.
Bone marrow biopsy
Biopsy of lymph nodes
In about 75% cases,cellular nodules containing plasma cells, neutrophilsand eosinophils are surrounded by bands of polarisable collagen.
Giant cells ,knoen as reed sternberg cells are pathognomic of this disease.
Potential treatment of the disease
Primary rolr of surgry is to obtain tissyur for biopsyu
Clinically involvd nodes- 3.6-44 gy
Prophylactic treatment 25-36 gy
Each tratnent fraction delivers 1.5-1.8gy
Complications of radiation therapy
Transient bone marrow suppression,radiation pneumonitis(5%),pericarditis(5%)
Bone marrow transplant
]used for advanced disease,relapsed disease,unresponsive to chemotherapy
combined modality treatment
started with chemotherapy-treats all sites of disease at the outset ,reduces bulky disease to facilitate subsequent irradiation
relapse after initial therrapu occute nost often within 4 yeats-late relapses may occur
aprox 10-30% [atients with advanced hodgkins disease dinit achieve complete remissions wirth initial treatment of they have relapse afrer initialu efedtive treatment eith chemotherapy
stage IV disease 60-90% 5year survival
I &II 70-95% 5year survival
CLINICAL ONCOLOGY PHILIP RUBIN
PRINCIPLESAND PRACTICE OF ONCOLOGY VINCENT
CANCER TREATMENT HASKELL DE VITA
ONCOLOGY HANBOOK M.D. ANDERSON