Commentary: Surgical, Tamoxifen, and Genetic Considerations in Breast Cancer, May 2023

A cohort study by Minami and colleagues assessed the association between surgery type (lumpectomy vs mastectomy) and change in frailty status in older patients with early-stage breast cancer (BC) undergoing locoregional therapy. The study included 31,084 women, age ≥ 65 years, with ductal carcinoma in situ (n = 9962) or stage I hormone receptor–positive (HR+) and ERBB2+ (human epidermal growth factor receptor 2 positive [HER2+]) BC (n = 21,122), of which 22.6% and 77.4% of patients underwent mastectomy and lumpectomy, respectively. The study showed that older patients who underwent mastectomy vs lumpectomy were more likely to experience worse frailty (adjusted odds ratio 1.31; 95% CI 1.23-1.39). Additionally, women who were robust vs having moderate to severe frailty at baseline, ≥ 75 years vs 65-69 years, or African American/Black vs non-Hispanic White, had significantly higher odds of decline. Given that prior data have shown comparable survival between lumpectomy and mastectomy, careful and thoughtful treatment considerations are needed before deciding to intensify surgical management in this population, even in women who do not appear frail at baseline.

Low-dose tamoxifen continues to prevent BC recurrence in breast noninvasive neoplasia

Low-dose tamoxifen is a treatment option for women with noninvasive BC, especially if the patient was not able to tolerate the standard dose of 20 mg daily. The phase 3 TAM-01 trial included 500 women with intraepithelial neoplasia of the breast who were randomly assigned to receive low-dose tamoxifen (5 mg once daily) or placebo. The 10-year follow-up analysis by Lazzeroni and colleagues showed that treatment with low-dose tamoxifen for 3 years continued to prevent a BC recurrence for at least 7 years after treatment cessation. After a median follow-up of 9.7 years, fewer cases of both invasive and in situ BC (hazard ratio 0.58; log-rank P = .03) and contralateral BC (hazard ratio 0.36; P = .025) were reported in the tamoxifen vs placebo group. These results are meaningful, especially in a setting of an optimal safety profile, where patients on low-dose tamoxifen were experiencing similar menopausal symptoms to placebo, and serious adverse events, such as deep vein thrombosis and pulmonary embolism, were not increased during low-dose tamoxifen therapy. This is different from the threefold increased risk reported with standard dosing.

Worse survival in BRCA1/2 germline mutation carriers receiving ET in HR+/HER2− BC

Inconsistent data have been reported on the prognostic impact of BRCA1/2 mutation in HR+ BC. A retrospective study by Frenel and colleagues included 13,776 patients with metastatic BC (MBC) from the Epidemiological Strategy and Medical Economics (ESME) MBC database, of which 676 and 170 patients were germline BRCA wild-type (gBRCAwt) and germline BRCA mutation (gBRCAm) carriers, respectively. They looked at outcomes and first-line endocrine treatment efficacy in patients with HR+/HER2- MBC, treated in a pre–cyclin-dependent kinase (CDK) 4/6 inhibitors era. The results showed that gBRCAm carriers had shorter overall survival (OS; adjusted hazard ratio [aHR] 1.26; P = .024) and progression-free survival (PFS; aHR 1.21; P = .017) compared with gBRCAwt carriers. Furthermore, among those treated with front-line endocrine therapy, gBRCAm patients had lower adjusted OS (aHR [95% CI] 1.54 [1.03-2.32]) and PFS (aHR [95% CI] 1.58 [1.17-2.12]) compared with gBRCAwt patients. Outcomes were similar for gBRCAm patients who received first-line chemotherapy compared with the gBRCAwt group (OS: aHR [95% CI] 1.12 [0.88-1.41]; first-line PFS: aHR [95% CI] 1.09 [0.90-1.31]). A previous retrospective study by Lambertini and colleagues, focusing on young patients with gBRCAm, also showed a tendency for a worse distant recurrence-free interval (aHR 1.39; 95% CI  0.94-2.05) in patients with HR+ BC. Additional studies are needed, especially in the setting of an evolving treatment landscape that includes CDK4/6 inhibitors and poly-ADP ribose polymerase (PARP) inhibitors.

