Locoregional PMRT is recommended for women with 4 or more positive axillary lymph nodes .
The role of PMRT in women with 1 to 3 positive axillary lymph nodes is unclear .
Locoregional PMRT is generally not recommended for women who have tumours that are less than 5 cm in diameter and who have negative axillary nodes .
OBJECTIVE To provide information and recommendations to assist women with breast cancer and their physicians in making decisions regarding the use of locoregional post-mastectomy radiotherapy ( PMRT ) .
OUTCOMES Locoregional control , disease-free survival , overall survival and treatment-related toxicities .
To reduce the risk of lymphedema , radiation of the entire axilla should not be used routinely after complete axillary dissection of level I and II lymph nodes .
The use of modern techniques in radiotherapy planning is recommended to minimize excessive normal tissue exposure , particularly to the cardiac and pulmonary structures .
Common short-term side effects of PMRT , including fatigue and skin erythema , are generally tolerable and not dose-limiting .
Severe long-term side effects , including lymphedema , cardiac and pulmonary toxicities , brachial plexopathy , rib fractures and secondary neoplasms , are relatively rare .
Radiotherapy-related lung fibrosis enhanced by tamoxifen.
BACKGROUND Tamoxifen is an anti-estrogen with proven efficacy and low toxicity in the treatment of breast cancer . However , tamoxifen has been shown to exert a number of nonhormonal as well as hormonal effects . One nonhormonal effect of tamoxifen is the induction of transforming growth factor-beta ( TGF-beta ) secretion . TGF-beta has been implicated in the pathogenesis of radiation-induced fibrosis . PURPOSE We investigated the development of lung fibrosis in breast cancer patients who were treated after mastectomy with radiotherapy , with or without simultaneous adjuvant treatment with tamoxifen .  METHODS Data from 196 women were included in the analysis . Eighty-four women were postmenopausal patients who participated in a r and omized trial testing tamoxifen as an adjuvant to postmastectomy radiotherapy .  The radiotherapy technique employed an 8-MV photon field covering the axillary and the infraclavicular and supraclavicular regions of the affected side of the chest ; the chest wall was treated with an abutted electron field . Optical density changes in pretreatment and post-treatment chest x-ray films were used to monitor the development of lung fibrosis ; lung reactions were assessed in the photon-irradiated field only . Logistic regression analysis was used to explore relationships between radiation dose and the development of lung fibrosis in patients either receiving or not receiving tamoxifen . All P values are from two-sided tests . RESULTS Among the 84 women who participated in the r and omized trial of radiotherapy plus tamoxifen ( n = 38 ) versus radiotherapy alone ( n = 46 ) , there was a significant association between tamoxifen treatment and the incidence of marked lung fibrosis ( relative risk = 2.0 ; 95 % confidence interval [ CI ] = 1.2 - 3.5 ; P = .01 ) . When logistic regression analysis was used to evaluate data from all 196 patients , a highly significant relationship was found between the incidence of lung fibrosis and total radiation dose ( P = .0005 ) . In the full analysis , an increased risk of marked lung fibrosis was found again for patients who received tamoxifen simultaneously with radiotherapy ( with patients receiving radiotherapy alone as the referent , odds ratio = 2.9 ; 95 % CI = 1.3 - 6.3 ; P = .007 ) . Patient age and menopausal status did not significantly influence the results . CONCLUSION Tamoxifen treatment during postmastectomy radiotherapy enhances the risk of radiation-induced lung fibrosis . IMPLICATION S In view of pre-existing data , we hypothesize that tamoxifen mediates the enhancement of radiation-induced lung fibrosis through the induction of TGF-beta secretion . If this hypothesis is correct , new strategies might be devised for preventing or reducing radiation-induced fibrosis . Because we studied a relatively small portion of the irradiated lung , we can not recommend changes in current therapeutic measures ; however , we strongly encourage additional studies of lung fibrosis in patients receiving tamoxifen and radiotherapy
Locoregional PMRT is recommended for women with 4 or more positive axillary lymph nodes .
The role of PMRT in women with 1 to 3 positive axillary lymph nodes is unclear .
Locoregional PMRT is generally not recommended for women who have tumours that are less than 5 cm in diameter and who have negative axillary nodes .
OBJECTIVE To provide information and recommendations to assist women with breast cancer and their physicians in making decisions regarding the use of locoregional post-mastectomy radiotherapy ( PMRT ) .
OUTCOMES Locoregional control , disease-free survival , overall survival and treatment-related toxicities .
To reduce the risk of lymphedema , radiation of the entire axilla should not be used routinely after complete axillary dissection of level I and II lymph nodes .
The use of modern techniques in radiotherapy planning is recommended to minimize excessive normal tissue exposure , particularly to the cardiac and pulmonary structures .
Common short-term side effects of PMRT , including fatigue and skin erythema , are generally tolerable and not dose-limiting .
Severe long-term side effects , including lymphedema , cardiac and pulmonary toxicities , brachial plexopathy , rib fractures and secondary neoplasms , are relatively rare .