staging

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staging

• Clinico_pathological staging is important for
• 1.It gives estimate of prognosis.
• 2.It is useful in planning of treatment.
• 3.It is useful in comparison of outcome from
  different centers.

Histological diagnoses is done by biopsy
Types of biopsies 1.Incisional biopsy removal
of a small portion of a tumour by.. a.
Endoscopic biopsies b. core-needle biopsy by
tru-cut needle. c. fine-needle aspiration
biopsy 2.Excisional biopsy the whole tumour is
removed with the draining lymph node
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TNM staging system

• T size of primary tumour.
• N extent of spread to regional L.N.
• M presence or absence of distant metastases.

Histological grading
It assesses the degree of differentiation a.
well-differentiated (good prognosis) b.
moderately differentiated (bad prognosis) c.
poorly differentiated (worst prognosis)
Screening for cancer
Is the detection of disease in an asymptomatic
population to improve outcomes by early diagnosis
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Criteria for screening

• The disease a. recognizable at early stage b.
  treatment at early stage is beneficial. C. common
  disease.
• 2.The test a. sensitive and specific. b.
  acceptable by people. c. safe and inexpensive.
• 3.The program a. Adequate further diagnostic
  tools. b. beneficial treatment is available. c.
  benefit more than physical and psychological
  harm.
• E.g.. Breast and colorectal cancer.

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The multi disciplinary team in cancer treatment

• 1. surgery the main aim of cancer surgery is
  local control of tumour, surgery can be a.
  diagnostic. b. curative. c. palliative. d.
  preventive. e.reconstructive .
• A. diagnostic surgery , e.g. obtaining tissue for
  diagnosis like in laparoscopy.
• B. curative surgery removal of the primary
  tumour and as much as possible of the surrounding
  tissue and L.N .
• C. palliative surgery like in inoperable
  carcinoma of head of pancreas , we anastamose the
  G.B to jejunum to alleviate .obst. Jaundice.
• D. preventive surgery like in F.A.P. treated by
  pan procto-colectomy .
• E. reconstructive surgery to restore the
  continuity of G.I.T.

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2.Radiotherapy

• Is the use of mega voltage x-ray or gamma rays
  which generates energy more than 1.1 million
  volt.
• Its advantages
• 1.it can treat deeply seated tumours.
• 2.it causes minimal skin reaction.
• 3.absorption of radiation is similar in all
  tissues.

Molecular effects of ionising radiation
ionising radiation interacts with tissue by tow
ways 1.direct action primary ionisation of
macromolecules. 2.indirect action by production
of reactive species from breakdown of water which
then causes damage to macromolecules (moving an
electron from H2O to form H2O this is called
free radical which causes most of the damage to
the DNA. The biological effect of radiation is
enhanced by oxygen which reacts with the free
radical. Radiation dosage is prescribed by Gray
which is the absorption of 1. joule (J) of
energy by one Kg of tissue.
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Radiobiology (the four Rs)

• 1.Repair after radiation damage there are two
  patterns of repair
• A. sublethal damage repair (SLD) takes 4-6 hrs
  after afraction of radiotherapy then the cell
  will be repaired . This happens to the normal
  cells.
• B. potentially lethal damage (PLD) happens after
  4-6 hrs of radiation. Cells will not be repaired
  (killed). This happens to cancer cells.
• 2.repopulation ,after killing cancer cells by
  radiotherapy in growth fraction this gives
  stimuli to cells inclonogenic fraction to start
  and repopulate tumour , so , tumour will shrink.
• 3.redistribution cells G2 or M are more
  sensitive to radiotherapy than cells in late S
  phase. This will synchronise the cells.
• 4.reoxygenation hypoxic cells are
  radio-resistant . So, every time we use
  radiothearpy oxygenated cells are killed. And the
  portion of hypoxic cells becomes oxygenated ,
  this takes 24 hrs.
• These four factors provides the reason for
  fractionation of radiotherapy.

