Effect of conjoint administration of tamoxifen and high-dose radiation on the development of mammary carcinoma

Kantorowitz, David A.; Thompson, Henry J.; Furmanski, Philip

doi:10.1016/0360-3016(93)90177-w

Cited by 29 publications

(11 citation statements)

References 16 publications

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“…Several clinical trials indicated that breast cancer patients who were treated with a combination of radiotherapy and TMX after lumpectomy/segmental mastectomy enjoyed better local control [16,17] and prolongation of relapse-free interval [18,19] in comparison to patients who received a monotherapy. Kantorowitz et al [20] treated MNU-induced mammary carci noma of the rat with TMX, fractionated radiotherapy or com bination of both modalities. They described best results re garding reduction in volume and number of the tumors for the combined treatment.…”

Section: Discussionmentioning

confidence: 99%

Effect of Tamoxifen and Estrogen Treatment on the Radiosensitivity of MCF-7 Breast Cancer Cells

Böhning¹,

Busch

Rave-Fränk³

et al. 1996

Oncol Res Treat

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Background: Due to the increasingly common use of endocrine therapy in adjuvant and palliative therapy of breast cancer, a significant number of patients will be treated with radiation therapy and Tamoxifen (TMX) at the same time. Methods: MCF-7 breast cancer cells, cultured by standard methods, were treated with varying doses of TMX or estrogen (ES) and/or graded doses of X-rays. The effects were measured by a clono-genic survival assay. Results: We found a marked decrease in the radiosensitivity of MCF-7 cells which were treated with TMX. This effect was time- and concentration-dependent, with a maximum at a 72-hour incubation. Treatment of the cells with estrogen (ES) increased their radiosensitivity at very high ES doses only. Conclusion: For patients treated with radiotherapy and TMX simultaneously, a negative effect can not be excluded.

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Section: Discussionmentioning

confidence: 99%

Effect of Tamoxifen and Estrogen Treatment on the Radiosensitivity of MCF-7 Breast Cancer Cells

Böhning¹,

Busch

Rave-Fränk³

et al. 1996

Oncol Res Treat

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“…The combination of tamoxifen and XRT did not show the antagonistic interaction which has been demonstrated in in vitro studies. Interestingly, tamoxifen decreased the rate of radiation-induced mammary tumors in this model (Kantorowitz et al 1993).…”

Section: Animal Studies On the Interaction Of Tamoxifen And Xrt In Brmentioning

confidence: 99%

Interactions between radiation and endocrine therapy in breast cancer.

Schmidberger¹,

Hermann²,

Hess³

et al. 2003

Endocrine-Related Cancer

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Adjuvant radiotherapy and adjuvant endocrine therapy are commonly given to patients with invasive breast cancer or with ductal carcinoma in situ (DCIS). Although both therapies have been well established through a number of randomized studies, little is known about a possible interaction of both treatment modalities if they are given simultaneously. A number of in vitro studies have indicated that tamoxifen treatment might reduce the intrinsic radiosensitivity of MCF-7 breast cancer cells. Conversely, estradiol treatment increases the intrinsic radiosensitivity of MCF-7 cells. In one available animal study, an antagonistic effect of tamoxifen and ionizing radiation (XRT) could not be observed. Retrospective analyses of randomized clinical studies have not indicated an antagonistic effect of tamoxifen on the effectiveness of XRT, since local control has been consistently higher when XRT was combined with tamoxifen, compared with treatment with XRT alone, regardless of whether tamoxifen was started simultaneously with radiotherapy or after completion of radiotherapy. Currently there are no clinical data available that would suggest an adverse effect of adjuvant tamoxifen treatment started prior to or simultaneously with radiotherapy in breast cancer or DCIS. However, since an antagonistic effect of tamoxifen and simultaneous chemotherapy has been reported recently, the issue of simultaneous versus sequential radiation and tamoxifen treatment in breast cancer should be addressed in further studies.

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“…In addition, irradiation and TAM may modify the oestrogen and progesterone receptor content in the cytosol in breast cancer cells and that could explain their change in radiation sensitivity (Paulsen et al, 1996). Results from a study in tumour-bearing rats (Kantorowitz et al, 1993) receiving fractionated RT, TAM, or both showed that, in contrast to in vitro results, the combination treatment reduced the probability of subsequent tumour development.…”

mentioning

confidence: 99%

Concomitant use of tamoxifen with radiotherapy enhances subcutaneous breast fibrosis in hypersensitive patients

et al. 2004

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Concomitant use of adjuvant tamoxifen (TAM) and radiation therapy (RT) is not widely accepted. We aim to assess whether this treatment is associated with an increased risk of developing subcutaneous fibrosis after conservative or radical surgery in breast cancer patients. We analysed 147 women with breast cancer treated with adjuvant RT, and who were included in the KFS 00539-9-1997/SKL 00778-2-1999 prospective study aimed at evaluating the predictive value of CD4 and CD8 T-lymphocyte apoptosis for the development of radiation-induced late effects. TAM (20 mg day À1 ) with concomitant RT was prescribed in 90 hormone receptorpositive patients. There was a statistically significant difference in terms of complication-relapse-free survival (CRFS) rates at 3 years, 48% (95% CI 37.2 -57.6%) vs 66% (95% CI 49.9 -78.6%) and complication-free survival (CFS) rates at 2 years, 51% (95% CI 40 -61%) vs 80% (95% CI 67 -89%) in the TAM and no-TAM groups, respectively. In each of these groups, the CRFS rates were significantly lower for patients with low levels of CD8 radiation-induced apoptosis, 20% (95% CI 10 -31.9%), 66% (95% CI 51.1 -77.6%), and 79% (95% CI 55 -90.9%) for CD8 p16, 16 -24, and 424%, respectively. Similar results were observed for the CFS rates. The concomitant use of TAM with RT is significantly associated with an increased incidence of grade 2 or greater subcutaneous fibrosis; therefore, caution is needed for radiosensitive patients.

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Effect of conjoint administration of tamoxifen and high-dose radiation on the development of mammary carcinoma

Cited by 29 publications

References 16 publications

Effect of Tamoxifen and Estrogen Treatment on the Radiosensitivity of MCF-7 Breast Cancer Cells

Effect of Tamoxifen and Estrogen Treatment on the Radiosensitivity of MCF-7 Breast Cancer Cells

Interactions between radiation and endocrine therapy in breast cancer.

Concomitant use of tamoxifen with radiotherapy enhances subcutaneous breast fibrosis in hypersensitive patients

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