Radiotherapy after breast‐conserving surgery for elderly patients with early‐stage breast cancer: A national registry‐based study

Abstract

Considerable controversies exist regarding whether elderly patients with early-stage breast cancer receiving breast-conserving surgery (BCS) should forgo radiotherapy. We utilized the National Cancer Database to analyze data of 115 516 women aged ≥70 years, treated with BCS for T1-2N0-1M0 breast cancer between 2004 and 2014. Multivariable Cox proportional hazards model was used to estimate hazard ratios (HR) and 95% confidence intervals (CI) for mortality 3, 5 and 10 years after 90 days of BCS associated with radiotherapy. Patients who received no radiotherapy had a higher mortality rate than those who received radiotherapy (5-year survival rate: 71.2% vs 83.8%), with multivariable-adjusted HRs of 1.65 (95% CI: 1.57-1.72) for 3-year mortality, 1.53 (1.47-1.58) for 5-year mortality and 1.43 (1.39-1.48) for 10-year mortality. The association held even for patients ≥90 years. This association was observed in all strata by reasons for radiotherapy omission, receipt of endocrine therapy or chemotherapy, calendar period and other clinical characteristics, with 40% to 65% increased 5-year mortality for patients without radiotherapy. This positive association persisted when analyses were restricted to patients with T1N0 and estrogen-receptor-positive disease who had received endocrine therapy (5-year mortality: HR 1.47 [1.39-1.57]) and in propensity score weighted analyses. Our study shows, in routine practice, elderly patients who received no post-BCS radiotherapy had higher total mortality than those who received radiotherapy. These findings suggest that the current recommendation of omission of post-BCS radiotherapy for elderly women with early-stage breast cancer may need to be reconsidered, particularly for those without contraindication.

The addition of radiotherapy to breast-conserving surgery improves survival for elderly patients with early breast cancer

“…Although high-quality evidence exists, the relatively short follow-up time and limited statistical power limit the results of prospective randomized trials for clinical practice. Studies with longer follow-up are required to detect significant differences in OS, but it is worth emphasizing that large retrospective population based-studies including ours have found early differences in OS ( 11 , 12 , 30 ). The large population-based studies not only provided real-world clinical evidence but may also compensate for any retrospective design-related drawbacks.…”

“…However, it should be noted that early patient enrollment, imprecise RT techniques, and insufficient endocrine therapy may impact the survival benefit of RT. Recently, two studies from the National Cancer Database (NCDB) showed a positive impact of RT in this population, they found that RT could improve the OS of patients, especially for those treated with endocrine therapy and RT ( 11 , 12 ). However, the NCDB does not record BC-related deaths in patients.…”

“…In this study, a total of 6551 patients died, while only 11.7% (n=766) of them died from BC. There was approximately 20-50% of patients had comorbidities at the BC diagnosis ( 12 , 17 , 18 ). Therefore, competing mortality is a major factor affecting survival in elderly BC patients.…”

“…However, there were also approximately 60% of patients receive RT after BCS in clinical practice ( 10 ). Moreover, although the information on BC death was not analyzed, several population-based studies have shown that the receipt of postoperative RT was associated with a better OS compared to those without RT ( 11 , 12 ). Therefore, the importance and necessity of RT after BCS in elderly BC remains considerably controversial.…”

Physicians’ Opinion on Intraoperative Radiotherapy as a Therapeutic De-Escalation Option in Older Women with Early Breast Cancer

“…Based on these findings, the U.S. national guidelines recommended omitting adjuvant radiotherapy after BCS for EBC women 70 years of age and older who are prescribed endocrine therapy [ 9 ]. However, whether radiotherapy is beneficial in the elderly is still a matter of debate, with results of recent studies using observational real-world data reporting higher mortality rates in those who did not receive radiotherapy after BCS [ 10 , 11 ].…”