Table 2.
Study characteristic table of included studies.
| Study Characteristics | ||||||
|---|---|---|---|---|---|---|
| Author, Year, Country | Data Source | Study Period | Patients (n), Age Range | Patient and Tumor Characteristics |
Treatment Findings | Breast-Cancer-Specific Survival (BCSSS) Outcomes |
| Bhoo-Pathy, 2015, Asia [8] |
5 hospital-based cancer registries | 2016–2011 | 205, 65–96 | Ethnicity, T stage, N stage, tumor grade, lymphovascular invasion | Less radiation use ≥65 vs. >65 (34.9% vs.67.8%) | No survival advantage with radiation in ≥65 (HR 1.34, CI 0.67–2.68, p > 0.05) |
| Kaplan, 2017, USA [9] | Institution-specific breast cancer registry data base | 1990–2014 | 59, 75–93 | Race, stage, histologic grade, nuclear grade, mean tumor size, N stage | No difference in radiation use ≥75 vs. <75 (79% vs. 75%, p = 0.821) Less use of chemotherapy ≥75 vs. <75 (40% vs. 76%, p < 0.001) Less use of surgery, radiation and chemotherapy in ≥75 vs. <75 75 (29% vs. 62%, p < 0.001) |
Less use of surgery, radiation and chemotherapy was not associated with a difference in 5-year BCSS (90% <75 vs. 83% ≥75, p = 0.322) |
| Kozak, 2019, USA [10] | SEER | 2010–2014 | 422, 70–100 | Race, region, grade, stage | Less use of radiation in ≥70 vs. <70 (46.3% vs. 53.6% <0.0001) Less use of chemotherapy ≥70 vs. <70 (42.2% vs. 83.1% p < 0.0001) |
Decreased use of radiation and chemotherapy in ≥70 vs. <70 was associated with a relative increase in cancer-specific mortality by 25% and increased breast cancer mortality rate (12.8% vs. 10.2%, p < 0.0001). |
| Syed, 2014, UK [11] | Prospective single institution | 1973–2010 | 127, 70–91 | Histological type, size, axillary lymph node status, grade | Less use of chemotherapy ≥70 vs. >70 (0% vs. 47%) | No difference in BCSS ≥70 vs. <70 (73% vs. 79%, p = 0.39) |
| Zhu, 2015, USA [12] | SEER | 2010–2011 | 1224, 70–100 | TN, stage, grade | Less use of surgery in ≥70 vs. <70 (92.8% vs. 94.6%, p = 0.002) Less use of RT in ≥70 vs. <70 (69.9% vs. 61.2%, p < 0.001) |
Surgery BCSS 1 HR 0.250, 95% CI, 0.186 to 0.337, p < 0.001 Radiation BCSS HR 0.504, 95% CI, 0,390 to 0.651, p < 0.001 Decreased surgery and radiation in ≥70 associated with 5.9% cancer-specific mortality vs. 2.7% in <70 (p < 0.0001) |
1 Breast-cancer-specific survival.