A cohort study by Minami and colleagues assessed the association between surgery type (lumpectomy vs mastectomy) and change in frailty status in older patients with early-stage breast cancer (BC) undergoing locoregional therapy. The study included 31,084 women, age ≥ 65 years, with ductal carcinoma in situ (n = 9962) or stage I hormone receptor–positive (HR+) and ERBB2+ (human epidermal growth factor receptor 2 positive [HER2+]) BC (n = 21,122), of which 22.6% and 77.4% of patients underwent mastectomy and lumpectomy, respectively. The study showed that older patients who underwent mastectomy vs lumpectomy were more likely to experience worse frailty (adjusted odds ratio 1.31; 95% CI 1.23-1.39). Additionally, women who were robust vs having moderate to severe frailty at baseline, ≥ 75 years vs 65-69 years, or African American/Black vs non-Hispanic White, had significantly higher odds of decline. Given that prior data have shown comparable survival between lumpectomy and mastectomy, careful and thoughtful treatment considerations are needed before deciding to intensify surgical management in this population, even in women who do not appear frail at baseline.

Low-dose tamoxifen continues to prevent BC recurrence in breast noninvasive neoplasia

Low-dose tamoxifen is a treatment option for women with noninvasive BC, especially if the patient was not able to tolerate the standard dose of 20 mg daily. The phase 3 TAM-01 trial included 500 women with intraepithelial neoplasia of the breast who were randomly assigned to receive low-dose tamoxifen (5 mg once daily) or placebo. The 10-year follow-up analysis by Lazzeroni and colleagues showed that treatment with low-dose tamoxifen for 3 years continued to prevent a BC recurrence for at least 7 years after treatment cessation. After a median follow-up of 9.7 years, fewer cases of both invasive and in situ BC (hazard ratio 0.58; log-rank P = .03) and contralateral BC (hazard ratio 0.36; P = .025) were reported in the tamoxifen vs placebo group. These results are meaningful, especially in a setting of an optimal safety profile, where patients on low-dose tamoxifen were experiencing similar menopausal symptoms to placebo, and serious adverse events, such as deep vein thrombosis and pulmonary embolism, were not increased during low-dose tamoxifen therapy. This is different from the threefold increased risk reported with standard dosing.

Worse survival in BRCA1/2 germline mutation carriers receiving ET in HR+/HER2− BC

Inconsistent data have been reported on the prognostic impact of BRCA1/2 mutation in HR+ BC. A retrospective study by Frenel and colleagues included 13,776 patients with metastatic BC (MBC) from the Epidemiological Strategy and Medical Economics (ESME) MBC database, of which 676 and 170 patients were germline BRCA wild-type (gBRCAwt) and germline BRCA mutation (gBRCAm) carriers, respectively. They looked at outcomes and first-line endocrine treatment efficacy in patients with HR+/HER2- MBC, treated in a pre–cyclin-dependent kinase (CDK) 4/6 inhibitors era. The results showed that gBRCAm carriers had shorter overall survival (OS; adjusted hazard ratio [aHR] 1.26; P = .024) and progression-free survival (PFS; aHR 1.21; P = .017) compared with gBRCAwt carriers. Furthermore, among those treated with front-line endocrine therapy, gBRCAm patients had lower adjusted OS (aHR [95% CI] 1.54 [1.03-2.32]) and PFS (aHR [95% CI] 1.58 [1.17-2.12]) compared with gBRCAwt patients. Outcomes were similar for gBRCAm patients who received first-line chemotherapy compared with the gBRCAwt group (OS: aHR [95% CI] 1.12 [0.88-1.41]; first-line PFS: aHR [95% CI] 1.09 [0.90-1.31]). A previous retrospective study by Lambertini and colleagues, focusing on young patients with gBRCAm, also showed a tendency for a worse distant recurrence-free interval (aHR 1.39; 95% CI  0.94-2.05) in patients with HR+ BC. Additional studies are needed, especially in the setting of an evolving treatment landscape that includes CDK4/6 inhibitors and poly-ADP ribose polymerase (PARP) inhibitors.

