Older women who take adjuvant treatment after lumpectomy may not need radiotherapy
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《英国医生杂志》
Results of two studies of breast cancer reported in the New England Journal of Medicine last week have prompted the authors of an accompanying editorial to propose that lumpectomy plus tamoxifen but without local irradiation "is a realistic choice" for some women over the age of 70 years.
A re-evaluation of the need for radiotherapy has been made against a changed background since earlier trials, says the editorial. These changes include improved imaging and techniques for locating tumours and the widespread use of adjuvant therapy with drugs such as tamoxifen, which reduces the risk of local recurrence and improves survival.
The first new trial compared local radiotherapy plus tamoxifen with tamoxifen alone in women aged 50 years or older who had undergone breast conserving surgery for breast cancer ( New England Journal of Medicine 2004;351: 963-70). The rate of local relapse was substantially lower in the radiotherapy plus tamoxifen group (0.6%) than in the tamoxifen alone group (7.7%) (hazard ratio 8.3 (95% confidence interval 3.3 to 21.2; P<0.004)).
The rate of axillary relapse differed significantly at five years (2.5% in the tamoxifen group and 0.5% in the group given tamoxifen plus irradiation), although overall survival at five years did not differ significantly between the two groups.
The authors of the editorial, Dr Ian Smith and Dr Gillian Ross of the Royal Marsden Hospital, London, said that these results reinforced findings from another recent trial that the addition of radiotherapy to lumpectomy and tamoxifen for tumours that are 1 cm in diameter or less reduced the risk of local recurrence.
However, the second study published last week led the editorial writers to reach a different conclusion. In this study women aged 70 years or more who had had early, oestrogen receptor positive breast cancer and who had undergone lumpectomy were randomly assigned to receive local irradiation ( New England Journal of Medicine 2004;351: 971-7). As with the first study, the use of radiotherapy reduced local recurrence at five years (recurrence was 4% in the tamoxifen group and 1% in the combined treatment group (P<0.001)).
But that was the only significant difference between the two groups. There were no significant differences in the rates of mastectomy for local recurrence or of distant metastases and no difference in overall survival at five years (87% in the group given tamoxifen plus irradiation and 86% in the tamoxifen only group (P=0.94)). The authors say that for women aged 70 or older with early, oestrogen receptor positive breast cancer, lumpectomy plus tamoxifen but without local irradiation "is a realistic choice."
These results "have important implications concerning the use of medical resources," says the editorial, because such women represent a large subgroup—approximately 40 000—of the women in the United States who develop breast cancer each year. "There are clear advantages in identifying subgroups in a large population of elderly women who do not require radiotherapy after lumpectomy and tamoxifen."
In the first trial, the rate of local relapse among women aged 50 years or more who were treated with tamoxifen alone—even among the subgroup with a good prognosis—rose from 5.9% after five years to 15.2% after eight years.
"For women over 70 years of age, however, this is likely to be less of an issue, since breast cancer in this age group is biologically less aggressive and is associated with a lower risk of local recurrence after breast-conserving surgery and with less time at risk," says the editorial.(David Spurgeon)
A re-evaluation of the need for radiotherapy has been made against a changed background since earlier trials, says the editorial. These changes include improved imaging and techniques for locating tumours and the widespread use of adjuvant therapy with drugs such as tamoxifen, which reduces the risk of local recurrence and improves survival.
The first new trial compared local radiotherapy plus tamoxifen with tamoxifen alone in women aged 50 years or older who had undergone breast conserving surgery for breast cancer ( New England Journal of Medicine 2004;351: 963-70). The rate of local relapse was substantially lower in the radiotherapy plus tamoxifen group (0.6%) than in the tamoxifen alone group (7.7%) (hazard ratio 8.3 (95% confidence interval 3.3 to 21.2; P<0.004)).
The rate of axillary relapse differed significantly at five years (2.5% in the tamoxifen group and 0.5% in the group given tamoxifen plus irradiation), although overall survival at five years did not differ significantly between the two groups.
The authors of the editorial, Dr Ian Smith and Dr Gillian Ross of the Royal Marsden Hospital, London, said that these results reinforced findings from another recent trial that the addition of radiotherapy to lumpectomy and tamoxifen for tumours that are 1 cm in diameter or less reduced the risk of local recurrence.
However, the second study published last week led the editorial writers to reach a different conclusion. In this study women aged 70 years or more who had had early, oestrogen receptor positive breast cancer and who had undergone lumpectomy were randomly assigned to receive local irradiation ( New England Journal of Medicine 2004;351: 971-7). As with the first study, the use of radiotherapy reduced local recurrence at five years (recurrence was 4% in the tamoxifen group and 1% in the combined treatment group (P<0.001)).
But that was the only significant difference between the two groups. There were no significant differences in the rates of mastectomy for local recurrence or of distant metastases and no difference in overall survival at five years (87% in the group given tamoxifen plus irradiation and 86% in the tamoxifen only group (P=0.94)). The authors say that for women aged 70 or older with early, oestrogen receptor positive breast cancer, lumpectomy plus tamoxifen but without local irradiation "is a realistic choice."
These results "have important implications concerning the use of medical resources," says the editorial, because such women represent a large subgroup—approximately 40 000—of the women in the United States who develop breast cancer each year. "There are clear advantages in identifying subgroups in a large population of elderly women who do not require radiotherapy after lumpectomy and tamoxifen."
In the first trial, the rate of local relapse among women aged 50 years or more who were treated with tamoxifen alone—even among the subgroup with a good prognosis—rose from 5.9% after five years to 15.2% after eight years.
"For women over 70 years of age, however, this is likely to be less of an issue, since breast cancer in this age group is biologically less aggressive and is associated with a lower risk of local recurrence after breast-conserving surgery and with less time at risk," says the editorial.(David Spurgeon)