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Tumour factors determining the success of
radiotherapy

• 1.radio sensitivity tumours are variable In
  their sensitivity to radiotherapy e.g. seminoma
  and lymphoma are more sensitive than soft tissue
  sarcoma.
• 2. tumour volume the larger the tumour is the
  higher proportion of cells that are hypoxic or
  anoxic . So more resistant to R.T.
• 3.the site of the tumour tumours which lie
  adjacent to organs which are easily damaged by
  R.T are difficult to treat.

Complications of R.T
It arises from inevitable damage to normal tissue
adjacent to the tumour . The most sensitive
tissues are 1.bone marrow . 2.gonads.
3.eyes. 4.mucosa of GIT. 5.lungs. 6.kidneys. 7.li
ver.
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Treatment planning

• Aims
• 1.maximum required dose is reached to the Tu.
• 2.minimal dose to nearby organs.
• To do so, we have to know
• A. the volume that needs to be treated.
• B. the required dose to kill the Tu.
• C. the arrangement of RT. fields

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Volume of Tu.

• 1.gross Tu. Volume (GTV) is the actual Tu.
  Volume.
• 2.clinical target volume (CTV) Tu.
  microscopical Tu. Cells around Tu.
• 3.planning target volume (PTV) is the above
  extra margine to allow for variation in shape and
  position of Tu.
• 4.treatment volume (TV) is the practical volume
  treated by the machine.
• 5.irradiated volume is all the above plus small
  margine due to scatter of R.T.

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Dosage of R.T

• Is the over all dose in Grays divided by the over
  all time of treatment
• 1.normal fractionation is Five fraction per week
  .
• 2.hypo fractionation is fewer than four fractions
  per week.
• 3. hyper fractionation two fractions per day
  ten fractions per week.

Field arrangement
1. single field is used for palliation. 2.parall
el opposed fields is used for head and neck
Tu. 3.multiple field for deeply seated TU. Like
prostate . U. Bladder .
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3.chemotherapy

• Classification of C.T agents are
• 1.alkylating agents .e.g. cyclophos phamide and
  melphalan.
• Action it binds to protein or DNA and inhibit
  their function.
• (non cycle specific)
• 2.anti-metabolites , e.g. 5-fluorouracil and
  methotrexate .
• Action they inhibit DNA synthesis leading to
  cell death. They work through the (S phase )
  (cycle specific).
• 3.vinca alkaloids , e.g. vinicristine
  ,vinblastine.
• Action arrest cell in mitosis (act at M) (cycle
  specific).
• 4.anti-biotics , e.g. adriamycin , bleomycin .
• Action binds to double stranded DNA preventing
  its replication (non- cycle specific).

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C.T drug resistance

• 1.interinsic resistance the TU. from the start
  is resistant to C.T by its own nature , e.g. lipo
  - sarcoma.
• 2.acquired resistance it arises after several
  exposures to the drug due to selection of
  resistant cells by destruction of sensitive cells.

Why C.T must be given intermittently and in
combination and over apro-longed period
Each time C.T is used growth fraction (G.F) is
killed , by time clonogenic fraction (C.F) will
transfer to be ( G.F) and TU. Shrinks . This
needs C.T to be given intermittently and over
apro-longe period and in combination to overcome
drug resistance
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Combination C.T

• How to choose combination C.T
• 1.each drug must be active against the TU. If
  used alone.
• 2.drugs must not be similar in toxicities.
• 3.they must have different mechanisms of action.
• 4. they must be used close to their maximum
  tolerable dose.

Response to C.T
1.cure H.D ,acute childhood leukaemia , chorio
carcinoma , E.sarcoma , willms TU. 2.improved
survival overian CA. , breast CA. , M.M
. 3.non-responsive CA. malignmant melanoma
thyroid carcinoma , R.C.C.
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Complications of C.T

• A. mild nausea, vomiting , mucositis ,
  alopecia.
• B. moderate leucopenia , thrombocytopenia.
• C. sever cardiac toxicity , (ADM) , lung
  fibrosis (bleomycin) , nephro toxicity
  (cisplatin) , second cancer formation.