A cohort study by Minami and colleagues assessed the association between surgery type (lumpectomy vs mastectomy) and change in frailty status in older patients with early-stage breast cancer (BC) undergoing locoregional therapy. The study included 31,084 women, age ≥ 65 years, with ductal carcinoma in situ (n = 9962) or stage I hormone receptor–positive (HR+) and ERBB2+ (human epidermal growth factor receptor 2 positive [HER2+]) BC (n = 21,122), of which 22.6% and 77.4% of patients underwent mastectomy and lumpectomy, respectively. The study showed that older patients who underwent mastectomy vs lumpectomy were more likely to experience worse frailty (adjusted odds ratio 1.31; 95% CI 1.23-1.39). Additionally, women who were robust vs having moderate to severe frailty at baseline, ≥ 75 years vs 65-69 years, or African American/Black vs non-Hispanic White, had significantly higher odds of decline. Given that prior data have shown comparable survival between lumpectomy and mastectomy, careful and thoughtful treatment considerations are needed before deciding to intensify surgical management in this population, even in women who do not appear frail at baseline.

Low-dose tamoxifen continues to prevent BC recurrence in breast noninvasive neoplasia

Low-dose tamoxifen is a treatment option for women with noninvasive BC, especially if the patient was not able to tolerate the standard dose of 20 mg daily. The phase 3 TAM-01 trial included 500 women with intraepithelial neoplasia of the breast who were randomly assigned to receive low-dose tamoxifen (5 mg once daily) or placebo. The 10-year follow-up analysis by Lazzeroni and colleagues showed that treatment with low-dose tamoxifen for 3 years continued to prevent a BC recurrence for at least 7 years after treatment cessation. After a median follow-up of 9.7 years, fewer cases of both invasive and in situ BC (hazard ratio 0.58; log-rank P = .03) and contralateral BC (hazard ratio 0.36; P = .025) were reported in the tamoxifen vs placebo group. These results are meaningful, especially in a setting of an optimal safety profile, where patients on low-dose tamoxifen were experiencing similar menopausal symptoms to placebo, and serious adverse events, such as deep vein thrombosis and pulmonary embolism, were not increased during low-dose tamoxifen therapy. This is different from the threefold increased risk reported with standard dosing.

Worse survival in BRCA1/2 germline mutation carriers receiving ET in HR+/HER2− BC

Inconsistent data have been reported on the prognostic impact of BRCA1/2 mutation in HR+ BC. A retrospective study by Frenel and colleagues included 13,776 patients with metastatic BC (MBC) from the Epidemiological Strategy and Medical Economics (ESME) MBC database, of which 676 and 170 patients were germline BRCA wild-type (gBRCAwt) and germline BRCA mutation (gBRCAm) carriers, respectively. They looked at outcomes and first-line endocrine treatment efficacy in patients with HR+/HER2- MBC, treated in a pre–cyclin-dependent kinase (CDK) 4/6 inhibitors era. The results showed that gBRCAm carriers had shorter overall survival (OS; adjusted hazard ratio [aHR] 1.26; P = .024) and progression-free survival (PFS; aHR 1.21; P = .017) compared with gBRCAwt carriers. Furthermore, among those treated with front-line endocrine therapy, gBRCAm patients had lower adjusted OS (aHR [95% CI] 1.54 [1.03-2.32]) and PFS (aHR [95% CI] 1.58 [1.17-2.12]) compared with gBRCAwt patients. Outcomes were similar for gBRCAm patients who received first-line chemotherapy compared with the gBRCAwt group (OS: aHR [95% CI] 1.12 [0.88-1.41]; first-line PFS: aHR [95% CI] 1.09 [0.90-1.31]). A previous retrospective study by Lambertini and colleagues, focusing on young patients with gBRCAm, also showed a tendency for a worse distant recurrence-free interval (aHR 1.39; 95% CI  0.94-2.05) in patients with HR+ BC. Additional studies are needed, especially in the setting of an evolving treatment landscape that includes CDK4/6 inhibitors and poly-ADP ribose polymerase (PARP) inhibitors.