neoplasia 4 Flashcards
tumor treatment modalities
surgery rad therapy chemo hormonal therapy immunotherapy small molecule therapy
local vs systemic
local = site of tumor = remove local area. systemic = whole body. destroy disseminated cells. probably metastatic tumor.
different intents to tumor treatment
- curative = generally willing to tolerate more side effects from treatment
- palliative - can’t cure patient, aim to improve quality over quantity of life
adjuvant therapy
therapy in conjunction with primary modality of treatment.
- usually chemo/radiation.
objective: eradicate microscopic tumor cells that have been left behind.
surgery- define local control palliative? neoadjuvant therapy? margin? performed on what kind of tumors? side effects?
local control = elimination of neoplastic process. establish milieu in which tumor recurrence is minimied
palliative - can do surgery. remove to relieve symptoms
chemo before surgery as pre-adjuvant. makes tumor more easily resectable
margin = zone on non-malignant tissue surrounding tumor
performed on solid (non-hematologic tumors
side effect = pain, loss of function, disfigurement, changes/damages to surrounding normal tissue
radiotherapy - local or systemic? method of treatment? brachytherapy? radiosensitive radio resistant chemo + radiotherapy? upper limit? palliation? side effects?
local.
external beam radiotherapy - radiation from external source, directed over chosen area.
brachytherapy - radioactive in wire or pellet. high dose to tumor w lose dose to surrounding tissue.
radiosensitive = shrink quickly in response
radio-resistane = require unacceptably high radiation dose to kill tumor cells
chemo can made radiation more sensitive
upper limit of radiation - if tumor comes back cant treat w radiation again.
palliation - yes and for cure sometimes.
side effects: acute - high turn over tissue affected. late= mutagenesis, pulmonary fibrosis.
chemo local / systemic? more active on what cells? targets? administered how? increase efficacy and reduce resistance how? side effects:
systemic. more toxic to mutated than normal.
more active against rapidly proliferating.
targets: directly damage DNA (crosslinks btw DNA); interfere with DNA synthesis; interfere w microtubule assemble
administered in cycles with recovery time in between
combo of drugs = greater efficacy & less resistance. ex: antibiotic in HIV - hit one genetic variant.
side effects: emesis, diarrhea, infertility, infections, bone marrow affected.
hormonal therapy responsive to what organs? anti-androgen therapies tumor must? side effects?
prostate, breast, uterus.
anti-androgen therapy- prostate. orchiectomy (remove testes and endogenous testosterone), LHRH agonist
anti-androgen therapy for breast cancer: aromatase inhibitor - block estrogen production. SERM - selective estrogen receptor modulator. ovarian ablation.
*tumor express hormone receptors for therapy to be effective. works more slowly than chemo.
side effects: menopause-like, bone loss, blood clot, endometiral cancer, mood disorder
immunotherapy
4 broad categories
bacillus calmette-guerin (BCG): bladder cancer.
tumor vaccines = prophylactic (HPV); therapeutic (less effective)
antibodies bind to and inhibit function of proteins expressed by by cancer cells.. - monoclonal antibodies.
CAR (chimeric antigen receptor) T-cell adoptive immunotherapy. genetically modified T-cell + T-cell signalling apparatus w antibody specfic for target. modify immune cells and put them back.
monoclonal antibody therapy
- mab
trastuzumab = mouse antibody binds to overexpressed receptors = prevents homodimerization. = better remission w chemo, not curative.
side effects: anaphylaxis, cardiomyopathy
rituximab: Ab against t CD20. againt b-cell malignancies. avoids myelosuppression of conventional chemo.
side effects: anaphylaxis, flu-like
immune checkpoint blockade therapy
anti-ctla-4 antibody
ctla-4 = inhibitory receptor. inhibits t-cell. function. anti-CTLA-4 blocks CTLA-4 binding. = increase immune function.
side effects: immune related, treated with corticosteroids.
PD-1: target on malignant tumors. it inhibits t-cell activation. Ab against PD-1 = increase T-cell activation
side effects: immune-related, colitis
treatment resistance
intrinsic vs acquired (emerges during ttreatment)
mechanisms: decreased drug transport/accumulation; accelerated inactivation, increase NDA repair, modification of cell types.
tumors are heterogenous.
therapeutic developments for clinical lab
- certain mutations
treatments become more personalized
prognostic significance
made malignancy more or less susceptible to certain chemo-therapy.
- lab helps determine most effective treatment. weigh benefit vs harm.
