[On the interaction of adjuvant radiotherapy and tamoxifen treatment for breast cancer].
BACKGROUND
Tamoxifen (TAM) is well established in the adjuvant therapy of breast cancer. However, the timing of TAM therapy, concurrent or after radiotherapy, is controversial.


METHODS
Literature is reviewed with respect to experimental and clinical data on interaction of TAM and radiation on tumor control and radiation side effects.


RESULTS
In vitro data support the concept of antagonistic effects of concurrent TAM and radiation on tumor cells, but in animal models a synergistic effect was seen. Considering the modulation of TAM effects by estrogen and growth factor receptors, two-dimensional systems may not be suitable for studying the interaction of TAM and radiation. From a clinical perspective, a tumor-protective effect of TAM therapy concurrent with radiation was not evident. However, prospective studies addressing this question adequately are not available at the time.


CONCLUSIONS
Although some studies indicate an enhancement of lung and subcutaneous fibrosis after TAM therapy, the side effects are mild and at this point do not seem to warrant withholding TAM.
Hoeller
Ulrike
U
Klinik für Strahlentherapie, Radioonkologie und Nuklearmedizin, Vivantes Klinikum Neukölln, Berlin. ulrike.hoeller@vivantes.de
Borgmann
Kerstin
K
Feyer
Petra
P
Souchon
Rainer
R
D000367:Age Factors; D000818:Animals; D018931:Antineoplastic Agents, Hormonal / Q000009:adverse effects / Q000494:pharmacology / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000401:mortality / Q000532:radiotherapy* / Q000601:surgery; D017326:Clinical Trials, Phase III as Topic; D003131:Combined Modality Therapy; D003627:Data Interpretation, Statistical; D005260:Female; D006801:Humans; D008168:Lung / Q000528:radiation effects; D008171:Lung Diseases / Q000139:chemically induced / Q000209:etiology; D008408:Mastectomy; D008875:Middle Aged; D009374:Neoplasms, Experimental; D011446:Prospective Studies; D011658:Pulmonary Fibrosis / Q000139:chemically induced / Q000209:etiology; D011878:Radiotherapy / Q000009:adverse effects; D011879:Radiotherapy Dosage; D018714:Radiotherapy, Adjuvant; D016032:Randomized Controlled Trials as Topic; D012189:Retrospective Studies; D012307:Risk Factors; D013629:Tamoxifen / Q000009:adverse effects / Q000494:pharmacology / Q000627:therapeutic use*; D013997:Time Factors; D014407:Tumor Cells, Cultured / Q000187:drug effects / Q000528:radiation effects
D018931:Antineoplastic Agents, Hormonal; D013629:Tamoxifen