Antitumor antibiotics
Antitumor antibiotics are natural-product cytotoxic drugs, dactinomycin, the anthracyclines, bleomycin, and mitomycin, that damage DNA or RNA directly. Clinicians treat lymphoma, pediatric solid tumors, germ cell tumors, and anal and bladder cancer with these agents as chemotherapy backbones, but each member carries a distinct, cumulative-dose-limited organ toxicity.
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What this article covers
- Overview
Antitumor antibiotics are natural-product cytotoxic drugs, dactinomycin (actinomycin D), the anthracyclines (doxorubicin, daunorubicin, idarubicin, epirubicin), bleomycin, and mitomycin, that damage…
- Epidemiology
Dactinomycin is used almost exclusively in children, for favorable-histology Wilms tumor, embryonal rhabdomyosarcoma, and Ewing sarcoma, and for gestational trophoblastic neoplasia in women of reproductive age.
- Risk factors
Cumulative dose: the dominant driver of anthracycline cardiotoxicity and bleomycin pulmonary toxicity; risk climbs once a lifetime threshold is approached.
- Pathophysiology
Dactinomycin is cell-cycle nonspecific: it wedges between guanine-cytosine base pairs of the DNA double helix and blocks RNA polymerase, halting transcription rather than replication.
- Clinical features
Dactinomycin: myelosuppression, mucositis, and a radiation-recall skin reaction in previously irradiated fields; a potent vesicant that requires a free-flowing line.
- Differential diagnosis
Alkylating agents (cyclophosphamide, ifosfamide): cell-cycle nonspecific DNA cross-linkers chosen alongside or instead of an antitumor antibiotic; unlike anthracyclines they have no cumulative…
- Diagnosis
What establishes toxicity: no diagnostic criterion covers the class as a whole; anthracycline cardiotoxicity is diagnosed by a fall in LVEF on serial echocardiography correlated with cumulative dose…
- Management
First-line, select the antitumor antibiotic as part of a multiagent regimen: these drugs are curative only in combination, never given alone.
- Complications
Anthracycline cardiomyopathy: dose-dependent and usually irreversible, about 1.5% after four cycles in the breast cancer setting, up to 26% at a cumulative dose of 550 mg/m2, with late presentations 10 to 20 years after treatment.
- Prognosis
Outcomes track the underlying cancer more than the drug class: ABVD cures most patients with Hodgkin lymphoma, and CHOP cures many patients with aggressive non-Hodgkin lymphoma.
- Prevention
Cap lifetime exposure: keep doxorubicin (or anthracycline-equivalent) below the 450-550 mg/m2 ceiling and bleomycin below the 400-unit ceiling described above.
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